12 - Psychological Disorders

ENDURING ISSUES IN PSYCHOLOGICAL DISORDERS

A recurring topic is the relationship between genetics, neurotransmitters, and behavior disorders (Mind-Body). We will also see that many psychological disorders arise because a vulnerable person encounters a particularly stressful environment (Person-Situation). Think about how you would answer the following question "What is normal?" and how the answer to that question has changed over time and differs even today across cultures (Diversity-Universality). Consider also whether a young person with a psychological disorder is likely to suffer from it later in life and, conversely, whether a well-adjusted young person is immune to psychological disorders later in life (Stability-Change).

PERSPECTIVES ON PSYCHOLOGICAL DISORDERS

How Does a Mental Health Professional Define a Psychological Disorder?

When is a person's behavior abnormal? This is not always easy to determine. There is no doubt about the abnormality of a man who dresses in flowing robes and accosts pedestrians on the street, claiming to be Jesus Christ, or a woman who dons an aluminum-foil helmet to prevent space aliens from "stealing" her thoughts. But other instances of abnormal behavior aren't always so clear. What about the three people we have just described? All of them exhibit unusual behavior. But does their behavior deserve to be labeled "abnormal"? Do any of them have a genuine psychological disorder?

The answer depends in part on the perspective you take. Society, the individual, and the mental health professional all adopt different perspectives when distinguishing abnormal behavior from normal behavior. Society's main standard of abnormality is whether the behavior fails to conform to prevailing ideas about what is socially expected of people. In contrast, when individuals assess the abnormality of their own behavior, their main criterion is whether that behavior fosters a sense of unhappiness and lack of well-being.

Mental health professionals take still another perspective. They assess abnormality chiefly by looking for maladaptive personality traits, psychological discomfort regarding a particular behavior, and evidence that the behavior is preventing the person from functioning well in life.

These three approaches to identifying abnormal behavior are not always in agreement. For example, of the three people previously described, only Claudia considers her behavior to be a genuine problem that is undermining her happiness and sense of well-being. In contrast to Claudia, Jack is not really bothered by his compulsive behavior (in fact, he sees it as a way of relieving anxiety); and Jonathan is not only content with being a loner, but he also experiences great comfort from the illusion of his dead mother's presence. But now suppose we shift our focus and adopt society's perspective. In this case, we must include Jonathan on our list of those whose behavior is abnormal. His self-imposed isolation and talk of sensing his mother's ghost violate social expectations about how people should think and act. Society would not consider Jonathan normal. Neither would a mental health professional. In fact, from the perspective of a mental health professional, all three of these cases show evidence of a psychological disorder. The people involved may not always be distressed by their own behavior, but that behavior is impairing their ability to function well in everyday settings or in social relationships. The point is that there is no hard and fast rule as to what constitutes abnormal behavior. Distinguishing between normal and abnormal behavior always depends on the perspective taken.

Identifying behavior as abnormal is also a matter of degree. To understand why, imagine that each of our three cases is slightly less extreme. Jack is still prone to double-checking, but he doesn't check over and over again. Claudia still spends much time on her hair, but she doesn't do so constantly and not with such chronic dissatisfaction. As for Jonathan, he only occasionally withdraws from social contact; and he had the sense of his dead mother's presence just twice over the last 3 years. In these less severe situations, a mental health professional would not be so ready to diagnose a mental disorder. Clearly, great care must be taken when separating mental health and mental illness into two qualitatively different categories. It is often more accurate to think of mental illness as simply being quantitatively different from normal behavior - that is, different in degree. The line between one and the other is often somewhat arbitrary. Cases are always much easier to judge when they fall at the extreme end of a dimension than when they fall near the "dividing line."

Historical Views of Psychological Disorders

The place and time also contribute to how we define mental disorders. Thousands of years ago, mysterious behaviors were often attributed to supernatural powers and madness was a sign that spirits had possessed a person. As late as the 18th century, the emotionally disturbed person was often thought to be a witch or to be possessed by the devil. Exorcisms, ranging from mild to severe were performed, many people endured horrifying tortures. Some people were even burned at the stake.

Not all people with mental illness were persecuted and tortured. Beginning in the late Middle Ages, some public and private asylums were established to care for people with mental illness. Even though these institutions were founded with good intentions, most were little more than prisons. In the worst cases, inmates were chained down and deprived of food, light, or air in order to "cure" them.

Little was done to ensure humane standards in mental institutions until 1793, when Philippe Pinel (1745-1826) became director of the Bicetre Hospital in Paris. Under his direction, patients were released from their chains and allowed to move about the hospital grounds, rooms were made more comfortable and sanitary, and questionable and violent medical treatments were abandoned (James Harris, 2003). Pinel's reforms were soon followed by similar efforts in England and, somewhat later, the United States where Dorothea Dix (1802-1887), a schoolteacher from Boston, led a nationwide campaign for the humane treatment of mentally ill people. Under her influence, the few existing asylums in the United States were gradually turned into hospitals.

The basic reason for the failed - and sometimes abusive - treatment of mentally disturbed people throughout history has been the lack of understanding of the nature and causes of psychological disorders. Although our knowledge is still inadequate, important advances in understanding abnormal behavior can be traced to the late 19th and 20th centuries, when three influential but often conflicting models of abnormal behavior emerged: the biological model, the psychoanalytic model, and the cognitive-behavioral model.

The Biological Model

The biological model holds that psychological disorders are caused by physiological malfunctions often stemming from hereditary factors. As we shall see, support for the biological model has been growing rapidly as scientists make significant advances in neuroscience, which directly links biology and behavior.

For instance, new neuroimaging techniques have enabled researchers to pinpoint regions of the brain involved in such disorders as schizophrenia (Gur et al., 2011; Heuvel & Fornito, 2014) and antisocial personality (Vollm, 2010). By unraveling the complex chemical interactions that take place at the synapse, neurochemists have spawned advances in neuropharmacology leading to the development of promising new psychoactive drugs. Many of these advances are also linked to the field of behavior genetics, which is continually increasing our understanding of the role of specific genes in the development of complex disorders such as schizophrenia (Ikuta et al., 2014; Lipina et al., 2011) and autistic spectrum disorder (Jones et al., 2013; Marui et al., 2011).

Although neuroscientific breakthroughs are indeed remarkable, to date no neuroimaging technique can clearly and definitively differentiate among various mental disorders (Pihi, 2010). And despite the availability of an increasing number of medications to alleviate the symptoms of some mental disorders, most drugs can only control - rather than cure - abnormal behavior. There is also some concern that advances in identifying the underlying neurological structures and mechanisms associated with mental illnesses may interfere with the recognition of equally important psychological causes of abnormal behavior (Dudai, 2004; Widiger & Sankis, 2000). Despite this concern, the integration of neuroscientific research and traditional psychological approaches to understanding behavior is taking place at increasingly rapid pace, and will undoubtedly reshape our view of mental illness in the future (Anderson, Mizgalewicz, & Illes, 2013; Zipursky, 2007).

The Psychoanalytic Model

Freud and his followers developed the psychoanalytic model during the late 19th and early 20th centuries. According to this model, behavior disorders are symbolic expressions of unconscious conflicts, which can usually be traced to childhood. The psychoanalytic model argues that in order to resolve their problems effectively, people must become aware that the source of their problems lies in their childhood and infancy.

The Cognitive-Behavioral Model

A third model of abnormal behavior grew out of 20th-century research on learning and cognition. The cognitive-behavioral model suggests that psychological disorders, like all behavior, result from learning. For example, a bright student who believes that he is academically inferior to his classmates and can't perform well on a test may not put much effort into studying. Naturally, he performs poorly, and his poor test score confirms his belief that he is academically inferior.

The Diathesis-Stress Model and Systems Theory

Each of the three major theories is useful in explaining the causes of certain types of disorders. The most exciting recent developments, however, emphasize integration of the various theoretical models to discover specific causes and specific treatments for different mental disorders.

One promising integrative approach is the diathesis-stress model. This model suggests that a biological predisposition called a diathesis must combine with a stressful circumstance before the predisposition to a mental disorder is manifested (S. R. Jones & Ferneyhough, 2007).

The systems approach, also known as the biopsychosocial model, examines how biological risks, psychological stresses, and social pressures and expectations combine to produce psychological disorders (Fava & Sonino, 2007). According to this model, emotional problems are "lifestyle diseases" that, much like heart disease and many other physical illnesses, result from a combination of risk factors and stresses. Just as heart disease can result from a combination of genetic predisposition, personality styles, poor health habits (such as smoking), and stress, psychological problems result from several risk factors that influence one another.

The Prevalence of Psychological Disorders

Psychologists and public health experts are concerned with both the prevalence and incidence of mental health problems. Prevalence refers to the frequency with which a given disorder occurs at a given time. If there were 100 cases of depression in a population of 1,000, the prevalence of depression would be 10%. The incidence of a disorder refers to the number of new cases that arise in a given period. If there were 10 new cases of depression in a population of 1,000 in a single year, the incidence would be 1% per year.

In 2005, the National Institute of Mental Health conducted a survey finding that 26.2% or approximately 57.7 million Americans were suffering from a mental disorder. While only about 6% were regarded as having a serious mental illness, almost half the people (45%) suffering from one mental disorder also met the criteria for two or more other mental disorders (Kessler, Chiu, Demler, & Walters, 2005). Notably, mental disorders are the leading cause of disability in the United States for people between the ages of 15 and 44 (The World Health Organization, 2004). Anxiety disorders are the most common mental disorder followed by mood disorders.

Globally, diagnostic interviews with more than 60,000 people in 14 countries around the world showed that over a 1-year period, the prevalence of moderate or serious psychological disorders varied widely from 12% of the population in the Americas to 7% in Europe, 6% in the Middle East and Africa, and just 4% in Asia (World Health Organization [WHO] World Mental Health Survey Consortium, 2004).

Mental Illness and the Law

Particularly horrifying crimes have been attributed to mental disturbance, because it seems to many people that anyone who could commit such crimes must be "crazy." But to the legal system,, this presents a problem: If a person is truly "crazy," are we justified in holding him or her responsible for criminal acts? The legal answer to this question is a qualified yes. A mentally ill person is responsible for his or her crimes unless he or she is determined to be insane. What's the difference between being "mentally ill" and being "insane"? Insanity is a legal term, not a psychological one. It is typically applied to defendants who were so mentally disturbed when they committed their offense that they either lacked substantial capacity to appreciate the criminality of their actions (to know right from wrong) or to conform to the requirements of the law (to control their behavior).

When a defendant is suspected of being mentally disturbed or legally insane, another important question must be answered before that person is brought to trial: Is the person able to understand the charges against him or her and to participate in a defense in court? This issue is known as competency to stand trial. The person is examined by a court-appointed expert and, if found to be incompetent, is sent to a mental institution, often for an indefinite period. If judged to be competent, the person is required to stand trial.

Classifying Abnormal Behavior

For nearly 60 years, the American Psychiatric Association (APA) has issued a manual describing and classifying the various kinds of psychological disorders. This publication, the Diagnostic and Statistical Manual of Mental Disorders (DSM), has been revised five times; the latest revision was published in May 2013. The DSM-5 (American Psychiatric Association, 2013) provides a complete list of mental disorders; with each category painstakingly defined in terms of significant behavior patterns. The DSM has gained increasing acceptance because its detailed criteria for diagnosing mental disorders have made diagnosis much more reliable. Today, it is the most widely used classification of psychological disorders.

MOOD DISORDERS

Most people have a wide emotional range; they can be happy or sad, animated or quiet, cheerful or discouraged, or overjoyed or miserable, depending on the circumstances. In some people with mood disorders, this range is greatly restricted. They seem stuck at one end or the other end of the emotional spectrum - either consistently excited and euphoric or consistently sad - regardless of life circumstances. Others with mood disorders alternate between the extremes of euphoria and sadness.

Depressive Disorders

The most common mood disorders are depressive disorders in which people may feel overwhelmed with sadness, lose interest in things they normally enjoy, experience intense feelings of worthlessness and guilt, or feel tired and apathetic, sometimes to the point of being unable to make the simplest decisions. Many depressed people feel as if they have failed utterly in life, and they tend to blame themselves for their problems. Seriously depressed people often have insomnia and lose interest in food and sex. They may have trouble thinking or concentrating - even to the extent of finding it difficult to read a newspaper. In fact, difficulty in concentrating and subtle changes in short-term memory are sometimes the first signs of the onset of depression (Janice Williams et al., 2000). In extreme cases, depressed people may be plagued by suicidal thoughts or may even attempt suicide (Hantouche, Angst, & Azorin, 2010). Sadly, the earlier the age of onset of depressive symptoms, the greater the likelihood that suicide may be attempted (A. H. Thompson, 2008).

Clinical depression is different from the "normal" kind of depression that all people experience from time to time. Only when depression is long lasting and goes well beyond the typical reaction to a stressful life event is it classified as a mood disorder (American Psychiatric Association, 2013).

DSM-5 distinguishes between major depressive disorder, which can be an episode of intense sadness that may last for several months, and persistent depressive disorder which involves less intense sadness (and related symptoms), but persists with little relief for a period of 2 years or more. Depression is two to three times more prevalent in women than in men (Kessler et al., 2003; Nolen-Hoeksema, 2006).

Children and adolescents can also suffer from depression. In very young children, depression is sometimes difficult to diagnose because the symptoms are usually different than those seen in adults. For instance, in infants or toddlers, depression may manifest as a "failure to thrive" or gain weight, or as a delay in speech or motor development. In school-aged children, depression may be manifested as antisocial behavior, excessive worrying, sleep disturbances, or unwarranted fatigue (Kaslow, Clark, & Sirian, 2008).

One of the most severe hazards of depression, as well as some of the other disorders described in this chapter, is that people may become so miserable that they no longer wish to live.

Suicide

Each year in the United States, approximately one suicide occurs every 17 minutes, or over 34,000 annually, making it the 11th leading cause of death (Centers for Disease Control, 2006; Holloway, Brown, & Beck, 2008). In addition, half a million Americans receive hospital treatment each year for attempted suicide. Indeed, suicides outnumber homicides by five to three in the United States. The suicide rate is much higher among Whites than among minorities (Centers for Disease Control, 2006). Compared to other countries, the suicide rate in the United States is below average (the highest rates are found in eastern European countries) (Curtin, 2004). More women than men attempt suicide, but more men succeed, partly because men tend to choose violent and lethal means, such as guns.

Although the largest number of suicides occurs among older White males, since the 1960s suicide attempt rates have been rising among adolescents and young adults. In fact, adolescents account for 12% of all suicide attempts in the United States, and in many other countries suicide ranks as either first, second, or third leading cause of death in that age group (Centers for Disease Control and Prevention, 1999; Zalsman & Mann, 2005). We cannot as yet explain the increase, though the stresses of leaving home, meeting the demands of college or a career, and surviving loneliness or broken romantic attachments seem to be particularly great at this stage of life. Although external problems such as unemployment and financial strain may also contribute to personal problems, suicidal behavior is most common among adolescents with psychological problems.

Several myths concerning suicide can be quite dangerous:

MYTH - Someone who talks about committing suicide will never do it.

FACT - Most people who kill themselves have talked about it. Such comments should always be taken seriously.

MYTH - Someone who has tried suicide and failed is not serious about it.

FACT - Any suicide attempt means that the person is deeply troubled and needs help immediately. A suicidal person will try again, picking a more deadly method the second or third time around.

MYTH - Only people who are life's losers - those who have failed in their careers and in their personal lives - commit suicide.

FACT - Many people who kill themselves have prestigious jobs, conventional families, and a good income. Physicians, for example, have a suicide rate several times higher than that for the general population; in this case, the tendency to suicide may be related to their work stresses.

People considering suicide are overwhelmed with hopelessness. They feel that things cannot get better and see no way out of their difficulties. This perception is depression in the extreme, and it is not easy to talk to someone out of this state of mind. Telling a suicidal person that things aren't really so bad does no good; in fact, the person may only view this as further evidence that no one understands his or her suffering. But most suicidal people do want help, however much they may despair of obtaining it. If a friend or family member seems at all suicidal, getting professional help is important. A community mental health center is a good starting place, as are the national suicide hotlines.

Bipolar and Related Disorders

Other mood disorders, which are less common than depression, involve manic episodes, in which the person becomes euphoric or "high," extremely active, excessively talkative, and easily distracted. People suffering from mania may become grandiose - that is, their self-esteem is greatly inflated. They repeatedly have unlimited hopes and schemes, but little interest in realistically carrying them out. People in a manic state sometimes become aggressive and hostile toward others as their self-confidence grows more and more exaggerated. At the extreme, people going through a manic episode may become wild, incomprehensible, or violent until they collapse from exhaustion.

The mood disorder in which both mania and depression are present is known as bipolar disorder. In people with bipolar disorder, periods of mania and depression may alternate (each lasting from a few days to a few months), sometimes with periods of normal mood in between. Occasionally, bipolar disorder occurs in mild form, with moods of unrealistically high spirits followed by moderate depression. Research suggests that bipolar disorder is much less common than depression and, unlike depression, occurs equally in men and women. Bipolar disorder, which usually emerges during late adolescence or early adulthood, also seems to have a stronger biological component than depression. In fact, a number of specific genes have been implicated as contributing to the development of bipolar disorder (K. H. Choi et al., 2011; Leszczynska-Rodziewicz, Mackiukiewicz, Szczepankiewicz, Poglodzinski, & Hauser, 2013).

Causes of Mood Disorders

Mood disorders result from a combination of risk factors although researchers do not yet know exactly how these elements interact to cause a mood disorder (Moffitt, Caspi, & Rutter, 2006).

Biological Factors

Genetic factors can play an important role in the development of depression (Haghighi et al., 2008; Karg, Burmeister, Shedden, & Sen, 2011) and bipolar disorder (K. H. Choi et al., 2011; Serretti & Mandelli, 2008). Strong evidence comes from studies of twins. If one identical twin is clinically depressed, the other twin (with identical genes) is likely to become clinically depressed also. Among fraternal twins (who share only about half their genes), if one twin is clinically depressed, the risk for the second twin is much lower (McGuffin, Katz, Watkins, & Rutherford, 1996). In addition, genetic researchers have identified a specific variation on the 22 chromosome that appears to increase an individual's susceptibility to bipolar disorder by influencing the balance of certain neurotransmitters in the brain (Hashimoto et al., 2005, Kuratomi et al., 2008; Steen et al., 2014).

A new and particularly intriguing line of research aimed at understanding the cause of mood disorders stems from the diathesis-stress model. Recent research shows that a diathesis (biological predisposition) leaves some people particularly vulnerable to certain stress hormones. Adverse or traumatic experiences early in life can result in high levels of those stress hormones, which in turn increases the likelihood of a mood disorder later in life (Bradley et al., 2008; Gillespie & Nemeroff, 2007).

Psychological Factors

Although a number of psychological factors are thought to play a role in causing severe depression, in recent years, researchers have focused on the contribution of maladaptive cognitive distortions. According to Aaron Beck (1967, 1976, 1984), during childhood and adolescence, some people undergo wrenching experiences such as the loss of a parent, severe difficulties in gaining parental or societal approval, or humiliating criticism from teachers and other adults. One response to such experience is to develop a negative self-concept - a feeling of incompetence or unworthiness that has little to do with reality, but that is maintained by a distorted and illogical interpretation of real events. When a new situation arises that resembles the situation under which the self-concept was learned, these same feelings of worthlessness and incompetence may be activated, resulting in depression. Considerable research supports Beck's view of depression (Clark & Beck, 2010; Kwon & Oei, 2003; Maag, Swearer, & Toland, 2009). Therapy based on Beck's theories has proven quite successful in treating depression.

Social Factors

Many social factors have been linked with mood disorders, particularly difficulties in interpersonal relationships. In fact, some theorists suggested that the link between depression and troubled relationships explains the fact that depression is two to three times more prevalent in women than in men (National Alliance on Mental Illness, 2003), because women tend to be more relationship oriented than men are in our society (Ali, 2008). Yet, not every person who experiences a troubled relationship becomes depressed. As the systems approach would predict, it appears that a genetic predisposition or cognitive distortion is necessary before a distressing close relationship or other significant life stressor will result in a mood disorder (Wichers et al., 2007).

ANXIETY DISORDERS

All of us are afraid from time to time, but we usually know why we are fearful, our fear is caused by something appropriate and identifiable, and it passes with time. In the case of anxiety disorders, however, either the person does not know why he or she is afraid, or the anxiety is inappropriate to the circumstances. In either case, the person's fear and anxiety just don't seem to make sense.

Anxiety disorders are more common than any other form of mental disorder. Anxiety disorders can be subdivided into several diagnostic categories, including specific phobias, panic disorder, and other anxiety disorders, as well as anxiety-related disorders such as obsessive-compulsive disorder and disorders caused by specific traumatic events.

Specific Phobias

A specific phobia is an intense, paralyzing fear of something that perhaps should be feared, but the fear is excessive and unreasonable. In fact, the fear in a specific phobia is so great that it leads the person to avoid routine or adaptive activities and thus interferes with life functioning. For example, it is appropriate to be a bit fearful as an airplane takes off or lands, but people with a phobia about flying refuse to get on or even go near an airplane. Other common phobias focus on animals, heights, closed places, blood, needles, and injury. Almost 10% of people in the United States suffer from at least one specific phobia.

Most people feel some mild fear or uncertainty in many social situations, but when these fears interfere significantly with life functioning, they are considered to be social anxiety disorders. Intense fear of public speaking is a common form of social phobia. In other cases, simply talking with people or eating in public causes such severe anxiety that the phobic person will go to great lengths to avoid these situations.

Agoraphobia is much more debilitating than social phobia. This term comes from Greek and Latin words that literally mean "fear of the marketplace," but the disorder typically involves multiple, intense fears, such as the fear of being alone, of being in public places from which escape might be difficult, of being in crowds, of traveling in an automobile, or of going through tunnels or over bridges. The common element in all of these situations seems to be a great dread of being separated from sources of security. Some sufferers are so fearful that they will venture only a few miles from home; others will not leave their homes at all.

Panic Disorder

Another type of anxiety disorder is panic disorder, characterized by recurring episodes of a sudden, unpredictable, and overwhelming fear or terror. Panic attacks occur without any reasonable cause and are accompanied by feelings of impending doom, chest pain, dizziness or fainting, sweating, difficulty breathing, and fear of losing control or dying. Panic attacks usually last only a few minutes, but they may recur for no apparent reason. For example, consider the following description:

Thirty-year-old Shelly Baker arrived at an anxiety clinic seeking help dealing with "panic attacks." The attacks, which were becoming more frequent, often occurred 2 or 3 times a day. Without any warning, she would suddenly experience a wave of "terrible fear." She was afraid that she would lose control and do something bizarre like running outside and screaming at the tope of her lungs.

Panic attacks not only cause tremendous fear while they are happening, but also leave a dread of having another panic attack, which can persist for days or even weeks after the original episode. In some cases, this dread is so overwhelming that it can lead to the development of agoraphobia: To prevent recurrence, people may avoid any circumstance that might cause anxiety, clinging to people or situations that help keep them calm.

In the various phobias and panic attacks, there is a specific source of anxiety. In contrast, generalized anxiety disorder is defined by prolonged vague but intense fears that are not attached to any particular object or circumstance. Generalized anxiety disorder perhaps comes closest to everyday meaning attached to the term neurotic. Its symptoms include the inability to relax, muscle tension, rapid heartbeat or pounding heart, apprehensiveness about the future, constant alertness to potential threats, and sleeping difficulties (Hazlett-Stevens, Pruitt, & Collins, 2009).

Anxiety-Related Disorders

As the name suggests, obsessive-compulsive disorder (OCD) involves obsession, which are involuntary thoughts or ideas that keep recurring despite a person's attempts to stop them, or compulsions, which are repetitive, ritualistic behaviors that a person feels compelled to perform. Obsessive thoughts are often horrible and frightening. One patient, for example, reported that "when she thought of her boyfriend, she wished he were dead"; when her sister spoke of going to the beach with her infant daughter, she "hoped that they would both drown" (Carson & Butcher, 1992, p. 190). Compulsive behaviors may be equally disruptive to the person who feels driven to perform them. Recall Jack, the engineer described at the beginning of the chapter, who couldn't leave his house without double- and triple-checking to be sure the doors were locked and all of the lights and appliances were turned off.

People who experience obsessions and compulsions often do not seem particularly anxious, so why is this disorder considered an anxiety-related disorder? The answer is that if such people try to stop their irrational behavior - or if someone else tries to stop them - they experience severe anxiety. In other words, the obsessive-compulsive behavior seems to have developed to keep anxiety under control.

Body dysmorphic disorder, or imagined ugliness, is a poorly understood type of somatoform disorder. Cases of body dysmorphic disorder can be very striking. One man, for example, felt that people stared at his "pointed ears" and "large nostrils" so much that eventually could not face going to work, so he quit his job. Claudia, the woman described at the beginning of the chapter who displayed such concern about her hair, apparently was suffering from a body dysmorphic disorder. Clearly, people who become that preoccupied with their appearance cannot lead a normal life. Ironically, most people who suffer body dysmorphic disorder are not ugly. They may be average looking or even attractive, but they are unable to evaluate their looks realistically.

Finally, two types of anxiety-related disorders are clearly caused by some specific highly stressful event. Some people who have lived through fires, floods, tornadoes, or disasters such as an airplane crash experience repeated episodes of fear and terror after the event itself is over. If the anxious reaction occurs soon after the event, the diagnosis is acute stress disorder. If a period of time elapses before symptoms appear, particularly in cases of military combat or rape, the diagnosis is likely to be posttraumatic stress disorder.

Causes of Anxiety Disorders

Like all behaviors, phobias can be learned. Consider a young boy who is savagely attacked by a large dog. Because of this experience, he is now terribly afraid of all dogs. In this case, a realistic fear has become transformed into a phobia. However, other phobias are harder to understand. Many people get shocks from electric sockets, but almost no one develops a socket phobia. Yet snake and spider phobias are common. The reason seems to be that through evolution we have become biologically predisposed to associate certain potentially dangerous objects with intense fears (Horwitz & Wakefield, 2012; Seligman, 1971).

Psychologists working from the biological perspective point to heredity, arguing that we can inherit a predisposition to anxiety disorders (Gelernter & Stein, 2009; Leigh, 2009; Leonardo & Hen, 2006). In fact, anxiety disorders tend to run in families. Researchers have located some specific genetic sites that may generally predispose people toward anxiety disorders (Goddard et al., 2004; Hamilton et al., 2004). In some cases, specific genes have even been linked to specific anxiety disorders, such as obsessive hoarding (Alonso et al., 2008).

Finally, we need to consider the role that internal psychological conflicts may play in producing feelings of anxiety. The very fact that people suffering from anxiety disorders often have no idea why they are anxious suggests that the explanation may be found in unconscious conflicts that trigger anxiety. According to this classical psychoanalytic view, phobias are the result of displacement, in which people redirect their anxiety from the unconscious conflicts toward objects or settings in the real world.

SOMATIC SYMPTOM AND RELATED DISORDERS

The term psychosomatic perfectly captures the interplay of psyche (mind) and soma (body). A psychosomatic illness is a real, physical disorder, but one that has, at least in part, a psychological cause. Stress, anxiety, and prolonged emotional arousal alter body chemistry, the functioning of bodily organs, and the body's immune system (which is vital in fighting infections). Thus, modern medicine leans toward the idea that all physical ailments are to some extent "psychosomatic."

Psychosomatic disorders involve genuine physical illnesses. In contrast, people suffering from somatic symptom and related disorders believe that they are physically ill and describe symptoms that sound like physical illnesses, but medical examinations reveal no organic problems. Nevertheless, the symptoms are real to them and are not under voluntary control. For example, in one kind of somatoform disorder, somatic symptom disorder, the person experiences vague, recurring physical symptoms for which medical attention has been sought repeatedly but no organic cause found. Common complaints are back pain, dizziness, abdominal pain, and sometimes anxiety and depression.

Conversion disorders are characterized by complaints of paralysis, blindness, deafness, seizures, loss of feeling, or pregnancy. In these disorders, no physical causes appear, yet the symptoms are very real. In cases of illness anxiety disorder, the person interprets some small symptom - perhaps a cough, a bruise, or perspiration - as a sign of a serious disease. Although the symptom may actually exist, there is no evidence that the serious illness does.

Somatic symptom and related disorders (especially conversion disorders) present a challenge for psychological theorists because they seem to involve some kind of unconscious processes. Freud concluded that the physical symptoms were often related to traumatic experiences buried in a patient's past. Cognitive-behavioral theorists look for ways in which the symptomatic behavior is being rewarded. From the biological perspective, research has shown that at least some diagnosed disorders actually were real physical illnesses that were overlooked or misdiagnosed. Nevertheless, most cases of conversion disorder cannot be explained by current medical science. These cases pose as much of a theoretical challenge today as they did when conversion disorders captured Freud's attention more than a century ago.

Dissociative Disorders

Dissociative disorders are among the most puzzling forms of mental disorders, both to the observer and to the sufferer. Dissociation means that part of an individual's personality appears to be separated from the rest. The disorder sometimes involves memory loss and a complete, though generally temporary, change in identity. Rarely, several distinct personalities appear in one person.

Loss of memory without an organic cause can occur as a reaction to an extremely stressful event or period. During World War II, for example, some hospitalized soldiers could not recall their names, where they lived, where they were born, or how they came to be in battle. But war and its horrors are not the only causes of dissociative amnesia. The person who betrays a friend in a business deal or the victim of rape may also forget, selectively, what has happened. Total amnesia, in which people forget everything, is rare, despite its popularity in novels and films. Sometimes an amnesia victim leaves home and assumes an entirely new identity; this phenomenon, known as dissociative fugue, is also very unusual.

In dissociative identity disorder, commonly known as multiple personality disorder, several distinct personalities emerge at different times. In the true multiple personality, the various personalities are distinct people with their own names, identities, memories, mannerisms, speaking voices, and even IQs. Sometimes the personalities are so separate that they don't know they inhabit a body with other "people." At other times, the personalities do know of the existence of other "people" and even make disparaging remarks about them. Typically, the personalities contrast sharply with one another, as if each one represents different aspects of the same person - one being the more socially acceptable, "nice" side of the person and the other being the darker, more uninhibited or "evil" side. Each personality may also exhibit distinctly different brainwave patterns (Dell'Osso, 2003).

The origins of dissociative identity disorder are not well understood and remain highly controversial (Boysen & VanBergen, 2014; Dell, 2006). Posttraumatic Theory suggests that it develops as a response to childhood abuse (Lev-Wiesel, 2008). The child learns to cope with abuse by a process of dissociation - by having the abuse, in effect, happen to "someone else," that is, to a personality who is not conscious most of the time. The fact that one or more of the multiple personalities in almost every case is a child (even when the person is an adult) seems to support this idea, and clinicians report a history of child abuse in more than three-quarters of their cases of dissociative identity disorder (Kidron, 2008; C. A. Ross, Norton, & Wozney, 1989). Social-Cognitive Theory, on the other hand, argues that media attention accounts for the dramatic increase in this disorder in recent years.

A far less dramatic (and much more common) dissociative disorder is depersonalization/derealization disorder, in which the person suddenly feels changed or different in a strange way. Some people feel they have left their bodies, whereas others find that their actions have suddenly become mechanical or dreamlike. This kind of feeling is especially common during adolescence and young adulthood, when our sense of ourselves and our interactions with others change rapidly. Only when the sense of depersonalization becomes along-term or chronic problem or when the alienation impairs normal social functioning can this be classified as a dissociative disorder (American Psychiatric Association, 2013).

SEXUAL DYSFUNCTIONS

Sexual dysfunction is the loss or impairment of the ordinary physical responses of sexual function for at least six months. In men, this usually takes the form of erectile disorder or erectile dysfunction (ED), the inability to achieve or maintain an erection. In women, it often takes the form of female sexual interest/arousal disorder, loss of interest in sex or the inability to become sexually excited or to reach orgasm. (These conditions were once called "impotence" and "frigidity," respectively, but professionals in the field have rejected these terms as too negative and judgmental.) Occasional problems with achieving or maintaining an erection in men or with lubrication or reaching orgasm in women are common. Only when the condition lasts for at least six months and when enjoyment of sexual relationships becomes impaired should it be considered serious.

The incidence of ED is quite high, even among otherwise healthy men. In one survey, 25% of 40- to 70-year-old men had moderate ED. Less than half the men in this age group reported having no ED (Lamberg, 1998). Fortunately, new medications popularly known as Viagra, Levitra, and Cialis are extremely effective in treating ED (Benard, Carrier, Lee, Talwar, & Defoy, 2010; S. B. Levine, 2006).

Although medications appear to help most male patients overcome ED, they are of little value unless a man is first sexually aroused. Unfortunately some men and women find it difficult or impossible to experience any desire for sexual activity to begin with. Sexual desire disorders involve a lack of interest in sex or perhaps an active distaste for it. Low sexual desire is more common among women than among men and plays a role in perhaps 40% of all sexual dysfunctions (R. D. Hayes, Dennerstein, Bennett, & Fairley, 2008; Warnock, 2002). The extent and causes of this disorder in men or women is difficult to analyze. Because some people simply have a low motivation for sexual activity, scant interest in sex is normal for them and does not necessarily reflect any sexual disorder (Meston & Rellini, 2008).

Other people are able to experience sexual desire and maintain arousal but are unable to reach orgasm, the peaking of sexual pleasure and the release of sexual tension. These people are said to experience orgasmic disorders. Male orgasmic disorder - the inability to ejaculate even when fully aroused - is rare yet seems to be becoming increasingly common as more men find it desirable to practice the delay of orgasm. Masters and Johnson (1970) attributed male orgasmic disorder primarily to such psychological factors as traumatic experiences. The problem may also occur as a side effect of some medications, such as certain antidepressants. The difficulty is considerably more common among women than among men.

Among the other problems that can occur during the sexual response cycle are premature ejaculation, a fairly common disorder that the DSM-5 defines as the male's inability to inhibit orgasm as long as desired, and genito-pelvic pain/penetration disorder, involuntary muscle spasms in the outer part of a woman's vagina during sexual excitement that make intercourse impossible. Again, the occasional experience of such problems is common; the DSM-5 considers them dysfunctions only if they are persistent and recurrent (Hunter, Goodie, Oordt, & Dobmeyer, 2009).

PARAPHILIC DISORDERS

Paraphilia is a term used to describe the use of unconventional sex objects or situations. However, not all people with paraphilia would be classified as having a paraphilic disorder or would require clinical intervention. Most people have unusual sexual fantasies at some time, which can be a healthy stimulant of normal sexual enjoyment. Only when the paraphilia causes distress or impairment to the person or whose satisfaction entails personal harm, or risk of harm to others is it considered to be a paraphilic disorder. Fetishism refers to the repeated use of a nonhuman object such as a shoe or underwear as the preferred or exclusive method of achieving sexual excitement (Darcangelo, Hollings, & Paladino, 2008). Most people who practice fetishism are male, and the fetish frequently begins during adolescence (Fagan, Lehne, Strand, & Berlin, 2005). Fetishes may derive from unusual learning experiences: As their sexual drive develops during adolescence, some boys learn to associate arousal with inanimate objects, perhaps as a result of early sexual exploration while masturbating or because of difficulties in social relationships (Bertolini, 2001).

Other unconventional patterns of sexual behavior are voyeurism, watching other people have sex or spying on people who are nude; achieving arousal by exhibitionism, the exposure of one's genitals in inappropriate situations, such as to strangers; frotteurism, achieving sexual arousal by touching or rubbing against a nonconsenting person in situations like a crowded subway car; and transvestic fetishism, wearing clothes of the opposite sex for sexual excitement and gratification; sexual sadism ties sexual pleasure to aggression. To attain sexual gratification, sadists humiliate or physically harm sex partners. Sexual masochism is the inability to enjoy sex without accompanying emotional or physical pain. Sexual sadists and masochists sometimes engage in mutually consenting sex, but at times sadistic acts are inflicted on unconsenting partners, sometimes resulting in serious injury or even death (Blum, 2012; Purcell & Arrigo, 2006).

One of the most serious paraphilic disorders is pedophilic disorder, which according to DSM-5 is defined as engaging in sexual activity with a child, generally under the age of 13. Pedophiles are almost invariably men under age 40 who are close to the victims rather than strangers (Barbaree & Seto, 1997). Although there is no single cause of pedophilic disorder, some of the most common explanations are that pedophiles cannot adjust to the adult sexual role and have been interested exclusively in children as sex objects since adolescence; they turn to children as sexual objects in response to stress in adult relationships in which they feel inadequate; or they have records of unstable social adjustment and generally commit sexual offenses against children in response to a temporary aggressive mood. Studies also indicate that the majority of pedophiles have histories of sexual frustration and failure, low self-esteem, an inability to cope with negative emotions, tend to perceive themselves as immature, and are rather dependent, unassertive, lonely, and insecure (L. J. Cohen & Galynker, 2002; Mandeville-Norden & Beech, 2009). Recent evidence has also found that pedophilic offenders may have structural anomalies in areas of the brain involved in impulse control and emotional regulation (Poeppl et al., 2013).

GENDER DYSPHORIA

The word "dysphoria" means an abnormal feeling of discontent or discomfort. Gender dysphoria is the strong desire to become - or the insistence that one really is - a member of the other sex. Some little boys, for example, want to be girls instead. They may reject boys' clothing, desire to wear their sisters' clothes, and play only with girls and with toys that are considered "girls' toys." Similarly, some girls wear boys' clothing and play only with boys and "boys' toys." When such children are uncomfortable being a male or a female and are unwilling to accept themselves as such, the diagnosis is gender dysphoria (Zucker, 2005).

The causes of gender dysphoria are not known. Both animal research and the fact that these disorders are often apparent from early childhood suggest that biological factors, such as prenatal hormonal imbalances, are major contributors. Research suggests that children with gender dysphoria have an increased likelihood or becoming homosexual or bisexual as adults (Wallien & Cohen-Kettenis, 2008).

PERSONALITY DISORDERS

Despite having certain characteristic views of the world and ways of doing things, people normally can adjust their behavior to fit different situations. But some people, starting at some point early in life, develop inflexible and maladaptive ways of thinking and behaving that are so exaggerated and rigid that they cause serious distress to themselves or problems to others. People with such personality disorders range from harmless eccentrics to cold-blooded killers.

One group of personality disorders, schizoid personality disorder, is characterized by an inability or desire to form social relationships and have no warm or tender feelings for others. Such loners cannot express their feelings and appear cold, distant, and unfeeling. Moreover, they often seem vague, absentminded, indecisive, or "in a fog." Because their withdrawal is so complete, persons with schizoid personality disorder seldom marry and may have trouble holding jobs that require them to work with or relate to others (American Psychiatric Association, 2013).

People with paranoid personality disorder often see themselves as rational and objective, yet they are guarded, secretive, devious, scheming, and argumentative. They are suspicious and mistrustful even when there is no reason to be; they are hypersensitive to any possible threat or trick; and they refuse to accept blame or criticism even when it is deserved.

A cluster of personality disorders characterized by anxious or fearful behavior includes dependent personality disorder and avoidant personality disorder. People with dependent personality disorder are unable to make decisions on their own or to do things independently. Rather, they rely on parents, a spouse, friends, or others to make the major choices in their lives and usually are extremely unhappy being alone. In avoidant personality disorder, the person is timid, anxious, and fearful of rejection. It is not surprising that this social anxiety leads to isolation, but unlike the schizoid type, the person with avoidant personality disorder wants to have close relationships with others.

Another cluster of personality disorders is characterized by dramatic, emotional, or erratic behavior. People with narcissistic personality disorder, for example, display a grandiose sense of self-importance and a preoccupation with fantasies of unlimited success. Such people believe they are extraordinary, need constant attention and admiration, display a sense of entitlement, and tend to exploit others. They are given to envy and arrogance, and they lack the ability to really care for anyone else (American Psychiatric Association, 2013).

Borderline personality disorder is characterized by marked instability in self-image, mood, and interpersonal relationships. People with this personality disorder tend to act impulsively, and, often, self-destructively. They feel uncomfortable being alone and often manipulate self-destructive impulses in an effort to control or solidify their personal relationships.

One of the most widely studied personality disorders is antisocial personality disorder. People who exhibit this disorder may lie, steal, cheat, and show little or no sense of responsibility, although they often seem intelligent and charming at first. The "con man" exemplifies many of the features of the antisocial personality, as does the person who compulsively cheats business partners, because she or he knows their weak points. Some antisocial personalities show little or no anxiety or guilt about their behavior. Indeed, they are likely to blame society or their victims for the antisocial actions that they themselves commit. As you might suspect, people with antisocial personality disorder are responsible for a good deal of crime and violence.

Approximately 3% of American men and less than 1% of American women suffer from antisocial personality disorder. It is not surprising that prison inmates show high rates of personality disorder ranging from 35% to 60% (Black, Gunter, Loveless, Allen, & Sieleni, 2010; Moran, 1999). Not all people with antisocial personality disorder are convicted criminals, however. Many manipulate others for their own gain while avoiding the criminal justice system.

Antisocial personality disorder seems to result from a combination of biological predisposition, difficult like experiences, and an unhealthy social environment (Gabbard, 2005; Moffitt, Caspi, & Rutter, 2006). Some findings suggest that heredity is a risk factor for the later development of antisocial behavior (Fu et al., 2002; Lyons et al., 1995). Research suggests that some people with antisocial personalities are less responsive to stress and thus more likely to engage in thrill-seeking behaviors, such as gambling and substance abuse, which may be harmful to themselves or others (Patrick, 1994; Pietrzak & Petry, 2005). One study found that men with antisocial personality disorder had a reduced ability to accurately judge facial expressions of anger and hostility in other people (Schonenberg, Louis, Mayer, & Jusyte, 2013). Another intriguing explanation for the cause of antisocial personality disorder is that is arises as a consequence of anatomical irregularities in the prefrontal region of the brain during infancy (Boes, Tranel, Anderson, & Nopoulos, 2008; A. R. Damasio & Anderson, 2003).

Some psychologists believe that emotional deprivation in early childhood predisposes people to antisocial personality disorder. The child for whom no one cares, say some psychologists, cares for no one. Respect for others is the basis of our social code, but when you cannot see things from another person's perspective, behavior "rules" seem like nothing more than an assertion of adult power to be defied.

Family influences may also prevent the normal learning of rules of conduct in the preschool and school years. A child who has been rejected by one or both parents is not likely to develop adequate social skills or appropriate social behavior. Further, the high incidence of antisocial behavior in people with an antisocial parent suggests that antisocial behavior may be partly learned and partly inherited. Once serious misbehavior begins in childhood, there is an almost predictable progression: The child's conduct leads to rejection by peers and failure in school, followed by affiliation with other children who have behavior problems. By late childhood or adolescence, the deviant patterns that will later show up as a full-blown antisocial personality disorder are well established (J. Hill, 2003; T. M. Levy & Orlans, 2004). Cognitive theorists emphasize that in addition to the failure to learn rules and develop self-control, moral development may be arrested in children who are emotionally rejected and inadequately disciplined (K. Davidson, 2008; Soyguet & Tuerkcapar, 2001).

SCHIZOPHRENIA SPECTRUM AND OTHER PSYCHOTIC DISORDERS

Schizophrenia spectrum and other psychotic disorders are severe conditions marked by disordered thoughts and communications, inappropriate emotions, and bizarre behavior that lasts for months or even years (E. Walker & Tessner, 2008). People with schizophrenia are out of touch with reality, which is to say that they are psychotic. Approximately 0.5% to 1% of people have schizophrenia. One meta-analysis of data from 46 different countries found the rate of schizophrenia was similar for men and women, and did not vary significantly across countries (Saha, Chant, & McGrath, 2008).

People schizophrenia often suffer from hallucinations, false sensory perceptions that usually take the form of hearing voices that are not really there. (Visual, tactile, or olfactory hallucinations are more likely to indicate substance abuse or organic brain damage.) They also frequently have delusions - false beliefs about reality with no factual basis - that distort their relationships with their surroundings and other people. Typically, these delusions are paranoid: People with schizophrenia often believe that someone is out to harm them. In addition, they often exhibit disorganized speech, typically displayed as rapidly changing topics within the same sentence, the repetition of words, or the meaningless use of rhyming words or nonsense words. Other common symptoms that may be associated with schizophrenia include a lack of emotional expression, a lack of interest in their environment, social withdrawal, and deterioration in personal hygiene. Because their world is utterly different from reality, people with schizophrenia usually cannot live a normal life unless they are successfully tested with medication.

In the past, the DSM recognized various subtypes of schizophrenic disorders. For example, disorganized schizophrenia often was characterized by giggling, grimacing, and frantic gesturing. People suffering from disorganized schizophrenia often showed a childish disregard for social conventions. People suffering from catatonic schizophrenia often remained immobile, mute, and impassive. Conversely, they might become excessively excited, talking and shouting continuously. Those suffering from paranoid schizophrenia often exhibited extreme suspiciousness and complex delusions. People with paranoid schizophrenia might believe themselves to be Napoleon or the Virgin Mary, or they might insist that Russian spies with laser guns are constantly on their trail because they have learned some great secret. Finally, people suffering from undifferentiated schizophrenia had several of the characteristic symptoms of schizophrenia - such as delusions, hallucinations, or incoherence - yet did not show the typical symptoms of any other subtype of the disorder.

DSM-5 no longer distinguishes between these traditional subtypes. Although each subtype was defined by predominant symptoms, the same symptoms sometimes appeared in other subtypes as well. The result was that the distinctions among the subtypes were often blurred, and that rendered them of limited value. Thus, DSM-5 simply identifies schizophrenia spectrum and other psychotic disorders without breaking them down into distinct subtypes.

Causes of Schizophrenia

Because schizophrenia is a very serious disorder, considerable research has been directed at trying to discover its causes (Keshavan, Tandon, Boutros, & Nasrallah, 2008). Many studies indicate that schizophrenia has a genetic component (Lichtenstein et al., 2009), though no single gene has been identified as a cause for schizophrenia (Pogue-Geile & Yokley, 2010). Instead more than 20 genes have been implicated as potentially contributing to the development of schizophrenia (Gottesman & Hanson, 2005; Oldmeadow et al., 2014).

People with schizophrenia are more likely than other people to have children with schizophrenia, even when those children have lived with adoptive parents since early in life. If one identical twin suffers from schizophrenia, the chances are almost 50% that the other twin will also develop this disorder. In fraternal twins, if one twin has schizophrenia, the chances are only about 17% that the other twin will develop it as well (Gottesman, 1991).

Considerable research suggests that biological predisposition to schizophrenia may involve the faulty regulation of the neurotransmitters dopamine and glutamate in the central nervous system (Lin, Lane, & Tsai, 2011; Miyake, Thompson, Skinbjerg, & Abi-Dargham, 2011). Some research also indicates that pathology in various structures of the brain may contribute to the onset of schizophrenia (Killgore, Rosso, Gruber, & Yurgelun-Todd, 2009; Lawrie, McIntosh, Hall, Owens, & Johnstone, 2008). Other studies link schizophrenia to some form of early prenatal infection or disturbance (Brown & Derkits, 2010). Despite these findings, however, no laboratory tests to date can diagnose schizophrenia based on the basis of brain or genetic abnormalities alone.

Studies of identical twins have also been used to identify the importance of environment in causing schizophrenia. Because identical twins are genetically identical and because half of the identical twins of people with schizophrenia do not develop schizophrenia themselves, this severe and puzzling disorder cannot be caused by genetic factors alone. Environmental factors - ranging from disturbed family relations to taking drugs to biological damage that may occur at any age, even before birth - must also figure in determining whether a person will develop schizophrenia. Finally, although quite different in emphasis, the various explanations for schizophrenic disorders are not mutually exclusive. Genetic factors are universally acknowledged, but many theorists believe that only a combination of biological, psychological, and social factors produces schizophrenia (van Os, Rutten, & Poulton, 2008). According to systems theory, genetic factors predispose some people to schizophrenia; and family interaction and life stress activate the predisposition.

NEURODEVELOPMENTAL DISORDERS

Children may suffer from conditions already discussed in this chapter - for example, depression and anxiety disorders. But other disorders are either characteristic of children or are first evident in childhood. The DSM-5 contains a long list of disorders usually first diagnosed in infancy, childhood, or adolescence. Two of these disorders are attention-deficit/hyperactivity disorder and autistic spectrum disorder.

Attention-deficit/hyperactivity disorder (ADHD) was once known simply as hyperactivity. The new name reflects the fact that children with the disorder typically have trouble focusing their attention in the sustained way that other children do. Instead, they are easily distracted, often fidgety and impulsive, and almost constantly in motion. In the United States about 7% or four and a half million school-aged children have ADHD, with boys (11%) being more than twice as likely as girls (4%) to be affected (Bloom & Cohen, 2006). About 4% of adults in the United States also display the symptoms of ADHD (Kessler et al., 2006). Research suggests that ADHD is present at birth, but becomes a serious problem only after a child starts school (Monastra, 2008). The class setting demands that children sit quietly, pay attention as instructed, follow directions, and inhibit urges to yell and run around. The child with ADHD simply cannot conform to these demands.

We do not yet know what causes ADHD, but considerable evidence indicates biological factors play an important role (Monastra, 2008; Nigg, 2005). Neuroimaging studies, for example, reveal individuals with ADHD display altered brain functioning when presented with tasks that require shifting attention. The deficiency appears to involve the frontal lobe, which normally recruits appropriate regions of the brain to solve a problem. In people with ADHD, however, the frontal lobe sometimes activates brain centers unrelated to solving a problem (Konrad, Neufang, Hanisch, Fink, & Herpertz-Dahlmann, 2006; Mulas et al., 2006; Murias, Swanson, & Srinivasan, 2007).

Deficits in the prefrontal cortex may also contribute to ADHD. Generally, the prefrontal cortex plays an important role in inhibiting unnecessary motor behaviors and directing attention. This inhibitory role of the prefrontal cortex may not function properly in people with ADHD making it difficult for them to reduce unnecessary motor activity and focus attention (Depue, Burgess, Willcutt, Ruzic, & Banich, 2010).

Family interaction and other social experiences may be more important in preventing the disorder than in causing it (C. Johnson & Ohan, 2005). That is, some exceptionally competent parents and patient, tolerant teachers may be able to teach "difficult" children to conform to the demands of schooling. Although some psychologists train the parents of children with ADHD in these management skills, the most frequent treatment for these children is a type of drug known as a psychostimulant. Psychostimulants do not work by "slowing down" hyperactive children; rather, they appear to increase the children's ability to focus their attention so that they can attend to the task at hand, which decreases the hyperactivity and improves their academic performance (Duesenberg, 2006; Gimpel et al., 2005). Unfortunately, psychostimulants often produce only short-term benefits; and their use and possible overuse in treating ADHD children is controversial (Comstock, 2011; Marc Lerner & Wigal, 2008).

A very different disorder that usually becomes evident in the first few years of life is autistic spectrum disorder (ASD) (Angus, 2011). While the severity of symptoms of ASD vary considerably among individuals, they generally include: problems with social and emotional interaction, severe difficulty in maintaining relationships and engaging in age-appropriate social activities, and deficits in verbal or nonverbal communication. Problems with nonverbal communication may include the inability to express or understand facial expressions, tone of voice, gesture, and normal eye contact. Excessive adherence to routines, highly restricted interests or focus, and in some areas stereotyped or repetitive speech or motor behaviors may also be present.

In the more severe cases, individuals with ASD may not speak at all, or develop a peculiar speech pattern called echolalia, in which they repeat the words said to them. As infants, they may even show distress at being picked up or held. Often they don't play as normal children do; they are not at all social and may use toys in odd ways, constantly spinning the wheels on a toy truck or tearing paper into strips. Individuals with ASD sometimes display the symptoms of intellectual disability (LaMalfa, Lassi, Bertelli, Salvini, & Placidi, 2004), but it is hard to test their intelligence because they may lack verbal communication skills (Dawson, Soulieres, Gernsbacher, & Mottron, 2007). The disorder lasts into adulthood in the great majority of cases.

We don't know exactly what causes ASD, but the overwhelming consensus is that it results almost entirely from biological conditions (Currenti, 2010; Goode, 2004; Zimmerman, Connors, & Pardo-Villamizar, 2006). Considerable evidence suggests that genetics play a strong role in causing the disorder (Campbell, Li, Sutcliffe, Persico, & Levitt, 2008; Rutter, 2005), though no specific gene or chromosome responsible for ASD has been identified (Losh, Sullivan, Trembath, & Piven, 2008). Neuroimaging studies have also implicated faulty development of the frontal lobes, the amygdala and cerebellum as contributing to the development of autism (Amaral, Schumann, & Nordahl, 2008). Along this line, one recent study found evidence that ASD may be directly traceable to defects present in areas of the prenatal brain that regulate social functioning, communication and emotion (Stoner, 2014). Another intriguing line of research has focused on abnormal antibodies found in the blood of some mothers of children with autistic spectrum disorder, but not in mothers of healthy children. When pregnant rhesus monkeys were injected with these antibodies, all of their offspring displayed autistic like behaviors, including atypical repetitive movements and hyperactivity (Martin et al., 2008).

GENDER AND CULTURAL DIFFERENCES IN PSYCHOLOGICAL DISORDERS

For the most part, men and women are similar with respect to mental disorders, but differences do exist. Many studies have concluded that women have a higher rate of psychological disorders than men do, but this is an oversimplification (Cosgrove & Riddle, 2004). We do know that more women than men are treated for mental disorders. But this cannot be taken to mean that more women than men have mental disorders, for in our society, it is much more acceptable for women to discuss their emotional difficulties and to seek professional help openly (H. Lerman, 1996).

Moreover, mental disorders for which there seems to be a strong biological component, such as bipolar disorder and schizophrenia, are distributed fairly equally between the sexes. Differences tend to be found for those disorders without a strong biological component - that is, disorders in which learning and experience may play a more important role. For example, men are more likely than women to suffer from substance abuse and antisocial personality disorder. Women, on the other hand, are more likely to suffer from depression, agoraphobia, simple phobia, obsessive-compulsive disorder, and somatization disorder (Craske, 2003; Faravelli, Scarpato, Castellini, & Lo Sauro, 2013; Rosenfield & Pottick, 2005). These tendencies, coupled with the fact that gender differences observed in the United States are not always seen in other cultures (Culbertson, 1997), suggest that socialization plays a part in developing a disorder: When men display abnormal behavior, it is more likely to take the forms of drinking too much and acting aggressively; when women display abnormal behavior, they are more likely to become fearful, passive, hopeless, and "sick" (Rosenfield & Pottick, 2005).

One commonly reported difference between the sexes concerns marital status. Men who are separated, divorced, or who have never married have a higher incidence of mental disorders than do either women of the same marital status or married men. But married women have higher rates than married men. What accounts for the apparent fact that marriage is psychologically less beneficial for women than for men?

Here, too, socialization appears to play a role. For women, marriage, family relationships, and child rearing are likely to be more stressful than they are for men (Erickson, 2005; Stolzenberg & Waite, 2005). For men, marriage and family provide a haven, for women, they are a demanding job. In addition, women are more likely than men to be the victim of incest, rape, and marital battering. As one researcher has commented, "for women, the U.S. family is a violent institution" (Koss, 1990, p. 376). The effects of stress are proportional to the extent that a person feels alienated, powerless, and helpless. Alienation, powerlessness, and helplessness are more prevalent in women than in men. The rate of depression among women is twice that of men, a difference that is usually ascribed to the more negative and stressful aspects of women's lives, including lower incomes and the experiences of bias and physical and sexual abuse (American Psychological Association, 2006; Blehar & Keita, 2003). These factors are especially common among minority women, so it is not surprising that the prevalence of psychological disorders is greater among them than among other women (Lagana & Sosa, 2004).

In summary, women do seem to have higher rates of anxiety disorders and depression than men do, and they are more likely than men to seek professional help for their problems. However, greater stress, due in part to socialization and lower status rather than psychological weakness, apparently accounts for this statistic. Marriage and family life, associated with lower rates of mental disorders among men, introduce additional stress into the lives of women, particularly young women (25 to 45); and in some instances this added stress escalates into a psychological disorder.

As the U.S. population becomes more diverse, it is increasingly important for mental health professionals to be aware of cultural differences if they are to understand and diagnose disorders among people of various cultural groups. Many disorders occur only in particular cultural groups. For example, ataque de nervios - literally translated as "attack of the nerves" - is a culturally specific phenomenon that is seen predominantly among Latinos. The symptoms of ataque de nervios generally include the feeling of being out of control, which may be accompanied by fainting spells, trembling, uncontrollable screaming, and crying, and, in some cases, verbal or physical aggressiveness. Afterwards, many patients do not recall the attack, and quickly return to normal functioning. Another example, taijin kyofusho (roughly translated as "fear of people"), involves a morbid fear that one's body or actions may be offensive to others. Taijin kyofusho is rarely seen outside of Japan.

The prevalence of childhood disorders also differs markedly by culture. Of course, it is adults - parents, teachers, counselors - who decide whether a child is suffering from a psychological disorder, and those decisions are likely to be influenced by cultural expectations. For example, in a series of cross-cultural studies, Thai children were more likely to be referred to mental health clinics for internalizing problems, such as anxiety and depression, compared to U.S. children, who were more likely to be referred for externalizing problems, such as aggressive behavior (Weisz et al., 1997).