Attention-Deficit/Hyperactivity Disorder (ADHD) Diagnosis

Diagnosis Criteria

Differential Diagnosis

Sources and resources

Diagnosis Criteria

Attention-deficit/hyperactivity disorder

Several persistent symptoms of hyperactivity/impulsivity and/or inattention for at least 6 months.
- - ICD-11: "A persistent pattern (e.g., at least 6 months) of inattention symptoms and/or a combination of hyperactivity and impulsivity symptoms that is outside the limits of normal variation expected for age and level of intellectual development. Symptoms vary according to chronological age and disorder severity."
  - DSM-5: "People with ADHD show a persistent pattern of inattention and/or hyperactivity–impulsivity that interferes with functioning or development."
  - DSM-5: "Inattention: Six or more symptoms of inattention for children up to age 16 years, or five or more for adolescents age 17 years and older and adults; symptoms of inattention have been present for at least 6 months, and they are inappropriate for developmental level."
  - DSM-5: "Hyperactivity and Impulsivity: Six or more symptoms of hyperactivity-impulsivity for children up to age 16 years, or five or more for adolescents age 17 years and older and adults; symptoms of hyperactivity-impulsivity have been present for at least 6 months to an extent that is disruptive and inappropriate for the person’s developmental level."

See symptoms lists below.

At least some symptoms are/were present before age 12.
- - ICD-11: "Evidence of significant inattention and/or hyperactivity-impulsivity symptoms prior to age 12, though some individuals may first come to clinical attention later in adolescence or as adults, often when demands exceed the individual’s capacity to compensate for limitations."
  - DSM-5: "Several inattentive or hyperactive-impulsive symptoms were present before age 12 years."
Symptoms are present in multiple different settings.
- - ICD-11: "Manifestations of inattention and/or hyperactivity-impulsivity must be evident across multiple situations or settings (e.g., home, school, work, with friends or relatives), but are likely to vary according to the structure and demands of the setting."
  - DSM-5: "Several symptoms are present in two or more settings, (such as at home, school or work; with friends or relatives; in other activities)."
Symptoms cause impairment.
- - ICD-11: "Several symptoms of inattention that are persistent, and sufficiently severe that they have a direct negative impact on academic, occupational, or social functioning."
  - ICD-11: "Several symptoms of hyperactivity/impulsivity that are persistent, and sufficiently severe that they have a direct negative impact on academic, occupational, or social functioning. These tend to be most evident in structured situations that require behavioural self-control."
  - DSM-5: "There is clear evidence that the symptoms interfere with, or reduce the quality of, social, school, or work functioning."
Symptoms are not better explained by another condition.
- - ICD-11: "Symptoms are not better accounted for by another mental disorder (e.g., an Anxiety or Fear-Related Disorder, a Neurocognitive Disorder such as Delirium)."
  - ICD-11: "Symptoms are not due to the effects of a substance (e.g., cocaine) or medication (e.g., bronchodilators, thyroid replacement medication) on the central nervous system, including and withdrawal effects, and are not due to a Disease of the Nervous System."
  - DSM-5: "The symptoms are not better explained by another mental disorder (such as a mood disorder, anxiety disorder, dissociative disorder, or a personality disorder). The symptoms do not happen only during the course of schizophrenia or another psychotic disorder."

Inattention symptoms:

ICD-11 inattention symptoms list:

Difficulty sustaining attention to tasks that do not provide a high level of stimulation or reward or require sustained mental effort; lacking attention to detail; making careless mistakes in school or work assignments; not completing tasks.
Easily distracted by extraneous stimuli or thoughts not related to the task at hand; often does not seem to listen when spoken to directly; frequently appears to be daydreaming or to have mind elsewhere.
Loses things; is forgetful in daily activities; has difficulty remembering to complete upcoming daily tasks or activities; difficulty planning, managing and organizing schoolwork, tasks and other activities.

DSM-5 inattention symptoms list:

Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other activities.
Often has trouble holding attention on tasks or play activities.
Often does not seem to listen when spoken to directly.
Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., loses focus, side-tracked).
Often has trouble organizing tasks and activities.
Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework).
Often loses things necessary for tasks and activities (e.g. school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).
Is often easily distracted.
Is often forgetful in daily activities.

Hyperactive-impulsive symptoms:

ICD-11 hyperactive-impulsive symptoms list:

Excessive motor activity; leaves seat when expected to sit still; often runs about; has difficulty sitting still without fidgeting (younger children); feelings of physical restlessness, a sense of discomfort with being quiet or sitting still (adolescents and adults).
Difficulty engaging in activities quietly; talks too much.
Blurts out answers in school, comments at work; difficulty waiting turn in conversation, games, or activities; interrupts or intrudes on others conversations or games.

DSM-5 hyperactive-impulsive symptoms list:

A tendency to act in response to immediate stimuli without deliberation or consideration of risks and consequences (e.g., engaging in behaviours with potential for physical injury; impulsive decisions; reckless driving).
Often fidgets with or taps hands or feet, or squirms in seat.
Often leaves seat in situations when remaining seated is expected.
Often runs about or climbs in situations where it is not appropriate (adolescents or adults may be limited to feeling restless).
Often unable to play or take part in leisure activities quietly.
Is often “on the go” acting as if “driven by a motor”.
Often talks excessively.
Often blurts out an answer before a question has been completed.
Often has trouble waiting their turn.
Often interrupts or intrudes on others (e.g., butts into conversations or games).

Subtypes (presentations):

Predominately inattentive presentation.

ICD-11: "All diagnostic requirements for Attention Deficit Hyperactivity Disorder are met and inattentive symptoms predominate."
DSM-5: "If enough symptoms of inattention, but not hyperactivity-impulsivity, were present for the past six months."

Predominately hyperactive-impulsive presentation.

ICD-11: "All diagnostic requirements for Attention Deficit Hyperactivity Disorder are met and symptoms of hyperactivity-impulsivity predominate."
DSM-5: "If enough symptoms of hyperactivity-impulsivity, but not inattention, were present for the past six months."

Combined presentation.

ICD-11: "All diagnostic requirements for Attention Deficit Hyperactivity Disorder are met and both hyperactive-impulsive and inattentive symptoms are clinically significant aspects of the current clinical presentation, with neither clearly predominating."
DSM-5: "If enough symptoms of both criteria inattention and hyperactivity-impulsivity were present for the past 6 months."

Differential Diagnosis

Disorders with similar symptoms

Disorders of intellectual development:

ICD-11 link: https://icd.who.int/browse11/l-m/en#/http%3a%2f%2fid.who.int%2ficd%2fentity%2f605267007

Inattention and hyperactivity due to inability to keep up with academics may be mistaken for ADHD.