Psychodynamic Perspective

As is similar in the etiology of unipolar depression, psychodynamic theorists suggest that bipolar disorder stems from a loss of a loved one or an imagined loss in early childhood (see Unipolar Depression Etiology). Some internalize the pain of the loss and become depressed, but others reject the loss and become manic. This confusion of feelings leads to the swinging moods present in bipolar disorder. While a few cases seem to fit the psychodynamic model, there has been little research on this method. The psychodynamic proposal of etiology is not often cited.

---

Biological Perspective

Neurotransmitters:

Because people with mania demonstrate the opposite behavior of those with depression, the neurotransmitter imbalances found in mania were suggested to be the opposite to those in depression. However, it has been shown that low serotonin levels are present in both manic people and depressed people. Similarly, fluctuations of norepinephrine seem to be linked to both mania and depression. Studies suggest that serotonin may  act as a regulator for norepinephrine activity. Low levels of serotonin with high levels of norepinephrine may produce manic symptoms, while low levels of serotonin with low levels of norepinephrine may produce depressive symptoms.

Ion activity:

The unusual transport of sodium and potassium ions may cause neurons to misfire. An excess of neuron activity may lead to mania, and a deficiency of neuron activity may lead to depression. Thus, the mood swings of those with bipolar disorder may be caused by the body’s unsuccessful attempt to regulate ion concentrations.

Brain Structure:

The physical structure of the brain may also play a role in causing bipolar disorder; it has been shown that the cerebellum and the basal gamglia are generally smaller in individuals with bipolar disorder than normal individuals. Also, there are abnormal structures in other areas of the brain controlling neurotransmitter and ion levels.

Genetic Factors:

There may be a genetic linkage on the X chromosome as well as on chromosomes 1, 4, 6, 10, 11, 12, 13, 15, 18, 21, and 22 for bipolar disorder. Most likely, the genetic linkage for bipolar disorder actually consists of several different genes on different interacting chromosomes. A significant predisposition may be found in individuals with a close family history of the disorder, suggesting a high probability of genetic inheritance of bipolar disorder.