treme changes in mood between low (depressed) and high (manic) states. It is one of several affective disorders which have marked and prolonged changes in an individual's mood or affect. The disorder used to be referred to as manic-depressive disorder, but in recent years there has been a tendency to call the disorder "bipolar illness" or "bipolar affective disorder" because of the two diametrically opposite affects involved (Cadoret, 1997).
The prevalence of manic-depressive illness is difficult to estimate. It usually manifests itself during the third to fourth decade of life, however, it can have its onset at any time between the ages of 15 and 70. The number of episodes during the lifetime of an individual can range from two to 30, with the episodes tending to occur closer together as the individual ages. Bipolar disorder carries a high risk of suicide, and studies have shown that, over long periods, approximately 15 percent of individuals with bipolar disorder die at their own hands.
The most frequent direction of mood change in bipolar disorder is toward depression, which is accompanied by a low energy level and a loss of interest in activities usually enjoyed. Thoughts come more slowly, and often there is difficulty in concentrating. The content of thought usually revolves around self-deprecatory themes, personal guilt, and morbid ideas about illness, death, accidents, and, in many cases, suicide. Characteristically, there are other distressing symptoms such as insomnia, sleeping too much, restless sleep, poor appetite, loss of weight, and often a pervasive anxiety and tension. This mood change usually lasts for weeks or months.
The opposite mood is the elated, euphoric, or manic mood. In this state there is an abundance of energy, overtalkativeness, and a diminished need for sleep. Thoughts come more rapidly, often so quickly that the individual cannot keep track of them. This is evident in the speech, wh...