Bipolar Disorder
The mean age of onset for bipolar disorder is the early twenties. It affects men and women equally; over the course of their lifetime, between 0.4 and 1.2 percent of men and women will develop bipolar disorder. At any given time, between o. 1 and 0.6 percent of the population are suffering from an episode. There is a high genetic correlation; first-degree relatives of bipolar patients have a 12 percent lifetime incidence, while another 12 percent will experience major depression.
Untreated, a manic episode will last an average of six months, and a major depressive episode eight to ten months. The interval between episodes decreases as time goes on. There is a high mortality rate, due to suicide (15 percent of untreated patients), accidental death due to risky behavior, and concurrent illness.
Many people with untreated bipolar disorder will die from alcoholism, lung cancer, accidents, or sexually transmitted disease; feeling so invulnerable during an episode, they simply do not take the precautions that most of us have come to accept as part of a sensible lifestyle.
Bipolar disorder seems to be a different kettle of fish from other kinds of depression, though the depressive episodes may look and feel the same as major depression. Bipolar disorder has such a high degree of genetic transmission, the manic episodes are so distinctive and limited to the disease, and the disease itself has such a unique response to a specific medication (lithium) that it makes sense to think of it as primarily a biogenetic disease that causes a chemical imbalance in the brain. This is not to say that the bipolar patient also doesn’t have to change his lifestyle to help his recovery.