Bipolar Disorder

In 1686, Théophile Bonet, a French pathologist, described a mental illness
he called maniaco-melancholicus. In 1854, Jules Falret, a French physician, described
folie circulaire, distinguished by alternating moods of depression and
mania. In 1899, Emil Kraepelin, a German psychologist, described manicdepressive
psychosis. Bipolar disorder has a lifetime prevalence of 1.2 percent.
It affects more than 2.3 million adult Americans each year. It is equally
common in men and women.
There is a genetic link to bipolar disorder. About 50 percent of all bipolar
disorder patients have at least one parent with a mood disorder. An increased level of calcium ions is found in the blood of patients with bipolar
disorder. There is also a lowered blood flow in the brain as well as slower
overall metabolism. Some research suggests that bipolar disorder may be
caused by disturbed circadian rhythms and related to disturbances in melatonin
secretion.

The DSM-IV-TR divides bipolar disorder into bipolar I disorder, bipolar II
disorder, and cyclothymic disorder. Bipolar I disorder is characterized by
the occurrence of one or more manic episodes or mixed episodes and one
or more major depressive episodes. Bipolar II disorder is characterized by
the occurrence of one or more major depressive episodes accompanied by
at least one hypomanic episode. Cyclothymic disorder is a chronic, fluctuating
mood disturbance involving periods of hypomanic episodes and periods
of major depressive episodes.

Treatment options include psychotherapy and medication. Mood stabilizers,
such as lithium and divalproex sodium, are the most commonly used
medications. Lithium is a naturally occurring substance that increases serotonin
levels in the brain. Side effects can include dry mouth, high overdose
toxicity, nausea, and tremor. Divalproex sodium increases GABA (gammaamino
butyric acid) in the brain. Neurotransmitters trigger either “go” signals
that allow messages to be passed on to other cells in the brain or “stop”
signals that prevent messages from being forwarded. GABA is the most common
message-altering neurotransmitter in the brain. Possible side effects of
divalproex sodium include constipation, headache, nausea, liver damage,
and tremor. Olanzapine increases levels of dopamine and serotonin. Side
effects include drowsiness, dry mouth, low blood pressure, rapid heartbeat,
and tremor. Anticonvulsants are also widely prescribed. Carbamazepine,
for example, increases GABA and serotonin. Possible side effects include
blurred vision, dizziness, dry mouth, stomach upset, or sedation. In
the case of severe mania, patients may take a tranquilizer or a neuroleptic
(antipsychotic drug) in addition to the mood stabilizer. During the depressive
episode, the person may take an antidepressant. ECT may also be helpful
during severe depressive episodes.