Mood Stabilizers

Some patients who have depression also have episodes of elevated mood
and erratic, uncontrolled behavior. These patients are diagnosed with bipolar
disorder, formerly known as manic-depression. The underlying cause
for this disorder is unknown, but there is a strong genetic predisposition. Evidence
suggests the condition is due to overactivity of the neurotransmitters.
Treatment for bipolar disorder consists of mood-stabilizing drugs. These
drugs control not only the “highs” but also the episodes of depression.
Lithium is a naturally occurring mineral that was observed to calm agitated
behavior in ancient Egypt. Its usefulness as a mood stabilizer was first
scientifically established in the 1940’s and it was approved in 1970 for use in
the United States. It is effective not only in stabilizing the mood during a
manic episode but also in the prevention of future episodes. A significant
problem with the use of lithium is that the dose at which it becomes effective is quite close to the dose which produces toxicity, characterized by drowsiness,
blurred vision, staggering, confusion, irregular heart beat, seizures,
and coma. Patients taking lithium must therefore have blood drawn on a
regular basis in order to determine drug levels. Patients who have poor kidney
function should not take lithium because it is excreted primarily through
the urine. Lithium’s side effects include nausea, diarrhea, tremor of the
hands, dry mouth, and frequent urination.
Drugs usually used for the treatment of seizures may also help stabilize
mood in bipolar patients, usually at lower doses than would be used for seizure
control. These include carbamazepine, divalproex, gabapentin, lamotrigine,
and topiramate. It is believed that these drugs increase the amount
of GABA at the synapse. GABA has a calming or inhibitory effect on the neurons.
Side effects of these medications include dizziness, nausea, headaches,
and visual changes.