IV.

Treatment

Depressive disorders are, thankfully, among the most treatable in psychiatry. They have been linked with the dysfunction of three major neurotransmitter systems (involving serotonin, dopamine, and noradrenalin) in the brain. Three major classes of drugs are used to treat depressive disorders: the tricyclic/tetracyclic antidepressants; the monoamine oxidase (MAO) inhibitors, which prevent the breakdown of monoamine transmitters; and the 5HT reuptake inhibitors.

The tricyclics act by blocking the reuptake of serotonin and noradrenalin into the neurons, prolonging the effects of these transmitters. The tetracyclics require following a special diet because they interact with tryamine, which is found in cheeses, beer, wine, chicken livers, and other foods, and causes elevation of blood pressure. (The tricyclic antidepressants require no special diet but may have a toxic effect on cardiac tissue.)

A recently launched class of effective antidepressants, called 5HT reuptake inhibitors, acts by blocking the reuptake of both serotonin and noradrenalin in the brain and is said to have fewer side-effects. These drugs have shown potential efficacy in treating many kinds of depression and include venlafaxine (Efexor) and fluoxetine (Prozac), which inhibits the reuptake of 5HT or 5HT and noradrenalin in the brain. Introduced in 1986, Prozac had been prescribed to more than 10 million people worldwide by 1994. Lithium carbonate, a common mineral, is used to control the manic phase of manic-depressive illness, although its action is not clearly understood. In smaller doses it is also used to regulate the mood fluctuations of this bipolar disorder. Carbamazepine is used in cases not responsive to lithium or lithium carbonate.

Electroconvulsive therapy (ECT) is considered by some practitioners as a last resort for patients with severe depression that is not responsive to drug therapy. Psychotherapy and counselling are other major forms of treatment which may be recommended alongside or instead of prescribed antidepressants.