University of Pittsburgh researchers report that the recurrence and severity of episodes of clinical depression, which affects an estimated 2.7 million Americans, can be reduced if sufferers continue to take high doses of certain antidepressants long after their symptoms abate.
Most psychiatrists treat depression by first giving patients relatively high doses of drugs such as imipramine, the one Pittsburgh researchers tested, and then maintaining them on lower levels.
"When a doctor uses a drug to control high blood pressure, he gets it under control and then keeps the patient on that dose," said David Kupfer, Pittsburgh's chairman of psychiatry and an author of the study published in the current issue of the Archives of General Psychiatry. "In the treatment of depression, and most other psychiatric disorders, that was never done. The emphasis was on acute treatment, not on prevention."
Although the Pittsbugh study did not look at drugs other than imipramine, Kupfer said "other tricyclic antidepressants will probably work the same way."
In the study, 128 patients with chronic depression initially were treated with imipramine and psychotherapy. After their depression was controlled, they were then divided into several groups: one group received psychotherapy and high doses of imipramine, another received psychotherapy only, a third was treated with the drug only while members of the fourth got a placebo and no psychotherapy.
All patients were followed for three years to see which treatment, if any, postponed a recurrence of depression.
At the end of three years, 80 percent of patients on high-dose imipramine had not relapsed, according to the study.
The study, however, did show that psychotherapy, even without medication, did make a difference, but it was less pronounced. Monthly therapy sessions prevented a relapse for an average of 18 months, while patients who got neither drugs nor a placebo relapsed in an average of 45 weeks.