Am J Psychiatry 1993; 150:562-565
Copyright © 1993 by American Psychiatric Association
Loss of drug effects during continuation therapy
FM Quitkin, JW Stewart, PJ McGrath, E Nunes, K Ocepek-Welikson, E Tricamo, JG Rabkin, D Ross and DF Klein
Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY.
OBJECTIVE: This study sought to determine what proportion of relapses
during continuation therapy with antidepressants can be attributed to loss
of nonspecific placebo effects while the patients are taking the drugs.
METHOD: Depressed patients were studied over a 12-week period. One hundred
sixty-four patients were randomly assigned to placebo, 174 to imipramine,
and 169 to phenelzine. At 6 weeks 35 were judged to be responders to
placebo, 70 to imipramine, and 96 to phenelzine. These patients continued
their double-blind treatment for weeks 7-12. RESULTS: Thirty-one percent of
the patients who were taking placebo, approximately 12% who were taking
imipramine, and approximately 9% who were taking phenelzine relapsed in the
7- to 12-week phase. Two different methods of estimating relapses suggested
that during the first 3 months of treatment, a large percentage of the
relapses of patients taking drugs was attributable to the loss of
nonspecific placebo effects rather than true drug effects. CONCLUSIONS: A
considerable proportion of relapses in the first 3 months of treatment with
antidepressants appears to be due to loss of placebo effects. These
clinically relevant data may be used to encourage patients who relapse
during this period, and who erroneously conclude that anti- depressant
effects are temporary, to try another medication.
