Am J Psychiatry 1993; 150:566-570
Copyright © 1993 by American Psychiatric Association
Further evidence that a placebo response to antidepressants can be identified
FM Quitkin, JW Stewart, PJ McGrath, E Nunes, K Ocepek-Welikson, E Tricamo, JG Rabkin and DF Klein
Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY.
OBJECTIVE: The authors' goal was to analyze the acute phase of
antidepressant drug treatment to identify placebo responses. METHOD:
Patients rated as improved after 6 weeks of double-blind treatment with
imipramine or phenelzine were followed for an additional 6 weeks of
double-blind treatment. Initial responses were classified according to the
speed of improvement (abrupt or gradual), the persistence or nonpersistence
of improvement, and the timing of improvement (early or late onset).
RESULTS: It was predicted that patients with nonpersistent, abrupt
responses to the drugs were actually experiencing a placebo response and
would have the worst prognosis. In fact, this group accounted for a
disproportionate number of the relapses. Nonpersistent responders to a drug
had a 23.7% relapse rate, but persistent responders had only a 9.0% relapse
rate, a significant difference. CONCLUSIONS: The authors conclude that a
significant proportion of relapses within the first 6 weeks of treatment
with an active drug are not related to loss of a true drug effect. Rather,
some are related to loss of nonspecific placebo effects, and abrupt
nonpersistent responses during drug treatment are most likely the result of
placebo effects.
