Am J Psychiatry 1997; 154:31-36
Copyright © 1997 by American Psychiatric Association
Prophylactic efficacy of phenelzine and imipramine in chronic atypical depression: likelihood of recurrence on discontinuation after 6 months' remission
JW Stewart, E Tricamo, PJ McGrath and FM Quitkin
New York State Psychiatric Institute, N.Y., USA. JWS6@Columbia.edu
OBJECTIVE: Demonstration of antidepressant efficacy beyond 6 months has
infrequently been addressed, and no long-term efficacy data exist for
patients with chronic atypical depression. METHOD: Sixty patients with
atypical depression (according to Columbia University criteria) of at least
2 years' duration and who had improved with imipramine or phenelzine were
stabilized for 6 months and then randomly continued the same medication or
placebo for 6 months. RESULTS: Several baseline differences suggested that
patients who entered the discontinuation trial on a regimen of phenelzine
were more chronically depressed than the imipramine-treated patients.
Survival analysis showed a marked advantage for phenelzine relative to
placebo. In addition, patients switched to placebo from phenelzine
experienced a recurrence of depressive symptoms significantly more often
than patients switched to placebo from imipramine. Patients maintained with
imipramine did not have lower relapse rates than those switched from
imipramine to placebo. Recurrence rates were 23% for patients maintained on
a regimen of phenelzine, 41% for those maintained on a regimen of
imipramine, 47% for those switched from imipramine to placebo, and 87% for
placebo- treated patients originally treated with phenelzine. CONCLUSIONS:
Patients with chronic atypical depression are at high risk of recurrence if
phenelzine is withdrawn 6 months after initial improvement. Similar
findings were not demonstrated for imipramine; this replicates acute trials
demonstrating imipramine's relative ineffectiveness in patients with
atypical depression. Differences in recurrence rates after the switch to
placebo from phenelzine and imipramine could be due to the two drugs'
different mechanisms of action or to baseline differences in the two
populations.
