A Comparative Trial of Imipramine and Chlorpromazine in Depressed Patients

Abstract

The majority of controlled trials of imipramine against placebo in the treatment of depression have indicated the general efficacy of the drug (9). Recently there has been renewed interest in the use of the phenothiazines in depression, and the question has been raised as to how far the actions of the imipramine-like drugs and of the phenothiazines can be differentiated. Structurally, the iminodibenzyl nucleus of imipramine closely resembles the phenothiazine nucleus, the only difference being replacement of the sulphur atom bridging the two benzyl rings in the latter by a CH2–CH2 group in the iminodibenzyl nucleus. Two controlled trials have suggested that in depressed patients the phenothiazines may be more valuable than has been previously realized and similar in overall efficacy to imipramine. Fink et al. (3) found both chlorpromazine and imipramine significantly better than placebo in the treatment of depressives, with only minor and insignificant differences between them. Similarly, in a relatively large collaborative trial, Overall et al. (11) found thioridazine as effective as imipramine. These authors subsequently employed a special statistical classification technique to stratify their patients into three subtypes according to initial symptom profiles (8). With respect to a variety of symptom ratings, this stratification revealed significant differences in drug effects. Imipramine proved superior in “retarded” depressives and thioridazine in “anxious” depressives, while no differences were found in “hostile” depressives.