tigations of MAOIs. Drugs were declared superior to placebos in 79% of the
tricyclic studies and in 54% of the MAOI studies.

Klerman and Cole ( 1965) found 23 studies comparing imipramine to
placebo. Eighteen of these studies (78%) indicated that the drug outcome was
better. However, the authors of 3 of these 18 positive papers felt that their
investigations as a whole did not present really convincing evidence of imipra-
mine's general superiority to the controls. Overall, the authors of the studies
felt that the drug was convincingly superior 15 times in the 23 trials (65%).
Incidentally, even this figure may be an overestimation of the number of trials
in which imipramine exceeded placebo. Thus, a commentary ( Beck, 1967)
on this review indicated that many studies were counted by Klerman and Cole
as showing positive results even though the superiority of the drug was slight
and short of statistical significance on a number of indices.

Klerman and Cole also combined the data across all the studies, permitting
an overall judgment as to whether the patients had or had not improved.
They concluded that 65% of the 550 imipramine-treated patients improved,
whereas 31% of the 459 controls evidenced similar improvement. They went
on to suggest that this improvement difference between drugs and placebo
might not be as large as the percentages indicated because some of the
improved patients were not improved enough to satisfy either themselves or
their physicians. Therefore, imipramine was deemed "not entirely satisfactory
treatment in many of the depressed patients to whom it was given" (p. 282 ).

Klein and Davis ( 1969) reviewed 65 studies comparing tricyclics with
placebo and indicated that 50 showed the drug to be superior (77%). They
found no striking overall outcome differences among the tricyclics. Although
there were differences in diagnostic groupings and types of measurement
among studies, it was felt that combining samples might give an approximate
summary statement of the efficacy of antidepressants. Therefore, the percent-
ages of improvement reported by the various studies were pooled. The number
of patients rated at least moderately improved was combined within the drug
and placebo groups respectively and compared with the number found to be
slightly improved, unchanged, or worse. In this way the reviewers derived a
figure of 70% as the rate of improvement on imipramine and 39% as the
placebo improvement rate. Overall it was concluded that imipramine was
superior to a placebo, although "not overwhelmingly so," with a treatment
superiority of about 30% more improvement for the active drug than for the
placebo. Similarly, in fewer studies, amitriptyline was found to be more
beneficial than placebo (62% vs. 24%).

In a more recent, widely cited review, Morris and Beck ( 1974) looked at
146 double-blind studies on antidepressant drugs utilized in the United States
in 1972. Two thirds of the 93 studies of tricyclics indicated that the drug was
superior to a placebo, whereas one third of the reports found no difference.
The box score outcome for the MAOIs revealed somewhat less success, with

-3-