A METAANALYSIS OF THE EFFECTS OF COGNITIVE THERAPY IN DEPRESSED-PATIENTS

Background. Cognitive therapy (CT) has been studied in 78 controlled c linical trials from 1977 to 1996. Method. The meta-analysis used Hedge s and Olkin d+ and included 48 high-quality controlled trials. The 276 5 patients presented non-psychotic and non-bipolar major depression, o r dysthymia of mild to moderate severity. Results. At post-test CT app eared significantly better than waiting-list, antidepressants (P<0.000 1) and a group of miscellaneous therapies (P < 0.01). But, CT was equa l to behaviour therapy. As between-trial homogeneity was not met, the comparisons of CT with waiting-list or placebo, and other therapies sh ould be taken cautiously. In contrast, between-trial homogeneity was h igh for the comparisons of CT with behaviour therapy and antidepressan ts. A review of eight follow-up studies comparing CT with antidepressa nts suggested that CT may prevent relapses in the long-term, while rel apse rate is high with antidepressants in naturalistic studies. Conclu sion. CT is effective in patients with mild or moderate depression. (C ) 1998 Elsevier Science B.V.