Magnitude of placebo response and drug–placebo differences across psychiatric disorders

Our findings indicate that the magnitude of placebo response and drug response were heterogeneous and were statistically significantly different among various psychiatric disorders. Although a noticeable degree of heterogeneity was detected in the drug-placebo ratio among various disorders, the differences did not reach statistical significance. This finding suggests that placebo use should be continued for newer agents being tested for all of the psychiatric disorders. These findings may help in the development of psychopharmacology trial designs and in the deliberations of ethics committees.