Differential effects of chlorpromazine, imipramine hydrochloride, and a placebo were examined in 159 black and 555 white depressed patients in a multihospital collaborative study. In making these comparisons, the effects of age and social class were controlled.
The major study findings were the differential effects of the active drugs for the black men and women. Chlorpromazine was the most efficacious treatment for black women, whereas imipramine was most efficacious for black men. These differences occurred on global ratings of improvement as well as on specific symptoms such as depression, anxiety, guilt-worthlessness, sleep disturbances, and social participation. Black patients also evidenced a higher improvement rate at one week, irrespective of treatment, than did the white patients.