Sex and race differences in response to drug treatment among schizophrenics.

The purpose of this study was to examine sex and race differences in improvement after 6 weeks of phenothiazine or placebo treatment among newly-admitted, acutely-ill schizophrenic patients. The following results were obtained. 1. Although patients on drug treatment improved more than patients receiving placebo in both sexes, the drug-placebo difference was larger for females than for males. a) On placebo treatment males improved markedly more than female patients. b) On drug treatment females improved slightly but significantly more than males. 2. Although more improvement was obtained in both white and Negro patients under drug treatment than under placebo, there was a greater drug-placebo difference among the white patients than the Negro patients. However, the results were less consistent than those on sex differences. a) On placebo treatment Negroes improve more than whites. b) Under drug treatment no race differences were detected. 3. Race differences under placebo were slightly more evident in ward behavior observed by the nurses than in psychopathology seen by the doctors during the interview. 4. A tentative interpretation of the results is offered in terms of an interaction between factors of genetic predisposition and psychological stress; i.e., improvers on placebo are those whose etiology is more highly loaded on psychological stress factors, and improvers on drug have higher loadings on genetic factors. The interpretation implies greater psychological stress in the etiology of males than females, and of Negroes than whites.