Smoking and Risk for Later Schizophrenia

Although the schizophrenia–smoking association is strongly established, whether smoking contributes to development of schizophrenia has been less studied. Using data on two Swedish cohorts, investigators prospectively sought links between smoking and subsequent development of schizophrenia and nonaffective psychoses, possible dose-response relationships, and effects of possible confounding factors such as low socioeconomic status (determined by parental education and neighborhood deprivation), drug abuse, and familial/genetic risk.

One study population involved 1,413,849 women initially studied during prenatal care (mean initial age, 27; mean follow-up, 18 years); the other involved 233,879 male conscripts (mean initial age, 18; mean follow-…