Relation of prenatal smoking exposure and use of psychotropic medication up to young adulthood.

The study objective was to determine the relation of prenatal smoking exposure to the use of psychotropic medication up to young adulthood by using population-based longitudinal register data consisting of all singletons born in Finland from 1987 to 1989 (n = 175,869). Information on maternal smoking was assessed during antenatal care and received from the Finnish Medical Birth Register. Information on the children's psychotropic medication (1994-2007) was received from the Drug Prescription Register, and the children's psychiatric diagnoses related to outpatient (1998-2007) and inpatient (1987-2007) care were derived from the Finnish Hospital Discharge Register. A total of 15.3% (n = 26,083) of the children were exposed to prenatal smoking. The incidence of psychotropic medication use was 8.3% in unexposed children, 11.3% in children exposed to <10 cigarettes per day (adjusted odds ratio = 1.36, 95% confidence interval: 1.29, 1.43), and 13.6% in children exposed to >10 cigarettes per day (odds ratio = 1.63, 95% confidence interval: 1.53, 1.74). The exposure was significantly associated with the risk for all medication use and for both single- and multiple-drug consumption even after adjustment (e.g., mothers' severe psychiatric illnesses). These findings show that exposure to smoking during pregnancy is linked to both mild and severe psychiatric morbidity.