Mothers who smoke during pregnancy put their children at greater risk of developing psychotic symptoms in their teenage years.
New research published in the October issue of the British Journal of Psychiatry shows a link between maternal tobacco use and psychotic symptoms.
Researchers from Cardiff, Bristol, Nottingham and Warwick Universities studied 6,356 12-year-olds from the Avon Longitudinal Study of Parents and Children. All the children completed an interview for psychotic-like symptoms, such as hallucinations or delusions. Just over 11% of the children (734) had suspected or definite symptoms of psychosis.
Smoking during pregnancy was found to be associated with an increased risk of psychotic symptoms in the children. The researchers observed a 'dose-response effect', meaning that the risk of psychotic symptoms was highest in the children whose mothers smoked the most heavily during pregnancy.
The study also examined whether alcohol use and cannabis use during pregnancy was associated with a higher risk of psychotic symptoms.
Drinking during pregnancy was associated with increased psychotic symptoms, but only in the children of mothers who had drunk more than 21 units of alcohol a week in early pregnancy. Only a few mothers in the study said they had smoked cannabis during pregnancy, and this was not found to have any significant association with psychotic symptoms.