Smoking in pregnancy linked to brain changes and teenage drug experimentation

PA 281/09 Children born to mothers who smoked during pregnancy are more likely to experiment with drugs in their teens, the findings of a new study suggest. Research carried out by The University of Nottingham and a number of Canadian Universities found that children exposed to cigarette smoke in the womb were more likely to experiment with drugs, such as alcohol, cigarettes and marijuana, during adolescence. The study, published in the Archives of General Psychiatry, suggests that prenatal exposure to maternal smoking may interfere with the development of the brain — particularly a part of the brain associated with evaluating rewards and regulating emotion called the orbitofrontal cortex. MRI scans of almost 400 teenagers found that in those whose mothers had smoked while pregnant, the orbitofrontal cortex (OFC) was thinner. Scientists found a correlation between thinning of the OFC and the likelihood of drug experimentation - the thinner the OFC, the more different drugs had been tried during adolescence. The most commonly used illegal substances among the participants in the study were alcohol, cigarettes, marijuana, stimulants and psychedelic drugs. The evidence suggests that maternal cigarette smoking may re-wire the "€˜reward"€ circuitry of the brain of the unborn child, altering the psychoactive effects of drugs and, in turn, drug-seeking behaviour.