Smoking pregnant women can develop schizophrenia?

A new study, published online Tuesday in the American Journal of Psychiatry, finds that heavy cigarette smoking by a pregnant woman raises the risk of her child developing the severe mental disorder by 38 percent.


The research was based on nicotine levels found in blood samples of pregnant mothers who gave birth in Finland between 1983 and 1998.

A team of European and American scientists matched the samples, which were provided by Finland’s national registry, against a database of nearly 1,000 cases of schizophrenia (and controls) to find patterns.

When the scientists analyzed the maternal blood serum samples for levels of cotinine, a marker of nicotine, they found that heavy smoking was associated with 20 percent of the mothers of children who had developed the disorder but only 15 percent of the mothers of controls.

Both heavy and moderate nicotine exposure were associated with offspring who later suffered from schizophrenia.

The study however doesn’t answer whether maternal smoking actually causes schizophrenia in offspring. And since smoking rates are known to be higher among people with the diagnosis, it’s possible that there is a correlation. That is, might pregnant women who smoke and have their own genetic risk factors for schizophrenia be more likely to have children with schizophrenia?