Michael Craig Miller, M.D., is editor-in-chief of the Harvard Mental Health Letter and an assistant professor of psychiatry at Harvard Medical School. Dr. Miller has an active clinical practice and has been on staff at Beth Israel Deaconess Medical Center for more than 25 years.
I've read that urban environments are associated with schizophrenia. Does city living really cause schizophrenia?
Cities do have higher rates of schizophrenia than rural areas. The urban rate is about double the rural rate. Researchers don't know why this difference exists.
The most noticeable symptom in schizophrenia is trouble with thinking. A person might have hallucinations (false perceptions) or delusions (false beliefs).
But the illness is more than that. People with schizophrenia also have trouble getting motivated. Their mood may be off. They may have trouble processing information.
Most scientists now agree that heredity is the chief cause of schizophrenia. That is, something in a person's genes makes them more likely to develop the illness. But scientists are still studying how a person's environment might contribute to the risk.
One study conducted in Sweden suggested that city life is more socially fragmented. School children in a large city school might feel less support and more stress than they would in a small town school. The stress might trigger the illness in a vulnerable teenager.
Some researchers think birth complications may be more common in cities. Urban babies might have had poorer nutrition during pregnancy. Or they may be more likely to be exposed to harmful drugs. But the connection to schizophrenia hasn't been proven.
Another idea is that infections put people at greater risk for schizophrenia. Viral infections, for example, may spread more easily when more people live close together.
Of course, it is possible that city living doesn't cause schizophrenia. It might be that more people with schizophrenia move to cities. But the rate does appear to be higher among people born in an urban center than in people who moved there.
All in all, city living is a small risk factor when compared to family history, such as having a parent with schizophrenia.
If you notice signs of illness — whether you live in the city or the country — discuss the problems with your doctor. Early treatment can make an important difference.