In cities, weak social ties may boost mental illness

From HealthDay News:

Weak social connections, or social fragmentation, may be one of the main reasons why people raised in cities are more likely to develop schizophrenia and other psychotic disorders than those who live in rural areas, the results of a study suggest.

"There is a substantial worldwide variation in incidence of schizophrenia. The clearest geographic pattern within this distribution of rates is that urban areas have a higher incidence of schizophrenia than rural areas," Stanley Zammit, of Cardiff University in Wales, and colleagues explained in their article, which is published in the September issue of the journal Archives of General Psychiatry.

In their study, Zammit and colleagues analyzed data from almost 204,000 people in Sweden and found that 328 (0.16 percent) had at some time been admitted to hospital for treatment of schizophrenia, 741 (0.36 percent) had been admitted for other non-affective psychoses, 355 (0.17 percent) with affective psychoses (such as mood disorders), and 953 (0.47 percent) with other psychoses.

The researchers examined whether individual, school or area characteristics are associated with psychosis and found that "being raised in more urbanized areas was associated with an increased risk of developing any non-affective psychotic disorder."

And, "this association was explained primarily by area characteristics rather than by characteristics of the individuals themselves. Social fragmentation was the most important area characteristic that explained the increased risk of psychosis in individuals brought up in cities," they wrote.

"Our findings highlight the concern that physical integration alone is not sufficient but that some of the positive characteristics traditionally conferred by segregation, such as a localized sense of safety, cohesion and community spirit, must also be maintained to enhance the mental health of individuals within the population," Zammit and colleagues concluded.