Are mental disorders more common in urban than rural areas of the United States?

Urban vs. rural residence is commonly cited as a risk factor for depression and other mental disorders, but epidemiological evidence for this relationship in the US is inconclusive. We examined three consecutive annual samples (2009-2011) of adolescents (age 12-17, N = 55,583) and adults (age 18 and over, N = 116,459) from the National Survey of Drug Use and Health (NSDUH) to compare the prevalence of major depression and other serious mental illness across four categories of urbanicity: (1) large metropolitan areas, (2) small metropolitan areas, (3) semi-rural areas, and (4) rural areas, with and without adjustment for other demographic risk factors. For adolescents, no association was observed between urbanicity and the prevalence of major depression, with or without statistical adjustments. For adults, no differences were found in the prevalence of major depression or serious mental illness between large metropolitan areas and rural areas, but the prevalence of both was slightly higher in the two intermediate urbanicity categories than in large metropolitan areas, with statistically significant odds ratios after adjustment ranging from 1.12 to 1.19. Contrary to expectations, the prevalence of mental disorders was not higher in the most urban compared with the most rural areas, suggesting that the move to identify mechanistic explanations for risk associated with the urban environment is premature. Evidence of slightly higher prevalence in small urban and semi-rural areas relative to large urban areas, reported for the first time, requires additional investigation.