Rural-Urban Differences & the Social Drift Hypothesis
Another important finding of most epidemiologic studies is that the prevalence of some mental disorders, particularly schizophrenia, has been found to be higher in urban and industrialized areas than in rural areas. A number of explanations for this finding have been suggested: social migration (the downward drift of persons and families experiencing schizophrenia to lower socioeconomic levels), inbreeding among the mentally ill, and the greater availability in urban areas of services for the chronically mentally ill. These differences may also reflect the comparative integration and stability of rural areas. Leighton and colleagues, in their study of rural Nova Scotia, found that depression (and other psychiatric disorders) were more common for all ages in “disintegrated” communities. Given the recent emphasis on the genetic basis of many psychiatric disorders, more research must be done on the degree of possible inheritance of these disorders in populations, and on the social drift hypothesis, before firm conclusions can be reached.