Sociodemographic Factors, Smoking and Common Mental Disorder in the Renfrew and Paisley (MIDSPAN) Study.

The relationships between common mental disorder measured by the General Health Questionnaire and sociodemographic variables and cigarette smoking were examined from baseline data in a community study of 15,406 men and women, aged between 45 and 64 years from two towns close to Glasgow. Between 1972 and 1976 all those respondents from Renfrew and Paisley between the ages of 45 and 64 years who met the residency criteria were invited to attend community clinics, where a clinical examination was carried out and the General Health Questionnaire was completed by 3783 (53.6 percent) men, and 4683 (56.1 percent) women. Women had a higher risk of disorder than men did. More women (20.3 percent) than men (15.4 percent) were possible cases of common mental disorder. Women showed a decrease in disorder with age but no apparent trend in men was observed. Marital status was significantly associated with disorder, with the widowed and separated showing especially high rates of psychiatric disorder. Married men, in contrast to married women, had relatively low levels of psychiatric disorder. Both social class and level of deprivation of the area were associated with psychiatric disorder. For both men and women there was a trend in disorder associated with social class; men in social class V had twice the level of psychiatric disorder compared to those in social class II. For women there was a shallow gradient showing higher levels of disorder with lower social class. Smoking habits were also related to psychiatric disorder; never- and exsmokers had relatively low rates of psychiatric disorder whereas, among current smokers, risk of psychiatric disorder, increased with the number of cigarettes smoked, though only for women.