Age–period–cohort effects on inequalities in psychological distress, 1981–2000

Background. In the closing decades of the twentieth century, changes in population sociodemographics took place that might be thought to have an adverse influence on the nation's psychological distress. Here, we examine the stability of social and gender inequalities in psychological distress throughout the 1980s and 1990s. Methods. The study uses data from the 1958 National Child Development Study and the 1970 British Cohort Study collected when the cohort members were aged between 23 and 42. Multilevel logistic regression models were used to examine the effects of social class, gender, age, period and cohort on psychological distress as measured by the Malaise Inventory. Results. We identify clear social inequalities in psychological distress during 1981–2000 that reduced in magnitude over this period. Non-linear age effects were observed: psychological distress improves in early adulthood but declines again on approaching mid-life. The 1970 cohort had poorer psychological distress than the 1958 cohort. Although women had higher rates of psychological distress than men, gender differences reduced in magnitude. Declining rates of women's psychological distress over time have not been matched in men. A reduction in social inequalities over time was also observed. Improvements in the psychological health of those in manual occupations were not equalled among those in non-manual occupations. Conclusions. Both social and gender inequalities have narrowed in the last two decades of the twentieth century.