Mental health and employment: The SAD story

This paper explores the relationship between health-related quality of life (HRQOL) measures and employment status in light of a constructed index related to Seasonal Affective Disorder that depends only on latitude and day of year. In models including demographic covariates and indicators for state, year, and quarter, more hours of darkness is associated with poorer HRQOL, which in turn is associated with a lower likelihood of employment. The relationships between the darkness index and HRQOL measures are stronger overall for women than for men. Inclusion of both the darkness index and the HRQOL measures in models of employment status determinants provides some evidence that the former operates through the latter in predicting a lower likelihood of employment. When specifying the darkness index as an instrument for HRQOL, each additional day of poor mental health per month leads to a 0.76 percentage point increase in the probability of unemployment among women.

► An index of darkness (measuring daylight length) is constructed and hypothesized to be related to Seasonal Affective Disorder. ► The darkness index as a potential instrument for health-related quality of life measures is explored. ► More hours of darkness is associated with poorer HRQOL, which in turn is associated with a lower likelihood of employment.