The impact of depression is unevenly distributed in the population

The aim of this study was to evaluate the impact of depression on quality of life in the general population by studying its effects on i) health-related quality of life (HRQoL), ii) health state utilities, and iii) the burden of disease in the population according to age, sex, marital status, education, economy and employment.

Cross-sectional survey in the County of Uppsala, Sweden. A statistical sample of the general population aged 20-64 years (N=4506) was used. Information on current state of depression was obtained by self-report. HRQoL was measured using Short Form 36 (SF-36). The time trade-off (TTO) method was used to measure health state utilities. The decrease of total health state utilities associated with depression in the population was used as a measure of burden of disease.

Depression was reported by 4.0% of the population. Those with depression scored significantly lower (P<0.001) than those without on all eight of the SF-36 domains. The depressed group also rated their health state utilities significantly lower than the others: 0.796 versus 0.933 (P<0.001). In the multivariate analysis of decrease in utilities with various medical disorders, depression was associated with the greatest decrease (-0.090, P<0.001). Persons with depression accounted for 10.9% of the total decrease in utilities in the whole population, but this proportion varied according to the specific subgroup. For example, 16.4% and 8.6% of the total burden of disease was linked to depression among single and married people, respectively. The corresponding figures for those with the lowest and highest incomes were 15.0% and 7.9%, respectively. Among the unemployed, persons reporting depression accounted for 15.3% of the decrease in utilities in contrast to 4.9% among the employed.

Depression has a strong impact on the quality of life and total disability in the general population. Further, the impact of depression is unevenly distributed in the population.