Background: Mental disorders are associated with disability, but the long-term effects of low subjective well-being on work ability in general population are not known. In this study we investigated whether self-reported life dissatisfaction predicts work disability.
Method: A nationwide sample of Finnish twins aged 18-54 years (N = 22,136), unselected for health status responded to a health questionnaire with a four-item life satisfaction scale (range 4-20) covering interest, happiness, easiness and loneliness of life in 1975 and 1981. Cox regression for all subjects and conditional logistic regression for discordant twin pairs were used to compare the risk of subsequent work disability (N = 1200) (Nationwide Disability Register) between the dissatisfied and satisfied.
Results: Life dissatisfaction predicted subsequent (1977-87) work disability pension due to psychiatric and non-psychiatric causes among the healthy at baseline, and that due to psychiatric causes among the ill. After controlling for age, marital status, social class and health behaviour, these risks remained significant. Repeatedly reported (1975 and 1981) life dissatisfaction was strongly associated with increased (age-adjusted) risk of subsequent (1982-87) work disability due to psychiatric and also that due to non-psychiatric causes among the healthy. When twin pairs discordant for end-point disability status were analysed, risk differences related to life satisfaction were only slightly decreased, but they did not differ significantly between monozygotic and dizygotic pairs.
Conclusion: Life dissatisfaction predicts subsequent work disability especially among the healthy.