Diagnosis-Specific Sickness Absence and Subsequent Common Mental Disorders: A Register-Linkage Cohort Study among Finnish Public Sector Employees

Sickness absence is associated with poor health outcomes, but little is known about its consequences for general mental health. This study examined the associations between diagnosis-specific sickness absence and subsequent common mental disorders (CMD). Register data on medically certified all-cause sickness absence and sickness absence due to mental disorders and musculoskeletal diseases from 2004–2007 were linked to the Helsinki Health Study 2007 and 2012 survey data on City of Helsinki employees in Finland (N = 3560). Using logistic regression and multinomial logistic regression, we analysed the associations between the total number of reimbursed sickness absence days in 2004-7 and CMD General Health Questionnaire 12) in 2007 and 2012 and CMD changes. Sickness absence due to mental disorders (age- and sex-adjusted odds ratio (OR)range: 2.16 to 2.93), musculoskeletal diseases (OR range: 2.79 to 2.93) and all-cause sickness absence (OR range: 1.48 to 3.20) were associated with CMD in 2007. In 2012, associations with lower ORs were observed. Associations were also found with changing and especially repeated (OR range: 1.49 to 3.40) CMD. The associations remained after adjusting for work-related covariates and health behaviours. Diagnosis-specific sickness absence showed persistent associations with subsequent CMD and their changes. Attention should be paid to both the short- and long-term consequences of sickness absence for employee mental health.