Religion and mental health in young adulthood: a register-based study on differences by religious affiliation in sickness absence due to mental disorders in Finland.

BACKGROUND: Religiosity and spirituality are known to be positively correlated with health. This is the first study to analyse the interrelation between religious denomination and sickness absence due to mental disorders using population register data with detailed ICD codes.

METHODS: The follow-up study was based on the entire population born in Finland between 1984 and 1996 (N=794 476). Each person was observed from age 20 over the period from 2004 to 2018. Cox proportional hazards models were applied to analyse the association between religious denomination and first-time sickness allowance receipts for any cause and mental disorder. Mental disorders were categorised as severe mental illness (F20-F31), depression (F32-F33), anxiety (F40-F48) and any other mental disorder (all other F codes). Men and women were analysed separately.

RESULTS: The differences in sickness absence due to mental disorder were substantial between religious affiliations. Compared with members of the Evangelical Lutheran state church, the relative hazard for mental disorders among non-affiliated women was 1.34 (95% CI 1.30 to 1.39), while that among women with other religions was 1.27 (95% CI 1.19 to 1.35), after adjusting for own and parental characteristics. The corresponding numbers for men were 1.45 (95% CI 1.39 to 1.50) and 1.42 (95% CI 1.30 to 1.54), respectively. The gradient was larger for severe mental illness and depression than for anxiety and other mental disorders. For any cause of sickness absence, there was no difference between Lutherans, non-affiliated individuals and those with other religions.

CONCLUSIONS: Epidemiologists and public health practitioners should further examine the association between mental disorders and church membership using administrative registers.