Antidepressant treatment initiation and public sick-leave compensation in the following year: a register-based prospective cohort study in Denmark

Mental disorders have caused increasing sickness absence and related benefit claims in the OECD countries. This study investigates the association between antidepressant treatment initiation and public sick leave compensation (PLSC) in the following year in Denmark.The study was designed as a register-based prospective cohort study. We included 39,401 adults (aged 18-65 years) with at least 12 consecutive months of full-time labour market attachment who had initiated first-time antidepressant monotherapy for depression or anxiety between 1 January 2015 and 31 December 2018. PLSC was estimated for the year following the incident prescription of various antidepressants for depression or anxiety disorders.The most frequently prescribed antidepressant medication was SSRIs (66.8%), with sertraline being the leading choice. Compared with sertraline, mirtazapine and mianserin were associated with the highest risks of PSLC in the year following initiation, with IRRs of 2.74 (95% CI: 2.63 to 2.86) and 5.79 (95% CI: 5.18 to 6.47), respectively. Compared with sertraline, citalopram (IRR 1.22, 95%CI 1.17-1.28), venlafaxine (IRR 1.34, 95%CI 1.23-1.45) and duloxetine (IRR 1.48, 95%CI 1.35-1.62) were all associated with increased PSLC. In contrast, paroxetine (IRR 0.85, 95% CI 0.74-0.98), fluoxetine (IRR 0.51, 95%CI 0.42-0.62) and vortioxetine (IRR 0.78, 95% CI 0.63-0.97) were all associated with a significantly lower risk of PSLC compared with sertraline.Antidepressant treatment initiation was associated with PLSC. The highest risk of PLSC was seen for antidepressants with sedative side effects. Some types of antidepressants were associated with a lower risk of PLSC in the year following treatment initiation.