The Role of Antipsychotics and Mood Stabilizers in Preventing Sickness Absence Among Employed Individuals With Bipolar Disorder: A Nationwide Register-Based Study

Introduction

Medication use may significantly affect work ability in bipolar disorder, but this area has been largely overlooked in research. We aimed to investigate how specific mood stabilizer and antipsychotic agents are associated with the risk of sickness absence among employed individuals with bipolar disorder.

Methods

We identified a nationwide cohort of 22,408 employed individuals with bipolar disorder, including 10,000 first-episode cases, and followed them from 2005 to 2018 through the nationwide administrative registers. The risk of sickness absence was analyzed using within-individual Cox regression where each person serves as their own control to eliminate selection bias.

Results

In the whole cohort, the monotherapies of lithium (HR = 0.75, 95% CI = 0.66–0.84), valproate (HR = 0.77, 0.70–0.85), and lamotrigine (HR = 0.87, 0.80–0.95) were associated with a lower risk of sickness absence than nonuse of mood stabilizers. In contrast, pregabalin monotherapy was associated with an increased risk of sickness absence (HR = 1.63, 1.34–1.99). Of antipsychotics, olanzapine was associated with a lower risk of sickness absence (HR = 0.75, 0.66–0.86) than antipsychotic nonuse. In the first-episode sample, lithium (HR = 0.51, 0.41–0.64), valproate (HR = 0.63, 0.52–0.75), lamotrigine (HR = 0.79, 0.68–0.91), and olanzapine (HR = 0.69, 0.54–0.87) monotherapies were associated with a lower hazard of sickness absence than nonuse.

Conclusions

Mood stabilizers including lithium, valproate, and lamotrigine, as well as olanzapine, of antipsychotics may reduce the risk of sickness absence, particularly, in first-episode patients. These findings encourage the continuous use of these medications to support occupational functioning among people with bipolar disorder.