Persistence of antidepressant treatment for depressive disorder in Taiwan.

OBJECT: We sought to explore factors associated with persistence of antidepressant treatment in Taiwan and to compare persistence rates across various antidepressants.

METHOD: This was a retrospective cohort study using medical claims in Taiwan. We collected data of all new antidepressant users with depressive disorder, aged 18 years or older, during the study period from January 1, 1998, to July 4, 2009. Overall antidepressant treatment persistence was defined as undergoing treatment for 180 days without exceeding a 30-day gap. We also assess the cause of treatment change of initial monotherapy, including discontinuation, switching or combination. The competing risks method was used to estimate cause-specific cumulative incidence and to determine associated factors.

RESULTS

Only 17.4% of patients continued overall antidepressant treatment and 7.6% continued initial antidepressant monotherapy for 180 days or more. Most patients change initial monotherapy through discontinuation, followed by switching and combination. Male gender, older age, comorbidity with anxiety or sleep disorders, and more concomitant use of drugs were associated with lower discontinuation rate. In terms of antidepressant comparisons, we found that patients treated with selective serotonin reuptake inhibitors are less likely to change initial monotherapy.

CONCLUSION

The overall persistence of antidepressant treatment in Taiwan was lower than in other countries.