Differential prevalence and demographic and clinical correlates of antidepressant use in American bipolar I versus bipolar II disorder patients

Aims: Antidepressant use is controversial in bipolar disorder (BD) due to questionable efficacy/psychiatric tolerability. We assessed demographic/clinical characteristics of baseline antidepressant use in BD patients. Methods: Prevalence and correlates of baseline antidepressant use in 503 BD I and BD II outpatients referred to the Stanford Bipolar Clinic during 2000–2011 were assessed with the Systematic Treatment Enhancement Program for BD (STEP-BD) Affective Disorders Evaluation. Results: Antidepressant use was 39.0%, overall, and was higher in BD II versus BD I (46.9% versus 30.5%, p = 0.0002). Both BD I and BD II antidepressant compared to non-antidepressant users had higher rates of complex pharmacotherapy (≥ 4 mood stabilizers, antipsychotics, and/or antidepressants) and use of other psychotropics. Antidepressant use in BD II versus BD I was higher during euthymia (44.0% vs. 28.0%) and subsyndromal symptoms (56.1% vs. 28.6%), but not depression or mood elevation. Limitations: American tertiary BD clinic referral sample receiving open naturalistic treatment. Conclusions: In our sample, antidepressant use was higher in BD II versus BD I patients, and was associated with markers of heightened illness severity in both BD I and BD II patients. Additional research is warranted to investigate these complex relationships.