Responses to clinical treatment of bipolar versus unipolar depressive episodes in women versus men.

Background: Whether responses to treatment of major depressive episodes differ between women and men or with bipolar (BD) and major depressive disorders (MDD) remains unresolved.

Aims: To test for diagnostic and sex differences in responses to treatment of depression.

Methods: We compared changes in the 21-item Hamilton Depression Rating Scale (HDRS₂₁) ratings of depression (n = 3243) between women (64.7%) and men, and between DSM-5-TR BD ([n = 253] and subtypes I [BD1] vs II [BD2]) and MDD (n = 2990), using bivariate comparisons and multivariate modeling.

Results: Treatments included clinically individualized use of antidepressants (by 92.4%, in doses averaging 90.0 mg/day imipramine-equivalent), sometimes with mood-stabilizing agents (32.1%), second-generation antipsychotics (18.8%), or psychotherapy (38.6%). Depression ratings decreased by 60.6% to a final mean HDRS score of 7.44; response rate (⩾50% reduction in HDRS) averaged 63.7%. Outcomes were very similar in women and men as well as with BD versus MDD, and between BD subtypes. Moreover, age, duration of illness, initial HDRS score, dose of antidepressant, and weeks of treatment, as well as sex and diagnosis were not associated with improvement of HDRS with treatment. Only 6/42 comparisons involving 21 individual HDRS items differed significantly in improvement between sexes or diagnoses. Results were very similar to the Montgomery-Åsberg Depression Rating Scale depression ratings. Only 2.0% of the subjects experienced mood-switching into clinical (hypo)mania and the final Young Mania Rating Scale ratings averaged 0.63.

Conclusions: Responses to clinical treatment (as % reduction of HDRS score, response rate, or final HDRS score) of depressed women versus men, and BD (including BD1 vs BD2) versus MDD were substantial and very similar.