Short-term venlafaxine v. lithium monotherapy for bipolar type II major depressive episodes: Effectiveness and mood conversion rate

Abstract

BackgroundControversy exists over antidepressant use in bipolar II depression.AimsTo compare the safety and effectiveness of antidepressant v. mood stabiliser monotherapy for bipolar type II major depressive episodes.MethodRandomised, double-blind, parallel-group, 12-week comparison of venlafaxine (n = 65) v. lithium (n = 64) monotherapy in adult out-patients (trial registration number NCT00602537).ResultsPrimary outcome – venlafaxine produced a greater response rate (67.7%) v. lithium (34.4%, P<0.001). Secondary outcomes – venlafaxine produced a greater remission rate (58.5% v. 28.1%, P<0.001); greater decline in depression symptom scores over time (β=–5.32, s.e. = 1.16, χ2 = 21.19, P<0.001); greater reduction in global severity scores over time (β=–1.05, s.e. = 0.22, χ2 = 22.33, P<0.001); and greater improvement in global change scores (β=–1.31, s.e. = 0.32, χ2 = 16.95, P<0.001) relative to lithium. No statistically significant or clinically meaningful differences in hypomanic symptoms were observed between treatments.ConclusionsThese findings suggest that short-term venlafaxine monotherapy may provide effective antidepressant treatment for bipolar II depression without a statistically significant increase in hypomanic symptoms relative to lithium.