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

BACKGROUND: Controversy exists over antidepressant use in bipolar II depression.

AIMS: To compare the safety and effectiveness of antidepressantv.mood stabiliser monotherapy for bipolar type II major depressive episodes.

METHOD: Randomised, double-blind, parallel-group, 12-week comparison of venlafaxine (n= 65)v.lithium (n= 64) monotherapy in adult out-patients (trial registration numberNCT00602537).

RESULTS: Primary 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, χ(2)= 21.19,P<0.001); greater reduction in global severity scores over time (β = -1.05, s.e. = 0.22, w(2)= 22.33,P<0.001); and greater improvement in global change scores (β = -1.31, s.e. = 0.32, χ(2)= 16.95,P<0.001) relative to lithium. No statistically significant or clinically meaningful differences in hypomanic symptoms were observed between treatments.

CONCLUSIONS: These 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.