Lower suicide risk with long‐term lithium treatment in major affective illness: a meta‐analysis

Abstract

Objective: To compare suicide rates with vs. without long‐term lithium treatment in major affective disorders. Method: Broad searching yielded 22 studies providing suicide rates during lithium maintenance; 13 also provide rates without such treatment. Study quality was scored, between‐study variance tested, and suicide rates on vs. off lithium examined by meta‐analyses using random‐effects regression methods to model risk ratios. Results: Among 5647 patients (33 473 patient‐years of risk) in 22 studies, suicide was 82% less frequent during lithium‐treatment (0.159 vs. 0.875 deaths/100 patient‐years). The computed risk‐ratio in studies with rates on/off lithium was 8.85 (95% CI, 4.12–19.1; P<0.0001). Higher rates off‐lithium were not accounted for by treatment‐discontinuation. Conclusion: Suicide risk was consistently lower during long‐term treatment of major affective illnesses with lithium in all studies in the meta‐analysis, including the few involving treatment‐randomization.