Lithium Anti-Suicidal Effect — MRCPsych Paper B MCQ

Correct answer: D — Lithium is associated with lower suicide risk, but randomised estimates remain imprecise because events are rare.

Explanation lettering: E = shown as A · A = shown as B · D = shown as C · B = shown as D · C = shown as E

B is the best answer. NICE recognises lithium as preventing suicide in adults with bipolar disorder and recommends it as first-line long-term pharmacological treatment. However, the evidence should not be presented as unequivocal. An older meta-analysis found significantly fewer suicides with lithium than placebo, whereas recent randomised-trial meta-analyses found lower point estimates for suicide and attempts but wide confidence intervals crossing no effect. Suicide is rare in trials, limiting statistical power. Lithium is therefore associated with an anti-suicidal benefit, particularly during long-term treatment of mood disorders, but its precise magnitude and independence from relapse prevention remain uncertain. A and E contradict the observed direction of effect. C confuses lithium with clozapine's evidence in schizophrenia. D is incorrect because the relevant evidence principally concerns maintenance treatment, not only acute mania.

Reference: Wang JX et al. The efficacy of lithium in the treatment of suicidal ideation, behavior and suicide: an updated systematic review and meta-analysis of randomized controlled trials. Journal of Affective Disorders. 2025. https://www.nice.org.uk/guidance/cg185/chapter/Recommendations