Study links lithium to lower risk of suicide-related behavior, and aggression may explain part of the effect
STUDY: Guan X et al, Bipolar Disorders 2026
STUDY TYPE: Multicenter cross-sectional study
FUNDING: National and provincial government research grants (China)
Background
Lithium has lowered suicide rates in large observational studies of unipolar and bipolar disorder, and a few randomized trials back that up (as a secondary measure). This study expands that adult-focused data to a broader, younger population.
The Study
- 585 patients aged 12–45 with bipolar disorder from 14 Chinese hospitals; 320 had used lithium in the past year, 265 had not.
- Lithium use versus suicide-related behavior (ideation, attempts, self-injury) was compared using adjusted regression and propensity matching.
- Aggression (Buss-Perry Aggression Questionnaire) was tested as a possible mediator.
Results
Lithium use was linked to a 45% lower risk of suicide-related behavior, including self-injury, in the fully adjusted model (OR=0.55, 95% CI 0.34–0.89) and after propensity matching (OR=0.53, 95% CI 0.33–0.86), holding up across robustness checks.
Higher aggression scores correlated with higher suicide-related risk in a linear pattern, accounting for about 21% of the lithium-suicide reduction.
Exploratory analysis found the same trend in all age groups, but significant broke down at that point as the sample size was too small.
Limitations
Cross-sectional design can’t establish causality, and lithium may have been prescribed to patients at lower risk. Data on dosing was not available; aggression was self-reported once.
Practice Implications
- This strengthens the case for lithium’s suicide protection in a broader, younger population than most prior studies covered.
- Suicide and aggression share common biological risks, and it makes sense that an anti-aggressive treatment would reduce “aggression against the self.”
—Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
