Higher lithium levels track with healthier arteries in bipolar disorder
STUDY: Tsai SY et al, J Affect Disord 2026
STUDY TYPE: Cross-sectional cohort study
FUNDING: National Science and Technology Council, Taiwan; National Health Research Institutes, Taiwan
Background
Cardiovascular disease, particularly stroke, is the top cause of death in bipolar disorder. Most mood stabilizers do not change or may increase this risk, but some studies show lithium protects. This one suggests how.
The Study
- 110 physically healthy adults with bipolar I disorder and 107 healthy controls, all ages 20–60
- Carotid artery wall thickness measured by ultrasound; elevated readings defined by American Society of Echocardiography standards
- Cross-sectional design; no follow-up
Patients with bipolar disorder had thicker carotid artery walls than controls (0.64 mm vs. 0.50 mm), and 76% exceeded the threshold for elevated readings, nearly double the rate in controls (40%).
Among patients, those with lithium levels above 0.6 mEq/L had meaningfully thinner artery walls (effect size, Cohen’s d = 0.45). In the multivariate model, higher lithium level, longer illness duration, and higher triglycerides together explained 34% of the variation in artery thickness. The 0.6 mEq/L threshold was the only cutoff to reach significance, coinciding with the minimum recommended for maintenance therapy.
Longer illness duration tracked with thicker arteries, the opposite of lithium’s direction.
Limitations
Cross-sectional design can’t establish causation. Single time-point lithium levels may not capture lifetime exposure. Concurrent antipsychotic use couldn’t be fully disentangled.
Practice Implications
- Lithium has medical risks, but benefits as well, and is the only mood stabilizer that extends the lifespan in bipolar disorder. While preliminary, these cardiovascular effects may partly explain why.
—Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
