Lithium as a Mood Stabilizer: Evidence Across Psychiatric Disorders

Lithium has remained a cornerstone of mood stabilization for over half a century, primarily in bipolar disorder. Increasing evidence suggests its therapeutic benefits extend across multiple psychiatric conditions. Despite advances in psychopharmacology, lithium continues to occupy a unique position due to its efficacy, neuroprotective potential, and anti-suicidal properties. This review aims to synthesize the available evidence on lithium as a mood stabilizer across psychiatric disorders, highlighting its clinical efficacy, underlying mechanisms, and therapeutic relevance beyond bipolar disorder. A systematic search of PubMed, Scopus, and Web of Science databases was conducted to identify clinical trials, meta-analyses, and observational studies from 1990 to 2025. Studies evaluating lithium in bipolar disorder, major depressive disorder, schizoaffective disorder, and related psychiatric conditions were included. Findings were categorized by disorder and outcome measures. Lithium demonstrates robust efficacy in preventing relapse and stabilizing mood in bipolar disorder. Evidence also supports its augmentation role in treatment-resistant depression and its potential in schizoaffective disorder. Long-term use is associated with reduced suicide risk, independent of diagnosis. Emerging data indicate possible benefits in borderline personality disorder and neuroprotective effects in neuropsychiatric populations. However, concerns remain regarding side effects, narrow therapeutic index, and declining clinical use. Lithium remains the most evidence-based mood stabilizer across psychiatric disorders, with proven efficacy and unique anti-suicidal properties. Broader clinical application and renewed research may reinforce its role as a transdiagnostic treatment.