Bipolar disorder in late life presents significant challenges due to high rates of medical service use, disability, increased mortality, and higher risk for suicide and dementia. Although lithium and divalproex are commonly prescribed mood stabilizers for older adults with bipolar disorder, there is limited research specifically addressing their use in this population. While lithium is widely recognized for its efficacy in midlife adults with bipolar disorder, its tolerability in older patients can be compromised, leading to the use of lower concentrations or alternative medications. Similarly, divalproex has shown potential in treating late-life mania but lacks definitive evidence from randomized controlled trials comparing its efficacy and tolerability to lithium or other agents.

A randomized, double-blind study was conducted to compare the tolerability and efficacy of lithium and divalproex in older adults with bipolar disorder presenting with mania. The results showed that both medications were generally well tolerated, with no significant differences in sedation or side effects between the two groups. Lithium demonstrated slightly greater efficacy in reducing mania severity, with more patients achieving a clinical response or remission by the ninth week. The study concluded that both lithium and divalproex are viable treatment options for older adults with bipolar disorder, with lithium showing a stronger effect on mania severity. It also suggested the potential benefit of using lithium over antipsychotics in elderly patients.

Reference: Young RC, Mulsant BH, Sajatovic M, et al. GERI-BD: A Randomized Double-Blind Controlled Trial of Lithium and Divalproex in the Treatment of Mania in Older Patients With Bipolar Disorder. Am J Psychiatry. 2017 Nov 1;174(11):1086-1093. doi: 10.1176/appi.ajp.2017.15050657. Epub 2017 Aug 4. PMID: 29088928; PMCID: PMC6214451.