“Our results, in conjunction with existing literature, indicate that in patients with bipolar disorder and suspected suicidal intentions, lithium should be considered as a suicide preventive strategy, with a balance between efficacy and tolerability,” Jie Song, Ph.D., of the Karolinska Institutet and colleagues wrote.
For the study, the researchers relied on Swedish population-based registers to track outcomes in individuals with bipolar disorder between October 1, 2005, and December 31, 2013. Among the 51,535 patients with bipolar disorder identified, a total of 10,648 suicide-related events occurred in 4,643 individuals (9.0%) during the follow-up period.
When the researchers compared periods when patients were taking either lithium or valproate with periods they were not, they found a 14% reduced rate of suicide-related events for periods when patients were on lithium compared with when they were not (hazard ratio, 0.86); this change was not seen in patients who received valproate treatment (hazard ratio, 1.02). The difference in hazard ratios of suicide-related events between lithium and valproate was statistically significant.
“Since the within-individual analyses drew information exclusively from people who attempted suicide during follow-up, our results demonstrated that the association between lithium and reduced suicide-related events existed even among a high-risk population, which is unlikely to be studied in randomized, controlled trials,” the authors wrote. “Future research on the mechanisms behind the association between lithium and suicidal behavior is warranted and could inform the neurobiology of suicidal behavior.”
For related information, see the Psychiatric News article “Lithium Is Regaining Favor Over Anticonvulsants,” by Jonathan Meyer, M.D., of the University of California, San Diego.
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