Lithium protects against suicide

Suicidal behaviour decreases among individuals with bipolar disorder during periods of lithium medication, according to an extensive register-based study conducted at Karolinska Institutet in Sweden. The results are published in The American Journal of Psychiatry.

More than one percent of the world’s population is affected by bipolar disorder. The disease is characterised by alternating periods of depression and elevated mood (mania). Medication with lithium and valproate prevents manic phases and has mood-stabilizing effects. It is known that people with bipolar disorder have a high risk of committing suicide, but whether the drugs reduce the risk of suicide has not been sufficiently investigated. Researchers at Karolinska Institutet have, therefore, conducted an extensive register-based study.

Many suicides could be avoided

”We now strongly augment the existing evidence that lithium treatment is protective against suicide attempts and suicide”, says Professor Paul Lichtenstein at Karolinska Institutet’s Department of Medical Epidemiology and Biostatistics. ”We estimate that more than ten per cent of attempted or completed suicides could have been avoided if these individuals had been continuously taking lithium during the study period”.

The study was performed in collaboration with the University of Gothenburg and included more than 51,000 individuals with bipolar disorder from the Swedish National Patient Registry over an eight-year period (2006-2013). During this period, 10,648 suicide-related events occurred. All participants in the study were compared to themselves during periods with and without medication with lithium and valproate, respectively. The risk of suicide-related events was reduced by 14 per cent while individuals were receiving lithium, as compared with the same individuals while not receiving lithium.

Lithium medication has decreased steadily

The study also demonstrates that valproate, the most common alternative to lithium, probably has no effect on suicidal behaviour. Lithium medication has decreased steadily in recent years in Sweden. Paul Lichtenstein believes that the results of the study are of relevance for clinical decisions.

”When a doctor is trying to find the best pharmacological treatment for the patient, the anti-suicidal effect of lithium should be taken into consideration, especially for patients with suspected suicidal intentions”, says Paul Lichtenstein.

The study was financed with grants from the Swedish Research Council, the Swedish Council for Working Life and Social Research, the Swedish foundation for Strategic Research, and the China Scholarship Council. No commercial interests have been reported.

Publication

‘Suicidal Behavior During Lithium and Valproate Medication: A Within-individual Eight Year Prospective Study of 50,000 Patients With Bipolar Disorder’, Jie Song, Arvid Sjölander, Erik Joas, Sarah E. Bergen, Bo Runeson, Henrik Larsson, Mikael Landén, Paul Lichtenstein. The American Journal of Psychiatry, online 9 June 2017.