Regional ECT, lithium, and clozapine use linked to lower suicide rates in male adolescents

A new study from Karolinska Institutet suggests that electroconvulsive therapy (ECT), lithium, and clozapine may reduce suicide rates in adolescent men with severe mental illness, consistent with previous findings in adults. The study, published in Nature Communications, compared treatment and suicide rates across different regions in Sweden.

Annually, there are 800,000 suicide deaths worldwide. Suicide is the leading cause of death among teenagers and young adults, with up to 90 percent of those affected having a serious psychiatric illness such as depression, bipolar disorder, or schizophrenia. 

ECT and the drugs clozapine and lithium are evidence-based treatments for these conditions. While previous studies have shown that these treatments reduce the risk of suicide in adults, it is unclear if they have the same protective effect in young people. Researchers at Karolinska Institutet have now tried to find an answer. 

“We studied if regional suicide rates in 15–19-year-olds were linked to the use of ECT, lithium, and clozapine in young people,” says Dr. Adrian E. Desai Boström, the study’s lead author and a postdoc researcher at the Department of Clinical Neuroscience, Karolinska Institutet.

The researchers analyzed registry data from 21 Swedish regions between 2016 and 2020. During this period, 632 individuals aged 15 to 24 committed suicide, of which 200 were between 15 and 19 years old.

The excess death rate was measured by comparing suicide levels among 15 to 19-year-olds and 20 to 24-year-olds in the same region. Regions with a comparatively lower suicide rate among 15 to 19-year-olds than 20 to 24-year-olds had higher usage of ECT, lithium, and clozapine in treating young patients.

As the study was observational, it cannot establish causal relationships. However, the findings align with previous research on adults, suggesting that ECT, lithium, and clozapine may also reduce suicide risk in adolescents.

“The results signal that early intervention with medico-psychiatric treatment for severe mental illness can reduce suicide rates in late-teenage boys”, he says. 

The study also highlights substantial regional variations in the use of ECT, lithium, and clozapine in adolescent psychiatric care.

“Our findings indicate unequal access to best-practice care for seriously ill young patients in Swedish child and adolescent psychiatry. Improved care holds the potential for lowering suicide death rates among young men in Sweden,” says Dr. Desai Boström.

“The next step for the research group is to evaluate whether these treatments can also be protective for other severe psychiatric diseases with high mortality rates and a relative lack of effective treatment. For example, they hope to investigate whether ECT could be used for severely affected eating disorder patients with comorbid depression.”

Dr. Desai Boström suggests that such studies could not only evaluate the impact of treatments on suicide risk but also on positive therapeutic outcomes like enhanced functional capacity, cognitive function, and long-term quality of life.

The study was funded by the Swedish Research Council and the researchers declare no conflicts of interest.

Publication: “Regional Clozapine, ECT and Lithium Usage Inversely Associated with 4 Excess Suicide Rates in Male Adolescents”, Adrian E. Desai Boström, Peter Andersson, Mathias Rask-Andersen, Håkan Jarbin, Johan Lundberg, Jussi Jokinen, Nature Communications, online 14 March 2023, doi: 10.1038/s41467-023-36973-4