Pharmacological and somatic treatment effects on suicide in adults: A systematic review and meta-analysis

Background: Suicide is a public health crisis. We conducted a systematic review and meta-analysis of the effects of psychopharmacologic and somatic therapies on suicide risk.

Methods: A systematic search of MEDLINE for studies evaluating the effects of pharmacologic (excluding antidepressants) or somatic interventions on suicide risk was conducted. Studies were included if they used a comparison group, reported on suicide death, assessed a psychopharmacological or somatic intervention, and included adults. Study quality was assessed using the Newcastle-Ottawa scale. Fifty-seven studies were included from 2940 reviewed citations.

Results: In bipolar disorder, lithium was associated with a reduction in the odds of suicide compared to active controls (odds ratio [OR] = .58, p = .005; k = 12) and compared to placebo/no lithium (OR = .46, p = .009; k = 9). In mixed diagnostic samples, lithium was associated with a reduction in the odds of suicide compared to placebo/no lithium (OR = .27, p < .001; k = 12), but not compared to active controls (OR = .89, p = .468; k = 7). In psychotic disorders, clozapine was associated with a reduction in the odds of suicide (OR = .46, p = .007; k = 7). Associations between suicide death and electroconvulsive therapy (OR = .77, p = .053; k = 11), non-clozapine antipsychotics in bipolar disorder (OR = .73, p = .090; k = 6) and antipsychotics in psychotic disorders (OR = .39, p = .069; k = 6) were not significant. There was no consistent relationship between antiepileptic mood stabilizers and suicide. There were insufficient studies to meta-analyze associations of suicide risk with vagus nerve stimulation, transcranial magnetic stimulation, magnetic seizure therapy, or transcranial direct current stimulation.

Conclusion: Lithium and clozapine have consistent data supporting protective effects against suicide in certain clinical contexts.