A systematic review of anti-suicidal effects of sedative-hypnotics and cognitive behavioral therapy for insomnia

Suicide accounts for over 700,000 deaths per year globally and remains a public health priority. Evidence suggests that sleep-related interventions may be effective in reducing depressive symptom severity and suicidal thoughts in patients diagnosed with depression and comorbid insomnia. This study aims to systematically review the efficacy of sedative-hypnotics and/or cognitive behavioral therapy for insomnia (CBT-I) on measures of suicidality.In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, PubMed, Medline, Cochrane Library, Embase, Scopus, and Web of Science were searched from inception to July 30, 2024. Studies were included if they (1) were randomized controlled trials (RCTs) and (2) reported on suicide-related measures associated with sleep interventions as a primary outcome, secondary outcome, or a safety measure. We endeavored to define and operationalize suicidality as suicidal ideation (SI), suicide attempts (SA), and suicide completion (SC). In cases where study authors failed to separate these three dimensions, the term "suicidality" was applied.Eighteen studies were identified meeting inclusion criteria, comprised of studies investigating benzodiazepines (n = 2), Z-drugs (n=4), orexin receptor antagonists (ORAs) (n=8), and CBT-I (n=4). Zolpidem reduces SI as well as insomnia (linear association = 0.12, p<0.05) as evidenced by improvement on both the Columbia-Suicide Severity Rating Scale (C-SSRS) and the Scale for Suicide Ideation (SSI). ORAs were not associated with either an increase or decrease in suicidality. CBT-I alleviates SI in patients with insomnia (t = -3.35, p<0.05).Effectively treating insomnia is associated with reduced SI. Available evidence suggests that Food and Drug Administration (FDA)-approved sedative-hypnotics do not increase the risk of suicidality.