Association between adverse childhood experiences and suicidal behavior in affective disorders: A systematic review and meta-analysis

Background Exposure to Adverse Childhood Experiences (ACEs) might increase the risk of suicide behaviors in the general adult population, while this association in individuals with affective disorders remains less characterized. Methods A comprehensive search was conducted in MEDLINE, PsycINFO, CINAHL, Web of Science, Scopus, and PubMed up to July 10th, 2024. Observational studies that compared the risk of suicide behaviors in individuals exposed and unexposed to ACEs were included. Pairwise random-effects meta-analyses were conducted, and the certainty of evidence was assessed with validated criteria. Results A total of 41 studies from 17 countries, comprising 19,588 participants, were analyzed. The main findings indicated a significant association between ACEs and suicidal behaviors, with an odds ratio (OR) of 1.98 (95% confidence interval [CI] 1.74-2.26), and a highly suggestive strength of association. This was consistent across diagnostic subgroups (i.e., Major Depressive Disorders, Bipolar Disorders, and mixed diagnoses). The association was confirmed for any ACE, with sexual abuse being the most frequently reported and showing the highest risk (OR 2.24; 95% CI 1.90-2.64), for suicidal ideation (OR 2.16; 95% CI 1.42-3.29), and for suicide attempts (OR 1.95; 95% CI 1.70-2.25), while death by suicide and non-suicidal self-injury were underreported. Meta-regression analyses did not suggest potential moderators, though underreporting was noted. Conclusions This meta-analysis shows that exposure to ACEs nearly doubles the risk of suicide behaviors in individuals with affective disorders, warranting the targeted clinical, research, and policy measures to timely address this global mental health issue.