Systematic review updates evidence for mental disorders’ role in suicide risk

Individuals with mental disorders were at increased risk for suicide, according to results of a systematic review and meta-regression analysis published in Journal of Psychiatric Research.

“This current systematic literature review aims to account for [prior] limitations by providing updated suicide risk estimates adjusted in a meta-regression for key demographic and methodological covariates that may contribute to variation in study reported estimates,” Modhurima Moitra, a predoctoral research associate of the Institute for Health Metrics and Evaluation at the University of Washington, and colleagues wrote. “We use the earlier review by Ferrari [and colleagues] (2014) as the basis and template for this work. We expand the search strings to incorporate self-harm and self-injury to maximize the scope of potentially eligible studies. Relevant data from 2010 to 2019 updates this systematic review, this the most comprehensive review of this risk-outcome pair to the best of our knowledge.”

The investigators searched four databases between 2010 and 2019 and included 20 longitudinal/case-control studies that were representative of the general population, used diagnostic instruments and quantified suicide risk. They assessed relative risks for suicide related to mental disorders and obtained pooled RRs adjusted for covariates and between-study effects using a multi-level meta-regression approach. Included studies yielded 69 RRs.

Moitra and colleagues tested disorder type, age, sex, use of psychological autopsy, study design and adjustment for confounders as predictors of pooled suicide risk. Results showed all assessed disorders significantly predicted suicide. Predicted adjusted RRs ranged from 4.11 for dysthymia to 7.64 for major depressive disorder. Further, the researchers observed an association between age an increased suicide risk. The use of retrospective design was linked to lower suicide risk vs. prospective study design among methodological covariates. Estimate adjustment or use of the psychological autopsy method did not significantly affect results. The researchers noted MDD, bipolar disorder and schizophrenia had the highest predicted RRs, and women had lower RRs than men across all disorders, although this latter association was not significant.

“This synthesized analysis shows that the magnitude of study-reported risk may vary depending on study methodology and disorders examined,” Moitra and colleagues wrote. “Therefore, study quality and choice of methods are important to consider in public reports on aggregated evidence. More research is needed to better quantify evidence for [mental disorder] burden and suicide risk with higher precision in low and middle-income settings. These efforts will assist policy makers in framing evidence-based suicide prevention strategies and make mental health care an important part of their agendas.”