The Association of Genetic Predisposition to Depressive Symptoms with Non-suicidal and Suicidal Self-Injuries.

Non-suicidal and suicidal self-injury are very destructive, yet surprisingly common behaviours. Depressed mood is a major risk factor for non-suicidal self-injury (NSSI), suicidal ideation and suicide attempts. We conducted a genetic risk prediction study to examine the polygenic overlap of depressive symptoms with lifetime NSSI, suicidal ideation, and suicide attempts in a sample of 6237 Australian adult twins and their family members (3740 females, mean age = 42.4 years). Polygenic risk scores for depressive symptoms significantly predicted suicidal ideation, and some predictive ability was found for suicide attempts; the polygenic risk scores explained a significant amount of variance in suicidal ideation (lowest p = 0.008, explained variance ranging from 0.10 to 0.16 %) and, less consistently, in suicide attempts (lowest p = 0.04, explained variance ranging from 0.12 to 0.23 %). Polygenic risk scores did not significantly predict NSSI. Results highlight that individuals genetically predisposed to depression are also more likely to experience suicidal ideation/behaviour, whereas we found no evidence that this is also the case for NSSI.
Competing Interests: Dominique F. Maciejewski, Miguel E. Renteria, Abdel Abdellaoui, Sarah E. Medland, Lauren R. Few, Scott D. Gordon, Pamela A.F. Madden, Grant Montgomery, Timothy J. Trull, Andrew C. Heath, Dixie J. Statham, Nicholas G. Martin, Brendan P. Zietsch, and Karin J.H. Verweij declare that they have no conflict of interest. Human and Animal Rights and Informed Consent All participants provided verbal informed consent and procedures were approved by the Human Studies Committee at Washington University and the Ethics Committee at Queensland Institute of Medical Research. Ethical standards The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation.