Further evidence for the association between childhood trauma and suicidal ideation in young individuals: A twin based study.

Background: Suicide is a major cause of death among youth. Childhood trauma (CT) has emerged as a leading environmental risk factor for suicidal ideation (SI). The present study intends to understand the association between CT and SI in a sample of twins, highlighting the relevance of CT per se, regardless of genetic vulnerability.

Methods: Data were derived from a general population young twin study, the TwinssCan project (N = 796; mean age = 17.4). Different types of CT (physical, emotional and sexual) were explored with CTQ and SI through SCL-90-R. The discordance within twin-pairs was used to dissect the genetic and CT effects in SI.

Results: Total CT and all subdomains were associated with an increased risk for SI. The within-pair differences analysis in monozygotic and dizygotic twins suggested that part of this association is not attributable to genetic predisposition, which points out the relevance of CT itself upon the increase of SI. This result converged with CT subdomain analyses of physical abuse and neglect.

Limitations: While within-pair twin analyses control for genetic risk, additional environmental shared and individual characteristics should be controlled for (such as poverty or protective factors). More detailed information on SI would be of great interest to better capture the complexity of this construct.

Conclusion: CT appears to be an important environmental risk factor for SI and at least partly independent of Gene-Environment correlation (rGE). This study highlights the importance of including the history of CT in psychiatric evaluations of patients. The burden of the psychosocial environment on SI could be disentangled by further research on environmental risk and protective factors.