Abstract
Adverse childhood experiences are consistently implicated in risk for suicidal thoughts and behaviors (STB). However, the nature of those experiences and their specific associations with STB remain unclear. The diathesis-stress model also suggests that the influence of adverse experiences depends on one's genetic liability, though results using measures of aggregate genetic risk need additional empirical support. This study aimed to improve our understanding of the roles of childhood adversity and genetic liability in risk for STB. Participants were from the National Longitudinal Study of Adolescent to Adult Health. First, we conducted a random split-half exploratory and confirmatory factor analysis in the full sample (N = 11,606) to investigate the latent structure of childhood adversity. Second, we ran logistic regressions to evaluate how childhood adversity, aggregate genetic liability for STB (operationalized with polygenic scores), and their interaction were related to suicide ideation and attempt in two ancestry groups (European [EA, N = 3424] and African [AA, N = 1172]). Findings indicate that the structure of childhood adversity was best represented by a 3-factor solution: Factor 1 referred to the availability of potentially hazardous items (substances, guns) in the home environment, Factor 2 reflected the witnessing of substance use, and Factor 3 represented abuse and neglect. In EA, Factor 1 was associated with suicide ideation and Factor 2 with suicide attempt. Our results also implicated Factor 3 in risk for suicide ideation and measures of genetic liability in both ideation and attempt. We did not find evidence of associations in the AA group, and no significant gene-by-environment interactions in either group. Our results inform prevention efforts, as they indicate the importance of specific features of the home environment (i.e., what is observed by children but also what is available to them) in addition to the experience of abuse and neglect.