Exploring suicidal ideation and self-harm after moderate-severe traumatic brain injury within a transdiagnostic framework.

More research is needed on suicidal ideation (SI) and self-harm (SH) following moderate-severe traumatic brain injury (TBI). Previous studies have shown limited, inconsistent associations with demographic and injury factors and relied on diagnosis-specific analyses of psychiatric factors. This cross-sectional survey included 387 individuals with moderate-severe TBI and examined correlations between SI, SH, and 35 other variables, including a series of transdiagnostic internalizing symptom dimensions. In the previous two weeks, 21% of participants reported SI and 5% reported SH, both generally at mild levels. While demographic and injury factors showed minimal associations, SI and SH were significantly correlated with higher internalizing symptoms, greater disability, and lower life satisfaction. Elastic net regression was used to select the most important correlates, including core negative affect (e.g., depressed mood), post-traumatic intrusion, obsessive-compulsive, and low positive affect symptoms. While each significantly explained only a small amount of unique variance (<1-7%), their combination accounted for 50% and 31% of the variance in SI and SH, respectively. We identified a transdiagnostic profile that may help guide assessment and treatment of SI and SH in individuals with moderate-severe TBI. Future research should aim to distinguish SH with and without suicidal intent and incorporate a control group.