Disinhibited and angry : investigating the relationship between social disinhibition and the components of aggression following severe TBI

Social disinhibition and aggression share many similarities. But unlike with aggression, research evidence about social disinhibition following severe traumatic brain injury (TBI) is limited and treatments are missing. Establishing the association between aggression and social disinhibition would facilitate a better conceptualization of these disorders. This study aimed to determine the relationship between social disinhibition and aggression following severe TBI. In this case–control study, 25 individuals with severe TBI and 25 control participants completed the Buss-Perry Aggression Questionnaire (BPAQ), Frontal Systems Behaviour Scale (FrSBe), and Social Disinhibition Interview (SDI). Hierarchical multiple regression analyses revealed that, when controlling for covariates, the inclusion of BPAQ Anger in the model led to a 13% increase in proportion of explained variance of social disinhibition (Adjusted R2 increased from .243 to .363, p < .005). BPAQ Anger was not a significant predictor of SDI scores. Similarly, BPAQ Physical aggression scores did not contribute to the prediction of FrSBe Disinhibition or SDI scores. In conclusion, higher levels of self-reported anger (but no other components of aggression) are associated with higher levels of self-reported social disinhibition. While these findings have potential implications for the treatment of social disinhibition, further research into the possible relationship with aggression should be conducted.