The Relations of Self-Reported Aggression to Alexithymia, Depression, and Anxiety After Traumatic Brain Injury.

OBJECTIVES: To compare self-reported aggression in people with and without traumatic brain injury (TBI) and examine the relations of aggression to alexithymia (poor emotional insight), depression, and anxiety.
SETTING: Rehabilitation hospital. PARTICIPANTS: Forty-six adults with moderate to severe TBI who were at least 3 months postinjury; 49 healthy controls (HCs); groups were frequency matched for age and gender.
DESIGN: Cross-sectional study using a quasi-experimental design. MAIN MEASURES: Aggression (Buss-Perry Aggression Questionnaire); alexithymia (Toronto Alexithymia Scale-20); depression (Patient Health Questionnaire-9); and trait anxiety (State-Trait Anxiety Inventory).
RESULTS: Participants with TBI had significantly higher aggression scores than HCs. For participants with TBI, 34.2% of the adjusted variance of aggression was significantly explained by alexithymia, depression, and anxiety; alexithymia accounted for the largest unique portion of the variance in this model (16.2%). Alexithymia, depression, and anxiety explained 46% of the adjusted variance of aggression in HCs; in contrast to participants with TBI, depression was the largest unique contributor to aggression (15.9%).
CONCLUSION: This was the first empirical study showing that poor emotional insight (alexithymia) significantly contributes to aggression after TBI. This relation, and the potential clinical implications it may have for the treatment of aggression, warrants further investigation.