Analysis of the mild TBI condition included nine studies that reported externalizing symptoms. The overall effect size for this group was -.531 (95% CI [-.882, -.180]; p=.003). Five studies included measures for the moderate severity group. The effect size for this group was -.257 (95% CI [-.445, -.069]; p=.007). Seven studies provided information for the severe TBI group. This effect size was -.909 (95% CI [-1.312, -.506]; p<.001).