PTSD symptoms moderate the effects of interpretation bias modification on hostile interpretation bias and trait anger.

Individuals with heightened anger tend to interpret ambiguous situations as hostile, maintaining their anger. Importantly, both hostile interpretation bias and anger have been linked to detrimental outcomes such as substance use disorders and suicide. Hostile interpretation bias modification (IBMH) has been found to efficaciously reduce hostile attribution bias, but findings have been mixed on its ability to reduce anger. One factor that may contextualize these findings are symptoms of posttraumatic stress disorder (PTSD), which have been found to be associated with both hostile interpretation bias and anger. PTSD symptoms were examined as a potential moderator of the effect of IBM-H in sample of trauma-exposed smokers elevated in anger (N = 76). IBM-H was compared to a health and relaxation video control. Among participants elevated (i.e., +1SD) in baseline PTSD symptoms, IBM-H saw significantly lower trait anger following treatment compared to control, though there was no effect of condition on anger in individuals low in PTSD symptoms. Further, among individuals high in PTSD symptoms, changes in hostile interpretation bias fully mediated the effect of IBM-H on anger. These findings provide preliminary support that IBM-H for anger may be most efficacious for those elevated in PTSD symptoms. However, the generalizability of these findings are limited given the sample consisted of trauma-exposed smokers who wished to quit smoking. Future research should examine the efficacy of IBM-H for anger in individuals with PTSD (both smoker and non-smokers) and for secondary outcomes such as substance use disorders, depression, and PTSD symptoms.