Interpretations of ambiguous situations in combat veterans with and without post-traumatic stress disorder

Deployed combat personnel are at increased risk of post-traumatic stress disorder (PTSD). People with PTSD often judge ambiguous information as negative or threatening (interpretation bias). However, this may be adaptive during deployment. The current study aimed to investigate the extent to which interpretation bias in combat personnel is associated with PTSD symptoms, rather than with appropriate situational awareness. Combat veterans with and without PTSD and civilians without PTSD generated explanations for ambiguous situations and judged the likelihood of various possible explanations. They also made judgements about future consequences of worst-case scenarios, and their coping ability. Veterans with PTSD generated more negative explanations for ambiguous situations, judged negative interpretations as more likely and felt less able to cope with the worst-case scenario than veteran and civilian controls. Veterans with versus without PTSD judged worst-case scenarios to have more severe and insurmountable consequences, although they did not differ significantly from civilians. Veteran versus civilian controls rated their coping ability as higher; this was the only difference between control groups. In summary, group differences in interpretation bias were associated with PTSD symptoms rather than combat role. Veterans without PTSD may be particularly resilient when coping with everyday adversity.