LAUSR

Objective: Cognitive performance in trauma-exposed populations, such as combat Veterans, has been shown to be worse than in nonexposed peers. However, cognitive performance has typically been within the normal range (within 1 SD of normative mean), and the prevalence of clinically significant cognitive dysfunction (i.e., performance more than 1 SD below the mean on multiple measures in a domain) in younger adults with trauma exposure remains unknown. The objective of our study was to measure this. Method: We applied Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–5) cutoffs for clinically significant cognitive dysfunction (>1 SD below the mean in multiple measures within a domain) in the domains of memory, executive function, and attention to a sample of combat-exposed Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND; N = 368, mean age = 31.7 years, 90% men) Veterans. We then compared psychiatric, physiological, and neural measures, as well as functional outcomes, between those with and without cognitive dysfunction. Results: Veterans with cognitive dysfunction (n = 129, 35.1%) had lower premorbid reading ability and more severe psychological distress, including increased anxiety, depression, posttraumatic stress disorder (PTSD), sleep difficulties, pain, and alcohol consumption. Those with cognitive dysfunction also had worse functional outcomes, with mild but significant disability. In contrast, we found associations between outcome and age, traumatic brain injury, physiological and neural measures to be weak or not significant. Conclusions: Together, this suggests that premorbid abilities and trauma-related psychological symptoms contribute significantly to cognitive dysfunction in OEF/OIF/OND Veterans, and that neurological insult and aging may play less of a role. Cognitive dysfunction may be at least partially ameliorated by treating trauma-related symptoms.