Women Report Worse Neurobehavioral Symptoms than Men following Mild Traumatic Brain Injury in U.S. Military Service Members.

Women are more directly involved in combat operations today than ever before, currently making up 18.6% of officers and 16.8% of enlisted personnel in the US military. However, women continue to be underrepresented in military research. Studies which do consider gender differences in traumatic brain injury (TBI) outcomes have shown that women report significantly more post-concussive symptoms compared to men. Conclusions for true gender differences related to TBI is hard to make without controlling for non-TBI factors. The objective of this study was to examine the effects of gender specific to mild TBI (MTBI) sequelae from injured and non-injured control groups and investigate the role of PTSD in symptom reporting. It should be noted that the terms gender and men/women are used in this paper in place of sex or males/females given we are not discussing biological attributes. A total of 966 U.S. military service members and veterans where include in the study. Of the total sample, 455 men and 46 women where in the MTBI group, 285 men and 31 women in the Injured Controls group (IC), 111 men and 38 women in the Non-injured Controls group (NIC). Postconcussive and quality of life symptoms were compared for men and women while controlling for combat exposure. MTBI and IC groups were also stratified by PTSD presentation. Measures used included the Neurobehavioral Symptom Inventory (NSI), PTSD Checklist (PCL-C), Traumatic Brain Injury Quality of Life (TBI-QOL), and Combat Exposure Scale. In the MTBI group, women had worse scores on NSI total, NSI Somatosensory and Affective clusters; and the TBI-QOL Anxiety, Fatigue, and Headache scales (n2=.018 to .032, small to small-medium effect sizes). When PTSD was present, women had worse scores on the NSI Somatosensory cluster only (n2=.029, small-medium effect size). In contrast, when PTSD was absent, women had worse scores on the NSI Somatosensory and Affective clusters, and the TBI-QOL Anxiety and Headache scales compared to men (n2=.032 to .063, small to medium effect sizes). In the IC group, women had worse scores on the NSI Cognitive cluster and the TBI-QOL Fatigue and Pain Interference scales (n2=.024 to .042, small to small-medium effect sizes). However, group differences were no longer found when stratified by PTSD sub-groups. In the NIC group, there were no significant group differences for all analyses. We were able to identify symptoms unique to women recovering from MTBI which were not present following other forms of physical injury or healthy controls. However, the impact of PTSD exacerbates the symptom profile and its comorbidity with MTBI equates most of the noted gender differences.