Lifetime blast exposure is not related to cognitive performance or psychiatric symptoms in US military personnel.

Objective

The present study aimed to examine the impact of lifetime blast exposure (LBE) on neuropsychological functioning in service members and veterans (SMVs). Method: Participants were 282 SMVs, with and without history of traumatic brain injury (TBI), who were prospectively enrolled in a Defense and Veterans Brain Injury Center (DVBIC)-Traumatic Brain Injury Center of Excellence (TBICoE) Longitudinal TBI Study. A cross-sectional analysis of baseline data was conducted. LBE was based on two factors: Military Occupational Speciality (MOS) and SMV self-report. Participants were divided into three groups based on LBE: Blast Naive (n = 61), Blast + Low Risk MOS (n = 96), Blast + High Risk MOS (n = 125). Multivariate analysis of variance (MANOVA) was used to examine group differences on neurocognitive domains and the Minnesota Multiphasic Personality Inventory-2 Restructured Form.

Results

There were no statistically significant differences in attention/working memory, processing speed, executive functioning, and memory (Fs < 1.75, ps > .1, ηp2s < .032) or in General Cognition (Fs < 0.95, ps > .3, ηp2s < .008). Prior to correction for covariates, lifetime blast exposure was related to Restructured Clinical (F(18,542) = 1.77, p = .026, ηp2 = .055), Somatic/Cognitive (F(10,550) = 1.99, p = .033, ηp2 = .035), and Externalizing Scales (F(8,552) = 2.17, p = .028, ηp2 = .030); however, these relationships did not remain significant after correction for covariates (Fs < 1.53, ps > .145, ηp2s < .032).

Conclusions

We did not find evidence of a relationship between LBE and neurocognitive performance or psychiatric symptoms. This stands in contrast to prior studies demonstrating an association between lifetime blast exposure and highly sensitive blood biomarkers and/or neuroimaging. Overall, findings suggest the neuropsychological impact of lifetime blast exposure is minimal in individuals remaining in or recently retired from military service.