Rapid-Response Impulsivity Predicts Depression and Posttraumatic Stress Disorder Symptomatology at 1-Year Follow-Up in Blast-Exposed Service Members

Abstract

Objective: To determine if elevated rapid-response impulsivity after blast exposure (as a putative marker of ventral prefrontal cortex [vPFC] damage) is predictive of future elevated affective symptomatology in blast-exposed service members.

Design: Longitudinal design with neurocognitive testing at initial assessment and 1-year follow-up assessment of psychiatric symptomatology by telephone interview.

Setting: Veterans Administration medical centers and postdeployment assessment centers at military bases.

Participants: Blast-exposed U.S. military personnel (N=84) ages 19 to 39 years old.

Interventions: Not applicable.

Main outcome measures: Center for Epidemiological Studies-Depression Scale (CES-D) scores, Posttraumatic Stress Disorder Checklist Version 5 (PCL-5) scores, and Alcohol Use Disorders Identification Test-C (AUDIT-C) scores at the 12-month follow-up telephone interview.

Results: After controlling for age and affective symptom scores reported at the initial assessment, commission errors on the Continuous Performance Test-II of the initial assessment were predictive of higher symptom scores on the CES-D and PCL-5 at follow-up, but were not predictive of AUDIT-C scores.

Conclusions: Elevated rapid-response impulsivity, as a behavioral marker of reduced top-down frontocortical control, is a risk factor for elevated mood and posttraumatic stress disorder symptoms over time in blast-exposed individuals. Future longitudinal studies with predeployment neurobehavioral testing could enable attribution of this relation to blast-related vPFC damage.

Keywords: Brain injuries, traumatic; Cognition; Depression; Explosions; Impulsive behavior; Rehabilitation; Veterans.

Figure 1.

Leverage plots illustrating the relationship between initial assessment Continuous Performance Test II (CPT-II) commission errors (CE; expressed as percent of non-targets to which the subject responded) and affective symptomatology at one-year follow-up, as calculated in multiple regression. After controlling for age and baseline symptomatology scores as covariates, CE rates showed a significant positive relationship with increased severity of PTSD symptoms endorsed on the PCL at one-year follow-up (regression β = .183, P = .049; A). Initial assessment CE rates also showed a significant relationship with severity of depressive symptoms endorsed on the CES-D at one-year follow-up (regression β = .191, P = .044; B).