Examining the Discrepancy Between Subjective Cognitive Complaints and Processing Speed Performance in Military Personnel with Traumatic Brain Injury

Objective: To examine correlates of the discrepancy between subjective cognitive complaints and processing speed performance in a sample of military personnel with and without traumatic brain injury (TBI).

Method: About 235 U.S. military service members (31 noninjured controls [NIC], 69 injured controls [IC], 70 uncomplicated mild TBI [mTBI], and 65 complicated mild/moderate/severe TBI [sTBI]) prospectively enrolled in a longitudinal TBI study completed neuropsychological testing, performance validity tests, and self-report measures of cognitive complaints and psychological symptoms. Service members were categorized as "Accurate Estimators," "Underestimators," and "Overestimators" based on discrepancies between their subjective cognition and processing speed performance.

Results: The NIC group was less likely to underestimate their cognitive abilities than the mTBI group (p < .05). Discrepancy groups significantly differed in processing speed scores (p < .001), with underestimators demonstrating the best objective cognitive performance. Spearman correlations revealed significant positive correlations between unadjusted discrepancy scores and psychological symptoms in the NIC, IC, and sTBI groups (ps < 0.05) but not the mTBI group (ps > 0.05). In contrast, discrepancy scores adjusted for premorbid intelligence were consistently and positively correlated with psychological symptoms across all injury groups (ps < 0.05).

Conclusions: Findings suggest that mTBI injuries may increase the likelihood of a patient underestimating their cognitive performance. Further, premorbid cognitive functioning is an important factor in evaluating discrepancies in self-reported cognitive complaints and processing speed performance.