Associations of post-traumatic stress disorder and depression with cognitive performance over the first year following Glasgow Coma Scale 13-15 traumatic brain injury: a TRACK-TBI Study.

BACKGROUND

The impact of comorbid post-traumatic stress disorder (PTSD) and depression on cognitive outcomes after traumatic brain injury (TBI) is not well understood.

OBJECTIVE

To investigate associations of PTSD and depression with cognitive performance over the first year post-injury.

METHODS

1550 participants with Glasgow Coma Scale 13-15 TBI from the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) Study were included. Participants underwent in-person assessments at 2 weeks, 6 months and 1 year post-injury. Meeting screening criteria for PTSD was determined using the PTSD Checklist for the Diagnostic and Statistical Manual of Mental Disorders. Meeting screening criteria for depression was determined using the Patient Health Questionnaire-9. Cognition was assessed using a five-test battery. Linear mixed effects models were used to examine associations of PTSD and depression with cognition after TBI.

FINDINGS: Participants had a mean age of 41 years, 34% were female, 65% did not meet screening criteria for PTSD or depression, 3% met screening criteria for depression only, 16% met screening criteria for PTSD only and 16% met screening criteria for both depression and PTSD in the first year post-TBI. Mean performance on all cognitive tests improved at a similar rate over the first year post-injury in all PTSD/depression groups, but cognitive test performance was consistently worse among individuals with concurrent PTSD and/or depression compared with individuals with neither.

CONCLUSIONS

Individuals with TBI meeting screening criteria for PTSD and/or depression have consistently worse cognitive performance over the first year post-injury compared with individuals without psychiatric comorbidities, but the average rate of cognitive improvement over the first year was similar regardless of PTSD/depression status.

CLINICAL IMPLICATIONS: Further work is warranted to determine if cognitive and psychiatric-focused interventions may improve rates of cognitive improvement post-injury among individuals with comorbid PTSD and/or depression so that these individuals may ultimately achieve levels of cognition comparable to individuals without psychiatric comorbidities.