Cognition, functional capacity, and self-reported disability in women with posttraumatic stress disorder: examining the convergence of performance-based measures and self-reports.

Individuals with posttraumatic stress disorder (PTSD) experience cognitive impairments and disability in everyday activities. In other neuropsychiatric disorders, impairments in cognition and functional capacity (i.e., the ability to perform everyday tasks) are associated with impairments in real-world functioning, independent of symptom severity. To date, no studies of functional capacity have been conducted in PTSD. Seventy-three women with moderate to severe PTSD underwent assessment with measures of cognition (MATRICS Consensus Cognitive Battery: MCCB), functional capacity (UCSD Performance-Based Skills Assessment-Brief: UPSA-B), PTSD (Clinician-Administered PTSD Scale and PTSD Symptom Scale-Self-report (PSS-SR)), and depression (Montgomery Asberg Depression Rating Scale). Patients also reported their subjective level of disability (Sheehan Disability Scale). Over-reporting of symptom severity was assessed using six validity items embedded within the PSS-SR. Results indicated that on average PTSD patients manifested mild impairments on the functional capacity measure, performing about 1/3 standard deviation below healthy norms, and similar performance on the MCCB. Both clinician-rated and self-rated PTSD symptom severity correlated with self-reported disability but not with functional capacity. Self-reported disability did not correlate with functional capacity or cognition. Greater self-reported disability, depression, and PTSD symptoms all correlated with higher scores on the PSS-SR validity scale. The divergence between objective and subjective measures of disability suggests that individuals' distress, as indexed by symptom validity measures, may be impacting self-reports of disability. Future studies of disability should incorporate objective measures in order to obtain a broad perspective on functioning.