Neurocognitive functioning over the course of trauma-focused psychotherapy for PTSD: Changes in verbal memory and executive functioning.

Abstract

Individuals with post-traumatic stress disorder (PTSD) have neurocognitive deficits in verbal memory and executive functioning. In this study, we examined whether memory and executive functioning changed over the course of treatment and which clinical variables were associated with change. Neuropsychological assessments were administered at baseline and endpoint of a randomized controlled trial as secondary outcome. Trauma survivors (n=88) diagnosed with PTSD received trauma-focused psychotherapy within a 17-week randomized controlled trial. Neuropsychological tests were the California Verbal Learning Test, Rivermead Behavioural Memory Test, Stroop Color Word Test, and Trail Making Test. Significant, small- to medium-sized improvements in verbal memory, information processing speed, and executive functioning were found after trauma-focused psychotherapy (Cohen's d 0.16-0.68). Greater PTSD symptom decrease was significantly related to better post-treatment neurocognitive performance (all p<.005). Patients with comorbid depression improved more than patients with PTSD alone on interference tasks (p<.01). No differences emerged between treatment conditions and between patients on serotonergic antidepressants and those who were not. This study suggests that neurocognitive deficits in PTSD can improve over the course of trauma-focused psychotherapy and are therefore at least partly reversible. Improvements over treatment are in line with previous neuropsychological and neuroimaging studies and effect sizes exceed those of practice effects. Future research should determine whether these changes translate into improved functioning in the daily lives of the patients. Patients with PTSD have difficulties performing verbal memory tasks (e.g., remembering a grocery list, recall of a story) and executive functioning tasks (e.g., shifting attention between two tasks, ignoring irrelevant information to complete a task). Verbal memory, information processing speed, and executive functioning significantly improved in patients with post-traumatic stress disorder over the course of trauma-focused psychotherapy. Improvements were equal in size for two different trauma-focused psychotherapies (Eye movement desensitization and reprocessing therapy and brief eclectic psychotherapy for PTSD). Medium-sized effects were found for recall of a story, whereas effects in other aspects of verbal memory, information processing speed, and executive functioning were small-sized. No causal attributions can be made because we could not include a control group without treatment for ethical reasons. Findings may be more reflective of patients who completed treatment than patients who prematurely dropped out as completers were overrepresented in our sample.