Intrusive trauma recollections is associated with impairment of interference inhibition and psychomotor speed in PTSD.

ABSTRACT

BACKGROUND: Intrusive cognitions that enter consciousness involuntarily are prominent symptoms of posttraumatic stress disorder (PTSD). The present study aimed to identify neuropsychological mechanisms involved. METHOD: Fifty PTSD outpatients and 50 healthy controls were tested using Finger Tapping, Simple and Choice Reaction Times and Stroop Tasks, to measure motor, psychomotor speed, response selection, and interference inhibition ability respectively. RESULTS: PTSD patients performed poorly in all tests, presumably owing to their generalized slowness of information processing and motor reaction. Psychomotor speed was a predictor of slowness and high error rate during the Stroop. Impaired inhibition, as measured by the interference index of the Stroop task, explained 9.7% of the predicated variance in frequency of re-experiencing PTSD symptoms and 23.5% of the predicated variance in augmentation of the interference response time. CONCLUSION: Impaired interference control may be related to internal (re-experiencing) and external (sensory) stimuli that leads to cognitive deficits in PTSD patients.