Inhibitory control impairments underlie associative memory deficits in posttraumatic stress disorder

Objective: Posttraumatic-stress disorder (PTSD) patients suffer from cognitive dysfunction and show impairments even in non-trauma-related memory. Research has focused on the relationship between associative-memory and PTSD severity due to patients’ tendency to over-generalize from traumatic cues to neutral ones, leading to escalation of traumatic symptoms. In this study we aim to test to what extent inhibitory control impairments are correlated to associative-memory deficits in PTSD. Method: Twenty PTSD and 22 control participants were included. Posttraumatic symptoms were assessed via a board-qualified psychiatrist and the Post-Traumatic Diagnostic Scale. Inhibitory abilities were evaluated using the anti-saccade task and memory performance was probed using a words/pictures item-association paradigm. Results: Generally, PTSD patients performed lower than controls in both tasks. Lower associative-memory performance was observed in posttraumatic patients and was attributed to increased false-alarm rate in this group. In addition, we observed a strong significant positive correlation between associative pictorial memory performance and inhibitory performance, and in accordance, a significant negative correlation between the number of false-alarm responses in the associative pictorial test and inhibitory performance in the PTSD group. Conclusions: These results support the hypothesis that inhibitory control impairments are associated with (pictorial) associative-memory deficits in PTSD.