Decreased non-emotional working memory capacity in women with PTSD: association with symptomatology.

Posttraumatic stress disorder (PTSD) is known to be associated with deficits in working memory (WM). However, findings regarding the relationship of PTSD with non-emotional WM have not necessarily been uniform. This study aimed to clarify the relationship between PTSD and non-emotional WM using the N-back task, a well-established WM task. A total of 111 women with PTSD and 120 healthy control women without trauma were enrolled. Most of the patients developed PTSD after experiencing interpersonal violence. Participants completed 0-back and 2-back tasks using non-emotional stimuli (number), as well as a standardised neuropsychological test battery and self-report questionnaires for PTSD and depression symptoms. The PTSD group showed significantly less accuracy in the 2-back task than the control group, while no significant difference was observed in the accuracy of the 0-back task. The PTSD group showed significantly prolonged reaction time compared to controls in both the 0-back and 2-back tasks. The prolonged reaction time in the 2-back task was significantly correlated with more severe overall symptoms and avoidance symptoms in the PTSD group after controlling for age. Individuals with PTSD exhibited reduced WM capacity. Drawing on a relatively large civilian sample, this study contributes to the accumulating evidence of such deficits. Notably, the observed association between WM dysfunction and avoidance symptoms suggests a symptom-specific cognitive profile in PTSD.