To Be or Not to Be Flexible: Selective impairments as a means to differentiate between depression and PTSD symptoms

During the course of their lives, most individuals experience at least one potentially traumatic event. For some individuals this experience may result in them developing depression and/or post-traumatic stress disorder (PTSD) symptoms. The aim of the present study was to test the interactive effect of traumatic exposure and impaired cognitive flexibility on the tendency to develop either depression or PTSD symptoms. Eighty-two college students (M age = 25.32, SD age = 4.09) were assessed for exposure to traumatic events, depressive and PTSD symptoms. In addition, they completed a performance-based learning paradigm to evaluate the unique patterns of cognitive flexibility, defined as reduced and enhanced updating of prior knowledge in the face of new information. We predicted and found that for individuals with reduced updating, greater exposure to trauma was associated with elevated depressive symptoms. Contrary to our prediction, for individuals with enhanced updating, greater exposure was associated with elevated PTSD symptoms. While cognitive flexibility is traditionally associated with adaptive outcomes, our results illuminate the important role of a delicate updating balance to adaptively cope with aversive life events. The findings highlight the possible different roles of cognitive flexibility in the development of psychopathology and may serve as a first step toward developing tailored prevention and treatment methods.