Reward Processing and Decision-Making in Posttraumatic Stress Disorder

Abstract

Theory suggests that, in those with posttraumatic stress disorder (PTSD), positive emotion is likely dampened due to reexperiencing of trauma-related stimuli. Prior research has extended positive emotion experiencing to reward processing research but has not yet examined how trauma cues affect reward processing (i.e., the anticipation of and satisfaction with reward) and decision-making in individuals with PTSD. We compared 24 individuals diagnosed with PTSD to 29 trauma-exposed controls in passive and decision-making phases of a wheel-of-fortune task, following both neutral and trauma inductions. Three types of spinners were used in the task: spinners that were obviously advantageous spinners, obviously disadvantageous spinners, and ambiguously advantageous spinners with outcomes averaging to a net gain. We hypothesized that the PTSD group would report lower reward expectation and lower outcome satisfaction and make less advantageous decisions, differences that would be exacerbated following a trauma prime. The PTSD group reported lower reward expectation than controls for the ambiguous spinners only, suggesting that the reduced anticipation of reward associated with PTSD may be specific to ambiguous stimuli. Reward expectation was not affected by the type of prime. Outcome satisfaction was not affected by PTSD or type of prime. Although only marginally significant, the PTSD group played the ambiguous spinners less often than controls, and played the obviously disadvantageous spinners significantly less often than controls, suggesting that those with PTSD are more aversive to loss. Our findings suggest that PTSD-related deficits are more robust for reward expectation than outcome satisfaction, and support future research examining the role of reward-related decision-making in PTSD.

Keywords: PTSD; decision-making; emotional numbing; posttraumatic stress; reward processing.