Associations among posttraumatic stress disorder symptoms, suicidal ideation, suicide attempts, and reward discounting.

Abstract

Posttraumatic stress disorder (PTSD) is associated with suicidal thoughts and behaviours. Decision-making processes and risk-taking are prominent for coping in both, but the implications for guaranteed and probabilistic reward discounting, important components in behavioural decision-making processes, are unclear. This study explored the relationships between PTSD and suicide risk with tendencies towards devaluing guaranteed rewards that are larger but delayed (i.e., delay discounting; DD) and devaluing larger but uncertain rewards (i.e., probability discounting; PD) for immediate but smaller rewards. The current study evaluated 498 participants (majority male [51.4%] and white [63.8%]; 33.3% screening positive for probable PTSD; 19.2% with lifetime suicide attempts; 30.8% with recent suicide ideation) on both delayed discounting and PD tasks. Provisional PTSD diagnosis, but not suicide attempts or ideation, was associated with increased PD (i.e., more devaluation of uncertain rewards). Conversely, PTSD interacted with both attempt history and ideation to predict increased delayed discounting (i.e., more devaluing of greater but delayed rewards). These results highlight how those with PTSD symptoms assign valuations to rewards, as well as how the addition of suicide risk interacts to impact these decision-making processes. While further research is needed, this suggests potential implications for treatment as they may benefit from structuring progress in smaller, more immediate goals.