Now or Later? Emotional Factors and Decision-Making in Cocaine Use Disorder
thesisposted on 2020-08-01, 00:00 authored by Jennifer K. Hoots
Cocaine use disorder (CUD) remains a major public health concern, contributing significantly to death and disability. One defining feature of CUD is the repeated use of cocaine at the expense of alternative rewards. While use of cocaine quickly leads to rewarding effects, working towards alternative, long-term goals tends to involve more delay until reward receipt. Rewards are generally perceived as worth less when people must wait longer to receive them, a phenomenon called delay discounting. Individuals with CUD show steep delay discounting, indicating that they perceive the value of the reward as quickly decreasing as the delay increases. This study focuses on the relationship of delay discounting with distress tolerance and depression symptoms, including anhedonia. These factors are functionally significant areas of deficit in CUD and show promise for future treatment. We hypothesized: (1) lower distress tolerance will relate to steeper delay discounting in treatment-seeking individuals with CUD and (2) higher levels of depression symptoms and anhedonia will relate to steeper delay discounting in treatment-seeking individuals with CUD, although we also tested for possible quadratic relationships with discounting. Participants included treatment-seeking individuals with CUD. Distress tolerance was measured using a self-report questionnaire (Distress Tolerance Scale) and a behavioral measure of pain tolerance (Cold Pressor Task). Depression symptoms were self-reported on the Beck Depression Inventory Second Edition, and anhedonia was self-reported on the Snaith-Hamilton Pleasure Scale. To assess the relationship between these factors and temporal decision-making, we used multiple regression analyses with AUClog and log k from the delay discounting task as dependent variables. Results showed that self-reported distress tolerance showed no relationship with delay discounting, but lower levels of physical distress tolerance were associated with steeper delay discounting. Depressive symptoms showed a quadratic relationship with delay discounting, such that low and high levels of depression were associated with steeper delay discounting than moderate levels. Anhedonia showed a quadratic relationship with delay discounting as well, but moderate levels of anhedonia were associated with steeper delay discounting in comparison to low and high levels. Findings provide insight into the distinct relationship which tolerating physical distress may have with delay discounting in CUD. The unique relationships reported here for depression and anhedonia with delay discounting likely indicate differential associations of mood and reward-processing with decision-making in CUD. These findings offer deeper insight into decision-making in this population and a variety of potential treatment targets for further analysis.