Background: Everyday decision-making in patients with obsessive-compulsive disorder (OCD) and anxiety is likely influenced by excessive fear and worry. However, the impact on specific cognitive aspects of decision-making, as operationalized in neuroeconomic models, has not previously been examined.
Methods: Fifty-nine participants (10 obsessive-compulsive disorder(OCD); 15 generalized anxiety disorder; 14 social anxiety disorder; 20 healthy controls) performed a two-gamble decision making choice task. Each gamble included a visual representation of the probabilities of gaining and/or losing points. Performance was modeled within Cumulative Prospect Theory framework, a prominent model for decision-making under risk (Tversky & Kahneman, 1992). In this paradigm, an S-shaped value function models diminishing sensitivity for increasing games/losses and loss-aversion. Additionally, an inverse S-shaped probability function over-weights, small probabilities and under-weights large probabilities. Using a non-linear regression model, the four parameters represented in these functions, were estimated for each participant, to generate a close fit of his/her performance on the task.
Results: OCD patients were found to have lower value discrimination then controls (p=.001), while neither of the other anxiety groups differed from healthy controls on any of the estimated parameters.
Conclusions: These findings suggest that lower value discrimination may contribute to impaired decision-making in OCD patients. This may be linked to the dysfunctional reward processing and anhedonia often demonstrated in these patients. The results support differentiation in decision-making between OCD and the two anxiety disorders. They also suggest that models utilizing Cumulative Prospect Theory may help to delineate aspects of decision-making that are altered in psychiatric disorders.