Obsessive compulsive symptoms and the simulation of future negative events

To explore whether Kahneman and Tversky's (1982) simulation heuristic might help account for why the obsessions of people with obsessive compulsive disorder (OCD) are so compelling to them. It was predicted that participants would be better able to simulate a scenario relevant to a central OCD fear than they would scenarios related to other OCD and non-OCD fears and that how well participants simulated feared scenarios would be associated with higher ratings of subjective probability for that outcome and consequently greater worry.

Individuals with obsessive compulsive symptoms mentally simulated hypothetical scenarios so as to enable comparison of a personally relevant to less relevant scenarios.

Thirty participants recruited from OCD support groups simulated four scenarios each and completed symptom and relevant construct measures.

Personally relevant scenarios were better simulated than less relevant scenarios. 'Goodness of simulation' (GOS) was related to worry about the feared outcome, but this was not mediated by raised subjective probabilities. GOS correlated with OCD symptomatology, anxiety, and depression but not with cognitive variables thought to be related to OCD phenomenology.

The overall findings converge with recent literature (O'Connor, 2002) emphasizing the importance of imagination and imaginary narratives in fuelling OCD symptoms.