Conceptualisation of a novel cognitive process in obsessive-compulsive disorder: A Delphi study on excessive rationalisation.

Background: Obsessive-compulsive disorder (OCD) is a common mental illness which involves intrusive thoughts and compulsive behaviours. Thought control strategies are a common factor in OCD, yet they are understudied and under-addressed in existing treatments. Excessive rationalisation is a novel conceptualisation of OCD-related thought control, describing a stressful process of arguing with or attempting to explain away unwanted thoughts. Investigation of this concept could offer a new perspective on the cognitive experience of OCD which may be missed or unappreciated within existing treatments. Method: The Delphi method was used to develop a pool of items that could describe this new concept. Twenty people with lived experience of OCD took part in four rounds. In the first round, responses to open-ended questions were used to generate a list of items which described the concept. In Rounds 2 and 3 participants rated the items so as to refine the initial list. In Round 4 participants ranked the items in order of how well they described excessive rationalisation. Results: Across the rounds a total of 61 items were generated. Thirty-one items were then discarded, either because they did not reach consensus, did not describe excessive rationalisation, or were redundant. Ninety per cent of participants (strongly) agreed that the final pool of 30 items described the concept of excessive rationalisation. Conclusions: The present research drew on lived experience to conceptualise a novel concept which may be important for understanding OCD and its persistence.