Prior to CBT treatment, nineteen obsessive–compulsive washers were administered Jones and Menzies's (1998a) obsessive–compulsive disorder (OCD) Origins Questionnaire (OOQ) in an attempt to examine the relevance of associative learning pathways in the aetiology of the disorder. The open-ended nature of the questions allows for the distinction between classical conditioning events and traumatic events in which no identifiable unconditioned stimulus can be found. On the basis of subjects' responses on the OOQ, associative learning was shown to account for only five cases of OC washing. Of note, depression was shown to facilitate the onset of OCD in these individuals. Every subject who experienced a relevant indirect learning event and went on to develop OCD, revealed they were experiencing depression at the time. No relationship was found between the mode of OCD acquisition and subsequent response to treatment. Finally, the data revealed that subjects who identified washing/cleaning concerns at the onset of their disorder, as distinct from subjects who identified other OC concerns (e.g. checking, hoarding) at the onset of their disorder, scored similarly on current level of severity and degree of intractability.