Predicting changes in obsessive compulsive symptoms over a six-month follow-up: A prospective test of cognitive models of obsessive compulsive disorder

Cognitive models of obsessive compulsive disorder (OCD) propose that OCD-related beliefs (e.g., inflated responsibility) and negative life events should predict changes in OC symptoms over time (Rachman, 1997, Behaviour Research and Therapy, 35, 793-802; Rachman, 1998, Behaviour Research and Therapy, 36, 385-401; Rachman, 2002, Behaviour Research and Therapy, 40, 625-639; Salkovskis, 1985, Behaviour Research and Therapy, 23, 571-583; Salkovskis & Kirk, 1997, In The science and practice of cognitive behavior therapy. Oxford: Oxford University Press). However, very little research has tested these longitudinal predictions. The current study sought to replicate and extend findings by Coles and Horng (2006, Cognitive Therapy and Research, 30, 723-746) showing that OCD-related beliefs and negative life events significantly predicted changes in the frequency of OC symptoms over 6 weeks. Results of the current study, using a 6-month prospective longitudinal design, provided modest support for cognitive models of OCD. Negative life events significantly predicted residual change in both the frequency of, and distress associated with, OC symptoms. Initial OCD-related beliefs significantly predicted residual change in the distress associated with OC symptoms, but there was much additional variance to be accounted for. Additional data are presented that both examine the specificity of these predictors to changes in OC symptoms versus social anxiety and depressive symptoms, and explore particular types of life events in predicting symptom changes over time.