Treatment expectancy for anxiety change and response to cognitive behavioral therapy for OCD

• Examined expectancy for anxiety change and treatment response in OCD.
• Expectancy for anxiety change increased from pre-treatment to session four.
• These increases were associated with reductions in OCD symptoms at end of treatment.
• Pre-treatment expectancy was negatively correlated with pre-treatment clinical factors.
• Results support a role of treatment expectancy in OCD.

Although research investigating the role of treatment expectancy in treatment response showed positive associations for various anxiety disorder diagnoses, among individuals with obsessive-compulsive disorder (OCD) the results have been mixed. The purpose of the present study was to investigate the extent to which pre-treatment expectancy for anxiety change, as well as early changes in expectancy for anxiety change, are associated with response to 12 weeks of group cognitive behavioral therapy for OCD. Although pre-treatment expectancy for anxiety change did not significantly predict treatment response, increases in expectancy for anxiety change from pre-treatment to session four were significantly associated with reductions in OCD symptom severity at the end of treatment. Negative associations were observed between pre-treatment expectancy for anxiety change and pre-treatment OCD symptom severity, depression, anxiety, and stress symptom severity, and intolerance of uncertainty. The results support a role of treatment expectancy in OCD, and highlight the importance of assessing expectancy for anxiety change multiple times throughout treatment.