Ten-year follow-up study of Japanese patients with obsessive-compulsive disorder

Aim: Obsessive-compulsive disorder (OCD) is a well-known chronic illness. This study retrospectively investigated 10-year outcomes and associated clinical factors in Japanese OCD patients. We focused on the impact of several sociocultural factors, including medical expenses and insurance systems specific to each country, on the differences or biases in follow-up procedures of OCD. Methods: Seventy-nine patients diagnosed with OCD who received a standardized combination of treatments for 10 continuous years were divided into three groups according to their improvement rates on the Yale-Brown Obsessive-Compulsive Scale after 10 years of treatment. Results: A survival analysis revealed that the rate of patients achieving full remission increased every year. Following 10 years of treatment, 56% of OCD patients experienced 'full remission' for at least 1 year. Consequently, 48% exhibited full remission, and 37% exhibited partial remission at the end-point of this study. We identified several factors that were predictive of poorer outcomes, including lower Global Assessment of Functioning Scale scores and the presence of hoarding symptoms or involvement behaviors. In addition, improvement rates after 1 year significantly predicted better 10-year outcomes. Conclusion: Our findings highlight the transcultural nature of long-term outcomes of OCD treatment, which appear to be independent of sociocultural differences.