Duration of untreated illness of patients with obsessive-compulsive disorder in Japan.

Aim: Obsessive-compulsive disorder (OCD) is a common and severe disease; however, the duration of untreated illness (DUI) of OCD is approximately 7 years, which is longer than that of other psychiatric disorders. Differences in medical environments have been reported to affect the DUI. Therefore, we surveyed the DUI of OCD in Japan and the reason for delayed treatment.

Methods: The study participants were outpatients who visited the OCD specialty outpatient clinic for the first time between June 1, 2017 and May 31, 2019. Obsessive-compulsive disorder was diagnosed using the criteria in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, and semistructured clinical interviews, which included asking the reason for the delay in seeking treatment and treatment drop-out history.

Results: Seventy-one patients met the inclusion criteria for the study. The mean period between OCD and the first visit to the hospital was 2.8 years and the mean DUI of OCD was 4.7 years. There was a significant difference in the history of tic disorders and treatment drop out between patients with a DUI of >2 years and those with a DUI of ≤2 years. The most common reason for delaying treatment was that the patient did not consider the symptoms of OCD to be those of an illness, and the most common reason for dropping out of treatment was lack of improvement.

Conclusions: This was the first study on the DUI of OCD in Japan. The DUI was relatively shorter than that found by studies in other countries. Stopping treatment lengthened the duration of the illness. Preventing the patient from dropping out of treatment could further shorten the duration of the illness.