Duration of untreated illness and response to SRI treatment in Obsessive-Compulsive Disorder

The duration of untreated illness (DUI) is a potentially modifiable parameter associated with worst prognosis in several psychiatric disorders, but poorly investigated in Obsessive-Compulsive Disorder (OCD). Our aims were to estimate the mean DUI in a large sample of individuals with OCD and its impact on response to the first ever adequate SRI treatment.

We retrospectively examined records of 251 patients with OCD (SCID-I, DSM-IV) who referred to our Department and were prospectively and naturalistically treated according to International Guidelines. The DUI was defined as the interval between age at onset and age at which patients received their first adequate pharmacological treatment. Response rates were compared in subjects with brief (≤24 months) versus long DUI. Logistic regression models predicting response and 12-week Y-BOCS score were run with DUI (among others) as independent variable.

The mean DUI was 106.19 ± 118.14 months, with a mean interval between onset of the disorder and when patients sought professional help of 82.27 ± 112.30 months. Response rates were significantly reduced in subjects with a long DUI, using both the cut-off of 24 months and the median value of 60 months. Regression analyses confirmed that a long (>24 months) DUI predicts poorer response and higher Y-BOCS scores at 12 weeks.

Our results, although preliminary, seem to suggest that a longer duration of untreated illness in OCD is associated with poorer outcome in terms of response to SRI treatments. It is imperative to do all the possible to shorten the DUI, both by improving access to mental health services, improving the ability of primary care physicians and mental health professionals to recognize OCD, and disseminate best-practice prescription guidelines.