Duration of Untreated Illness As a Predictor of Treatment Response and Remission in Obsessive-compulsive Disorder

Objectives: The Duration of Untreated Illness (DUI), defined as the time elapsing between the onset of a disorder and the beginning of the first pharmacological treatment, has been increasingly investigated as a predictor of outcome and course across different psychiatric disorders. Purpose of this naturalistic study was to evaluate the influence of DUI on treatment response and remission in a sample of patients with obsessive-compulsive disorder (OCD).

Methods: Sixty-six outpatients with a DSM-IV diagnosis of OCD were included in the study. Patients received, according to their clinical conditions, an open pharmacological treatment of 12 weeks and were evaluated by the administration of the Yale Brown Obsessive Compulsive Scale (Y-BOCS) at baseline and endpoint. Treatment response was defined as a decrease .25% on Y-BOCS score compared to baseline, while remission was defined as an endpoint Y-BOCS total score #10. A logistic regression was performed considering DUI as the independent continuous variable and treatment response and remission as the dependent variables. Moreover, the sample was divided into two groups according to a categorical cut-off for the DUI of 24 months and odds ratios (OR) were calculated on the basis of the same variables.

Results: DUI, considered as a continuous variable, was not predictive of treatment response (OR51.00, P50.15) nor remission (OR51.00, P50.59). When considered as a categorical variable, however, a DUI # 24 months was predictive of treatment response (OR50.27, P50.03).

Conclusions: Results from the present naturalistic study suggest a complicated relationship between DUI and treatment outcome in OCD encouraging further investigation with larger samples in order to better define long versus short DUI in this condition.