Y-BOCS was a clinician-administered instrument used to assess the severity of obsessive compulsive disorder (OCD) symptoms and to monitor treatment response. The scale included 10 items: 5 items assessed obsessions and 5 items assessed compulsions. Each item was rated from 0 to 4, generating an obsessions subscale score (0-20), a compulsions subscale score (0-20), and a total score ranging from 0 to 40. Higher scores indicated greater OCD symptom severity. Negative change (or reduction in score) indicates improvement.

Improvement is measured by a lower total score

The Y-BOCS is a clinician-administered scale used extensively in research and clinical practice to both rate severity of obsessive compulsive disorder (OCD) and to monitor improvement during treatment. It is designed to rate the severity of obsessions and compulsions as well as the type of symptoms in patients with OCD. The scale consists of 10 items; the first 5 items assess obsessions, and the last 5 items assess compulsions. Subscale scores can be calculated for obsessions and compulsions, each on a scale of 0 to 20. A total score ranging from 0 to 40 can then be correlated to overall severity. The higher the number on the Y-BOCS, the more severe the symptoms.