Although no online test can replace an evaluation by a qualified mental health professional, the Yale-Brown Obsessive-Compulsive Scale is clinician-rated as reliable, according to an abstract from the Archives of General Psychiatry on PubMed. The test is available on Psychology-Tools.com.
The Yale-Brown Obsessive-Compulsive Scale is a self-scored rating system that asks the reader 10 questions regarding his thoughts and behaviors during the previous week, explains Psychology Tools. The person rates himself on the frequency and severity of his obsessions, which are distressing or distracting thoughts or impulses that often conflict with his personality, morals or ideals. He also rates the frequency and severity of any compulsions, which are behaviors that he feels he must perform, even when they make little sense. Total scores range from zero, which indicates no symptoms, to 40, which means that symptoms are severe, explains PubMed.