The goals of therapy are to diminish symptoms and to ameliorate or reverse their effects on the patient's interpersonal, work place and social functioning. A modest proportion of patients will achieve freedom from significant symptoms. The clinician can use the Y-BOCS symptom checklist to obtain a record of the patient's current and past symptoms. Patients may not reveal embarrassing symptoms or symptoms that they believe may suggest they are "crazy" until a trusting therapeutic relationship has been established. If completing a Y-BOCS severity rating is impractical, a useful gauge of severity is how much time obsessions and, separately, compulsions, are occupying "an average day in the past week."

Treatment planning depends on careful evaluation. As noted earlier, comorbid depressive and anxiety disorders will commonly be present. These comorbid conditions may not respond to the particular serotonin reuptake inhibitor (SRI) prescribed for the patient's OCD. Treatment approaches to such cases, including several kinds of psychotherapy, are also available. If a patient is abusing alcohol to reduce anxiety, this problem must be addressed. The presence of a tic disorder, schizotypal or borderline personality disorders, or a personal or family history of hypomania or mania should be explored, since these would influence therapy choices.

A comprehensive treatment plan evolves as one gets to know the patient. Experienced clinicians will exercise their clinical judgement in tailoring the plan to their patients' needs, preferences, capacities, situation and history. For a patient with isolated, mild to moderate OCD, a combination of an SRI and exposure and response prevention in vivo is a reasonable initial strategy in most cases. In certain situations, such as the patient with low motivation or anergia secondary to major depression, medications alone may be preferable. In still other cases, medications may be needed to decrease the intensity of symptoms so that the patient can subsequently comply with behavioral treatment. There is insufficient data to draw any conclusions about the relative efficacy of medications alone, exposure and response prevention alone, and their combination, but many experienced clinicians believe that the combination offers more rapid improvement and greater protection against relapse. All patients should be guided to educate themselves through various OCD related resources.