Only one form of psychotherapy has been found in multiple controlled trials to be effective in treating OCD. It is termed exposure and response prevention (ERP). Both components, exposure to feared situations or thoughts, and the prevention of rituals, whether physical or mental, are necessary to maximize the treatment response. Clinicians can easily learn the basic principles from published sources. Most of the behavior therapy literature concerns patients with cleaning or checking rituals. Whether other OCD symptoms respond as well is yet to be determined. About 50% of patients presenting for treatment can benefit from behavior therapy without medications. About 20% to 30% are resistant to therapy and 20% drop out of treatment before achieving much benefit. At follow-up six months to three or more years after treatment, 65-75% of patients are much improved or improved, but 25% show no lasting benefit.
Behavior therapy is often surrounded by a number of misconceptions: symptom substitution will occur; interrupting rituals is dangerous to the patient; thoughts are ignored in behavior therapy; symptoms are all due to simple learning processes (operant and classical conditioning); drug therapy is incompatible with behavior therapy; and, behavior therapy is effective for all patients. None of these is true. Several clinical characteristics have been found to predict a poor response to behavior therapy: severe depression (the patient cannot habituate his anxiety); hypomania or mania (which impair compliance); severe family problems (which impair compliance); and, schizotypal personality disorder.
Informally asking the patient to expose himself to a particular feared situation and resist performing the compulsion may be helpful, especially after several months of effective drug treatment. The following steps would be pursued in a more formal application of this treatment:
- Explain the rationale of therapy. The patient must agree to tolerate the discomfort associated with not performing the ritual. Explain that one first changes behavior; after a week or more, anxiety decreases; and, after about month, the associated obsessions markedly diminish in frequency and intensity.
- Analyze the relationship of the compulsion to environmental events (at home and elsewhere) and to other factors that increase or decrease the compulsion.
- Document what the patient avoids doing or exposing himself to in order to avoid the anxiety that exposure would bring.
- Analyze the thoughts, images and impulses that increase anxiety or compulsions, e.g., belief in the importance of rituals to prevent the undesired event; the presence of depression; family actions that maintain the patient's symptoms, for example by cooperating with rituals or by creating stresses.
- Construct a hierarchy of compulsions and avoidances from the least to the most anxiety-provoking.
- Design written homework for exposure in vivo with response prevention for two to three hours after exposure focusing on one, or at most two, compulsions per week, starting with the least anxiety-provoking situations.
The therapist's modeling of the desired behavior adds nothing to the effectiveness of behavior therapy, but patients of therapists who are rated respectful, understanding, encouraging, challenging, and explicit improve more. Gratifying a patient's dependency needs and being permissive are negatively related to outcome. Prolonged exposure, e.g., 80 minutes at a time is more effective than eight, separate 10-minute exposures.