From The Quarterly, Winter 2011

Obsessive-compulsive disorder (OCD), the most severe of the anxiety disorders, is typified by intrusive, distressing thoughts that lead to compulsive, repetitive behaviors that can greatly diminish quality of life and curtail normal activity. Medication or psychotherapy, specifically a form of cognitive behavioral therapy called exposure and response prevention, can reduce OCD symptoms, but not for every patient and not permanently, and treatments are often difficult to sustain or have negative side effects.

Selective serotonin reuptake inhibitors (SSRIs) like fluoxetine (Prozac) and paroxetine (Paxil), which are antidepressant drugs that target the serotonin neurotransmitter system, can be effective in treating OCD, but only at very high doses. Adding low doses of antipsychotic medications helps in about half of cases, but can have serious side effects. New research is testing the usefulness of medications that modulate glutamate, a different neurotransmitter system.

Exposure and response prevention is a psychotherapeutic rather than a pharmacological intervention. In this therapy, the patient, guided by the therapist, confronts the feared thing and stays in the anxious moment until the fear is lessened or extinguished. For the technique to work it  requires time, patience, a skilled therapist and a willing patient.

Motivational interviewing, a therapy used for treating substance abuse, is being tested to see whether it can improve patient adherence in OCD treatment. Researchers are also examining a new use for an old drug, D-cycloserine, developed to treat tuberculosis, which can be added to exposure therapy to speed the fear extinction process.

Among laboratory technologies exploring the neurobiology of OCD, advances in imaging methods have made it possible to examine the living brain in real time. Imaging studies have shown that people with OCD have abnormal activity in a brain circuit involved in planning and organization, which includes the thalamus, a main role of which is to filter incoming information. One theory about OCD is that the thalamus is not gating incoming information appropriately. The need to learn whether everyone with OCD has the same brain abnormality has now led to expanded efforts to develop better animal models for study.

H. Blair Simpson, M.D., Ph.D.

NARSAD Young, Independent Investigator

Associate Professor of Psychiatry and Director of the Child and Adolescent Research and Education Program, Yale University School of Medicine