Obsessive-compulsive disorder: Part II

Content provided by the Faculty of the Harvard Medical School

Obsessive-compulsive disorder: Part II

Treating the symptoms and studying the brain.

A diagnosis of obsessive-compulsive disorder (OCD) may be delayed for years because a person with the disorder suffers from shame or obsessional doubt or is reluctant to undertake anything new. But Dr. Michael Jenike of Harvard Medical School has said that a general practitioner can identify the vast majority of cases by asking three questions: Do you have any repetitive thoughts that interfere seriously with your life? Do you wash excessively? Do you constantly check to see that things are right?

OCD should be distinguished from related symptoms that occur in other disorders. In depression, ruminations are always guilty and sad. In generalized anxiety disorder, brooding is not constantly about one subject and not accompanied by compulsive rituals. And unlike obsessions, anxious and depressed thoughts are not usually regarded as alien intrusions. In eating disorders, obsessions are confined to food and body size. Autism or schizophrenia may cause ordering and arranging rituals, but they are usually less complex and seemingly purposeful than the compulsions of obsessive-compulsive disorder, and the patient does not try to resist them.

Nor is OCD identical with (or necessarily related to) obsessive-compulsive personality: conscientious, orderly, morally rigid, fussy about details, indecisive, perfectionistic. The symptoms of OCD are not character traits, although it can be difficult to tell the difference if a person has many obsessions and rituals.

Behavioral treatment

The most widely accepted and best supported treatments for OCD are based on behavioral principles. The theory is that compulsive rituals encourage the habit of obsessional thinking by repeatedly, though only temporarily, relieving tension and anxiety. So therapy must break the learned association between compulsive rituals and relief from obsessional thoughts.

The standard method is called exposure and response prevention (ERP). Patients are exposed repeatedly to the sources of their obsessions and prevented from performing the rituals, until the obsessions lose their compelling quality. In behavioral terms, the conditioned pattern is extinguished.

This idea — essentially, resisting the compulsions — may seem like simple common sense, but working it out usually requires help. The therapist and patient describe the obsessions and the situations that provoke them, list them in order of associated discomfort, attention, or anxiety, and proceed by small steps. For example, a patient who avoids public telephones for fear of germs might be advised to touch a telephone. He is then asked to imagine that his hand and everything he touches is contaminated, but to delay washing until the anxiety fades. When there is only a mental ritual, the therapist might ask the patient to think the obsessional thought and avoid reciting the magic formula.

The treatment usually takes three or four months of weekly sessions. Patients practice daily and record the results to track their progress. Some patients can work alone with a manual or self-help book, or, according to one study, with a computer. Exposure is best done at the times and places where the symptoms are most likely to arise, which often means at home.

About three-quarters of adults who start ERP complete the program, and three-quarters of them — 50% over all — improve significantly. But it takes time and work; a meta-analysis of 52 trials found that success depended mainly on how long the therapist and patient spent practicing.

Another type of behavioral treatment is habit reversal — substituting another act for the compulsive behavior. This method can be useful for habitual skin-picking, touching, and arranging compulsions. The patient tracks obsessional urges and diverts them with deep breathing, muscle relaxation, or fist-clenching.

Saturation works for some: The patient concentrates so hard on the repellent thought that it becomes meaningless and no longer compelling. In one variant, patients record their obsessions or mental rituals on audiotapes and listen over and over. Obsessional thoughts can also be avoided by "changing the channel" — directing attention to other thoughts. And some advocates of non-resistance suggest a form of meditation — just let the thoughts pass, observe them without judgment, and try to suppress anxiety.

Other approaches

Cognitive techniques are sometimes added to help patients free themselves of obsessional doubt, an exaggerated sense of responsibility, and an excessive need for control. It's not a matter of persuading them that their thinking is wrong; they already know that. But they may need to question an implicit and unacknowledged belief that thoughts can come under their complete control ("Do not think about a white bear" is one challenge to this notion), or that having a thought is morally equivalent to acting on it. They have to understand that everyone has unacceptable thoughts at times. They can be asked: Are all thoughts equally important? Do you believe others should be judged by their actions rather than their thoughts? How do you reconcile your view of yourself with the views of others about you?

Some people with OCD cannot effectively practice behavior therapy because they are depressed or have personality disorders or serious family problems. Insight-oriented therapy may help them complete behavioral treatment, live more comfortably with the remaining symptoms, and find ways to occupy time no longer consumed by obsessions and rituals. Assertiveness training may help them reduce anxiety and guilt associated with obsessions. Mutual aid groups are also becoming more popular as a way people with OCD can exchange sympathy and ideas and help themselves by helping others.

Especially when exposure is practiced mostly at home, families may need to become involved to supervise and encourage the patient. Family support groups may be useful for them, especially if compulsive rituals have been monopolizing a household's attention.

Anti-obsessional drugs

The main drug treatments for OCD are antidepressants that enhance the activity of the neurotransmitter serotonin. Some believe clomipramine (Anafranil), a tricyclic antidepressant, is the most effective. Like all tricyclics, though, it may cause uncomfortable side effects, including dizziness, drowsiness, dry mouth, constipation, weight gain, and sometimes heart rhythm disturbances. Today most physicians prefer a selective serotonin reuptake inhibitor: fluoxetine (Prozac), fluvoxamine (Luvox), sertraline (Zoloft), paroxetine (Paxil), or citalopram (Celexa). Venlafaxine (Effexor), which combines serotonin and norepinephrine reuptake inhibition, is another, more recent alternative. The main potential side effects are insomnia, nausea, and loss of sexual desire. A second-generation antipsychotic drug like risperidone (Risperdal) may be added in severe cases, especially when obsessions are so intense that they resemble delusions.

On average, OCD requires higher doses than depression, and the antidepressants take longer to start working — as long as three months. About half of patients eventually get some relief, but almost all relapse quickly when they stop taking the drug, unless they practice ERP. Some may prefer drug treatment because they find behavior therapy too expensive, too challenging, or unavailable. Others take drugs in the hope of reducing their fears and doubts enough to make behavior therapy tolerable. In several studies, the combination of drugs and behavior therapy has been found more effective than drugs alone.

Psychosurgery

Very rarely, and as a last resort, when obsessive-compulsive symptoms are incapacitating and no other treatment works, a surgeon can interrupt targeted nerve circuits in the brain. This approach is considered only in the most intractable cases, and even so it provides some relief for only about half of patients. They often take months to respond, which suggests that the brain is slowly substituting new connections for old. The regions affected are critical for decision and action, so surgery may lead to apathy or emotional unresponsiveness.

The outcome

Obsessive and compulsive symptoms rarely go away completely, even after treatment. According to a meta-analysis published in 2004, it has not been proved that the gains persist beyond a year unless treatment continues.

In a 40-year follow-up of patients admitted to hospitals with OCD, Swed­ish researchers found that more than 80% improved but only about 20% made a complete recovery. Most of the improvement occurred early in the course of the illness, and about 50% continued to have OCD for more than 30 years, although they often learned to cope with the symptoms. These were severe cases, and the average person with obsessive-compulsive symptoms can reasonably hope for a better long-term outcome.

Inside the brain

Scientists engaged in the complex project of discovering where psychiatric disorders reside in the brain have had some success with obsessive-compulsive disorder. The malfunction is mainly in a circuit connecting the frontal lobes of the cerebral cortex. The frontal lobes of the cerebral cortex govern judgment, planning, and decision-making and the basal ganglia filter messages to and from the cortex to regulate body movements and other functions. Injuries and diseases that damage the basal ganglia, such as Huntington's disease, can cause obsessive and compulsive symptoms.

Functional brain imaging provides further evidence. When the brain of a patient with a cleanliness obsession is scanned by positron emission tomography (PET) while she holds a dirty towel, two regions are abnormally active: parts of the prefrontal cortex and the caudate nuclei, which are part of the basal ganglia. There is also some evidence that drug treatment or behavior therapy can correct this abnormality. It looks as though the lower brain region is working unusually hard, but ineffectively, in an effort to quiet the frontal cortex. So obsessional thoughts reverberate, suggesting a need for decision and action, until the tension is released by a compulsive ritual. Some (disputed) studies even imply that there is a connection between specific obsessive and compulsive symptoms and specific parts of the frontal lobes and basal ganglia.

Chemical messengers in the path connecting the frontal lobes and basal ganglia include serotonin and dopamine. The role of these neurotransmitters is unclear, though. Selective serotonin reuptake inhibitors are an effective treatment for OCD, and drugs that increase the activity of dopamine tend to make the symptoms worse. Scientists don't yet know how changes in serotonin circuits improve OCD symptoms. To complicate matters, there are many different kinds of serotonin and dopamine nerve receptors with imperfectly understood functions.

Obsessive-compulsive disorder may be related to a common type of infectious disease — the group A beta-hemolytic streptococcal infections, which include strep throat and scarlet fever. Antibodies recruited by the immune system to defeat these bacteria can attack the body's own tissues, damaging the heart and inflaming the joints. There are signs that, especially in children, these antibodies can also infiltrate the brain — the basal ganglia, in particular — causing the condition awkwardly named "pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections," or PANDAS. The symptoms of this controversial diagnosis include obsessional thinking and compulsive behavior.

There is additional evidence that these symptoms can appear soon after a streptococcus infection. In a study comparing children ages 4–13 with OCD, Tourette's syndrome, and tic disorders to healthy controls, researchers found a high rate of strep infections in the three months before the symptoms appeared. A child who suffered several infections of the group A beta-hemolytic streptococcal type had nearly 14 times the average risk of developing OCD or related disorders in the following year.

Obsessions evolving

Washing, checking, straightening, and hoarding — and the associated disgust, doubt, and anxiety — are adaptations to threats of death, disease, or social ostracism. Humans have always had to store goods, avoid injury and disease, protect their families, and control their aggressive and sexual impulses. The brain systems that exercise these functions, provided by natural selection, may malfunction spectacularly in obsessive-compulsive disorder but can also produce harmless symptoms. Children often show some of the same arranging, ordering, and collecting tendencies that run wild in people with OCD. The children's sidewalk game celebrated in the rhyme, "Step on a crack, break your mother's back," is a kind of incipient compulsive ritual. And similar symptoms seem to occur in animals. Obsessions and compulsions may be related to behavior patterns like courtship dances. Some researchers have compared OCD to a disorder called canine acral lick, in which dogs compulsively lick away the fur and skin on their legs; it's treated with the same drugs used for OCD.

Endophenotypes

Many scientists now think that the current classification of psychiatric disorders, mostly by their obvious, visible symptoms, is inadequate for the purpose of identifying causes and developing treatments. Most human psychiatric symptoms cannot be studied in animals. Even the distinctions among psychiatric disorders are unclear. Symptoms overlap, and most patients have more than one disorder. Critics of the present system think OCD is a good example of this difficulty, because of its range and variety of symptoms and its links to both anxiety disorders and other disorders in the OCD spectrum.

With the help of brain imaging and genetic technology, scientists may eventually identify endophenotypes — genetically based biological traits or markers that are common in the families of people with a psychiatric disorder and may be related to the overt symptoms (phenotype) of more than one disorder. Certain processes that underlie obsessional thinking and compulsive washing, checking, or ordering might be identified even when they appear in milder forms than OCD, or in people with disorders like Tourette's syndrome, autism, and schizophrenia. One study suggests that low blood levels of serotonin and low serotonin receptor sensitivity may fit the description of an endophenotype for obsessions and compulsions.

Evolutionary theory and the study of endophenotypes suggest that different components of OCD may have different genetic roots and, some day, different treatments. This research also implies that OCD differs from everyday ruminations and rituals only in degree — more intense, persistent, and time-consuming consequences of some of the biological processes that underlie all thoughts that won't go away and things that must be done over and over.

Last updated:	September 05, 2008