This article originally appeared in the January 2006 Harvard Women’s Health Watch and is provided courtesy of Harvard Health Publications.

When thoughts become obsessions

How many germs are on that doorknob? What if the house burns down? A person with obsessive-compulsive disorder thinks about these things all the time.

We all have disturbing thoughts, but most of us quickly dismiss them or keep them in perspective. We use the restaurant restroom, wash our hands, and go back to enjoy dinner. We turn off the stove or space heater before leaving the house and then focus on our driving — not on the danger of a fire at home.

For someone with obsessive-compulsive disorder (OCD), it’s not so easy. Thoughts of danger become obsessions. Recurrent ideas, images, or impulses intrude and can’t be dispelled, creating intense fear and anxiety. To relieve the distress, a person with OCD feels she must engage in repetitive behaviors or rituals, such as washing hands repeatedly, checking the stove innumerable times, or repeating a mantra.

Some common obsessions are fear of dirt or germs, fear you have harmed someone, concerns about losing control or becoming violent, intrusive sexual or aggressive thoughts, an inflated sense of responsibility, a need to tell the whole truth all the time, or a need to have things “just so.” Common compulsions include washing, cleaning, checking, hoarding, counting, arranging, touching, repeating certain actions or phrases, or constantly asking for reassurance.

Sometimes OCD has a religious focus, a preoccupation with avoiding blasphemous thoughts and doing the morally correct thing at all times. This manifestation of OCD, called scrupulosity, may result in repeated requests to be forgiven, repetition of religious rituals until they feel “just right,” or hypervigilance in carrying out religious practices. Scrupulosity is distinguished from strong religious beliefs by its rigid focus on details rather than the larger principles of faith.

When is it OCD?
No matter what the content of a person’s obsessions and compulsions, a diagnosis of OCD is considered only if these thoughts are persistent and time-consuming, make no sense, cause suffering, or interfere with the individual’s life.

“When you can’t get out the door because you have to keep rechecking the stove, or you’re counting everything backwards and forwards, or your behavior has become uncomfortable for you and the people around you, then we consider OCD. We’re talking about a different order of magnitude from someone who likes a clean house and makes a thorough shopping list before a party,” says Dr. Margaret Ross, assistant professor of psychiatry at Harvard Medical School.

In the past, severe OCD was sometimes confused with schizophrenia. But even though sufferers may fear that they’re going crazy, they generally aren’t psychotic. They know that their own brains are creating the unwanted thoughts, and they are usually aware that the rituals they perform don’t make sense.

The origins of OCD
No one knows exactly what causes OCD. It affects about 2.5% of the population, and at least 20% of sufferers have a family member who is also affected. Even when more than one family member has OCD, their obsessions and compulsions can be quite different, so it’s not as simple as a child learning fears and behaviors from a parent or sibling. There’s almost certainly a hereditary component; probably more than one gene is involved, in combination with environmental triggers.

Many experts believe that OCD is a result of abnormal brain chemistry — in particular, problems with serotonin, a neurotransmitter involved in various psychological and physical functions. According to Dr. Michael Jenike, professor of psychiatry at Harvard Medical School, certain areas of the brain become hyperactive when people who have OCD are having symptoms. Research also suggests that OCD can develop following certain kinds of infections, brain tumors, or physical trauma.

Depression and OCD often occur together, particularly in adults. Depression can worsen OCD symptoms, and the struggle to cope with untreated OCD can lead to depression. Certain other conditions may occur with OCD. Some researchers believe chronic hair pulling, skin picking, tics, and eating disorders are part of a spectrum of OCD disorders.

OCD usually begins before age 25 and often in childhood, but in about 15% of people it starts after age 35. Diagnosis may be delayed if a person keeps her suffering a secret and arranges her life to accommodate her symptoms.

Certain factors can exacerbate symptoms, such as the stress of a divorce, bereavement, or retirement. In women, OCD symptoms may emerge for the first time — or worsen — in response to hormonal shifts that occur as part of the menstrual cycle, during pregnancy, or after delivery. During perimenopause or menopause, OCD symptoms worsen in some women and subside in others.

Treatment approach
OCD is usually treated with medications and cognitive behavioral therapy (CBT). Some people do well with medication, some with CBT, but most do best with a combination of the two. Sometimes another kind of psychotherapy is added to help a patient better understand her situation and the connections between her thoughts and behaviors.

“Although CBT is the core treatment,” explains Dr. Ellen Blumenthal, a psychiatrist at Massachusetts General Hospital, “traditional therapy may provide additional support by encouraging a woman to cope with her illness and pursue treatment, deal with life stresses that can worsen symptoms of OCD, and learn to create a satisfying life and relationships incorporating OCD and its treatment.”

Both dynamic psychotherapy and cognitive behavioral therapy can also help treat the depression that often accompanies OCD.

Medications to treat OCD
Six medications have been found effective for treating OCD. Five are selective serotonin reuptake inhibitor (SSRI) antidepressants: fluoxetine (Prozac), fluvoxamine (Luvox), sertraline (Zoloft), paroxetine (Paxil), and citalopram (Celexa). The sixth, which has been used the longest, is the tricyclic antidepressant clomipramine (Anafranil). These drugs increase the amount of serotonin that’s available to receptors on nerve cells and, within a few weeks, seem to induce changes in the receptors themselves.

The antidepressants given to treat OCD generally take several weeks to work. Side effects (which may subside with time) include dry mouth, increased dreaming, a small amount of weight gain, tiredness, and lowered libido. If side effects are intolerable, your physician may lower the dose or suggest a different drug. If you don’t respond to a particular drug, your psychiatrist may switch you to a different one, add a second drug, or suggest CBT if you aren’t already receiving it.

Cognitive behavioral therapy
The basic behavioral treatment strategy is exposure and response prevention (ERP). It helps by breaking OCD’s characteristic cycle of obsessive thoughts, anxiety in response to those thoughts, and rituals performed to relieve the anxiety.

During a CBT session, the patient is exposed to the feared thought or situation but isn’t allowed to perform her usual ritual. The exposure can be real (she’s asked to touch something dirty and is prevented from washing her hands) or imaginary (she’s asked to imagine a fire that could occur if she didn’t check and recheck the stove). During an exposure, the therapist will teach you how to control your anxiety. Between sessions (which are usually once or twice a week), you’ll be given exposure homework.

ERP takes advantage of a normal cognitive process called habituation. Just as you become accustomed to traffic noise if you live in an urban area, a person with OCD can gradually learn to tolerate a feared situation or thought without becoming overly anxious. The rituals she performs to relieve her anxiety start to lose their power as she learns to master her anxiety without them.

The length of therapy depends on the severity of the OCD and the intensity of treatment and practice. Afterward, you must continue to practice and apply the skills you’ve learned, particularly at times of stress or if symptoms begin to reemerge.

Brain-imaging techniques have shown that CBT can change brain function. For example, by measuring blood flow in different parts of the brain, researchers have shown that the caudate nucleus, a region believed to be involved in intrusive thoughts, is overactive in people with OCD but calms down after successful cognitive behavioral therapy.

Limitations on treatment
CBT is less effective when a person with OCD doesn’t recognize that her obsessions and behaviors don’t make sense or won’t give up her rituals. Hoarding, which can be a symptom of OCD, is often particularly resistant to therapy. It tends to worsen with age, and hoarders may not enter treatment until a local health department becomes involved.

If a person develops OCD symptoms in response to a traumatic experience — for example, avoiding the number 55 because that was the speed limit when a car crash occurred — exposure therapy is unlikely to help unless the person’s post-traumatic stress disorder is also treated.

Although the benefits of exposure treatment are well documented, not all cognitive behavioral therapists are experienced in this approach or regularly use it.

Additional treatment approaches
Therapists may incorporate other strategies in addition to exposure and response prevention:

Cognitive restructuring. The person with OCD learns how to challenge irrational beliefs and thought patterns that cause anxiety and trigger rituals.
Meditation. Mindfulness meditation can help patients learn to remain detached as they watch typical OCD thoughts emerge and disappear, realizing that “it’s not me — it’s my OCD” and that not all such thoughts must be acted upon.
Family therapy. To reduce fear and distress, family members sometimes accommodate a person’s illness, for example, by helping with checking or washing, or by providing reassurance. These well-meaning actions only strengthen the hold of OCD. In CBT, family members learn about the disorder, explore the impact of OCD on the family, and agree on how to respond to various situations.