Obsessions are intrusive, irrational thoughts -- unwanted ideas or impulses that repeatedly well up in a person's mind. Again and again, the person experiences disturbing thoughts, such as "My hands must be contaminated; I must wash them"; "I may have left the gas stove on"; "I am going to injure my child." On one level, the sufferer knows these obsessive thoughts are irrational. But on another level, he or she fears these thoughts might be true. Trying to avoid such thoughts creates great anxiety.

Compulsions are repetitive rituals such as handwashing, counting, checking, hoarding, or arranging. An individual repeats these actions, perhaps feeling momentary relief, but without feeling satisfaction or a sense of completion. People with OCD feel they must perform these compulsive rituals or something bad will happen.

Most people at one time or another experience obsessive thoughts or compulsive behaviors. Obsessive-compulsive disorder occurs when an individual experiences obsessions and compulsions for more than an hour each day, in a way that interferes with his or her life.
OCD is often described as "a disease of doubt." Sufferers experience "pathological doubt" because they are unable to distinguish between what is possible, what is probable, and what is unlikely to happen.

People from all walks of life can get OCD. It strikes people of all social and ethnic groups and both males and females. Symptoms typically begin during childhood, the teenage years or young adulthood.

A large body of scientific evidence suggests that OCD results from a chemical imbalance in the brain. For years, mental health professionals incorrectly assumed OCD resulted from bad parenting or personality defects. This theory has been disproven over the last 20 years. OCD symptoms are not relieved by psychoanalysis or other forms of "talk therapy," but there is evidence that behavior therapy can be effective, alone or in combination with medication. People with OCD can often say "why" they have obsessive thoughts or why they behave compulsively. But the thoughts and the behavior continue.

People whose brains are injured sometimes develop OCD, which suggests it is a physical condition. If a placebo is given to people who are depressed or who experience panic attacks, 40 percent will say they feel better. If a placebo is given to people who experience obsessive-compulsive disorder, only about two percent say they feel better. This also suggests a physical condition.

Clinical researchers have implicated certain brain regions in OCD. They have discovered a strong link between OCD and a brain chemical called serotonin. Serotonin is a neurotransmitter that helps nerve cells communicate.

Scientists have also observed that people with OCD have increased metabolism in the basal ganglia and the frontal lobes of the brain. This, scientists believe, causes repetitive movements, rigid thinking, and lack of spontaneity. Successful treatment with medication or behavior therapy produces a decrease in the over activity of this brain circuitry. People with OCD often have high levels of the hormone vasopressin.

People with OCD generally attempt to hide their problem rather than seek help. Often they are remarkably successful in concealing their obsessive-compulsive symptoms from friends and co-workers. An unfortunate consequence of this secrecy is that people with OCD generally do not receive professional help until years after the onset of their disease. By that time, the obsessive-compulsive rituals may be deeply ingrained and very difficult to change.

OCD will not go away by itself, so it is important to seek treatment. Although symptoms may become less severe from time to time, OCD is a chronic disease. Fortunately, effective treatments are available that make life with OCD much easier to manage.

OCD usually starts at an early age, often before adolescence. It may be mistaken at first for autism, pervasive developmental disorder, or Tourette's syndrome, a disorder that may include obsessive doubting and compulsive touching as symptoms.

Like depression, OCD tends to worsen as the person grows older, if left untreated. Scientists hope, however, that when the OCD is treated while the person is still young, the symptoms will not get worse with time.

Heredity appears to be a strong factor in OCD. If you have OCD, there's a 25-percent chance that one of your immediate family members will have it. It definitely seems to run in families.
OCD can be effectively treated with medication and behavior therapy. Both affect brain chemistry, which in turn affects behavior. Medication can regulate serotonin, reducing obsessive thoughts and compulsive behaviors.