Obsessions and compulsions can turn up in families previously untouched by mental illness, but are more likely to cluster in families with histories of OCD or its frequent companion, depression.
Until recently, OCD, which affects about 2 percent of the population, was considered among the most treatment-resistant tments and new therapeutic techniques pioneered in Europe.
Although it affects men and women in equal numbers, children with OCD are twice as apt to be boys.
Throughout history, OCD sufferers from Samuel Johnson to Howard Hughes have been slaves to the intrusive, irrational thoughts known as obsessions, and the senseless, repetitive rituals, or compulsions, that accompany them.
Among the most compelling arguments is the connection between OCD and Tourette's Syndrome, a disease marked by involuntary tics, multiple motor movements and the uncontrollable blurting of sounds, phrases and in some cases, obscenities.