OCD seems, in large part, to be a hereditary illness. However, it is not fully understood why different family members frequently have different types of OCD. It seems unfair that one family member could have organizational obsessions and another, health preoccupations, but that neither one could really understand the other. Yet that's what often happens.

On the other hand, it may be that if all family members had the same kind of OCD, no one would ever get help for it. The behavior might become “normalized” within the family — that is, it would seem perfectly natural, at least in that household, for people to stay in the bathroom for hours, say, or routinely go over homework again and again before considering turning it in.

Still, it is often useful for therapists, when attempting to arrive at a proper diagnosis, to inquire about other extended family members' “unusual behaviors.”

Can OCD Be “Helped Along?”

It does appear possible, and perhaps even probable, that certain environmental factors do (or, at least, can) contribute to the development of OCD in those who are already predisposed toward it. Some of these are abuse, problems in relationships, and constricting childhoods marked by demands for order or adherence to rules.

Some researchers also believe that a single traumatic event can set off the first major episode in a person already genetically predisposed toward OCD. However, it is no longer believed that these events and conditions alone are responsible for causing it.

An Ounce of Prevention?

Unfortunately, it is not possible, at least as of this writing, to prevent OCD from developing in a predisposed person, or to make sure that any children you have will not also have it. (In fact, this is true whether or not you, your partner, or both of you, have OCD. That said, the disorder is usually seen more often in people whose family members have it, or have had it, than in others.) There are also medical treatments that may reverse some of the damage certain strep infections can create in children.

However, although OCD is not preventable, it is quite treatable and, unlike a relatively short time ago, can now be considered manageable. And it is infinitely possible, now that so much is known about the disorder and its treatment, to prevent it from getting worse once it's recognized.