About 7 million Americans are significantly affected by obsessive-compulsive disorder, according to Dr. Jonathan Grayson, author of Freedom from Obsessive-Compulsive Disorder. Dr. Oz talks with Dr. Grayson about the characteristics associated with OCD and the best treatment options available.

Dr. Grayson says that for every obsessive behavior, there is some consequence the patient fears—anything from fear of germs to fear of death. People with OCD try to avoid the things they fear or, if they're unavoidable, use rituals to deal with them.

OCD is both a learned and biological disorder, Dr. Grayson says. "There is a part of our brain that responds to uncertainty with discomfort, so that makes sense evolutionarily. There's a part of our brain that responds with satisfaction when we complete things; we wouldn't do all of the things that we do if we didn't get something from it," he says. "When someone has OCD, the threshold is less, so it takes less uncertainty for them to feel more anxious."

Dr. Grayson offers exposure and response prevention therapy for his OCD patients, which he considers to be the best practice for this condition. Exposure and response prevention is a two-step process—first helping people understand why they want the treatment and what the goal of treatment is (to help them live in a risky world), and then having the patients give up all their rituals. For example, if someone's rituals include lots of washing, Dr. Grayson says he'd probably put a stop to all hand-washing.

If you notice somebody exhibiting OCD behaviors, you're just seeing the surface, Dr. Grayson says. "You are seeing the part that they felt they couldn't control. In their minds, they are always multitasking; they're constantly in mental agony. Whatever you see, no matter how awful it looks, it's still 10 times worse in their head."