What causes OCD?
No one has found a single, proven cause for OCD. Some research shows that it may have to do with chemicals in the brain that carry messages from one nerve cell to another. One of these chemicals, called serotonin (say "sair-a-tone-in"), helps to keep people from repeating the same behaviors over and over again. A person who has OCD may not have enough serotonin. Many people who have OCD can function better when they take medicines that increase the amount of serotonin in their brain.
Written by familydoctor.org editorial staff