while there is no known specific cause for obsessive compulsive disorder (ocd) family history and chemical imbalances in the brain are thought to contribute to the development of the illness. generally while people who have relatives with ocd are at a higher risk of developing the disorder most people with the illness have no such family history. a specific chromosome/gene variation has been found to possibly double the likelihood of a person developing ocd. it is thought that an imbalance of the chemical serotonin in the brain may also contribute to the development of ocd. some life stressors like being the victim of sexual abuse as a child can increase the chance of developing ocd as an adult.
what causes ocd?