There are three main theories as to different reasons why people develop OCD but as yet there is no single known cause. The theories include genetics, physical changes in the brain and infection. It is important that causes of OCD are realized as treatment is more successful the earlier it is received. Many years ago it was believed that if a child suffered from this disorder it was due to problems either growing up or in the family, this theory has since been discredited.
OCD can run in families but it is not definite that if a parent has OCD that the child will develop it; they will however, be in a higher risk group of developing the disorder. Children with OCD that have a parent with the disorder don’t necessarily have the same rituals, for example the parent may wash their hands excessively and the child may check things. Scientists have discovered a gene that plays an important role in the onset of OCD. It is hoped by studying this gene in more detail they will be able to assess who is in at higher risk and to be able to develop better therapies for people with OCD.
There is a marked physical change in the brain of someone with OCD. Serotonin, a chemical that carries signals to different parts of the brain (neurotransmitter), levels are usually low. In these cases ssri (serotonin reuptake inhibitors) antidepressants can help as they increase the amount of serotonin the body produces, thus alleviating some of the symptoms. Scans have also shown there is a structural difference in certain parts of the brain.
OCD sometimes develops after certain types of infection, commonly streptococcal bacterial infections. Due to the nature of this infection, the body’s immune system tries to fight it and attacks some of the adjoining cells in the brain causing swelling and the onset on OCD.