We are just beginning to know how OCD works in the brain, and it will probably take decades before we really have a clear idea. That said, this is one of the most hotly contested questions in psychology and psychiatry today.
Two camps of scientists are currently researching how OCD actually works in the brain. Researchers who focus on medicine and brain imaging (PET scans, magnetic imaging, etc.) are attempting to find exactly how brain structures “talk” using neurotransmitters (chemical messengers) to discover what the communication differences are between the brains of people who do and do not have OCD. It is their hope that by discovering what areas of the brain are active and what chemicals are being released when someone is experiencing an obsession or compulsion, they will be able to develop medical procedures or medications that will combat OCD.
The other camp of research is interested in developing talk and behavioral therapies for OCD. Their basic focus is on how a thought becomes an obsession and why people develop the compulsions that they perform in response to the obsession. Because it will probably take a long time for the first camp to develop the technologies that may be required for specific medications or surgeries, this second group is interested in developing therapies that can be implemented in the near future; therapies based on the types of thoughts that individuals with OCD have and the behaviors they perform.
The goal of both camps is to develop the best forms of treatment, and it is hoped that someday a combination of medical and behavioral therapies will be designed to best treat OCD.