There are many options for providing treatment to individuals with OCD.
You can take a medical route, going to medical school to become either a physician or a psychiatrist. If you do this, you will work mainly in the area of prescribing medications for people with OCD.
You can also go to nursing school and work as a psychiatric nurse in a psychiatric hospital treating people with OCD. Some nurses get even further training as nurse practitioners and are able to prescribe medications, often under the supervision of a physician.
Or, you could go to graduate school in the areas of social work, education, counseling, or psychology. You can either get a master’s degree and start to work with patients with OCD or go on for your doctorate in any of these fields and work with OCD. After completing your doctorate, you can even do specialized training in OCD during a fellowship.
Other people that treat individuals with OCD may be members of the clergy, chiropractors, expressive therapists (music therapy, art therapy, dance/movement therapy, etc.) or surgeons. While OCD may not have been a major area of their studies, they may work in conjunction with other providers to assist individuals with OCD.
Please recognize that there is considerable cost to going to many of the different schools for careers in the areas mentioned above, although some programs offer free tuition in return for your working for the academic department.
It is best to talk to some people who are in the field about how they came to work with OCD so that you can get some different ideas about what route may be the best one for you. Good luck!