Katharine Wyatt

Katharine Wyatt, M.D., Ph.D., is a character on Grey's Anatomy. She is an attending psychiatrist who has been a therapist for many doctors at Seattle Grace Mercy West Hospital, including Meredith Grey, Erica Hahn, and Owen Hunt.

Abilities
Medicine: As an M.D., it can be assumed that Dr. Wyatt is at least proficient in the field of medicine and more than competent in the specialty of psychiatry, since that is the branch of medicine she practices.

Psychiatry/Psychology (possibly): Dr. Wyatt has also achieved a Ph.D., presumably in the field of psychology or something closely related to her occupation as a psychiatrist. This would mean that she has mastered the field and is considered an expert in whatever field she achieved her Ph.D. in.