Mother and daughter, Karen and Bridget, are seen here during the early stages of now-15-year-old Bridget's therapy. Bridget believes her mother is contaminated and fears that her mother will somehow contaminate her, too. ABC News was granted rare access to witness Bridget's treatment, a method called Exposure and Response Prevention Therapy.
Watch "Primetime: Family Secrets" TONIGHT at 10 p.m. ET.
(ABC News )