About Yarmouth Comprehensive Treatment Center in South Yarmouth, MA Adults who live in or near South Yarmouth, Massachusetts, can receive customized outpatient treatment for opioid addiction at Yarmouth Comprehensive Treatment Center (CTC). Our South Yarmouth methadone clinic offers medication-assisted treatment (MAT), which provides patients with prescription medication and counseling to help them achieve long-term recovery from opioid addiction. MAT has been offered at methadone clinics in the United States for many decades.