About Lowell Comprehensive Treatment Center in Lowell, MA Lowell Comprehensive Treatment Center (CTC) is an outpatient methadone clinic located in Lowell, Massachusetts, that provides medication-assisted treatment (MAT) to adults age 18 and older of all genders. Our multidisciplinary team of doctors, nurses, and counselors provides treatment for people who are struggling with addictions to heroin, prescription painkillers, and other opioids. Many methadone clinics have discovered through years of research that MAT can improve a patient’s recovery outcome and reduce their likelihood of experiencing relapse.