Outpatient Addictions Service

The Outpatient Addictions Service (OAS) helps patients 18 and older. Our staff includes psychiatrists, psychiatric nurse practitioner and licensed clinical social workers. We are experienced in both Addictions and Dual Diagnosis Treatment.

Please note: Due to a high demand for our services, CHA is prioritizing appointments for patients who are either enrolled in Primary Care at CHA or are residents of our service area (Cambridge, Chelsea, Everett, Malden, Revere, Somerville, and Winthrop, MA). If you or your child do not meet these criteria, our staff may be able to assist you in finding a referral service.

Intake: Our "walk-in" info and intake time is Tuesday at 11:30 AM. Clients get a comprehensive intake assessment to match them to the most appropriate level of care.


Intensive Outpatient Program (IOP)

  • Monday, Wednesday, and Friday: 9 a.m. - 12 noon. Typically a 4 week program.

Outpatient Groups

  • Offered at various times in day and evening.Most groups require a pre-screening appointment with the clinician running the group.
  • Typically upon completion of IOP program, or for individuals who have had prior treatment in the past.  Most groups require 30 days of sobriety, and include: Relapse Prevention, Clean Living, Opiate Recovery, Men's Recovery, and Dual Recovery.
  • Groups are also offered for clients in the early stages of thinking about their addiction with no sobriety commitment.
  • Specialty groups include: DBT for substance abusers, Yoga/Stress Reduction, and a Parenting group.

Individual Treatment

  • The Outpatient Addictions Service (OAS) has limited capacity to provide individual psychotherapy. The "treatment of choice" is generally group psychotherapy.
  • Case Management
  • Help finding community services and support.


  • Focuses on treating those individuals with both psychiatric and addiction disorders. To be eligible for ongoing medication management, people must be engaged in outpatient treatment through the Outpatient Addiction Service - either individual or group.

    Contact Us

  • Outpatient Addictions

    26 Central Street Somerville, MA 02143
    P: (617) 591-6051 F: (617) 591-6054

    Admin Hours
    M - F: 9 am - 5 pm