South Bay Mental Health Center was founded in 1986 in Brockton, Massachusetts, a city of 100,000 approximately 25 miles south of Boston. Under the leadership of Dr. Peter Scanlon, South Bay's original staff of twelve clinicians focused on delivering outpatient mental health services to children and families. South Bay's innovative, community-based approach to services helped eliminate many barriers that prevent and disrupt families from receiving treatment. This approach was immediately successful and sought after by referral agencies.
The success of clinical programs offered in the Brockton area led to requests for services from surrounding communities. In 1990, South Bay opened an outpatient clinic in Plymouth. The Plymouth site quickly grew and led to the opening of a site in Weymouth in 1991. In response to growing requests for services in new communities, South Bay opened clinics in Attleboro, Fall River, South Yarmouth, and Lowell in the early 1990's. To compliment the existing mental health services, South Bay began providing outpatient substance abuse counseling services in 1992.
In 1993, South Bay diversified its programs by expanding into Adult Day Services and Early Intervention. A day treatment program was opened to care for adults who have been hospitalized. South Bay opened its first Early Intervention program in 1993 to provide educational and developmental services for infants, toddlers and their families. Early Intervention programs in Fall River and Lowell soon followed to meet the growing demand for services. Two years later, a children's therapeutic day activity program was established to divert children from inpatient settings. In 1995, South Bay's Day Services Division was also approved to open a partial hospital program for adults.