About MHMR of Tarrant County For over 50 years, MHMR has provided community-based services for youth and adults with intellectual and developmental disabilities (IDD), mental health conditions, and substance use disorders, as well as babies and young children with developmental delays. MHMR employees use a person-centered approach to fulfill the mission: We Change Lives! Using innovative approaches, MHMR partners with community organizations to provide services and a hopeful future.