mississippi psychiatric assnDistrict Branch 23 of the American Psychiatric Association, the Mississippi Psychiatric Association was chartered in the State of Mississippi in 1967. MPA is a membership organization of psychiatric physicians, who diagnose and treat brain disorders and substance use disorders throughout the state. MPA strives to continuously improve the ability of our members to provide quality, evidence-based and collaborative psychiatric services to persons with mental health needs and their families. The Association advocates for the welfare of all those with mental illness while fostering the medically-based principles of psychiatry.