Tennessee Code Title 4. State Government § 4-3-1603

(a) The department of mental health and substance abuse services has jurisdiction and control over the mental health facilities of the state, regardless of the names by which the facilities are known.

(b) The department, through its appropriate officials, has the duty and power to provide the best possible care for persons with mental illness or serious emotional disturbance in the state by improving existing facilities, by developing future facilities and programs, and by adopting a preventive program for mental illness and serious emotional disturbance, all as provided in applicable provisions of title 33.

(c) The department of mental health and substance abuse services shall administer title 33, chapter 2, part 4.