In this chapter:
(1) "Chemical dependency" means the abuse of, a psychological or physical dependence on, or an addiction to alcohol or a controlled substance.
(2) "Chemical dependency treatment center" means a facility that provides a program for the treatment of chemical dependency under a written treatment plan approved and monitored by a physician and that is:
(A) affiliated with a hospital under a contractual agreement with an established system for patient referral;
(B) accredited as a chemical dependency treatment center by the Joint Commission on Accreditation of Healthcare Organizations;
(C) licensed as a chemical dependency treatment program by the Texas Commission on Alcohol and Drug Abuse; or
(D) licensed, certified, or approved as a chemical dependency treatment program or center by another state agency.
(3) "Controlled substance" means an abusable volatile chemical, as defined by Section 485.001, Health and Safety Code, or a substance designated as a controlled substance under Chapter 481, Health and Safety Code.