Texas Health and Safety Code - HEALTH & SAFETY § 773.093. Consent

(a) Consent for the release of confidential information must be in writing and signed by the patient, a parent or legal guardian if the patient is a minor, a legal guardian if the patient has been adjudicated incompetent to manage the patient's personal affairs, an attorney ad litem appointed for the patient, or a personal representative if the patient is deceased. The written consent must specify:

(b) The patient or other person authorized to consent may withdraw consent to the release of any information by submitting a written notice of withdrawal to the person or program to which consent was provided. Withdrawal of consent does not affect any information disclosed before the date on which written notice of the withdrawal was received.

(c) A person who receives information made confidential by this chapter may disclose the information to others only to the extent consistent with the authorized purposes for which consent to release the information was obtained.