§ 137.009.Conflicting or Contrary Provisions

A priority rule and an evidentiary rule, and both give the declaration unusual weight.

Mental health treatment instructions in a declaration supersede any contrary or conflicting instructions given by a medical power of attorney under the Health and Safety Code or by a guardian appointed after the execution of the declaration.

The declaration wins against both, and the reason is who is speaking. A declaration is the principal’s own voice, recorded while competent; an agent or guardian is another person deciding on their behalf.

Note the timing qualifier on guardians: the declaration supersedes a guardian appointed after the execution of it. A guardian already in place when the declaration was made is not addressed by this sentence.

The rule is confined to mental health treatment instructions. A medical power of attorney continues to govern everything else, so the two documents operate side by side rather than one displacing the other.

Subsection (b) is the more consequential provision. Those instructions shall be conclusive evidence of a declarant’s preference in a medication hearing under the Health and Safety Code.

"Conclusive evidence" ends one question and not another. What the person preferred is settled by the document and cannot be contradicted by testimony about what they would have wanted.

What the hearing still decides is whether to order the medication anyway. The preference is conclusively established; the outcome is not.

Read with the override section, the two fit together. That section allows treatment contrary to a declaration where a medication hearing authorizes it, and this ensures the hearing begins with the principal’s own preference beyond dispute.