California Code, Penal Code - PEN § 2672

(a) For purposes of this article, “informed consent” means that a person must knowingly and intelligently, without duress or coercion, and clearly and explicitly manifest his consent to the proposed organic therapy to the attending physician.

(b) A person confined shall not be deemed incapable of informed consent solely by virtue of being diagnosed with a mental health disorder.

(c) A person confined shall be deemed incapable of informed consent if the person cannot understand, or knowingly and intelligently act upon, the information specified in Section 2673.

(d) A person confined shall be deemed incapable of informed consent if, for any reason, he or she cannot manifest his or her consent to the attending physician.