As used in this chapter, unless the context requires a different meaning: “Disorder” includes any physical or mental disorder or impairment, whether caused by injury, disease, genetics, or other cause. “Incapable of making an informed decision” means unable to understand the nature, extent, or probable consequences of a proposed treatment or unable to make a rational evaluation of the risks and benefits of the proposed treatment as compared with the risks and benefits of alternatives to the treatment. Persons with dysphasia or other communication disorders who are mentally competent and able to communicate shall not be considered incapable of giving informed consent. “Treatment” includes the provision, withholding, or withdrawal of a specific treatment or course of treatment upon a showing that the requirements of subsection G of § 37.2-1101 have been met.