In cases involving a person who is involuntarily admitted because of a mental illness or is judicially certified as eligible for admission to a training center for persons with intellectual disability, disposition shall be in accordance with the provisions of Chapter 8 (§ 37.2-800 et seq.) of Title 37.2. A child shall not be committed pursuant to §§ 16.1-278.2 through 16.1-278.8 or the provisions of Title 37.2 to a maximum security unit within any state hospital where adults determined to be criminally insane reside.