After commitment of any child to the Department, if the Department finds, as a result of psychiatric examinations and case study, that such child has mental illness or a developmental disability, it shall be the duty of the Department to obtain treatment for the child’s mental condition. If the Department determines that transfer to a state hospital, training center, or other appropriate treatment facility is required to further diagnose or treat the child’s mental condition, the proceedings shall be in accordance with the provisions of § 37.2-806 or §§ 16.1-341 through 16.1-345, except that provisions requiring consent of the child’s parent or guardian for treatment shall not apply in such cases. No child transferred to a state hospital pursuant to this section or the provisions of Title 37.2 shall, however, be held or cared for in any maximum security unit where adults determined to be criminally insane reside and such child shall be kept separate and apart from such adults.