As used in sections 17a-560 to 17a-575, inclusive, unless specifically provided otherwise, “hospital” means the Whiting Forensic Hospital, including the diagnostic unit established under the provisions of § 17a-562, or any other facility of the Department of Mental Health and Addiction Services which the commissioner may designate as appropriate. The words “hospital” or “diagnostic unit”, as used in sections 17a-566, 17a-567, 17a-570 and 17a-575 when applied to children or youths under the age of eighteen, mean any facility of the Department of Children and Families designated by the Commissioner of Children and Families. “Board” means the advisory and review board appointed under the provisions of § 17a-565. “Commissioner” means the Commissioner of Mental Health and Addiction Services or in the case of children, the Commissioner of Children and Families.