The Commission for Mental Health, Developmental Disabilities, and Substance Abuse Services shall have a chairman and a vice-chairman. The chairman shall be designated by the Governor from among the members and shall serve as chairman at his pleasure. The vice-chairman shall be elected by and from the members of the Commission and shall serve for a term of two years or until the expiration of his regularly appointed term. (1973, c. 476, s. 131; 1977, c. 679, s. 3; 1981, c. 51, s. 1; 1989, c. 625, s. 23.)