Discharge of individuals admitted to and continuing to receive functional services as a result of an order of court for commitment to custody shall be effected under the following circumstances:

(1) upon attainment of age 21, provided that there has been no request for continuation of functional services;

(2) upon determination by the commissioner or his designated agent that the circumstances which resulted in the order of commitment no longer justify further care or custody and that no further functional services by the department are required; provided, however, that prior to such discharge the committing court shall be given notice 1 week prior to the proposed action; or

(3) by court order.

L.1965, c. 59, s. 78.