Section 12E. A minor twelve years of age or older who is found to be drug dependent by two or more physicians may give his consent to the furnishing of hospital and medical care related to the diagnosis or treatment of such drug dependency. Such consent shall not be subject to disaffirmance because of minority. The consent of the parent or legal guardian of such minor shall not be necessary to authorize hospital and medical care related to such drug dependency and, notwithstanding any provision of section fifty-four of chapter one hundred and twenty-three to the contrary, such parent or legal guardian shall not be liable for the payment of any care rendered pursuant to this section. Records shall be kept of such care. The provisions of this section shall not apply to methadone maintenance therapy.