The confidential relations and communications between any person licensed under provisions of this chapter and such licensee’s client or patient are placed on the same basis as those provided by law between attorney and client, and nothing in this chapter shall be construed to require any such privileged communications to be disclosed, unless such disclosure is required by a court order. Confidential relations and communications between a client or patient and any person working under the supervision of a person licensed under this chapter which are necessary and customary for diagnosis and treatment are privileged to the same extent as though those relations or communications were with the supervising person licensed under this chapter, unless such disclosure is required by a court order. This section shall not apply to hearings conducted pursuant to N.H. Rev. Stat. § 135-C:27 through 135-C:54 or RSA 464-A.