Section 135B. Except as hereinafter provided, in any court proceeding and in any proceeding preliminary thereto and in legislative and administrative proceedings, a client shall have the privilege of refusing to disclose and of preventing a witness from disclosing, any communication, wherever made, between said client and a social worker licensed pursuant to the provisions of section one hundred and thirty-two of chapter one hundred and twelve, or a social worker employed in a state, county or municipal governmental agency, relative to the diagnosis or treatment of the client's mental or emotional condition.

If a client is incompetent to exercise or waive such privilege, a guardian shall be appointed to act in the client's behalf under this section. A previously appointed guardian shall be authorized to so act.

Upon the exercise of the privilege granted by this section, the judge or presiding officer shall instruct the jury that no adverse inference may be drawn therefrom.

The privilege granted hereunder shall not apply to any of the following communications:

(a) If a social worker, in the course of making a diagnosis or treating the client, determines that the client is in need of treatment in a hospital for mental or emotional illness or that there is a threat of imminently dangerous activity by the client against himself or another person, and on the basis of such determination discloses such communication either for the purpose of placing or retaining the client in such hospital; provided, however, that the provisions of this section shall continue in effect after the client is in said hospital, or placing the client under arrest or under the supervision of law enforcement authorities;

(b) If a judge finds that the client, after having been informed that the communications would not be privileged, has made communications to a social worker in the course of a psychiatric examination ordered by the court; provided, however, that such communications shall be admissible only on issues involving the client's mental or emotional condition but not as a confession or admission of guilt;

(c) In any proceeding, except one involving child custody, adoption or adoption consent, in which the client introduces his mental or emotional condition as an element of his claim or defense, and the judge or presiding officer finds that it is more important to the interests of justice that the communication be disclosed than that the relationship between the client and the social worker be protected;

(d) In any proceeding after the death of a client in which his mental or emotional condition is introduced by any party claiming or defending through or as a beneficiary of the client as an element of the claim or defense, and the judge or presiding officer finds that it is more important to the interests of justice that the communication be disclosed than that the relationship between client and social worker be protected;

(e) In the initiation of proceedings under paragraph C of section twenty-three or under section twenty-four of chapter one hundred and nineteen, or section three of chapter two hundred and ten or to give testimony in connection therewith;

(f) In any proceeding whereby the social worker has acquired the information while conducting an investigation pursuant to section fifty-one B of chapter one hundred and nineteen;

(g) In any other case involving child custody, adoption or the dispensing with the need for consent to adoption in which, upon a hearing in chambers, the judge, in the exercise of his discretion, determines that the social worker has evidence bearing significantly on the client's ability to provide suitable care or custody, and that it is more important to the welfare of the child that the communication be disclosed than that the relationship between client and social worker be protected; provided, however, that in such case of adoption or the dispensing with the need for consent to adoption, a judge shall determine that the client has been informed that such communication would not be privileged; or

(h) In any proceeding brought by the client against the social worker and in any malpractice, criminal or license revocation proceeding in which disclosure is necessary or relevant to the claim or defense of the social worker.