We granted the application for discretionary appeal in this divorce case to determine the scope of the privilege that protects communications between a psychiatrist and patient. We hold the psychiatrist-patient privilege extends to a person authorized to practice medicine who devotes a substantial portion of his or her time in the diagnosis or treatment of a mental or emotional condition, including alcohol or drug addiction.
James Wiles sought the psychiatric records of a patient of his wife Mary Wiles, a licensed medical doctor with a specialty in internal medicine. He contends that the records are relevant to the issues of custody and visitation because the couple’s three children have *595seen the patient frequently.1 Dr. Wiles and her patient opposed production of the records based on the psychiatrist-patient privilege. The trial court denied Mr. Wiles’ motion to compel and granted Dr. Wiles’ motion to quash the subpoena, holding that a medical doctor who is treating patients for psychiatric problems may claim the psychiatrist-patient privilege. The judge certified the order for immediate review. We affirm.
1. The Georgia Civil Practice Act provides for the discovery of “any matter, not privileged, which is relevant to the subject matter involved in the pending action.” Although there is no privilege for general physician-patient communications in Georgia, two statutes extend a privilege against disclosure to the confidential communications between a psychiatrist or licensed psychologist and patient. See OCGA §§ 24-9-21 (5); 43-39-16; Nat. Stop Smoking Clinic-Atlanta v. Dean, 190 Ga. App. 289 (378 SE2d 901) (1989).2
OCGA § 24-9-21 (5) provides for the exclusion of the communications between a psychiatrist and patient on grounds of public policy.3 The purpose of the privilege is to encourage the patient to talk freely without fear of disclosure and embarrassment, thus enabling the psychiatrist to render effective treatment of the patient’s emotional or mental disorders. 1 C. McCormick, McCormick on Evidence, § 98 at 369-370 (J. Strong 4th ed. 1992). The privilege may be asserted only on behalf of the patient’s interest. Wills v. Wills, 215 Ga. *596556 (111 SE2d 355) (1959). It does not apply to communications between a court-appointed psychiatrist and defendant during mental examinations in preparation for a criminal trial because the requisite professional relationship does not exist. Massey v. State, 226 Ga. 703, 704 (177 SE2d 79) (1970), cert. denied, 401 U. S. 964 (1971). A patient who is a party may waive the privilege by calling the psychiatrist as a witness to testify about the party’s mental condition. Fields v. State, 221 Ga. 307, 308-309 (144 SE2d 339) (1965).
2. The Georgia Code does not define “psychiatrist” or the practice of psychiatry. The state licenses physicians to “practice medicine” through the Composite State Board of Medical Examiners. OCGA § 43-34-20. To obtain a license, a person must graduate from a medical or osteopathic college, provide evidence of good moral character, complete a board-approved internship or residency training, and pass a board examination. OCGA § 43-34-27 (Supp. 1993). Doctors of medicine licensed to practice in the state obtain a medical specialty, such as psychiatry, based on their internship and residency. See generally Rules of Composite St. Bd. of Med. Examiners, ch. 360-2, Ga. Comp. Rules & Regs. (1993) (specifying requirements for medical licenses).
The case law is inconsistent concerning whether the practice of psychiatry is limited to medical doctors with a specialty in psychiatry. In considering whether the psychiatrist-patient privilege extended to a family practitioner consulted by a man accused of rape, the Court of Appeals stated that it did not pertain to “a physician in any specialty other than psychiatry.” Barnes v. State, 171 Ga. App. 478, 482 (320 SE2d 597) (1984). On the other hand, this court has allowed medical doctors who are not psychiatrists to testify as expert witnesses on the sanity, mental development, and mental capacity of persons.
In our opinion whether an examining physician is or is not a psychiatrist is a matter which may affect the extent of his expertise in evaluating mental condition [s], and therefore may affect the weight of any opinion or evaluation,. . . but it does not affect admissibility.
Petty v. Folsom, 229 Ga. 477, 481 (192 SE2d 246) (1972). Similarly, the Court of Appeals ruled that the statutory requirement of a psychiatric evaluation was satisfied by a county medical examiner “qualified to give such an opinion who may not be a board-certified psychiatrist.” Henderson v. State, 157 Ga. App. 621, 623 (278 SE2d 164) (1981).
No other state with a psychiatrist-patient privilege has limited the term “psychiatrist” to medical doctors specially trained to practice psychiatry, as the dissent proposes and the Court of Appeals held *597in Barnes. See 8 J. Wigmore, Wigmore on Evidence, § 2380, n. 5 (J. McNaughton rev. ed. 1961) (Supp. 1994). The problem with this definition is that it places inordinate emphasis on the training of medical doctors while ignoring their time spent in practice. States generally have defined a psychiatrist as a licensed medical doctor who spends a substantial portion of time practicing psychiatry or who is engaged in the diagnosis or treatment of a mental or emotional condition.4
In construing the psychiatrist-patient privilege, this court must give a reasonable interpretation to the statutory language to carry out the legislative intent. Mayor &c. of Hapeville v. Anderson, 246 Ga. 786 (272 SE2d 713) (1980). Communications between the psychiatrist and patient are protected because “most psychiatric analysis and treatment must come from the mind of the patient.” Gilmore v. State, 175 Ga. App. 376, 378 (333 SE2d 210) (1985). As one treatise explains:
“Among physicians, the psychiatrist has a special need to maintain confidentiality. His capacity to help his patients is completely dependent upon their willingness and ability to talk freely. This makes it difficult if not impossible for him to function without being able to assure his patients of confidentiality and, indeed, privileged communication .... A threat to secrecy blocks successful treatment.”
1 McCormick on Evidence at 370 (quoting four sources).
Consistent with this purpose, we interpret “psychiatrist” in OCGA § 24-9-21 to mean “a person licensed to practice medicine, or reasonably believed by the patient so to be, who devotes a substantial portion of his or her time engaged in the diagnosis and treatment of a mental or emotional condition, including alcohol or drug addiction.” This definition protects the communications of the patient who seeks treatment for mental disorders from a medical doctor with the expec*598tation that the communications will be confidential. It acknowledges the absence of a general physician-patient privilege in this state by restricting the privilege to medical doctors who spend a significant amount of time diagnosing and treating mental illness. It is consistent with the cases in this court that have allowed medical doctors to testify as experts about mental conditions, such as the sanity of criminal defendants. Finally, the definition is fair in protecting people who need psychiatric treatment but live in an area of the state not served by a physician who has completed post-graduate training in psychiatry.
It is not necessary at this time to delineate what constitutes a substantial portion of a doctor’s time. Like all discovery matters, this determination is a matter within the discretion of the trial court. The trial court in this case found that Dr. Wiles is the doctor to whom the Union County Mental Health Department refers patients for psychiatric treatment. Dr. Wiles testified that she treats one-third of her patients for mental problems, considers counseling as part of her medical practice, and has treated the patient involved in this case for a mental condition for two years. Unlike the family practitioner in Barnes who was consulted for a referral to a psychiatrist, Dr. Wiles is a licensed medical doctor who spends a substantial portion of her time treating mental and emotional conditions. Therefore, the trial court did not abuse its discretion in determining that Dr. Wiles’ patient is entitled to the benefit of the psychiatrist-patient privilege. We affirm the order of the trial court.
Judgment affirmed.
All the Justices concur, except Hunt, C. J., Carley and Thompson, JJ., who dissent.We do not address the relevancy of the psychiatric records of a person who is not a party to a divorce action since the issue was not raised on appeal.
One authority describes the general physician-patient privilege as the “most common source of protection against the disclosure of psychotherapist-patient communications, in the absence of an express psychotherapist-patient statutory privilege.” Annotation, “Privilege, In Judicial or Quasi-Judicial Proceedings, Arising From Relationship Between Psychiatrist or Psychologist and Patient,” 44 ALR3d 24, 40-42 (1972). According to another treatise, thirty-six states have a general physician-patient privilege and nine states have a psychotherapist-patient privilege. See J. Wigmore, Wigmore on Evidence, § 2380, n. 5 (McNaughton rev. ed. 1961) (Supp. 1994); see also 2 S. Stone & R. Taylor, Testimonial Privileges, §§ 7.01, n. 3 & 7.03, n. 17 (2d ed. 1993) (concluding forty-one states have some form of the physician-patient privilege and the remaining' nine states, except West Virginia, protect persons engaged in “psychotherapy”). Georgia, Alabama, Connecticut, Maryland, and Tennessee have a psychiatrist-patient privilege; Florida and Kentucky have incorporated their psychiatrist-patient privilege into a psychotherapist-patient privilege. See infra note 4; Ky. R. Evid. 507.
The statute providing for the psychiatrist-patient privilege states:
24-9-21. Confidentiality of certain communications.
There are certain admissions and communications excluded on grounds of public policy. Among these are:
(1) Communications between husband and wife;
(2) Communications between attorney and client;
(3) Communications among grand jurors;
(4) Secrets of state; and
(5) Communications between psychiatrist and patient.
Code section 43-39-16 places the confidential communications between a licensed psychologist and client on the same basis as the attorney-client relationship.
Compare Conn. Gen. Stat. § 52-146d (1993) (defining “psychiatrist” as “a person licensed to practice medicine who devotes a substantial portion of his time to the practice of psychiatry, or a person reasonably believed by the patient to be so qualified”) and Md. Cts. & Jud. Proc. Code Ann. § 9-1-9 (1989) (same) with Fla. Stat. Ann. § 90.503 & law revision council note (West 1979) (placing psychiatrist-patient privilege and psychologist-patient privilege under a psychotherapist-patient privilege and defining “psychotherapist” to include “[a] person authorized to practice medicine in any state or nation, or reasonably believed by the patient so to be, who is engaged in the diagnosis or treatment of a mental or emotional condition, including alcoholism or other drug addiction”); see also Ala. Code § 34-26-2 (1991) (extending privilege to relations between “licensed psychiatrists” and “clients”); Tenn. Code Ann. § 24-1-207 (Supp. 1994) (protecting communications between a patient and “a licensed physician when practicing as a psychiatrist in the course of and in connection with a therapeutic counseling relationship”); Agnor’s Georgia Evidence, § 6-4 at 107 (L. Rumsey 3d ed. 1992) (describing a “psychiatrist” as “a licensed physician engaged in treating a patient for a mental condition”).