The principal issue in this case is whether the statutory psychotherapist-patient privilege applies to communications made during drug counseling. We conclude that the privilege does not apply. For the reasons discussed below, we reverse in part and remand the case to the Court of Appeals for further proceedings.
The state initiated a petition to terminate the parental rights of mother. ORS 419.523 (1987).1 At the time of the hearing, on May 10,1989, mother was incarcerated on forgery convictions. Mother admitted that she is dependent on controlled substances, but she testified that she had not used drugs while incarcerated, that she had participated while incarcerated in what she referred to as “Christian counseling,” and that she was committed to remaining drug-free. She said that, when released, she would seek treatment from Teen Challenge, a residential drug treatment program. Mother did not deny that her drug dependency had made her unfit as a parent before her incarceration.
In response, the state argued that mother’s short-term abstinence in a highly structured prison environment did not show that she would remain drug-free after her release. The state attempted to introduce evidence about mother’s prior, unsuccessful counseling for drug dependency in 1986 and 1987. Specifically, the state sought to introduce mother’s drug counseling records and testimony of two of her former drug counselors. Mother objected, asserting that that evidence was inadmissible under OEC 504. OEC 504 reads, in part:
*172“ (2) A patient has a privilege to refuse to disclose and to prevent any other person from disclosing confidential communications made for the purposes of diagnosis or treatment of the patient’s mental or emotional condition among the patient, the patient’s psychotherapist or persons who are participating in the diagnosis or treatment under the direction of the psychotherapist, including members of the patient’s family.”
OEC 504(l)(c) defines “psychotherapist” as a person who is:
‘ ‘ (A) Licensed, registered, certified or otherwise authorized under the laws of any state to engage in the diagnosis or treatment of a mental or emotional condition; or
“(B) Reasonably believed by the patient so to be, while so engaged.”2
The trial court excluded the evidence on the basis of OEC 504. At the end of the hearing, the trial court concluded that:
“[Mother] was unfit as a parent by reason of conduct and conditions seriously detrimental to the children up until the time she entered prison in December 1988. However, this court specifically concludes that the state has failed to prove by clear and convincing evidence that such unfitness has not terminated, nor has it proved that it is improbable that the children can be integrated into the home of the parent in the foreseeable future due to conduct or conditions not likely to change.” (Emphasis in original.)
The trial court, therefore, dismissed the state’s petition to terminate mother’s parental rights.
The state appealed. It argued, inter alia, that the trial court erred, because the legislature intended to exclude drug counseling from the privilege. The Court of Appeals held that the psychotherapist-patient privilege does not encompass drug counseling. The court’s reasoning was twofold. First, OEC 504, which was based on proposed FRE 504,3 *173deleted the part of the federal version that expressly included drug counseling. Second, the Court of Appeals found this passage in the legislative commentary to OEC 504 to be persuasive:
“The Legislative Assembly intends to exclude, from the definition of ‘psychotherapist,’ a person who is specifically consulted for a problem of drug and alcohol dependency.”
State ex rel Juv. Dept. v. Ashley, 101 Or App 268, 271, 790 P2d 547 (1990).
The Court of Appeals then considered mother’s argument that, even if the privilege does not apply, exclusion of the evidence was harmless error. The court disagreed, reasoning that “the excluded evidence could contain information crucial to” determining whether mother “is capable of recovering from her dependency in the foreseeable future, which would allow the reintegration of her children into her home.” State ex rel Juv. Dept. v. Ashley, supra, 101 Or App at 272. The court reversed the judgment of the circuit court and remanded the case. Ibid.
On review, mother disputes both the Court of Appeals’ reading of OEC 504 and its disposition of the case. We will consider each of those issues in turn.
With respect to the psychotherapist-patient privilege, mother argues that the Court of Appeals misinterpreted OEC 504. She challenges in particular the court’s reliance on the legislative commentary, which, she contends, does not accurately reflect the intent of the legislature.
As a threshold matter, we observe that the Oregon Evidence Code applies generally to all actions, suits, and proceedings in circuit courts. OEC 101(2). OEC 503 and OEC 504, relating to privileges, apply at all stages of all such actions, suits, and proceedings. OEC 101(3). A proceeding to terminate parental rights, ORS 419.525, is a proceeding within the meaning of the Code. See State ex rel Juv. Dept. v. *174Martin, 271 Or 603, 605, 533 P2d 780 (1975) (psychiatrist-patient privilege, then provided by ORS 44.040(l)(d) and (2), applied in proceeding to terminate parental rights). OEC 504 applies, then, to this case.
In interpreting OEC 504, our task is to discern the intent of the legislature. ORS 174.020. We begin with the words of the statute. ORS 174.010; Whipple v. Howser, 291 Or 475, 479, 632 P2d 782 (1981).
The pertinent passages in OEC 504(l)(c) and (2) provide that the privilege applies to diagnosis or treatment of a “mental or emotional condition.” The phrase “mental or emotional condition” neither unambiguously includes nor unambiguously excludes drug dependency. “Mental or emotional condition” may mean quite different things to a psychiatrist, a psychologist, an internist, a research physician, a social worker, a patient, a member of the clergy, a legislator, and a judge.4 Cf. Mattiza v. Foster, 311 Or 1, 4, 803 P2d 723 (1991) (the term “bad faith” is not self-explanatory). The *175intent of the legislature is not clear from the terms and context of the statute. We turn, therefore, to legislative history.
The Advisory Committee on the Oregon Evidence Code (Advisory Committee) proposed a version of OEC 504 that defined “mental or emotional condition” expressly to include “drug addiction”:
“A patient has a privilege to refuse to disclose and to prevent any other person from disclosing confidential communications in a civil action, suit or proceeding, made for the purposes of diagnosis or treatment of the patient’s mental, physical or emotional condition, including drug addiction, among the patient, the patient’s psychotherapist, regular physician or surgeon or persons who are participating in the diagnosis or treatment under the direction of the psychotherapist or regular physician or surgeon.” Proposed OEC Report, Interim Committee on the Judiciary, December 1980, p 76 (“Proposed OEC Report”) (emphasis added).
The proposed definitions of psychotherapist and physician likewise expressly included certain persons diagnosing or treating “drug addiction”:
“(c) ‘Psychotherapist’ means:
“(A) A person authorized to practice medicine in any state or nation, or reasonably believed by the patients so to be, while engaged in the diagnosis or treatment of a mental or emotional condition, including drug addiction; or
“(B) A person licensed or certified as a psychologist under the laws of any state or nation, while similarly engaged.
“(d) ‘Regular physician or surgeon’ means a person authorized and licensed or certified to practice medicine in any state or nation, or reasonably believed by the patients so to be, while engaged in the diagnosis or treatment of a mental, emotional or physical condition, including drug addiction.” Id. at 76 (emphasis added).
The Advisory Committee’s commentary stated that the committee included drug addiction to encourage drug-dependent persons to seek assistance. Id. at 78. The Advisory Committee had based its version of the privilege on proposed FRE 504. Id. at 77. Proposed FRE 504 expressly included drug addiction as a mental or emotional condition:
*176‘ ‘A patient has a privilege to refuse to disclose and to prevent any other person from disclosing confidential communications, made for the purposes of diagnosis or treatment of his mental or emotional condition, including drug treatment, among himself, his psychotherapist or persons who are participating in the diagnosis or treatment under the direction of the psychotherapist, including members of the patient’s family.” Proposed FRE 504 (emphasis added).
Psychotherapist was defined as:
“[A] person authorized to practice medicine in any state or nation, or reasonably believed by the patient so to be, while engaged in the diagnosis or treatment of a mental or emotional condition, including drug addiction[.]” Proposed FRE 504(a)(2) (emphasis added).
When the Interim Joint Committee on the Judiciary (Interim Committee) designed its proposed rule, however, it deleted drug addiction from both the rule and the commentary. Proposed OEC Report, supra, at 75-76. The Interim Committee made the change in response to a concern raised by then-Circuit Court Judge Robert E. Jones. He stated that, in his experience, federally funded programs for drug addicts would not provide status reports on probationers to the courts, because of federal confidentiality rules. As a result, judges could not monitor probationers to see that they were observing the conditions of their probation. He did not want a state privilege similarly to prevent courts from obtaining valuable, and otherwise available, information about people on probation. The Interim Committee decided that it did not want to extend the psychotherapist-patient privilege to treatment for drug addiction. Representative Frohnmayer moved to omit the words “including drug addiction” from the general rule of privilege, OEC 504(2), and from the definition of psychotherapist, OEC 504(l)(c)(A). He stated that deleting the passages about drug counseling would show the intent of the Interim Committee and force the legislature to make an affirmative change if it wanted to include drug dependency under the protection of the privilege. Hearing no objection, the Chair ordered that that material be deleted. Minutes, Interim Joint Committee on the Judiciary, Subcommittee on Evidence, May 27,1980, pp 17-18.
The proposed evidence code was submitted to the 1981 Legislative Assembly as House Bill 2030. The Interim *177Committee, whose work we have described above, had been formed by the 1979 Legislative Assembly. Accordingly, its intentions cannot be imputed automatically to the 1981 Legislative Assembly. Nonetheless, in this instance, three factors make the background of OEC 504 in the Interim Committee relevant to discerning the intent of the 1981 legislature. First, the membership of the Interim Committee and the 1981 substantive committees that considered HB 2030 overlapped. The House Committee on the Judiciary and Senate Justice Committee considered the proposed psychotherapist-patient privilege during the 1981 session. Each of those committees had three members who had served on the Interim Joint Committee on the Judiciary. Second, each of the substantive committees discussed OEC 504, including the issue of drug dependency, explicitly during the 1981 session, as we will describe more fully below. Third, the materials before both substantive committees contained as exhibits the Advisory Committee’s version of OEC 504, with the references to “drug addiction,” and the Interim Committee’s version, without them. House Committee on the Judiciary, HB 2030, Exhibit W; Senate Justice Committee, HB 2030, Exhibit A. See, e.g., State v. Stockfleth, 311 Or 40, 50, 804 P2d 471 (1991) (turning to workings of interim committee for guidance on legislative intent); Charmley v. Lewis, 302 Or 324, 328-29, 729 P2d 567 (1986) (analyzing legislative intent by tracing origins of Oregon Evidence Code from advisory committee through the legislature); State v. DeMello, 300 Or 590, 597-600, 716 P2d 732 (1986) (relying on interim committee commentary and testimony by interim committee member before Senate committee in interpreting provision of Oregon Vehicle Code).
The House Committee on the Judiciary discussed OEC 504 in its work session on July 2, 1981. Staff counsel to the committee presented a memorandum from the Mental Health Division asking to include drug and alcohol dependency as mental or emotional conditions in OEC 504. Exhibit WW, HB 2030. Counsel said that, in response to the memorandum, he had written in the commentary that the Legislative Assembly intended to include chemical dependency.
Judge Jones shared the concern that he had previously expressed to the Interim Committee. After his *178testimony, the Chair of the House Committee on the Judiciary stated that he would oppose the inclusion of drug and alcohol dependency in OEC 504. Staff counsel was instructed to rewrite the commentary to state that the legislature intended to exclude from the definition of “psychotherapist” a person who is consulted specifically for drug or alcohol dependency. Minutes, House Committee on the Judiciary, Subcommittee 1, July 2, 1981, p 7. The commentary was so written.
On July 29, 1981, the Senate Justice Committee discussed the same issue. A representative of the Metropolitan Public Defender’s office (MPD) testified in favor of amending OEC 504 or the commentary to include drug and alcohol counseling. A member of the committee moved to include them. Another member said that he would not support their inclusion. He reasoned:
“We are very, very concerned that in fact with drugs and alcohol related problems, in which I understand the vast bulk of crimes are committed, * * * the person is either under the influence of drugs or alcohol. * * * I would be very concerned that we would be undermining the ability of the police authority to get into those issues * * * I have real reservations about doing anything at this particular time that hindérs the police.”
Another member agreed and summarized Judge Jones’ testimony to the Interim Committee. According to this committee member, Judge Jones had warned that judges would not be willing to put people with chemical dependency on probation if the judges could not monitor compliance with conditions of probation through drug counseling status reports.
Staff counsel to the Senate Justice Committee asked how one could, as a practical matter, separate drug problems from mental or emotional problems. The Chair of the Senate Justice Committee agreed that it could be difficult. Some members of the committee were unsure whether a patient’s communications about drug use, made during treatment for other mental or emotional problems, would be privileged. Some expressed concern that a distinction between programs denominated drug treatment and other kinds of therapy would be unworkable. The MPD representative stated that the committee’s greatest concern — that the inclusion of drug *179counseling in the privilege would undermine law enforcement — was unfounded. In his experience with criminal trials, he said, the state did not call drug counselors as witnesses to discuss the defendants’ communications. A committee member observed that, if that were true, then MPD was arguing “a non-issue.” The MPD representative agreed with him and also noted that, in therapy, drug problems would be difficult to separate from emotional or mental problems. The MPD representative withdrew his proposed amendment. Tape Recording, Senate Justice Committee, July 29,1981, Tape 325, Side A. The commentary remained the same thereafter.
Ordinarily, a committee’s inaction or failure to adopt a proposed amendment, as distinct from its affirmative act, is insufficient to permit an inference about its intent. Three things are important here, however. First, the version of OEC 504 contained in HB 2030, which became law, differs in a material way from proposed FRE 504, on which it was modeled. We generally give meaning to the difference between an Oregon statute and the statute or model code from which it was borrowed. See State v. Dyson, 292 Or 26, 32-34, 636 P2d 961 (1981) (giving effect to difference between wording of model code and wording of statute); cf. Fifth Ave. Corp. v. Washington Co., 282 Or 591, 597-98, 581 P2d 50 (1978) (in amending statute, material change in wording is presumed to intend change in meaning). The history that we have recounted demonstrates that the legislative committees were conscious of that difference. Accordingly, it is particularly appropriate that we give effect to the deletion of references to “drug addiction.” Second, the commentary to OEC 504 was prepared at the time of the hearings on HB 2030. The history that we have described illuminates the circumstances of its preparation and shows that the substantive committees were aware of the proposed commentary. Third, the substantive committees were made aware of the policy choice that the Interim Committee had made, which differed from the recommendation of the Advisory Committee.
To summarize, although we are not bound by the commentary, State v. McClure, 298 Or 336, 344, 692 P2d 579 (1984), in this instance, it accurately reflects the intent of the *180legislative committees to exclude from the definition of psychotherapist a person consulted specifically for drug dependency, OEC 504(l)(c), notwithstanding the person’s credentials. Because of the context of the section’s history, we conclude that the legislative committees intended to exclude drug dependency from “mental or emotional condition[s]” under both OEC 504(2) and OEC 504(l)(c).5 Logic dictates the same result as legislative history. OEC 504 defines both privileged “communications” and “psychotherapists” by reference to the purpose of the consultation — the “diagnosis or treatment” of a “mental or emotional condition.” OEC 504(l)(c) and (2). It would make no sense to exclude drug dependency from the scope of “mental or emotional condition [s]” in one subsection but not the other. We hold that the psychotherapist-patient privilege does not apply to communications made during the diagnosis or treatment of drug dependency when that is the specific purpose of the diagnosis or treatment.6
Mother points out the policy considerations that, in her view, justify an opposite conclusion. Whatever may be the merit of her position, we are not free to disregard the rule as we believe it was intended to be read.
In this case, mother consulted the two therapists specifically for treatment of her drug dependency. Accordingly, their testimony and the drug treatment records are not privileged under OEC 504, and it was error to exclude that evidence. We next must decide what disposition is appropriate in the light of that error.
Mother argues that, even if the privilege does not apply, excluding the evidence was harmless error. She cites OEC 103(1), which provides:
*181“Evidential error is not presumed to be prejudicial. Error may not be predicated upon a ruling which admits or excludes evidence unless a substantial right of the party is affected.”
She argues that, to warrant reversal, there must be a substantial likelihood that the error affected the outcome of the proceeding in the trial court and that the disputed evidence would not have had that effect.
Mother’s reliance on a harmless error analysis under OEC 103(1) is misplaced, and the Court of Appeals erred in deciding the case on that basis. In a proceeding to terminate parental rights, the Court of Appeals is required to review the record de novo.7 ORS 19.125(3). That is, it must make its own decision about the facts,8 not simply analyze the trial court’s findings to determine whether improperly excluded evidence would have influenced the trial court. In making its decision, the Court of Appeals must consider the excluded evidence that should have been admitted. Remand to the trial court is not an appropriate disposition, unless the proponent of the excluded evidence was precluded from making a complete offer of proof. Cf. State v. Olmstead, 310 Or 455, 461, 800 P2d 277 (1990) (offer of proof was not required where it would have been futile). That is not the situation here.
The state’s offer of proof covered three files concerning mother’s drug counseling, but only very limited testimony. With respect to one of mother’s drug counselors, the state established his credentials, identified and offered his file, and said:
“I don’t plan on making an offer of proof with testimony from [the drug counselor,] since his file has been offered. And, if on review, someone disagrees with the trial court, they can get, I think, any evidence from that file.”
The offer of proof concerning the other drug counselor consisted only of asking him where he worked, what his job was, and *182whether he had a waiver from mother to discuss her treatment. The state also offered two additional drug treatment files, which the trial court sealed. Nothing in the record suggests that the proponent considered the offer of proof to be incomplete.
On this record, there is, therefore, no proper basis for the Court of Appeals’ disposition of the case. We remand the case to the Court of Appeals for de novo review of the record and for a decision affirming or reversing the judgment of the circuit court.
The decision of the Court of Appeals is affirmed in part and reversed in part, and the case is remanded to the Court of Appeals for further proceedings consistent with this opinion.
ORS 419.523 (1987) provided in part:
“(1) The parental rights of the parents of a child within the jurisdiction of the juvenile court * * * may be terminated as provided in this section and ORS 419.525. * * *
“(2) The rights of the parent or parents may be terminated as provided in subsection (1) of this section if the court finds that the parent or parents are unfit by reason of conduct or condition seriously detrimental to the child and integration of the child into the home of the parent or parents is improbable in the foreseeable future due to conduct or conditions not likely to change.”
That statute was amended by Oregon Laws 1989, chapter 907, section 2, in a manner not relevant to this case.
The state argued at trial that mother failed to show that her former drug counselors were “authorized under the laws of any state” to provide treatment. In other words, according to the state, mother failed to show that the drug counselors were psychotherapists under OEC 504(l)(c)(A). Even if the state is correct about the credentials of mother’s drug counselors, however, the record demonstrates that mother reasonably believed that they possessed the requisite qualifications. OEC 504(l)(c)(B).
Proposed FRE 504 was never enacted. According to one commentator:
*173“The rules of privilege adopted by the United States Supreme Court as part of the Federal Rules of Evidence generated so much opposition and controversy in Congress that Congress ultimately deleted them to avoid further delay in the passage of the federal rules.” Kirkpatrick, Reforming Evidence Law in Oregon, 59 Or L Rev 43, 69-70 (1980) (footnote omitted).
Psychiatrists themselves disagree about what constitutes a “mental condition” or whether that concept has any validity at all. See Brooks, Law, Psychiatry and the Mental Health System 21-89 (1974) (compilation of psychiatry scholars’ essays discussing differing concepts of mental illness). The drafters ofproposed FRE 504 expressly included the words “drug addiction” in apparent recognition of the ambiguity of the general phrase, “mental or emotional condition.”
Chemical dependency is considered by some to be a physical, rather than a mental or emotional, condition. One recent scholarly article points out that drug dependence “involves the physiological as well as the psychological.”
“[W]hen methadone programs originally came into existence, they were based on a medical model which took metabolic changes after addiction to be central. This model was developed by Dole and Nyswander (Dole 1970) * * *. In terms of this model, the craving for opiates is seen as physiologically based, permanent, and subject to correction only by the administration of another opiate such as methadone (Dole 1970). * * *
“While this early medical model is conservative, * * * it promotes the belief that addiction no longer need be seen as symptomatic of underlying psychological problems [citations omitted].” Covington, Addict Attitudes Toward Legalization of Heroin, 14 Contemp Drug Probs 315, 323 (1987).
Methadone remains an acceptable treatment for heroin addiction. Rosenbaum, Irwin and Murphy, De Facto Destablization as Policy: The Impact of Short-Term Methadone Maintenance, 15 Contemp Drug Probs 491 (1988).
The August-September 1991 edition of the Oregon State Bar Bulletin is devoted to the topic of “Drugs, Alcohol & Lawyers.” A physician whose practice is limited to treatment of chemical dependency writes that the most productive area of research concerns the role of brain chemistry. Chemical dependency is most influenced, he states, by how the addictive substance “affects the reward centers in the brain.” Jacobsen, Puzzled by Addiction?, 51 OSB Bulletin 21, 22 (Aug-Sept 1991).
The version of the Oregon Evidence Code, HB 2030, that went to the floor in 1981 included OEC 504 without the phrases on “drug addiction” that had appeared in the Advisory Committee’s original proposal. There was no specific discussion of OEC 504 in the floor debates before its enactment. House Committee on the Judiciary, July 11, 1981, Tape 28; Tape Recording, Senate Justice Committee, August 1, 2,1981, Tape 237.
Confidential communications about drug dependency that are made during the course of, and are an integral part of, diagnosis or treatment of a mental or emotional condition that is covered by the privilege, are privileged.
In contrast, this court is not required to review the record de novo. “When the Court of Appeals has tried a cause anew upon the record, the Supreme Court may limit its review of the decision of the Court of Appeals to questions of law.” ORS 19.125(4).
We do not mean to suggest that the Court of Appeals must make written findings of fact.