Quaere: May the State, in a rape case, offer expert testimony on "rape trauma syndrome" to prove that the alleged victim did not consent to sex with the alleged assailant?
*338The trial court held such evidence admissible, and the defendant was convicted of third degree rape. The Court of Appeals reversed. We hold that expert testimony on rape trauma syndrome is inadmissible because it lacks scientific reliability and unfairly prejudices a defendant accused of rape. We affirm the Court of Appeals and remand for a new trial.
The conviction arose from an incident in August 1984 involving the defendant and R.J., a close family friend and neighbor. R.J. was 16 at the time of the incident. Both parties essentially related the same version of events leading up to sexual intercourse. R.J. testified that the defendant offered to hug and touch her for $100, she attempted to leave, but he then locked the door and forced her to have both oral sex and sexual intercourse, after which he permitted her to leave and pleaded with her not to turn him in. The defendant admitted that he made the alleged $100 offer, but said he did so jokingly in response to her statement that "I don't do anything for free." The defendant also admitted that the two did later engage in both oral sex and sexual intercourse, but he asserts that the encounter was entirely consensual and that no force was involved.
At the trial, R.J.'s mother and friends testified as to their observations of R.J. after the incident. They stated that she was emotionally distraught and had had nightmares of the incident for several days thereafter. This testimony was admitted over the objection that it was hearsay, its admission was deemed proper by the Court of Appeals, and its propriety has not been challenged in the present appeal.
The testimony at issue here was given by Kelleen Ber-mensolo, a counselor for the Lutheran Social Services Rape Crisis Network in Spokane. Bermensolo testified that she had a master's degree in social work and 4 years' experience working with 150 to 200 victims of rape and sexual assault. She stated that she had counseled R.J. on a weekly basis for several months "after the rape."
The prosecutor asked Bermensolo whether R.J. was "suffering emotional trauma" and Bermensolo replied "[y]es. *339Defense counsel then objected to this testimony "based on the foundation laid." The court sustained the objection, following which the prosecutor further questioned Bermensolo about her experience in dealing with rape victims. She stated:
In every rape victim that I have seen they exhibit consistent symptoms . . . For example, body soreness, guilt, shame, feelings about the trial, nightmares, flashbacks, these are common symptoms that rape victims experience. There is a specific profile for rape victims and [R. JJ fits in.
(Italics ours.) In response to defense counsel's questions as to whether trauma can come from sources other than rape, Bermensolo later explained that she relied on "what the symptoms show according to the rape trauma syndrome." She also stated that this syndrome was developed by Ann Burgess and Lynda Holmstrom. See Burgess & Holmstrom, Rape Trauma Syndrome, 131 Am. J. Psychiatry 981 (1974).
Defense counsel then again questioned Bermensolo: "[T]he bottom line that I am asking, it is possible . . . [that] symptoms that are manifested by rape crisis victims could also be manifested for some other reason than rape; isn't that true?" Bermensolo replied: "My training is in the area of sexual assault and when the symptoms are apparent that fit the sexual assault with the rape trauma syndrome, I can't say . . . what a reaction would be in another area."
The trial court admitted Bermensolo's testimony over the objection of defense counsel. The court found the defendant not guilty of second degree (forcible) rape but guilty of third degree (nonconsensual) rape. The trial court considered Bermensolo's testimony in reaching its decision.
The Court of Appeals reversed, holding that an inadequate foundation had been laid for the introduction of testimony on rape trauma syndrome. The State appealed. We accepted review.
Two issues are presented:
First, did the defendant at trial properly raise his objection to the admissibility of expert testimony on rape *340trauma syndrome, to preserve this question for appeal?
Second, should such testimony be deemed inadmissible because (1) "rape trauma syndrome" is a theory which has not gained general acceptance within the scientific community, and (2) such testimony constitutes an opinion as to the guilt of the defendant, thereby invading the exclusive province of the finder of fact?
I
The State argues that at trial defense counsel did not specifically object to the scientific reliability or acceptance of "rape trauma syndrome", and is thereby precluded from raising this issue on appeal. We disagree.
ER 103(a)(1) provides:
Error may not be predicated upon a ruling which admits . . . evidence unless . . .
(1) ... a timely objection or motion to strike is made, stating the specific ground of objection, if the specific ground was not apparent from the context. . .
(Italics ours.) Defense counsel at trial objected to Bermen-solo's qualifications to testify on rape trauma syndrome, "based on the foundation laid." Although counsel did not specifically raise a challenge to the reliability of rape trauma syndrome as a means of proving rape, this ground for objection is readily apparent from the circumstances. On voir dire, defense counsel repeatedly asked whether trauma or emotional distress can come from sources other than rape or sexual assault. When Bermensolo specifically stated that she was relying on rape trauma syndrome, he again inquired whether this syndrome was unique to rape. Defense counsel's questions were more than adequate to apprise the trial court of his objection to the use of rape trauma syndrome as a fact-finding method in a rape case.
The State alternatively argues that any possible error concerning testimony on rape trauma syndrome was self-invited by defense counsel and is therefore not subject to appellate review. See State v. Kaiser, 34 Wn. App. 559, 565, 663 P.2d 839, review denied, 100 Wn.2d 1004 (1983). *341The State relies on the fact that Bermensolo used the term "rape trauma syndrome" only in response to defense counsel's questions. We deem this circumstance immaterial when viewed in light of the entire course of questioning.
The prosecutor originally asked Bermensolo if, in her opinion, R.J. was suffering from "emotional trauma". When defense counsel objected to this testimony, the prosecutor questioned her further. Bermensolo responded by describing symptoms commonly found in rape victims and added, " [tjhere is a specific profile for rape victims and [R.J.] fits in." Such testimony, elicited from the prosecutor, was tantamount to an assertion that R.J. suffered from "rape trauma syndrome", even though Bermensolo did not use that precise term until later in the proceedings. Defense counsel did not invite any possible error precluding judicial review.
II
The defendant contends that the trial court erred in admitting into evidence, and relying upon, expert testimony on "rape trauma syndrome". We agree.
The admissibility of expert testimony is governed by ER 702, which provides:
If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.
Under this rule, (1) the witness must be qualified as an expert; (2) the opinion must be based upon an explanatory theory generally accepted in the scientific community, and (3) the expert testimony must be helpful to the trier of fact. State v. Allery, 101 Wn.2d 591, 596, 682 P.2d 312 (1984). Kelleen Bermensolo's qualifications as an expert have not been challenged on appeal. Thus, we address only the second and third prongs of this 3-prong test.
*342A
Scientific Reliability of "Rape Trauma Syndrome" as a Means of Proving Rape
In Washington, expert testimony based on new scientific theories is admissible only if it meets the standard enunciated in Frye v. United States, 293 F. 1013, 1014 (D.C. Cir. 1923). Under this standard, the scientific principle from which deductions are made must be sufficiently established to have gained general acceptance in the scientific community. State v. Canaday, 90 Wn.2d 808, 812, 585 P.2d 1185 (1978) (citing Frye). This standard has frequently been applied to determine the admissibility of scientific evidence. See Allery ("battered woman syndrome" evidence admissible); State v. Martin, 101 Wn.2d 713, 719, 684 P.2d 651 (1984) (hypnosis evidence inadmissible); State v. Woo, 84 Wn.2d 472, 473-75, 527 P.2d 271 (1974) (polygraph evidence inadmissible in the absence of stipulation by both parties); State v. Maule, 35 Wn. App. 287, 295-96, 667 P.2d 96 (1983) (court disallowed expert testimony regarding characteristics of sexually abused children when no scientific basis for such testimony was cited); State v. Steward, 34 Wn. App. 221, 223-24, 660 P.2d 278 (1983) (court disallowed expert testimony regarding alleged propensity of babysitting boyfriends to inflict child abuse); State v. Mulder, 29 Wn. App. 513, 514-15, 629 P.2d 462 (1981) ("battered child syndrome" evidence admissible).
Here, the question is whether rape trauma syndrome has been generally established as a scientifically reliable means of proving that a rape occurred. As this is a question of first impression in this State, we turn to both the literature on the subject and the opinions of other jurisdictions for guidance.
1. Scientific Treatises
The term "rape trauma syndrome" was first coined by Ann Burgess and Lynda Holmstrom in the 1974 article, previously noted, describing symptoms commonly experienced by victims of rape. Burgess & Holmstrom, Rape *343Trauma Syndrome, 131 Am. J. Psychiatry 981 (1974). The authors state at page 982:
Rape trauma syndrome is the acute phase and long-term reorganization process that occurs as a result of forcible rape or attempted forcible rape. This syndrome of behavioral, somatic, and psychological reactions is an acute stress reaction to a life-threatening situation.
Studies conducted by both Burgess and Holmstrom and other authors assert that victims of rape may display any of a wide-ranging variety of symptoms. In the acute phase (immediately after the rape) any or all of the following may be observed: physical trauma, tension headaches, sleep pattern disturbances, gastrointestinal irritability, humiliation, embarrassment, anger, revenge, and self-blame. In the "long-term reorganization process", victims may display a number of additional symptoms, including: nightmares, changing one's residence, changing one's phone number, fear of indoors, fear of outdoors, fear of being alone, fear of crowds, fear of men, and sexual fears. Burgess & Holm-strom, at 982-84; see also L. Ledray, Recovering From Rape 70-90 (1986); H. Benedict, Recovery 21-40 (1985); C. Dean & M. deBruyn-Kops, The Crime and the Consequences of Rape 105-08, 110-13 (1982); J. Williams & K. Holmes, The Second Assault: Rape and Public Attitudes 81-87 (1981); C. Warner, Rape and Sexual Assault 145-49 (1980); Bassuk, A Crisis Theory Perspective on Rape, in The Rape Crisis Intervention Handbook 124-26 (S. McCombie ed. 1980); S. Katz & M. Mazur, Understanding the Rape Victim: A Synthesis of Research Findings 215-31 (1979).
One overriding theme permeates the literature on this subject: namely, that there is no "typical" response to rape. See, e.g., Ledray, at 71 ("There is really no such thing as a 'normal' response to rape"); T. McCahill, L. Meyer, & A. Fischman, The Aftermath of Rape lb (1979) ("Clearly, the concept of a typical rape victim has no place within the context of postrape adjustment"). One commentator explains,
*344[e]ach rape victim responds to and integrates the experience differently depending on her age, life situation, the circumstances of the rape, her specific personality style, and the responses of those from whom she seeks support.
Notman & Nadelson, The Rape Victim: Psychodynamic Considerations, 133 Am. J. Psychiatry 408, 409 (1976). Thus, the symptoms displayed by victims occur in various combinations and sequences. Moreover, Burgess & Holm-strom concede that victims of rape may display one of two directly conflicting emotional manifestations which are referred to as "styles". Some women display an "expressed style" (outwardly emotional) while others display a "controlled style" (calm, composed and subdued). Among the latter group, some display no visible symptoms at all. Burgess & Holmstrom, at 982-83.
Because the symptoms associated with "rape trauma syndrome" embrace such a broad spectrum of human behavior, the syndrome provides a highly questionable means of identifying victims of rape. Indeed, the American Psychiatric Association indicates that the stress and trauma associated with rape is merely one type of a larger phenomenon known as "post-traumatic stress disorder". Similar symptoms may be triggered by any psychologically traumatic event that is "generally outside the range of usual human experience", including simple bereavement, chronic illness, marital conflict, assault, military combat, natural disasters, automobile accidents, bombing, or torture. American Psychiatric Ass'n, Diagnostic and Statistical Manual of Mental Disorders 236-38 (3d ed. 1980); see also Horowitz, Wilner, Kaltreider & Alvarez, Signs and Symptoms of Posttraumatic Stress Disorder, 37 Archives of Gen. Psychiatry 85 (1980). Even those symptoms more especially applicable to sexual experiences may not be caused by rape. Authorities indicate that they may be caused by any "sexually stressful experience". See Notman & Nadelson, at 408; Note, Checking the Allure of Increased Conviction Rates: The Admissibility of Expert Testimony on Rape Trauma Syndrome in Criminal Proceedings, 70 *345Va. L. Rev. 1657, 1696 (1984).
Several authors have also criticized the methodology of the studies which have been conducted to determine symptoms of rape victims. Among the shortcomings cited are the following: (1) differences in definitions and criteria for "rape"; (2) unrepresentative, biased, or inadequate sampling of victims; (3) inadequate means of eliciting information about victims; (4) lack of long-term assessments of victims; and (5) lack of a control group (i.e., a group of nonraped women) against which to compare the symptoms observed in rape victims. Ruch & Leon, Type of Sexual Assault Trauma: A Multidimensional Analysis of a Short-Term Panel, 8 Victimology 237, 238-39 (1983); Kilpatrick, Resick & Veronen, Effects of a Rape Experience: A Longitudinal Study, 37 J. Soc. Issues 105, 108-09 (1981); Kilpat-rick, Veronen & Resick, The Aftermath of Rape: Recent Empirical Findings, 49 Am. J. of Orthopsychiatry 658, 658-59 (1979); S. Katz & M. Mazur, at 3-27; Note, 70 Va. L. Rev. at 1667-80. One commentator succinctly describes the inherent difficulties in conducting reliable studies:
It is difficult to design a scientific study investigating the impact of sexual assault on survivors. A controlled study would require obtaining data from a large sample of women, following these women over time, and later reassessing the sample to determine the incidence and impact of sexual assault. However, such a study is not feasible.
J. Becker, L. Skinner & G. Abel, Sequelae of Sexual Assault: The Survivor's Perspective, in The Sexual Aggressor: Current Perspectives on Treatment 263 (1983). Largely because of these methodological shortcomings, "available studies are inconsistent as to the length of recovery time and the variables affecting the dynamics of rape victimization." Ruch & Leon, at 239.
These findings cast grave doubt on the reliability of employing "rape trauma syndrome" to prove that an alleged victim was, in fact, raped. Three noted authorities have concluded:
*346An obvious first step in addressing the needs of rape victims is to obtain accurate information regarding the aftermath of rape.
Unfortunately . . . this first step has been more of a stumbling lurch than a measured advance. To date, investigations of how a rape experience affects women over time have been scarce and methodologically poor. . . . Therefore, these studies provide little, if any, scientifically valid data regarding the effects of a rape experience, although they do provide interesting anecdotal impressions.
Kilpatrick, Veronen & Resick, at 658-59.
2. Judicial Opinions and Observations
The admissibility of expert testimony on rape trauma syndrome has been considered in a number of other jurisdictions. The courts are sharply divided on the issue. Some have held such testimony inadmissible to prove that the alleged victim did not consent to intercourse and was, therefore, raped. State v. Saldana, 324 N.W.2d 227 (Minn. 1982); State v. Taylor, 663 S.W.2d 235 (Mo. 1984); People v. Bledsoe, 36 Cal. 3d 236, 681 P.2d 291, 203 Cal. Rptr. 450 (1984). Others have held such testimony admissible for this purpose. State v. Marks, 647 P.2d 1292 (Kan. 1982); State v. Liddell, _ Mont. _, 685 P.2d 918 (1984); State v. Huey, 145 Ariz. 59, 699 P.2d 1290 (1985); State v. Allewalt, 308 Md. 89, 517 A.2d 741 (1986) (5-to-2 opinion held testimony on "post-traumatic stress disorder" admissible in rape case to prove lack of consent).
We find the opinions which exclude the testimony persuasive. The courts which have admitted rape trauma syndrome testimony believe it sufficient that the myriad of symptoms encompassed therein are "generally accepted to be a common reaction to sexual assault." Marks, at 1299; Huey, at 63; Allewalt, at 107. We find, however, that this is not the relevant question. The issue is not whether rape victims may display certain symptoms; the issue is whether the presence of various symptoms, denominated together as "rape trauma syndrome", is a scientifically reliable method admissible in evidence and probative of the issue of *347whether an alleged victim was raped. See Allewalt, at 115 (Eldridge, J., dissenting). The literature on the subject demonstrates that it is not.
In Bledsoe, at 250, the California Supreme Court emphasized that rape trauma syndrome was not intended to be a forensic, fact-finding device. Rather, it is an "'umbrella' concept, reflecting the broad range of emotional trauma experienced by clients of rape counselors." The court cogently points out how rape trauma syndrome differs significantly from other seemingly similar methods of proof:
There is, however, a fundamental difference between rape trauma syndrome and both the battered child syndrome and the other scientific methods of proof that have in the past been evaluated against the Frye standard of reliability. Unlike fingerprints, blood tests, lie detector tests, voiceprints or the battered child syndrome, rape trauma syndrome was not devised to determine the "truth" or "accuracy" of a particular past event — i.e., whether, in fact, a rape in the legal sense occurred — but rather was developed by professional rape counselors as a therapeutic tool, to help identify, predict and treat emotional problems experienced by the counselors' clients or patients. As the professional literature makes clear — and as the expert testimony in this case also reveals — because in the past women who have brought charges of rape have traditionally had their credibility or motives questioned by the police and others, rape counselors are taught to make a conscious effort to avoid judging the credibility of their clients. As one expert in the field recently wrote: "when a woman seeks services from a psychologist, she wants and deserves help for her problems, not judgment. Judgment is appropriate for courtrooms, not for psychologists' offices. . . ."
Thus, as a rule, rape counselors do not probe inconsistencies in their clients' descriptions of the facts of the incident, nor do they conduct independent investigations to determine whether other evidence corroborates or contradicts their clients' renditions. Because their function is to help their clients deal with the trauma they are experiencing, the historical accuracy of the clients' descriptions of the details of the traumatizing events is not vital in their task.
*348(Footnotes and citation omitted.) Bledsoe, at 249-50.
Likewise, Saldana and Taylor also rejected expert testimony on rape trauma syndrome. Saldana explicitly found that this syndrome is not the type of scientific test that reliably determines whether a rape has occurred, as the characteristic symptoms may follow any psychologically traumatic event. Saldana, at 229. Taylor similarly concluded that at best, the syndrome might identify persons who had been subjected to a traumatic experience — perhaps even a stressful sexual experience. But to suggest that the syndrome reliably indicates rape "is indeed a chasm too wide and deep to leap." Taylor, at 241.
We agree, and hold that under the Frye standard, expert testimony on rape trauma syndrome is not a scientifically reliable means of proving lack of consent in a rape case.
B
Prejudicial Nature of Expert Testimony on "Rape Trauma Syndrome"
Expert testimony is not admissible unless it will be helpful to the trier of fact. State v. Allery, 101 Wn.2d 591, 596, 682 P.2d 312 (1984). Included in this equation is the question of whether the prejudicial nature of the testimony is so great as to render such testimony inadmissible. See State v. Mulder, 29 Wn. App. 513, 516, 629 P.2d 462 (1981); State v. Steward, 34 Wn. App. 221, 224, 660 P.2d 278 (1983). The defendant contends that expert testimony on rape trauma syndrome is unfairly prejudicial because it constitutes an opinion as to the guilt of the defendant, thereby invading the exclusive province of the finder of fact. We agree.
No witness, lay or expert, may testify to his opinion as to the guilt of a defendant, whether by direct statement or inference. State v. Garrison, 71 Wn.2d 312, 315, 427 P.2d 1012 (1967); State v. Haga, 8 Wn. App. 481, 492, 507 P.2d 159, review denied, 82 Wn.2d 1006 (1973). Here, rape counselor Bermensolo testified that, in her opinion, R.J. suffered from rape trauma syndrome, and that " [t]here is a specific profile for rape victims and R.J. fits in." In Sal-*349dana, at 230, the Minnesota Supreme Court aptly observed that:
[permitting a person in the role of an expert to suggest that because the complainant exhibits some of the symptoms of rape trauma syndrome, the complainant was therefore raped, unfairly prejudices the [defendant] by creating an aura of special reliability and trustworthiness.
Accord, Bledsoe, at 251. The danger of prejudice is especially acute where, as here, the expert expressly uses the term "rape trauma syndrome." As one court cogently notes, n[t]he term itself connotes rape.” Taylor, at 241. It carries with it an implied opinion that the alleged victim is telling the truth and was, in fact, raped. Taylor; see Bledsoe, at 251 n.14. It constitutes, in essence, a statement that the defendant is guilty of the crime of rape.
We add, however, that we do not share the view, espoused by some courts, that an expert witness' decision to avoid the term "rape trauma syndrome" thereby renders such testimony admissible. In State v. Allewalt, 308 Md. 89, 517 A.2d 741 (1986), for example, the court allowed an expert witness to testify that the alleged victim suffered from a form of "post-traumatic stress disorder" with rape as the likely stressor. The court suggested that the same testimony would be inadmissible had it been labeled as testimony on "rape trauma syndrome". Allewalt, at 98, 108. We find such semantic distinctions unpersuasive. In the present case, the testimony of rape counselor Bermensolo, whether it be denominated as a form of "post-traumatic stress disorder", "rape trauma syndrome" or otherwise, was unfairly prejudicial and hence inadmissible.
We do not imply, of course, that evidence of emotional or psychological trauma suffered by a complainant after an alleged rape is inadmissible in a rape prosecution. The State is free to offer lay testimony on these matters, and the jury is free to evaluate it as it would any other evidence. We simply hold that the State may not introduce expert testimony which purports to scientifically prove that an alleged rape victim is suffering from rape trauma syndrome.
*350We adopt the views summarized by the following observations in Saldana:
The scientific evaluation of rape trauma syndrome has not reached a level of reliability that surpasses the quality of common sense evaluation present in jury deliberations. ... To allow such testimony would inevitably lead to a battle of experts that would invade the jury's province of fact-finding and add confusion rather than clarity.
Saldana, at 230.
The decision of the Court of Appeals vacating the conviction of the defendant is affirmed and the cause is remanded for a new trial.
Dolliver, Dore, Andersen, Goodloe, and Durham, JJ., concur.