Gillerman, J.
On September 1, 1992, the defendant, Deborah Conaghan, pleaded guilty to the charge of manslaughter in connection with the death of her five year old son, Garrett. On April 29, 1997, approximately four and one-half years later, the defendant filed a motion in the Superior Court to withdraw her guilty plea. She subsequently filed a motion for a psychiatric examination on December 2, 1997, and a nonevidentiary hearing on the motion was held on December 16, 1997. The motion judge, who was not the trial judge, denied both motions on January 12, 1998.
The defendant claims that the judge erred in denying her motion to withdraw her guilty plea or, in the alternative, that he erred in failing to grant her an evidentiary hearing because she presented substantial evidence that (1) her former boyfriend inflicted the fatal injuries upon her son; (2) to the extent that she may have contributed to her son’s death, she suffered from battered woman’s syndrome and other psychological disorders and therefore lacked the state of mind necessary to support a conviction; and (3) her plea was the product of intimidation and coercion and therefore was not voluntary.
The defendant also argues that the motion judge erred in denying her motion for a psychiatric examination. While her claim for an independent psychiatric examination was specifically denied, the defendant contends that the judge failed to consider her alternate claim that she was entitled to be examined by a psychiatrist designated by the court.
1. The plea hearing. At the plea hearing, the Commonwealth contended that the following facts would be proven if the defendant’s case proceeded to trial.
The defendant is divorced from Garrett’s father. During the summer of 1991, Garrett stayed with his father, who was living in New Jersey. Garrett returned to the defendant’s residence at the end of August. At that time, the defendant was living with her boyfriend, Paul Haynes (Haynes).
Garrett entered the first grade in September, 1991. On October [306]*3061, 1991, Garrett’s teacher noticed bruises on his hands and sent him to the school nurse. The nurse noticed additional bruising on his right forearm and on his temple. The nurse filed a report with the Department of Social Services (DSS), and an investigation was commenced. When questioned by a DSS investigator, the defendant stated that the bruising occurred when Garrett fell against a car as he was riding his bicycle.
On October 3, 1991, Garrett was examined by a pediatrician who determined that the injuries were not accidental. However, when the doctor spoke to the defendant about the cause of Garrett’s injuries, she provided the same explanation that she had given the DSS investigator, i.e., that Garrett had fallen against a car while riding his bike.
On October 12, 1991, at approximately 1:30 p.m., the defendant brought Garrett into the emergency room at St. Vincent Hospital. He was unconscious, with no heartbeat or other vital signs. The defendant told the emergency personnel that Garrett had slipped in the bathroom, fallen backward, and struck the back of his head. She stated that he then had a seizure and lost consciousness. His body went limp, and his lips changed color. It was at that time that the defendant decided to take Garrett to the hospital. He died at approximately 3:00 p.m. that afternoon.
Police officers went to the defendant’s house later that day to question her. She told the officers that earlier in the day, she had given Garrett lunch, after which he had rushed into the bathroom. He vomited into the sink, and the defendant helped him wash his face. Garrett then slipped on water that the defendant had spilt on the floor while she was washing his face. He fell back, hit his head on the floor, and went into a seizure. The defendant also told the police that Garrett’s hands had been bruised when he ran into a car with his bicycle.
The next day, an autopsy was performed on Garrett’s body. The autopsy revealed that he had suffered three subdural hematomas of varying age. One was consistent with having been sustained on the day that he died, one was sustained approximately fourteen days before that, and the third was older and could not be dated. It was determined that the cause of death was blunt trauma, and that the recent hematoma had aggravated his fourteen day old subdural hematoma, thereby causing his brain to swell, resulting in death.
On October 17, 1991, police officers again interviewed the [307]*307defendant. She initially gave them the same account that she had given five days earlier, but she changed her story when one of the officers said that he did not believe her.1 The officers asked her a number of questions about events on the day that Garrett died, and she gave them a statement.
The defendant stated that on the day of Garrett’s death, he vomited in the bathroom and, to punish him, the defendant took him into the kitchen. She told the police, “I pushed him with my right hand on his chest or head. Garrett would fall down. Then he got back up and I would push him again and Garrett would fall on the floor. This happened two or three times. Then he just fell on the floor and went into a seizure.” In answer to additional questions the defendant said she had given him the same form of punishment four or five times previously. On those occasions, she said, “Garrett was disobeying or not listening to me so instead of hitting him I kept pushing him onto the floor. I pushed him two to three times and every time I pushed him he got up and I pushed him again.” The use of this means of punishment had caused Garrett to develop a “lazy eye” and had also caused him to begin vomiting regularly.
The defendant also told the police that after she had knocked Garrett down several times on the day of his death, he went into a seizure. She took him into his bedroom to get him dressed. While in the bedroom, Garrett stopped breathing, and his lips turned blue. Asked to describe the seizure, the defendant-said Garrett fainted, fell forward, hit the front of his head, and was shaking on the ground. After relating these facts to the police, the defendant signed her statement. The defendant acknowledged to the judge that her statement to the police was “true and accurate.”
Earlier in the proceeding, the judge had probed the defendant’s mind. He questioned her about her prior psychiatric treatment, asked whether she was on any medication, discussed the effects of her medication, asked whether she was under the influence of drugs or alcohol, and asked if she had had a period of psychiatric examination in connection with this case. All these questions were answered in the negative or otherwise to the satisfaction of the judge.
[308]*308During the colloquy, the defendant stated that she was pleading guilty of her own free will. She replied, “No,” when she was asked if anyone had threatened her or made any promises to her in order to get her to plead guilty. She also replied, “No,” when the judge asked her if she was confused by anything he said and if she had any questions about the plea procedure. She acknowledged that throughout the proceedings against her she had been represented by a good lawyer who had worked in her best interest. The judge told the defendant the maximum sentence for manslaughter was twenty years in a State prison, and the defendant said she understood that.
Finally, the judge asked the defendant, “And may I understand that you are pleading guilty for but one reason, that being that you are, in fact, guilty, which is to say that you did do the things that [the prosecutor] told me you did?” The defendant answered, “Yes.” The plea judge then concluded, “I find that the plea of guilty is freely, willingly, voluntarily and intelligently offered and it is accepted.”
2. Motion to withdraw the defendant’s guilty plea.
(a) Standard of review. A postconviction motion to withdraw a guilty plea is treated as a motion for a new trial. Commonwealth v. DeMarco, 387 Mass. 481, 482 (1982). See Commonwealth v. Russin, 420 Mass. 309, 315 (1995). “The judge is to apply the standard set out in rule 30 [Mass.R.Crim.P. 30(b), 378 Mass. 900 (1979)] ‘rigorously,’ and may grant a motion to withdraw a guilty plea only if ‘it appears that justice may not have been done.’ ” Commonwealth v. Facella, 42 Mass. App. Ct. 354, 355 (1996), quoting from Commonwealth v. DeMarco, 387 Mass. at 486-487. The motion is addressed to the sound discretion of the judge. Commonwealth v. Correa, 43 Mass. App. Ct. 714, 716 (1997). “Contrary to the defendant’s contention, the judge properly exercised his discretion in concluding that [her] motion did not raise a ‘substantial issue,’ and that an evidentiary hearing was not required.” Commonwealth v. Facella, supra at 355, citing Commonwealth v. DeVincent, 421 Mass. 64, 67, 69 (1995).
(b) Consideration of the defendant’s supplementary materials. The defendant filed various documents in support of her motion to withdraw her guilty , plea, including the transcript of her plea colloquy hearing; an affidavit from her attorney; an affidavit from the defendant herself; the transcript from the trial [309]*309of her former boyfriend, Haynes, in an unrelated case2; several investigative reports; and her prison medical records. In rendering a decision on the motion, the judge considered only the motion itself, the defendant’s colloquy transcript, and the affidavits of the defendant and her attorney. He refused to consider the defendant’s medical records, the investigative reports, and the transcript of Haynes’s trial, stating that “[these] materials . . . are not in affidavit form and have been afforded no weight.” The defendant contends that the motion judge erred in failing to consider all of the materials submitted with her motion.
As a general rule, a judge may decide a motion for a new trial based solely on affidavits, and additional testimony need not be heard. See Commonwealth v. Lopez, 426 Mass. 657, 663 (1998) (“It is . . .an axiom of rule 30(b) practice, . . . that the judge may decide a rule 30(b) motion based solely on affidavits”); Commonwealth v. Pingaro, 44 Mass. App. Ct. 41, 48 (1997). However, when a defendant attacks a conviction based upon a guilty plea, she has the choice between two tactics. “[S]he may stand on the contemporaneous record, the record made in the case through the stage of the colloquy and conviction. If the defendant chooses this route, it is not open to the Commonwealth to introduce extraneous evidence tending to show that the defendant in fact acted freely and intelligently in tendering the plea. . . . Alternatively, the defendant may offer extraneous evidence to supplement (or contradict) the record, but in that event the Commonwealth has a like right to offer evidence.” Commonwealth v. Nolan, 19 Mass. App. Ct. 491, 492 (1985) (citations omitted). See Commonwealth v. Foster, 368 Mass. 100, 108 n.7 (1975) (“Where ... the contemporaneous record is sufficient on its face, but the defendant claims that his plea was nevertheless involuntary or unknowing for reasons not appearing of record, not only may the defendant introduce relevant evidence, but the Commonwealth may respond with evidence to the contrary from outside the original record”); Commonwealth v. Glines, 40 Mass. App. Ct. 95, 100 (1996).
Here, the defendant elected the second alternative and offered additional evidence to contradict the record in this case. The [310]*310judge relied on Mass.R.Crim.P. 30(c)(3), 378 Mass. 901 (1979), in deciding to give no weight to the materials that were not in affidavit form. While rule 30(c)(3) does require the party moving for postconviction relief to submit affidavits in support of the motion, it does not preclude the parties from introducing relevant evidence by other means, and there is no decisional authority requiring that evidence submitted to supplement or contradict the record in challenging a guilty plea be presented in the form of an affidavit.3 See Commonwealth v. Foster, supra; Commonwealth v. Glines, supra.4 The motion judge erred in concluding that he had no discretion to consider the materials that were not in affidavit form.
The motion judge’s failure to consider the additional materials does not preclude us from reviewing the defendant’s submissions. We are in as good a position as the motion judge, who was not the plea judge, to assess the strength of the defendant’s claims. See Commonwealth v. Haley, 413 Mass. 770, 773 (1992); Commonwealth v. Curtis, 417 Mass. 619, 626 (1994). Thus, we have considered all of the materials submitted in support of the defendant’s motion.
(c) The defendant’s claim that Haynes inflicted the fatal injuries. The defendant’s first ground for the withdrawal of her guilty plea is that it was her former boyfriend Haynes who actually inflicted the fatal injuries on Garrett. In her affidavit, the defendant states that Haynes physically abused Garrett on a regular basis. On the day of Garrett’s death, she claims that she took Garrett into the bathroom to clean him up after he vomited, and Haynes accompanied her. Haynes then began to push Garrett. At the direction of Haynes, she also pushed Garrett to the floor. She also states in her affidavit that “[b]y far, the greatest [311]*311number of blows and the most severe blows inflicted on Garrett prior to his death were inflicted by Paul Haynes.”
The motion judge did not credit the defendant’s affidavit, and we reach the same conclusion. The critical difficulty is that the affidavit, written four and one-half years after Garrett’s death, contradicts the written statement she gave to the police shortly after Garrett’s death — admitting that on the day of Garrett’s death she repeatedly pushed him to the floor — and it contradicts her affirmation of her statement to the police at her plea hearing one year after Garrett’s death. Moreover, the defendant admits in her affidavit that she participated in abusing Garrett on the day of his death.5 There is no merit to the defendant’s claim that Haynes was solely responsible for Garrett’s death.
(d) The defendant’s claim that she lacked the state of mind necessary to support her conviction. The defendant further claims that she is entitled to an evidentiary hearing or is entitled to withdraw her guilty plea because she lacked the mental state necessary to support her involuntary manslaughter conviction.6 She argues that she cannot be held responsible for Garrett’s death as either a principal or a joint venturer because she suffers from battered woman’s syndrome. To the extent that she participated in “punishing” Garrett, she maintains that her will was overborne by the “psychological coercion” which Haynes inflicted upon her.
“The battered woman’s syndrome[7] has been described as a ‘series of common characteristics that appear in women who are abused physically and psychologically over an extended [312]*312period of time by the dominant male figure in their lives.’ ” Commonwealth v. Moore, 25 Mass. App. Ct. 63, 66 (1987), quoting from State v. Kelly, 97 N.J. 178, 193 (1984). “Among the characteristics of such abused women are a decrease in self-esteem, an emotional dependence upon the dominant male and [a] type of psychological ‘learned’ helplessness arising out of an inability to predict or control the violence directed against them.” Commonwealth v. Moore, supra, quoting from People v. Torres, 128 Misc. 2d 129, 132 (N.Y. Sup. Ct. 1985).
Violent behavior directed against women occurs in cycles consisting of three stages. “During the first stage, there is mostly verbal abuse, with minor physical abuse.” Stage two is “characterized by an escalation of the abuse ‘until there is an explosive instance where the woman is physically beaten up.’ ” Stage three “consists of a respite, with no abuse for a short period of time. This cycle continues throughout the relationship with a decrease in the time between the batterings.” Commonwealth v. Lazarovich, 410 Mass. 466, 471 (1991).
We conclude that the defendant’s affidavit does not state facts sufficient to demonstrate that she suffers from battered woman’s syndrome. The affidavit describes the cruelty of what she and Haynes did to Garrett8 rather than the beatings that she may have suffered at the hands of Haynes. Although the defendant has provided evidence that Haynes emotionally abused her, there is no evidence that he physically abused her prior to Garrett’s death. The defendant indicates in her affidavit that Haynes did not become physically abusive to her until after Garrett’s death. Thus, there is no evidence of “an explosive instance” of violence between the defendant and Haynes prior to Garrett’s death. See ibid. Because the defendant has not provided suf[313]*313ficient evidence to demonstrate a cycle of abuse in her relationship with Haynes, her claim that she suffers from battered woman’s syndrome cannot succeed.9
Furthermore, the defendant fails to demonstrate that she suffered from the “psychological ‘learned’ helplessness” associated with the battered woman’s syndrome. Commonwealth v. Moore, 25 Mass. App. Ct. at 66. In her affidavit, she describes an occasion where she refused to obey Haynes’s order to strike Garrett on his penis with a spoon. The description of this incident indicates that the defendant was capable of appreciating the wrongfulness of her actions. There is nothing in her affidavit to suggest that she was helpless or that she could not recognize her own misconduct.
The defendant also fails to explain adequately what happened to Garrett on the day of his death.10 She states in her affidavit that “[a]t the direction of Haynes, I also pushed Garrett.” This is the only explanation she provides for the actions that she took on that day. She does not claim that Haynes threatened to harm her physically if she did not push Garrett, nor does she claim that she feared that he would harm her if she failed to follow his instructions.
We conclude that the defendant has not sufficiently demonstrated that she suffered from battered woman’s syndrome. As a result, her argument that she lacked the mental state necessary to support her manslaughter conviction because she suffered from battered woman’s syndrome must fail. She has asserted no other grounds to support her claim that she should not be held responsible for her own conduct. Thus, the defendant has failed to raise a substantial issue regarding her claim that she lacked the requisite mental state to support her conviction.
At bottom, the defendant is claiming that her guilty plea was not voluntary, and we turn to that claim.
(e) The defendant’s claim that her guilty plea was not [314]*314voluntary. The defendant claims she is entitled to withdraw her guilty plea because it was involuntary. She asserts that Haynes coerced her into pleading guilty. At the beginning of their relationship, Haynes told the defendant that he had a friend in the Mafia named Tony who would “take care of” any problems he (Haynes) had. When the defendant did not obey Haynes or if she displeased him in any way, he threatened her by making reference to Tony. The defendant also observed that Haynes possessed a handgun. Because she believed his statements about Tony and because she knew he owned a firearm, the affidavit states that she feared the consequences of displeasing or upsetting him.
The defendant’s affidavit continues. After Garrett’s death, the defendant claims that Haynes constantly told her what she should say to the police. He said that she should “cover” for him and assume sole responsibility for Garrett’s death because he believed that he would receive a sentence of fife imprisonment if he were charged and convicted for Garrett’s death. Haynes instructed her to turn herself in to the police, which she did on May 6, 1992. While she was in custody, Haynes visited her and told her what to say to her lawyers and the authorities. He told her that she should plead guilty instead of going to trial because that would end the investigation, and he would not be charged. Haynes “pressured and warned” her to plead guilty. She stated that “[b]ecause I thought that I loved him and feared the consequences if I did not plead guilty, I chose to remain quiet about Haynes’s involvement in Garrett’s death and the pressure which he exerted on me to plead guilty.”
“Where a defendant wishing to withdraw a guilty plea challenges the voluntary or intelligent nature of his plea, it is ordinarily the Commonwealth’s burden to show by means of a contemporaneous or reconstructed record of the plea that it was entered understandingly and voluntarily.” Commonwealth v. Correa, 43 Mass. App. Ct. at 716. See Commonwealth v. Quinones, 414 Mass. 423, 431-432 (1993). Here, the defendant does not claim that she made her plea unknowingly; rather she claims only that her plea was involuntary because it was made at the direction of Haynes.
“The concept of voluntariness . . . requires that the defendant tender the plea free ‘from coercion, duress, or improper inducements.’ ” Commonwealth v. Correa, supra at 717, quoting from Commonwealth v. Duest, 30 Mass. [315]*315App. Ct. 623, 631 (1991). “To determine the voluntariness of the defendant’s plea, the judge should conduct a real probe of the defendant’s mind. . . . The judge should [also] determine whether the plea was ‘being extracted from the defendant under undue pressure,’ . . . whether the defendant was being treated for or was aware of any mental illness from which [s]he may be suffering, . . . and whether the defendant was under the influence of alcohol or drugs.” Commonwealth v. Correa, supra at 717-718 (citations omitted).
The Commonwealth has met its burden of showing that the defendant’s plea was made voluntarily. We have described the judge’s probing colloquy with the defendant earlier in this opinion, including specifically the inquiry whether the defendant was threatened by anybody or whether anyone made promises to her in order to obtain the guilty plea. The defendant’s answer was an unequivocal “no.” That inquiry satisfied constitutional standards, see Commonwealth v. Nolan, 19 Mass. App. Ct. at 494-495, and the standards of Mass.R.Crim.P. 12(c)(5), 378 Mass. 869 (1979). The defendant makes no claim to the contrary.
The defendant’s supplemental materials are not persuasive. Her affidavit offers two explanations for her guilty plea: (i) “Haynes told me that, rather than going to trial, I should plead guilty and take full responsibility for Garrett’s death. That way, the investigation would be over, and he would not be charged and (ii) although the defendant told the judge no one had forced her to plead guilty, in fact “Haynes had pressured and warned me to plead guilty. Because 7 thought that I loved him and feared the consequences if I did not plead guilty, I chose to remain quiet about Haynes’s involvement in Garrett’s death.” (Emphasis supplied.) The affidavit does not describe any coercion, and while it refers to a fear of the “consequences,” the feared “consequences” are not identified, and in any event, these unmentioned consequences are fused with her alleged “love” for him — this for the man who, according to her affidavit, was principally responsible for the death by beating of her own son. Further, as noted earlier, the defendant’s affidavit was written more than four years after her son’s death. “That time interval engenders an initial skepticism about the defendant’s argument that [her] plea[] w[as] coerced” by Haynes. Commonwealth v. Facella, 42 Mass. App. Ct. at 355.
While some of the defendant’s materials do indicate that [316]*316Haynes carried a gun and that he told other women the same story he relayed to the defendant regarding his friend in the Mafia named Tony, this evidence, standing alone, does not bear on the issue of whether Haynes coerced the defendant into pleading guilty after Garrett’s death, and the defendant’s affidavit, when focused on the issue of coercion, makes no mention of Haynes’s weapon, or of “Tony.”
The defendant was represented by competent counsel who made an eloquent plea on her behalf for a substantially reduced sentence. Neither the record of the original proceedings, nor the supplementary materials, raise a substantial issue whether the defendant’s plea was voluntary. The motion judge may — as he did here — discredit untrustworthy affidavits. There being no substantial issue raised by the motion or affidavits, no evidentiary hearing was required. See Commonwealth v. Lopez, 426 Mass. at 663. Whatever “pressure” Haynes may have put on the defendant, if any, to plead guilty in this case is not enough to convince us that this is a case which “truly warrants revisitation ... in the interests of justice.” Ibid. Based on the contemporaneous record of her plea hearing, as well as her affidavit, there is no triable issue, see Commonwealth v. Pingaro, 44 Mass. App. Ct. at 51 n.13, defeating any claim that the plea should be withdrawn in the interests of justice. See Commonwealth v. Facella, 42 Mass. App. Ct. at 355, quoting from Commonwealth v. DeMarco, 387 Mass. at 486-487 (a motion to withdraw a guilty plea is to be allowed only if “it appears that justice may not have been done”).11 See also Huot v. Commonwealth, 363 Mass. 91, 100 (1973) (sufficient evidence to demonstrate voluntary and knowing guilty plea under standard in effect prior to Boykin v. Alabama, 395 U.S. 238 [1969], where defendant admitted responsibility for homicide and admitted he realized the nature of the sentence).
We conclude that the defendant is not entitled to withdraw her guilty plea nor is she entitled to an evidentiary hearing.
3. Motion for a psychiatric examination. On December 2, [317]*3171997, the defendant filed a motion requesting that the court approve funds for an independent psychiatric examination pursuant to G. L. c. 261, §§ 27A-27G, in order to determine (1) whether she suffered from battered woman’s syndrome or any other psychological disorder at the time of the alleged offense and (2) whether she lacked the state of mind necessary to support a conviction. In the alternative, she requested an examination by a psychiatrist designated by the court.
The motion judge found that the defendant was not entitled to an independent examination pursuant to G. L. c. 261, §§ 27A-27G. Chapter 261, § 27C(4), as amended by St. 1980, c. 539, § 7, assures an indigent defendant those fees or costs which are “reasonably necessary to assure [him] as effective a prosecution, defense or appeal as he would have if he were financially able to pay” (emphasis added). The defendant’s request for an independent examination was made in connection with a postconviction Mass.R.Crim.P. 30(b) motion to withdraw her guilty plea. “[A] motion for postconviction relief ... is distinguishable from an ‘appeal,’ which is ordinarily defined as ‘[r]esort to a superior (i.e. appellate) court to review the decision of an inferior (i.e. trial) court or administrative agency.’ ” Commonwealth v. Davis, 410 Mass. 680, 684 n.6 (1991), quoting from Black’s Law Dictionary 96 (6th ed. 1990). Because the defendant’s request in this case did not involve a “prosecution, defense or appeal,” the judge denied the motion.
The defendant concedes that the motion judge did not err in refusing to provide her with funds for an independent psychiatric examination pursuant to §§ 27A-27G. However, she claims that the motion judge failed to consider her alternate claim that she is entitled to an examination by a court-appointed psychiatrist. It does appear from the motion judge’s memorandum of decision that he failed to consider this claim.
The defendant asserts that she is entitled to an examination by a court-appointed psychiatrist pursuant to G. L. c. 123, § 15(a), as inserted by St. 1986, c. 599, § 38, which provides:
“Whenever a court of competent jurisdiction doubts whether a defendant in a criminal case is competent to stand trial or is criminally responsible by reason of mental illness or mental defect, it may at any stage of the proceedings after the return of an indictment or the issuance of a criminal complaint against the defendant, order an [318]*318examination of such defendant to be conducted by one or more qualified physicians or one or more qualified psychologists. . . . When an examination is ordered, the court shall instruct the examining physician or psychologist in the law for determining mental competence to stand trial and criminal responsibility.” (Emphasis added.)
Even if the battered woman’s syndrome defense were available to the defendant, it would not support her claim under c. 123, § 15(a). “Lack of criminal responsibility requires the existence of a mental disease or defect, which causes the defendant to lack the substantial capacity either to appreciate the wrongfulness of his or her acts, or to conform his or her conduct to the requirements of the law.” Commonwealth v. Hall, 45 Mass. App. Ct. 146, 152 (1998), quoting from Commonwealth v. Seabrooks, 425 Mass. 507, 515 (1997). Many courts have found that battered woman’s syndrome is not a mental disease, defect or illness. See Commonwealth v. Hall, supra at 149 (expert witness testified that battered woman’s syndrome is “not itself a diagnosis or an illness”); United States v. Johnson, 956 F.2d 894, 899-900 (9th Cir. 1992) (“Battered woman’s syndrome is not a gross, identifiable mental defect”); People v. Aris, 215 Cal. App. 3d 1178, 1194 (1989) (battered woman’s syndrome is not a mental illness); State v. Borrelli, 227 Conn. 153, 169 n.13 (1993); Bechtel v. State, 840 P.2d 1, 7 (Okla. Crim. App. 1992) (battered woman’s syndrome is “not a mental disease in the context of insanity”). See also United States v. Marenghi, 893 F. Supp. 85, 91 n.10 (D. Me. 1995) (“There is no consensus among courts regarding whether the syndrome is properly characterized as a defect”). Rather, battered woman’s syndrome is considered to be a form of post-traumatic stress disorder, which is “an anxiety-related disorder . . . occurring] in response to traumatic events outside the normal range of human experience.” State v. Riker, 123 Wash. 2d 351, 359 (1994), quoting from State v. Janes, 121 Wash. 2d 220, 233 (1993). See People v. Christel, 449 Mich. 578, 588 n.15 (1995); Commonwealth v. Stonehouse, 521 Pa. 41, 62 (1989); State v. Bednarz, 179 Wis. 2d 460, 467 (Ct. App. 1993).
Here, the defendant has offered no evidence to show that battered woman’s syndrome is a mental disease or defect that could have prevented her from being held criminally responsible for Garrett’s death. Cf. Commonwealth v. Hall, supra at 153 (no error in refusal to instruct on lack of criminal responsibility [319]*319where, although expert opined that defendant suffered from battered woman’s syndrome, nothing in expert’s testimony indicated that the condition “either prevented [defendant] from understanding the wrongfulness of her behavior or prevented her from controlling her actions”). Thus, we conclude that the defendant is not entitled to an examination by a court-appointed psychiatrist based on her claim that she suffers from battered woman’s syndrome.
The defendant also argues that she suffers from “other disorders that may have affected her conduct and state of mind.” The defendant’s medical records show that she has been diagnosed with “bipolar disorder” and depression. Again, the defendant has offered no evidence to show that these conditions constitute defects that could have precluded her from being criminally responsible for Garrett’s death. Cf. Commonwealth v. Mellone, 24 Mass. App. Ct. 275, 281 (1987) (no error in refusal to allow psychiatrist’s testimony that the defendant suffered from untreated bipolar disorder and alcoholism, where proposed testimony shed no light on defendant’s capacity to form the specific intent to kill).
We conclude that the defendant was not entitled to a psychiatric examination by a court-appointed psychiatrist. The denial of the defendant’s motions to withdraw her guilty plea, and for a psychiatric examination, is affirmed.
So ordered.