Appellant was convicted of manslaughter and sentenced to from five to fifteen years’ imprisonment. He had been charged with second degree murder for aiding and abetting his employer, Davis, in the shooting of one Jenkins during an altercation. The District Court allowed this appeal in forma pauperis and we appointed new counsel. After the case was heard by a division of this court, a rehearing en banc was ordered sua sponte.
In this appeal appellant urges that the court’s charge to the jury was fatally defective in two respects. First, the court failed to state that, if acquitted by reason of insanity, appellant would be confined in a mental hospital until it was determined that he was no longer dangerous to himself or others. D.C.Code § 24-301 (d). This statement is required unless it “appears affirmatively on the record” that the defendant did not want it. Lyles v. United States, 103 U.S.App.D.C. 22, 25, 254 F.2d 725, 728, certiorari denied, 356 U.S. 961, 78 S.Ct. 997, 2 L.Ed.2d 1067.
Second, in its charge the court twice enumerated the alternative verdicts available to the jury. But both times it failed *849to include “not guilty because of insanity.” Thus, before charging on the issue of insanity, the court instructed the jury to return one of the following five possible verdicts: (1) guilty of second degree murder, (2) guilty of manslaughter, (3) guilty of assault with a dangerous weapon, (4) guilty of assault, or (5) not guilty. (Tr. 275.) Later the court did charge the jury on criminal responsibility, concluding: “If you * * * are not satisfied beyond a reasonable doubt that the act was not a product of a mental defect, then your verdict must be not guilty because of insanity.” (Tr. 288.)
After the charge was concluded, the court called a bench conference at which defense counsel expressed substantial1 satisfaction with the instructions, making no reference to or request concerning the so-called Lyles instruction on mandatory commitment of persons found not guilty by reason of insanity. Thereupon the court told the jury:
“I am going to repeat something that I said to you earlier and that is that you may return any one of five possible verdicts in this case. Your verdict may be either guilty of second degree murder or guilty of manslaughter or guilty of assault with a dangerous weapon or guilty of assault or not guilty.” (Tr. 290.)
The Government urges us to find from defense counsel’s failure to object to the court’s charge that it “appears affirmatively” that appellant did not want the Lyles instruction on hospital confinement, and that the omission of an insanity ver-diet from the court’s lists of alternatives must be deemed harmless because of reference to it elsewhere. The Government also urges that the evidence was insufficient to require an instruction on responsibility, hence any defects in the instruction are immaterial. We do not agree that the instruction was unnecessary.
I.
Under Davis v. United States, 160 U.S. 469, 16 S.Ct. 353, 40 L.Ed. 499, if there is “some evidence” supporting the defendant’s claim of mental disability, he is entitled to have that issue submitted to the jury. Under Durham v. United States, 94 U.S.App.D.C. 228, 214 F.2d 862, evidence of a “mental disease” or “mental defect” raises the issue. The subject matter being what it is, there can be no sharp quantitative or qualitative definition of “some evidence.” Certainly it means more than a scintilla,2 yet, of course, the amount need not be so substantial as to require, if uncontroverted, a directed verdict of acquittal.3 The judgment of the trial judge as to the sufficiency of the evidence is entitled to great weight on appeal, but, since the defendant’s burden is merely to raise the issue, any real doubt should be resolved in his favor.4
In this case a psychiatrist and a psychologist testified that the defendant had a “mental defect,” principally because his I.Q. rating shown by various tests was below the “average” intelligence range of 90 to 110. His overall I.Q. was 68. Neither witness was able to say whether ap*850pellant’s mental defect stemmed from organic injury or from some other cause. But the psychiatrist testified that some organic pathology can only be established by autopsy and that McDonald’s defect probably prevented him from progressing beyond the sixth grade.
The witnesses also explained generally how mental defect affects behavior. The psychologist testified that a person suffering from a mental defect would have less ability than normal persons to distinguish between right and wrong in complex situations (Tr. 233); would tend to act impulsively under stress (ibid.); and would readily become dependent upon and be strongly influenced by someone who befriended him (Tr. 234-235). The witness testified further that McDonald had a mental defect, which she defined as “a state of mental development which does not reach the level of average intelligence,” (Tr. 245) and that “if McDonald had a person on whom he was dependent * * * and if that person should produce a gun and threaten another * * * McDonald [would not] be as able as the average adult to assess and evaluate the situation and the consequences of whatever action he might take * * * ” (Tr. 235).5 The psychiatrist stated that McDonald would lack the ability of normal persons to foresee the consequences of his acts and offered an opinion that appellant’s relationship to Davis was to some extent a product of his mental deficiency.
Evidence of a 68 I.Q. rating, standing alone and without more, is not evidence of a “mental defect,” thus invoking the Durham charge. Where, as here, other evidence of mental abnormality appears, in addition to the I.Q. rating, the Davis case would control and the instruction should be given. The introduction of competent evidence of mental disorder raises the issue of causality sufficient for jury consideration. See Durham v. United States, 94 U.S.App.D.C. 228, 241, n. 49, 214 F.2d 862, 875, n. 49; Blocker v. United States, 107 U.S.App.D.C. 63, 274 F.2d 572; Goforth v. United States, 106 U.S.App.D.C. 111, 269 F.2d 778; United States v. Amburgey, D.D.C., 189 F.Supp. 687. Cf. Tatum v. United States, 88 U.S.App.D.C. 386, 190 F.2d 612.
It does not follow, however, that whenever there is any testimony which may be said to constitute “some evidence” of mental disorder, the Government must present affirmative rebuttal evidence or suffer a directed verdict. A directed verdict requires not merely “some evidence,” but proof sufficient to compel a reasonable juror to entertain a reasonable doubt concerning the accused’s responsibility.6 Durham v. United States, 94 U.S.App.D.C. at 232, n. 8, 214 F.2d at 866, n. 8; Hall v. United States, 4 Cir., 295 F.2d 26. See 9 Wigmore, Evidence, § 2487; Abbott, Two Burdens of Proof, 6 Harv.L.Rev. 125. Whether uncontradicted evidence, including expert opinion evidence, which is sufficient to raise a jury question on the mental issue is also sufficient to require a directed verdict depends upon its weight and credibility. Douglas v. United States, 99 U.S.App.D.C. 232, 239 F.2d 52. Davis v. United States, 160 U.S. 469, 16 S.Ct. 353, 40 L.Ed. 499, clearly supports this position. There the Supreme Court said that the jury, in considering an insanity plea, must weigh all the evidence, including the presumption of sanity. 160 U.S. at 488,16 S.Ct. at 358. Whether uncontradicted expert testimony overcomes' the presumption depends upon its weight and credibility, and weight and credibility ordinarily are for the jury. See Stewart v. United States, 94 U.S.App.D. C. 293, 295, 214 F.2d 879, 882.
II.
Our eight-year experience under Durham suggests a judicial defini*851tion, however broad and general, of what is included in the terms “disease” and “defect.” In Durham, rather than define either term, we simply sought to distinguish disease from defect. Our purpose now is to make it very clear that neither the court nor the jury is bound by ad hoc definitions or conclusions as to what experts state is a disease or defect. What psychiatrists may consider a “mental disease or defect” for clinical purposes, where their concern is treatment, may or may not be the same as mental disease or defect for the jury’s purpose in determining criminal responsibility. Consequently, for that purpose the jury should be told that a mental disease or defect includes any abnormal condition of the mind which substantially affects mental or emotional processes and substantially impairs behavior controls. Thus, the jury would consider testimony concerning the development, adaptation and functioning of these processes and controls.
We emphasize that, since the question of whether the defendant has a disease or defect is ultimately for the triers of fact, obviously its resolution cannot be controlled by expert opinion.7 The jury must determine for itself, from all the testimony, lay and expert, whether the nature and degree of the disability are sufficient to establish a mental disease or defect as we have now defined those terms. What we have said, however, should in no way be construed to limit the latitude of expert testimony.8 Carter v. United States, 102 U.S.App.D.C. 227, 236, 252 F.2d 608, 617.
III.
Having determined in Part I hereof that the charge on criminal responsibility was required, we revert now to a consideration of the other contentions made by the parties with respect to that charge as given. The able and experienced trial court, in the course of the charge, failed to give the Lyles instruction concerning the disposition of a defendant acquitted by reason of insanity, and we are unable, from our study of the record, to say that this defendant affirmatively waived it. Lyles v. United States, supra, 103 U.S.App.D.C. at 25-26, 254 F.2d at 728-729. Since the case will have to be retried, it may be well simply to note two other inadvertences in the court’s- charge which we are confident will not recur on retrial.
As heretofore indicated, following a bench conference after the judge had concluded his charge, an additional instruction was given the jury, outlining the alternative possible verdicts, without including not guilty by reason of insanity. Also, in its concluding remarks relating to mental responsibility of the accused, the court charged as follows:
“If you find that this defendant committed this offense, that is, murder in the second degree or the lesser included offenses and you further find that at the time he committed this offense he was suffering from a mental disease or defect which affected him, that he was incapable of distinguishing right from wrong or if he could tell right from wrong was incapable of controlling his actions, then you would find that the defendant’s act was the product of the defendant’s mental abnormality.” (Tr. 283.)
This is not an accurate statement of the test for criminal responsibility in this Circuit. We think the jury may be instructed, provided there is testimony on the point, that capacity, or lack thereof, to distinguish right from wrong and ability to refrain from doing a wrong or unlawful act9 may be considered in determining whether there is *852a relationship between the mental disease and the act charged. It should be remembered, however, that these considerations are not to be regarded in themselves as independently controlling or alternative tests of mental responsibility in this Circuit. They are factors which a jury may take into account in deciding whether the act charged was a product of mental disease or mental defect. Wright v. United States, supra, 102 U.S.App.D.C. at 44, 250 F.2d at 12; Misenheimer v. United States, 106 U.S.App.D.C. 220, 271 F.2d 486, certiorari denied, 361 U.S. 971, 80 S.Ct. 603, 4 L.Ed.2d 550.
Reversed and remanded.
. Defense counsel requested a further charge upon a matter not relevant here. The court denied the request.
. Battle v. United States, 209 U.S. 36, 38.
. Compare Tatum v. United States, 88 U.S.App.D.C. 386, 190 F.2d 612; Durham v. United States, 94 U.S.App.D.C. 228, 232, 214 F.2d 862, 866; Wright v. United States, 102 U.S.App.D.C. 36, 39, 250 F.2d 4, 7; Logan v. United States, 109 U.S.App.D.C. 104, 284 F.2d 238; Fitts v. United States, 10 Cir., 284 F.2d 108; United States v. Currens, 3 Cir., 290 F.2d 751, 761; Hall v. United States, 4 Cir., 295 F.2d 26.
. In considering the quantum of evidence necessary to raise the issue of criminal responsibility, we cannot ignore our experience that in most cases the accused does not possess the knowledge and financial ability required to seek and obtain expert testimony in his behalf. Ordinarily such persons can only obtain examinations by psychiatrists employed in government institutions, and if these examinations are inadequate, “the [resulting] inadequacy of the evidence is not a point in favor of the prosecution.” Williams v. United States, 102 U.S.App.D.C. 51, 55-56, 250 F.2d 19, 23-24.
. McDonald’s testimony suggests that he was financially and socially dependent upon Davis. (See Tr. 161-163.)
. Wright v. United States, 102 U.S.App.D.C. 36, 250 F.2d 4; Douglas v. United States, 99 U.S.App.D.C. 232, 239 F.2d 52; Satterwhite v. United States, 105 U.S.App.D.C. 398, 267 F.2d 675; Hopkins v. United States, 107 U.S.App.D.C. 126, 275 F.2d 155; Campbell v. United States, 113 U.S.App.D.C. 260, 307 F.2d 597.
. See, however, Isaac v. United States, 109 U.S.App.D.C. 34, 284 F.2d 168, where the evidence required the direction of a judgment of acquittal by reason of insanity.
. See Note 9, infra.
. An expert may not be compelled to testify in these terms if he believes they are essentially moral or legal considerations beyond the scope of his special competence as a behavioral scientist. Stewart v. United States, 101 U.S.App.D.C. 51, 53, 247 F.2d 42, 44.