Appellant, a drug addict with schizoid traits, was indicted in seven counts for offenses allegedly committed during the holdup of a store. At his trial, the sole defense was insanity. This issue was submitted to the jury, and it found him guilty on five counts.1 He now contends that the trial judge erroneously refused to enter a judgment of acquittal, and misinstructed the jury on the relationship between his mentality, his addiction and the acts comprising the offenses. We affirm.
I
It is against a background of fundamentals judicially formulated that we must examine appellant’s claim that the evidence required his acquittal. With us, “an accused is not criminally responsible if his unlawful act was the product of mental disease or mental defect,” 2 a standard thus combining a quality of mind and its linkage with the offending conduct. Exculpation entails an “abnormal condition of the mind which substantially affects mental or emotional processes and substantially impairs behavior controls,” 3 and which “made the effective or decisive difference between doing and not doing the act.” 4 An insanity defense, legitimately invoked, though involving narcotism as an operative factor, stands or falls according to the Government’s capability to dispel all reasonable doubt in that regard.5
*989Our decisions also define boundaries within which the interplay of drug addiction is confined. The fact of addiction standing alone, does not permit a finding of mental disease or defect.6 Evidence of that fact, however, has probative value in conjunction with evidence of mental illness,7 and the effect of a deprivation of narcotics on behavioral controls is a relevant circumstance. 8 We have recognized, too, that extensive and protracted addiction may so deteriorate such controls as to produce irresponsibility within our insanity test.9 But we have also made it plain that although a narcotic habit is causally connected with the crime, the defense is negated if the power of self-restraint is not diminished significantly.10
During the nearly five days of trial, three psychiatrists, two psychologists and four laymen gave testimony supplying antithetical answers to most of the critical inquiries. To indicate the decisional possibilities open to the jury, we need only summarize briefly the ultimate facts authorized, more frequently alternatively, by the proofs.11 All experts agreed that appellant was chronically addicted to the use of heroin and that the criminal acts were in some wise connected with his addiction. They also concurred in the opinion that he had schizoid tendencies12 but that, addiction aside, they did not amount to mental illness.13 One psychiatrist felt that appellant had a schizoid personality which led to the addiction, and to mental disease as the combinational result. The other two psychiatrists were firm in their views that appellant was not mentally sick.14
*990In similar fashion, the evidence suggested divergent solutions for the problems of causality. The one psychiatrist finding mental illness opined that the offenses charged were its product,15 but much of the testimony indicated the contrary. Two police officers stated, on personal observation, that appellant did not appear to be in a stage of withdrawal when arrested. The evidence discloses no symptom of withdrawal until about twenty hours after he was taken into custody. The two remaining psychiatrists concluded that withdrawal when the offenses were committed was medically improbable.16
In this milieu, the trial judge was called upon to “determine whether upon the evidence, giving full play to the right of the jury to determine credibility, weigh the evidence, and draw justifiable inferences of fact, a reasonable mind might fairly conclude guilt beyond a reasonable doubt.”17 Of course, as only recently we said, “the facts adduced as to the existence and impact of an accused’s mental condition may be so overwhelming as to require a judge to conclude that no reasonable juror could entertain a reasonable doubt.”18 But when insanity is raised as a defense to crime, a judgment of acquittal by reason thereof, we have emphasized, should be granted only in exceptional cases.19 And “in view of the complicated nature of the decision to be *991made — intertwining moral, legal, and medical judgments — it will require an unusually strong showing to induce us to reverse a conviction because the judge left the critical issue of criminal responsibility with the jury.” 20 We think it clear that in this case the trial judge left it where it belonged.21
II
After both sides rested, appellant submitted to the court three written requests for instructions to the jury, two of which were granted in substance The other, set forth below,22 was properly denied. The request was inaccurate in its statement that “[a] 11 the psychiatrists who testified * * * stated that in their opinion * * * [the] crimes were causally related to the addiction in the sense that he was deprived of narcotics at the time and was under a compulsive need to obtain them and to obtain money with which to obtain them.”23 Nor was it true that “the relationship of [appellant’s] addiction to the crimes [is] not substantially disputed.” 24 And, to the extent that the request sought to license the jury to “find that his narcotic addiction alone was such a mental abnormality as to substantially affect his mental or emotional processes and substantially impair his behavior controls,” it flew into the face of our previous decisions.25 The trial judge was not required to give the instruction in the shape in which it was proffered 26
Appellant’s present position involves, however, a shift in emphasis as to the interconnection of his addiction and the insanity defense he advanced. While in the trial court the thrust of his claim was that narcotic addiction may of itself be a mental abnormality crippling emotional processes, he now insists that the jury should have been instructed to consider his addiction, not alone but in rela*992tion to other circumstances, as supporting the insanity defense. We have indeed recognized that “[t]here may well be some cases where prolonged and extensive use of narcotics has substantially impaired the capacity to control behavior, and a ‘mental disease’ within our [insanity] standards may result.”27 And when we pointed out that “a mere showing of narcotics addiction, without more, does not constitute ‘some evidence’ of mental disease or ‘insanity’,”28 we hastened to add that this was “not to say that evidence that an accused is an addict is without probative value along with other evidence on the issue of responsibility.” 29 Certainly, considering the evidence, the trial judge might properly have given an instruction focusing consideration on the combination of appellant’s long-standing addiction and other indicia of mental involvement.
But appellant did not request specifically an instruction of the latter type, nor was the charge objected to on account of the fact that the trial judge did not volunteer one. In such circumstances, we would not set any sort of novel precedent were we to ignore the point.30 On the other hand, the evidence was strong, not only as to appellant’s addiction, but also as to a quantum of mental weakness arising independently of it, and appellant’s request did implore, albeit faintly some advice associating the two for the benefit of the jury. We are thus constrained to explore the kind and degree of guidance the trial court afforded in this regard.
The trial judge gave a full and completely fair insanity charge during the course of which twice, for purposes of emphasis, he supplied the basic definition of mental illness:
“A mental disease, or a mental defect, in the eyes of the law for the purpose of this case, includes any abnormal condition of the mind which substantially affect [ste] the mental or emotional processes, and substantially impairs behavioral control.
“The term, ‘behavioral control,’ refers to the processes and ability of a human being to regulate and control his conduct and his actions.”
We note initially that this definition, which the judge described as “the gist of the whole case,” did not exclude, but was itself broad enough to embrace, combina-tional consideration of addiction with other factors in the determination of mental abnormality. Indeed, at one stage of the charge, “addiction” was put on the same plane with “disease” and “defect,” eo nomine, as mental “conditions” which, weighed circumstantially with labels removed, might establish blameworthiness. Referring to the labels, including “narcotic addiction,” the witnesses had used in their testimony, the judge admonished that
“ * * * you must realize that the core of this problem is not one of labels, or technical, medical jargon. It is not a question of whether some condition is classified as being underlying, classified as being a disease, a defect, or addiction.
*993“Bather, the key question that will unlock the door is whether this defendant, at the time he committed the act alleged in the indictment, was suffering from an abnormal condition of the mind and, if so, whether that condition substantially affected his mental or emotional processes and substantially impaired his behavioral control.” (Emphasis supplied.)
Additionally, the trial judge in his charge referred to the “voluminous testimony in this case concerning the narcotic addiction of the defendant,” and told the jury that “[njarcotic addiction, without something more” would not establish insanity. This rather clearly implied that coupled with “something more” addiction might amount to insanity. This implication was soon made explicit when the judge, very much in line with the theory of the defense, informed the jury that it might
“ * * * consider whether the defendant in this case was using drugs at the time of the alleged offense and, if so, whether at the time of the alleged offense, the intake and the effect of the drug so substantially affected his controlled [sic] processes and so substantially impaired his behavioral control so that he could not control his common sense at the time.”
Benefited by hindsight, one may say that the instructions did not connect mentality with addiction as clearly as might have been done. But in our view they did not disfavor but actually encouraged the alliance. It seems to us that there was enough to have the jury understand that any factor or group of factors — including narcotic addiction and barring only “[njarcotic addiction, without something more”— which met the test for insanity would suffice to immunize appellant from conviction.31 We think, too, that an assumption that to have said more might have resulted in a different verdict would involve a high degree of speculation. At the very least, we must appraise the situation as clearly unexceptional and the probability of prejudice as quite doubtful. In these circumstances, we feel that reversal is neither required nor warranted.32
While, on this appeal, we so conclude, we utilize this opportunity to say a word of caution. We trust that, with what we have said, it is now clear that defense counsel should ask for an instruction on the combinational effect of any narcotic addiction and mental deficiency indicated by substantial evidence. Trial judges will in the future be well advised to consider such an instruction in appropriate situations, whether requested or not.33 We affirm here because we perceive no prejudice, but in another case there quite easily could be. A proper determination *994of criminal responsibility is too transcendent a matter to be exposed to that sort of risk.
Affirmed.
. Assault with a dangerous weapon (two counts), assault on a police officer, robbery and carrying a pistol without a license. D.C.Code §§ 22-502, 22-505, 22-2901,22-3204 (1967 ed.). Concurrent sentences were imposed on all counts.
. Durham v. United States, 94 U.S.App.D.C. 228, 241, 214 F.2d 862, 874-875, 45 A.L.R.2d 1430 (1954).
. McDonald v. United States, 114 U.S.App. D.C. 120, 124, 312 F.2d 847, 851 (en banc 1962).
. Carter v. United States, 102 U.S.App.D.C. 227, 236, 252 F.2d 608, 617 (1957).
. See Green v. United States, 127 U.S.App.D.C. 272, 383 F.2d 199, 200-201 (1967); Greene v. United States, 122 U.S.App.D.C. 150, 151, 352 F.2d 366, 367 *989(1965); Heard v. United States, 121 U.S.App.D.C. 37, 38, 39, 40, 348 F.2d 43, 44, 45, 46 (1964); Castle v. United States, 120 U.S.App.D.C. 398, 400 n. 1, 347 F.2d 492, 494 n. 1 (1964), cert. denied 381 U.S. 929, 85 S.Ct. 1568, 14 L.Ed.2d 687 (1965); Brown v. United States, 118 U.S.App.D.C. 76, 77, 331 F.2d 822, 823 (1964); Hightower v. United States, 117 U.S.App.D.C. 43, 46, 325 F.2d 616, 619 (1963), cert. denied 384 U.S. 994, 86 S.Ct. 1903, 16 L.Ed.2d 1009 (1966); Horton v. United States, 115 U.S.App.D.C. 184, 185, 317 F.2d 595, 596 (1963).
. Green v. United States, supra note 5, at 200, 201 of 383 F.2d; Heard v. United States, supra note 5, 121 U.S.App.D.C. at 38, 348 F.2d at 44; Castle v. United States supra note 5, 120 U.S.App.D.C. at 401, 402, 347 F.2d at 495-496 (concurring opinion). See also Hutcherson v. United States, 120 U.S.App.D.C. 274, 280, 345 F.2d 964, 970 (concurring opinion), cert. denied 382 U.S. 894, 86 S.Ct. 188, 15 L.Ed.2d 151 (1965).
. Green v. United States, supra note 5, at 201 of 383 F.2d; Heard v. United States, supra note 5, 121 U.S.App.D.C. at 38, 348 F.2d at 44.
. See Heard v. United States, supra note 5, 121 U.S.App.D.C. at 39-40, 348 F.2d at 45-46; Castle v. United States, supra note 5, 120 U.S.App.D.C. at 399, 347 F.2d at 493. See also Greene v. United States, supra note 5, 122 U.S.App.D.C. at 151, 352 F.2d at 367.
. Green v. United States, supra note 5, at 201 of 383 F.2d. See also Hutcherson v. United States, supra note 6, 120 U.S.App.D.C. at 280, 345 F.2d at 970 (concurring opinion).
. See Green v. United States, supra note 5, at 201 of 383 F.2d; Heard v. United States, supra note 5, 121 U.S.App.D.C. at 38 n. 2, 39-40, 348 F.2d at 44 n. 2, 45-46; Castle v. United States, supra note 5, 120 U.S.App.D.C. at 399-400, 347 F.2d at 493-494; Hightower v. United States, supra note 5, 117 U.S.App.D.C. at 45-46, 325 F.2d at 618-619.
. We do not intend to imply that the expert witnesses limited themselves to bare conclusions. On the contrary, they supported their individual views in a manner sufficient, in our view, to promote adequate understanding by the jury.
. Additionally, two of the lay witnesses related incidents of abnormal behavior on appellant’s part.
. One of the psychologists testified that there was no mental defect, but that he found a severe schizoid personality trait disturbance. The other psychologist stated that an examination of appellant in 1960 revealed schizophrenic trends.
. One testified that appellant’s schizoid characteristics were not sufficiently severe to constitute mental illness. The other found schizoid features only to a very limited degree and did not “even agree he has a schizoid personality.”
. The witness reasoned: Appellant had a schizoid personality which of itself did not impair behavioral controls. This personality disorder led to his addiction, and the combination resulted in mental disease. The criminal acts were committed to obtain money with which to purchase narcotics, with the result that the crimes were causally related to the addiction and were the product of mental disease.
This witness was unable to determine whether appellant was in a stage of withdrawal at the time of commission of the offenses. He stated, however, that he believed a statement by appellant that he was withdrawing at that time and that, if so, his behavioral controls would have been impaired.
. To one of these witnesses it was “impossible” that a person “committing this type of an offense in the manner in which it was described” was in withdrawal. Rather, it seemed to the witness, appellant was in the “extremely long period * * * of perfectly rational, reasonable, coherent and normal behavoir” following an intake of narcotics. The other witness thought that there was “probably and very likely some connection” between the addiction and the offenses in that “in the search for narcotics, he committed this act in order to get money,” but that an addict “is in perfectly good possession of his faculties and he is able to do what he has to do pretty much” during “a variable period” between the “flash” which follows one injection of heroin and the withdrawal which may precede the next. “This is the period,” the witness continued, “when he knows what he is doing and he goes about doing what he wants to do.” From the fact that for so long after his arrest appellant did not complain of withdrawal symptoms, this witness “would have to assume that prior to that time, he was in an adequate state of control and, gradually, did he begin to experience these symptoms of discomfort.”
. Curley v. United States, 81 U.S.App.D.C. 389, 392, 160 F.2d 229, 232, cert. denied 331 U.S. 837, 67 S.Ct. 1511, 91 L.Ed. 1850 (1947) . See also, Rowe v. United States, 125 U.S.App.D.C. 218, 219, 370 F.2d 240, 241 (1966); Wright v. United States, 102 U.S.App.D.C. 36, 39, 250 F.2d 4, 7 (en banc 1957); Bates v. United States, 95 U.S.App.D.C. 57, 58-59, 219 F.2d 30, 32, cert. denied 349 U.S. 961, 75 S.Ct. 891, 99 L.Ed. 1283 (1955) ; Cooper v. United States, 94 U.S.App.D.C. 343, 345, 218 F.2d 39, 41 (1954); Pritchett v. United States, 87 U.S.App.D.C. 374, 375, 185 F.2d 438, 439 (1950), cert. denied 341 U.S. 905, 71 S.Ct. 608, 95 L.Ed. 1344 (1951); McGuire v. United States, 84 U.S.App.D.C. 64, 66, 171 F.2d 136, 138 (1948) .
. King v. United States, 125 U.S.App.D.C. 318, 324, 372 F.2d 383, 389 (1966).
. Douglas v. United States, 99 U.S.App.D.C. 232, 237, 239 F.2d 52, 57 (1956). See also Gray v. United States, 115 U.S.App.D.C. 324, 327, 319 F.2d 725, 728 (concurring opinion), cert. denied 375 U.S. 849, 84 S.Ct. 104, 11 L.Ed.2d 76 (1963); Campbell v. United States, 113 U.S.App.D.C. 260, 261, 307 F.2d 597, 598 (1962); Turberville v. United States, 112 U.S.App.D.C. 400, 403, 303 F.2d 411, 414, cert. denied 370 U.S. 946, 82 S.Ct. 1607, 8 L.Ed.2d 813 (1962).
. King v. United States, supra note 18, 125 U.S.App.D.C. at 324, 372 F.2d at 389.
. Compare Castle v. United States, supra note 5, 120 U.S.App.D.C. at 400, 347 F.2d at 494; Rivers v. United States, 117 U.S.App.D.C. 375, 376, 330 F.2d 841, 842 (1964). See also Horton v. United States, supra note 5, 115 U.S.App.D.C. at 185, 317 F.2d at 596.
. The requested instruction read:
“The theory of the defense is that at the time of the crimes in question, the defendant was suffering from an abnormal condition of the mind called a schizoid personality disorder, and that this mental abnormality was associated with another abnormal condition of both mind and body, namely narcotic addiction. All the psychiatrists who testified both for the defendant and for the government, stated that in their opinion the defendant was actively addicted to narcotics on the date of the crimes, and that those crimes were causally related to the addiction in the sense that he was deprived of narcotics at the time and was under a compulsive need to obtain them and to obtain the money with which to obtain them. The fact of defendant’s addiction and the relationship of that addition to the crimes are not substantially disputed. What is disputed is whether the narcotic addiction was the symptom [sic] and manifestation of an underlying mental illness.
“You are instructed that if the defendant was under a compulsive need to obtain narcotics at the time of the offenses, and if he committed the offenses for that reason, then you may find that his narcotic addiction alone was such a mental abnormality as to substantially affect his mental or emotional processes and substantially impair his behavior controls. You are further instructed that in considering to what extent defendant’s narcotic addiction was a mental abnormality, you may consider the causes of his addiction: whether his addiction was the voluntary act of a mentally normal person or whether it was the act of a person suffering from underlying abnormality.”
. See notes 15 and 16, supra, and related text.
. See notes 15 and 16, supra, and related text.
. See the cases cited supra note 6.
. See Guerini Stone Co. v. P. J. Carlin Const. Co., 240 U.S. 264, 283, 36 S.Ct. 300, 60 L.Ed. 636 (1916); Ruffin v. United States, 106 U.S.App.D.C. 97, 98-99, 269 F.2d 544, 545-546, cert. denied 361 U.S. 865, 80 S.Ct. 129, 4 L.Ed.2d 107 (1959).
. Green v. United States, supra note 5, at 201 of 383 F.2d.
. Heard v. United States, supra note 5, 121 U.S.App.D.C. at 38, 348 F.2d at 44.
. Ibid.
. Very recently we refused, in circumstances quite similar to those appearing here, to consider on its merits a contention that another aspect of the addiction-insanity problem should have been a subject ■ of the charge. Castle v. United States, supra note 5, 120 U.S.App.D.C. at 400-401, 347 F.2d at 494-495. See also Singer v. United States, 380 U.S. 24, 38, 85 S.Ct. 783, 13 L.Ed.2d 630 (1965); Shepherd v. United States, 108 U.S.App.D.C. 240, 242, 281 F.2d 603, 605, cert. denied 364 U.S. 916, 81 S.Ct. 281, 5 L.Ed.2d 229 (1960); McCall v. United States, 89 U.S.App.D.C. 153, 154, 191 F.2d 470, 471 (1951). It seems that we cannot too strongly or too frequently call attention to the importance of adherence to the requirements of F.R.Crim.P. 30 if counsel’s instructional wishes are to be effectuated.
. Compare Castle v. United States, supra note 5, 120 U.S.App.D.C. at 400, 347 F.2d at 494, where we affirmed a conviction although we recognized that the trial judge’s charge “perhaps suffers somewhat, in terms of its helpfulness to the jury in evaluating the defense of insanity based on drug addiction, from its failure to refer expressly to the relationship which narcotics addiction may be found to have to mental disease or defect.” See also Ruffin v. United States, supra note 26, 106 U.S.App.D.C. at 98-99, 269 F.2d at 545-546; May v. United States, 84 U.S.App.D.C. 233, 250, 175 F.2d 994, 1011, cert. denied 97 L.Ed. 666, 338 U.S. 830, 70 S.Ct. 58, 94 L.Ed. 505 (1949) ; Weldon v. United States, 87. U.S.App.D.C. 113, 116, 183 F.2d 832, 835 (1950) , cert. denied 343 U.S. 967, 72 S.Ct. 1063, 96 L.Ed. 1364 (1952).
. Compare Hardy v. United States, 119 U.S.App.D.C. 364, 365, 343 F.2d 233, 234 (1964), cert. denied 380 U.S. 984, 85 S.Ct. 1353, 14 L.Ed.2d 276 (1965); Jackson v. United States, 91 U.S.App.D.C. 60, 198 F.2d 497, cert. denied 344 U.S. 858, 73 S.Ct. 96 (1952) ; Cratty v. United States, 82 U.S.App.D.C. 236, 242, 163 F.2d 844, 850 (1947).
. We are advertent to the difficult problems trial judges frequently encounter in deciding whether to charge on particular subjects, especially when unsolicited legal propositions might impinge upon defense strategy, which is the responsibility of counsel. We suggest that ofttimes the dilemma can be dissolved by the simple expedient of thrashing the matter out with counsel before the charge is delivered.