Edit: Later, in R v Robazzini  VSCA 8, the Court of Appeal considered argument that different drugs prevented earlier instances of drug-fueled violence as laying an adequate foundation for using voluntary pre-offence intoxication as an aggravating feature.
57 In my opinion his Honour correctly treated the appellant’s drug taking as an aggravating factor. The logical implication of the submission made by counsel for the appellant is that drug or alcohol consumption at the time of offending cannot be treated as an aggravating factor unless the appellant has previously offended after taking exactly the same drug or drugs (and perhaps even the same quantity of that drug). That view should be rejected.
58 The question the judge was required to ask himself was whether the appellant could reasonably have foreseen that he might act violently if he took a cocktail of drugs. The appellant had been a poly-drug user for many years. In 2003 he threatened to kill his employer with a gun, when he was a user of amphetamines and cannabis. The 2006 offences also occurred after he had taken a mixture of illicit and legal drugs. He had some understanding of the effects of drugs on him, reporting to Dr Keuneman that:
… for over 30 years he had noticed a tendency in himself towards recurrent anger and ‘snapping easily‘ at other people, which he himself ascribed largely to his many years of drug usage.
59 Dr Keuneman observed that the appellant had ‘some insight into the role of a lifetime of illicit drug use … and his propensity to act erratically or violently with these substances on board’. Mr Joblin also said that the appellant’s drug use had a disinhibiting effect. It can be assumed that he was aware of these opinions.
60 If a person acts violently after taking a legal or illicit drug for the first time, he may be unaware of the effect that the drug may have on him, so that his drug use should not be taken into account as an aggravating factor. In this case however, the appellant had used a number of different drugs for many years. He was well aware that they had a disinhibiting effect on him. His moral culpability is not reduced because the ‘cocktail’ he took before he committed these offences was not precisely the same as the different mixtures of drugs he may have taken on other occasions when he acted violently.
In Edwards v The Queen  VSCA 87 the Court didn’t spend very long on the issue before approving Cannon J’s decision to treat use of amphetamine as an aggravating factor [at 23]. This appeal probably highlights a discrepancy between the lower courts and appellate authority on the use of intoxication as mitigation.
Dutch courage is the traditional term (used in cases like R v O’Connor (1980) 146 CLR 64) to refer to an accused voluntarily intoxicating themselves in preparation for the commission of a crime. The expression rarely features today in law or in common usage, but the legal presumption that dutch courage offers no defence still applies.
In O’Connor, Stephen J (who was part of the majority) said:
I have already twice referred to those cases which involve “Dutch courage”, of which the facts of Attorney-General (Northern Ireland) v Gallagher  UKHL 2;  AC 349 provide an instance, or in which there is knowledge on the accused’s part, when he takes excessive quantities of alcohol or drugs, that he is prone to violence when intoxicated. They are, no doubt, prime instances in which an accused should not be able to gain any advantage from his intoxication; nor does he seem likely to in a jurisdiction where the Majewski principle has no operation. In the case of the former the necessary mens rea would seem to be supplied by the act of consciously becoming intoxicated so as to be better fitted for the contemplated crime. In the latter case there is surely recklessness. An accused’s tendency to violent crime when intoxicated, known to him when he takes the fatal drink or drugs, would be evidence of recklessness sufficient on conventional principles to involve mens rea. If lack of contemporaneity is thought to be a difficulty, the analogy of the innocent agent, represented by the drunken state, as the mere instrument of the guilty mind, represented by the previously sober state, may, as is suggested by Smith & Hogan, Criminal Law, 4th ed. (1978),p. 190, be thought to overcome it: R v O’Connor at 103.
(An excellent article by Peter Ridgway summarising O’Connor, Majewski and the use of expert evidence in intoxication cases is in the Murdoch University Electronic Journal of Law, titled Intoxication, Intention and the Role of the Expert Witness.)
The influence of alcohol and/or drugs is frequently relied on in sentencing to lessen moral culpability for offending, but such a plea is not always successful: R v De Jesus (1986) 20 A Crim R 402. In that case, Smith J said at 405:
The applicant also seeks an extension of time for leave to appeal against the effective sentence of twelve years imprisonment imposed with respect to the two crimes of rape with a direction that the applicant serve a period of six years before becoming eligible for parole. The single ground of appeal is “that the sentence was manifestly excessive having regard to the high state of intoxication the applicant was in at the time of the commission of the said offences”.
Such a ground cannot sustain a great deal of argument. It may be that these offences came to be committed because the applicant had had far too much to drink on each occasion but it has been repeatedly stated in this Court that drunkenness will not be taken into account as a mitigating factor. The day has long past when somebody can come along and say, “I have committed these offences but I was full of drink”. If the alcohol is self-induced then that is no answer at all in relation to crimes of which intent is not an element.
There’s been an inclination by the courts recently to treat voluntary intoxication – of drugs or alcohol, or a combination of the two – as a circumstance of significant aggravation. It’s referred to as reckless intoxication. Key to the principle is, as the name suggests, a foresight of the probable consequences that the behaviour will lead to: R v Hay  VSCA 147.
The reasoning is similar to that adopted by the High Court in Jiminez v The Queen (1992) 173 CLR 572 about driver fatigue: the accused might have a diminished mental capability at the time of the offending, but their culpability is increased by the fact that they were aware of the likely consequences of their actions leading up to their diminished capacity.
In R v Martin  VSCA 291 the Court of Appeal dealt with an appeal on sentence that asserted that the intoxication of the appellant should not have been treated as an aggravating factor. This was the same Mr Martin discussed here in April. He had consumed a combination of cannabis and amphetamine and killed a motorist whilst under the delusion that he was being chased by aliens. Bongiorno J rejected the claim of cannabis-induced psychosis under s 20 of the Crimes (Mental Impairment and Fitness to be Tried) Act 1997 at trial, and the accused was convicted.
The Court of Appeal considered Mr Martin’s use of illicit drugs, against medical advice and in the context of a long-standing addiction, to be an aggravating feature of his offending when they heard his appeal on sentence.
If the prosecution don’t raise reckless intoxication as an aggravating feature at sentencing, it’s highly unlikely that the Crown would be permitted to raise it as a fresh ground on appeal: DPP v Dowie  VSCA 15; DPP v Avci  VSCA 256.