Involuntary Intoxication

Self-induced intoxication gives a defendant little. Under § 2.08(1) it matters only when it negatives an element of the offense, so the defendant must show that the drinking or drug use prevented a required mental state from forming.¹ Involuntary intoxication is treated far more generously. When it leaves the actor without the capacity that responsibility presupposes, it operates as an affirmative defense, meaning a defense that applies even after the prosecution has proved every element, because it supplies a separate reason not to hold the defendant responsible. Section 2.08(4) states the rule: intoxication that is not self-induced, or that is pathological, is an affirmative defense if it leaves the actor, at the time of the conduct, without substantial capacity either to appreciate the criminality of the conduct or to conform it to the requirements of law.²

The difference follows from the reason voluntary intoxication is refused as an excuse. The law holds a voluntary drinker to the standard of a sober person because the loss of judgment traces back to the drinker's own choice to take a substance known to intoxicate, and that choice stands in for the culpability the impaired state erased. Remove the choice and the substitute disappears. An actor who was forced to drink, who took a substance without knowing what it was, who reacted unforeseeably to prescribed medicine, or who was overcome by a quantity that would not ordinarily intoxicate has no culpable act in the history of the impairment, so the resulting incapacity resembles any other incapacity produced by causes the actor did not bring about. That is the situation the insanity defense addresses, and the consequences line up accordingly. When involuntary intoxication produces incapacity at the level the jurisdiction's insanity test requires, the defense applies even though the condition is only temporary, whereas the same incapacity from voluntary intoxication gives no defense beyond its relevance to mental state unless it becomes permanent.³

Case law recognizes four kinds of involuntary intoxication: coerced intoxication, innocent or mistaken intoxication, an unanticipated reaction to a drug taken on medical advice, and pathological intoxication.⁴ Each removes the actor's fault at a different point. Coercion overrides the actor's choice, a mistake about the substance means the actor consumed something other than what was chosen, a prescribed drug is taken for treatment with no thought of intoxication, and a pathological reaction is out of all proportion to the amount taken. Pathological intoxication needs a separate note because the actor in that case knowingly took the substance, so it would fall within the self-induced category if the analysis stopped at knowledge. Section 2.08(4)(b) therefore names it separately, and the Code defines it by its grossly excessive degree, given the amount of the intoxicant, and by the actor's lack of knowledge of the susceptibility.⁵

Involuntary intoxication can defend in two ways, and the two work differently. First, evidence of it is admissible to disprove the mental state an offense requires, whether that state is specific or general intent, and a defendant who in fact lacked the mens rea as a result is entitled to acquittal.⁶ The general-intent point is less settled in practice. Because the intoxication was acquired without fault, acquittal of a general-intent offense seems warranted, although little case law addresses the matter, and general intent is often understood as intent to perform the physical acts, which an actor is unlikely to lack short of being comatose.⁷ Second, in most jurisdictions involuntary intoxication can ground a temporary insanity claim, and some jurisdictions recognize only that use.⁸ Illinois treats it as a form of the insanity defense, while other states keep the two defenses separate.⁹

Involuntary origin does not by itself excuse. Even when intoxication was contracted without fault, a defendant impaired to a lesser degree is treated like anyone else who has difficulty conforming to the law through no fault of their own, and remains responsible.¹² Section 2.08(4) therefore applies only when the impairment reaches substantial incapacity, so an analysis that stops at the question whether the defendant chose to become intoxicated skips half of the test.¹³ Successful claims are also uncommon, and courts construe the coercion requirement so strictly that acquittal on that ground is exceedingly rare.¹⁴ The sections below begin with the capacity standard that governs every form, and then take up coerced, innocent or mistaken, medication-related, and pathological intoxication in turn.

The Capacity Standard

The capacity standard is the element that every form of involuntary intoxication must satisfy, whatever the source of the impairment. Section 2.08(4) makes intoxication an affirmative defense when it is not self-induced or is pathological and, by reason of it, the actor at the time of the conduct lacks substantial capacity either to appreciate the criminality of the conduct or to conform it to the requirements of law.¹⁶ The provision therefore has two layers. The first concerns where the intoxication came from, which the later sections take up form by form, and the second concerns what the intoxication did to the actor, which is the subject here. Both layers must be present. An actor whose intoxication was self-induced and was not pathological stays outside the provision however severe the incapacity, and is left with the argument that the intoxication negatived an element of the offense.¹⁷

The two capacities map onto the two ways a person's responsibility can fail, and each has its own logic. The first, the capacity to appreciate criminality, is cognitive: an actor who cannot grasp that the conduct is wrong has no means of bringing its wrongfulness to bear on the decision to act, which is the state of mind the M'Naghten test asks about in insanity cases.¹⁸ The second, the capacity to conform conduct to the requirements of law, is volitional: the actor may see the wrong clearly, yet the intoxication has removed the power to hold back, which is the concern of the irresistible-impulse formulation.¹⁹ The prongs are alternatives, so either capacity is enough to complete the element. A rule demanding the loss of both would deny the defense to an actor who understood perfectly well that the act was wrong but, because of a substance never chosen, could not stop, and that actor is no more blameworthy than one who could not tell right from wrong.

The word substantial qualifies both prongs and sets the threshold at approximately the level of incapacity at which a jurisdiction would find an actor legally insane.²⁰ The threshold has a reason. If any loss of judgment or self-control sufficed, nearly every actor who was involuntarily exposed to an intoxicant could claim the defense, and the line between excuse and responsibility would disappear. The Code instead treats an actor whose personality is altered to a lesser degree like anyone else who has difficulty conforming to the law through no fault of their own and is still held responsible.²¹ The measure is also taken at the time of the conduct, so only the actor's condition then counts, and the incapacity may be temporary.²²

Origin alone settles little, as English law illustrates on the mental-state route in Regina v. Kingston. A defendant who claimed to have been secretly drugged by a blackmailer committed an indecent assault on a boy whom the blackmailer had lured to his flat, and the trial judge told the jury that a drugged intent is still an intent.²⁴ The Court of Appeal set the conviction aside, reasoning that when a surreptitiously administered drug makes a person form an intent that would not otherwise have been formed, the operative fault is not the person's own.²⁵ The House of Lords reversed, with Lord Mustill describing a case of disinhibition, in which the drug was not alleged to have created the desire acted upon but only to have released it, and rejecting the argument that the absence of moral fault is by itself enough to negate the mental element.²⁶ An innocent source therefore opens the door to the defense, and the degree of incapacity decides whether the defendant can walk through it.

The capacity language comes from the Code's own insanity test, and jurisdictions divide over whether involuntary intoxication is a separate defense or a species of insanity. In most jurisdictions it can ground a temporary-insanity claim, and some recognize that use alone.²⁷ Illinois treats it as a form of the insanity defense, and other states keep the two separate.²⁸ The division matters because a state that folds the defense into insanity measures capacity by its own insanity test and no other. Indiana requires that the intoxication have at least temporarily put the accused into a state resembling insanity (Heyward v. State), South Carolina applies the M'Naghten test (State v. Pittman), and Texas, after its legislature narrowed the insanity defense to the question whether the defendant knew the conduct was wrong, held that the involuntary-intoxication test narrowed along with it (Mendenhall v. State).²⁹ In such a state an actor who knew the act was wrong but could not control it has no capacity-based defense, though the same actor could satisfy the Code's volitional prong.

A concurring opinion in City of Minneapolis v. Altimus shows how some judges understand the defense. The court treated the statutory insanity standard as the test for a claim of involuntary intoxication, and a concurring judge would have gone further.³⁰ His reasoning was that courts, not legislatures, have traditionally defined the defenses that follow from the principle of mens rea, that involuntary intoxication rests on the absence of volitional fault in the actor, and that it is therefore one of those defenses, so he would have directed an instruction under § 2.08(4).³¹ That view is a concurrence and not a holding. It explains why a court might regard the defense as part of ordinary culpability doctrine rather than a branch of insanity, while the standard the court actually applied was the statutory insanity test.

The capacity standard is not the only way involuntary intoxication helps a defendant. Evidence of it is also admissible to disprove the mental state an offense requires, and at common law it excuses where the intoxication left the actor incapable of forming the required mens rea.³² The two routes differ in threshold and in effect. The capacity route demands substantial incapacity of one of the two kinds and excuses an actor whose conduct satisfied every element, while the mental-state route demands only that the particular mental state was in fact absent and works by defeating that element. A defendant whose impairment falls short of substantial incapacity is therefore not necessarily out of options, since the evidence may still be offered on a required mental state.

Exam Analysis Steps

Because the defense has a source layer, a capacity layer, and a separate fallback on the mental-state element, it is best run in order. The steps are these:

Identify whether the intoxication was not self-induced or was pathological, since a self-induced source takes the case outside § 2.08(4).
Fix the moment of the conduct and ask whether the intoxication then left the actor without substantial capacity to appreciate the criminality of what was done.
If it did not, ask separately whether the intoxication left the actor without substantial capacity to conform the conduct to the requirements of law, because either prong completes the defense.
Check how the jurisdiction frames the defense, because a state that treats it as a form of insanity applies its own insanity test in place of the Code's two prongs.
If neither prong is met, ask whether the intoxication in fact prevented a mental state that the offense requires, which defeats that element without any affirmative defense.

Coerced Intoxication

Coerced intoxication is the first of the four kinds of involuntary intoxication, and it stands apart from the others because the actor knows exactly what is being consumed.³⁴ A person forced to drink is not mistaken about the liquor, does not react to it abnormally, and is not following a doctor's instructions. What removes the case from the voluntary category is the pressure under which the substance went in. The Code's definition of self-induced intoxication supplies the mechanism: intoxication is self-induced when the actor knowingly introduces the substance and knows or ought to know its tendency to intoxicate, unless the actor takes it on medical advice or “under such circumstances as would afford a defense to a charge of crime.”³⁵ The coerced actor does knowingly take a known intoxicant, so the first part of the definition alone would classify the intoxication as self-induced, and it is the final clause that carries the case out of that category.

The clause follows from the reason the law refuses a defense to the ordinary drunk. A person who drinks by choice has made a decision that fairly stays with them when the consequences arrive, whereas a person who drinks because refusal means serious violence has made no choice of that kind. Rather than writing a separate coercion test, the Code borrows the existing law of defenses: if the circumstances of ingestion would themselves excuse a crime, as a threat of serious violence can under the doctrine of duress, they also remove the fault in taking the substance. Once the intoxication is classified as not self-induced, it falls within involuntary intoxication, which is a defense.³⁶ Classification is only the first layer, though, because the capacity standard just discussed still governs, and a coerced drinker who remained able to appreciate the wrongfulness of the conduct and to control it has no affirmative defense. Evidence of the coerced intoxication remains admissible in that case to disprove a required mental state.³⁷

Hypothetical Illustration

A robber presses a knife to a bartender's throat and orders him to finish a bottle of whiskey or be stabbed. The bartender drinks it, understanding perfectly well what the liquor is and what it will do. Because the ingestion occurred under direct duress, the circumstances would afford a defense to a crime, so the intoxication is not self-induced, and the capacity standard is open to him if his impairment becomes substantial.³⁸

Change the pressure and the answer changes with it. At a retirement party, a group of coworkers needle a colleague to finish a bottle of whiskey, teasing that she is no fun if she refuses, but nobody threatens her. She drinks it. Her circumstances would afford no defense to any crime, so the intoxication is self-induced, and she is left with the argument that it negatived a required mental state.³⁹

The fact that moved the answer is the threat. The usual mistake is to treat urging by friends as coercion, even though encouragement and teasing, however persistent and however many people join in, leave the actor free to decline without suffering anything the law recognizes as compulsion. The exception asks whether the circumstances of ingestion would afford a defense to a crime, and a person who is merely urged to drink has no such defense to point to. The ingestion therefore stays knowing and chosen, the intoxication stays self-induced, and the actor gains nothing beyond the ordinary route of showing that the intoxication prevented a mental state the offense requires.⁴⁰

Innocent or Mistaken Intoxication

Coerced intoxication escapes the self-induced label through the final clause of the Code's definition. Innocent or mistaken intoxication escapes it through the definition's two knowledge requirements: the actor must knowingly introduce the substance into the body, and the actor must know or ought to know its tendency to cause intoxication.⁴² Failing either requirement keeps the intoxication out of the self-induced category. The reason follows from why the law withholds a defense from the ordinary drinker in the first place. A person who drinks knowing what the drink will do has chosen to run the risk of impairment, and that choice fairly stays with the person when the consequences arrive. A person who has no idea that a drink contains an intoxicant has made no such choice, so the ground for refusing a defense is missing. Reported cases of this kind are uncommon, though the category is one of the four recognized kinds of involuntary intoxication.⁴³

The category has two forms, and each fails a different part of the definition. In the innocent form, the actor does not know that an intoxicant is present at all, as when a prankster spikes the punch at a school dance. The actor knowingly drinks punch but has not knowingly introduced the intoxicant, and nothing about ordinary punch would tell a reasonable drinker that it tends to intoxicate. In the mistaken form, the actor knows that he is taking something but is wrong about what it is, so the second requirement, knowledge of its tendency to intoxicate, is the one that fails. The standard illustration is spiked punch at a senior prom: a student who drinks punch that was spiked without his knowledge and suffers a psychosis as a result is involuntarily intoxicated, and People v. Scott is a reported case in which spiked punch led to psychosis.⁴⁴

The words “knows or ought to know” give the second requirement an objective edge.⁴⁶ Actual ignorance does not keep the self-induced label off if a reasonable person in the actor's position would have recognized that the substance tends to intoxicate. A drinker who tastes straight liquor in a supposedly soft drink and keeps drinking therefore falls on the self-induced side of the line, while a drinker who tastes nothing unusual does not. The question to ask about any spiked-drink fact pattern is why the actor did not know, because ignorance that a reasonable person would have shared supports the defense and ignorance that a reasonable person would have overcome does not.

Once the intoxication is classified as not self-induced, it counts as involuntary intoxication, and the capacity standard from the preceding section becomes available. An actor whose innocent intoxication leaves the actor without substantial capacity to appreciate criminality or to conform conduct to the law has an affirmative defense, even if the incapacity is only temporary.⁴⁷ Classification alone does not carry the defense, because a defendant impaired to a lesser degree has no incapacity defense even when the intoxication was entirely involuntary. The Code treats an actor whose personality is altered to a lesser degree like others who have difficulty conforming to the law through no fault of their own and are still held responsible.⁴⁸ The innocent drinker cannot be blamed for becoming intoxicated, but the drinker still performed the act, which is why blamelessness about the intoxication does not by itself excuse it.⁴⁹ At common law the result is similar: involuntary intoxication excuses where it left the defendant incapable of forming the required mens rea.⁵⁰

The driver's case is the version of the doctrine students most often get wrong. They find an innocent source, conclude that the intoxication is involuntary, and then stop, treating an innocent source as a complete defense. Regina v. Kingston, discussed above, shows why that conclusion fails. The defendant there had been drugged by a blackmailer, so the innocence of the source was never in doubt, yet the House of Lords rejected the argument that the absence of moral fault negates the mental element, reasoning that the drug had released a desire rather than created it.⁵² The same limit holds under the Code. Evidence of innocent intoxication helps on the mental-state route only to the extent that it actually left a required mental state absent, which is the element-negation inquiry that governs intoxication generally.⁵³

When the offense requires recklessness, two further points apply. The recklessness rule taught earlier, under which self-induced unawareness of a risk is immaterial, speaks only of self-induced intoxication, so an actor whose intoxication was innocent is not automatically barred from relying on the resulting unawareness. The threshold question, however, is whether ingesting the substance was itself reckless. A drunk who acts on an unreasonable belief that deadly force is needed cannot rely on self-defense, because the act of getting drunk is itself reckless, and that recklessness follows the actor into the offense. Recklessness in ingesting presupposes a choice to ingest. An actor who swallowed an unlabeled substance from a stranger, with reason to suspect its effect, is therefore a harder case than the prom student whose cup was spiked behind his back.

Medication Reactions

The third kind of involuntary intoxication covers an unanticipated reaction to a drug the actor took on medical advice.⁵⁵ The Code reaches this case through its definition of self-induced intoxication, which excludes substances the actor introduces pursuant to medical advice.⁵⁶ Because the exclusion is part of the definition, a qualifying reaction is classified as not self-induced before any question of capacity arises. The reason lies in who made the choice. The ordinary drinker is refused a defense because he knowingly ran the risk of impairment, and that choice stays with him when the consequences arrive. A patient following a prescriber's instructions has relied on someone else's judgment about what the drug will do, and a psychological reaction that nobody predicted is not a risk the patient chose to run. A rule that charged patients with every unforeseen side effect would also penalize the conduct the medical system depends on, which is following the prescriber's directions.

The standard illustration is United States v. MacDonald. A nineteen-year-old soldier with a clean record, an Eagle Scout before he enlisted, wanted to quit smoking, and an Army doctor prescribed Chantix for that purpose.⁵⁷ Not long after he started the medication he began having strange thoughts, including thoughts of killing someone, and without provocation he took a knife and stabbed another soldier fifty times, killing him. The Court of Appeals for the Armed Forces held that the trial judge erred by refusing to give the jury instructions on involuntary intoxication.⁵⁸ That holding concerns the jury's role: jurors had to be instructed so that they could decide whether the prescribed drug had produced involuntary intoxication, and the outcome was left to that finding. The facts that carried the case are all visible. A doctor prescribed the drug for a medical purpose, the soldier took it for that purpose, and the strange thoughts began only after he started taking it.

The same prescription produces a different result when the patient adds alcohol. In State v. Anderson the Wisconsin Supreme Court ruled that a person who mixes prescription medication with alcohol is responsible for any resulting mental state.⁵⁹ The fact that moved the answer is the alcohol. The medical advice that removes the drug from the self-induced category covers the substance the prescriber directed the patient to take, and it supplies no justification for the drinking, which the actor chose for himself. Alcohol is an ordinary voluntary intoxicant, so the resulting state is treated like any other voluntary intoxication, which matters only to the extent that it negatives an element of the offense.⁶⁰ Once the patient combines the two, the resulting mental state can no longer be traced to a risk taken on a doctor's word, because part of its cause is a risk the patient took on his own.

The first patient's position is the starting point of the defense, and it does not complete the defense. Classification as involuntary intoxication makes the capacity standard from the preceding section available, and that standard still requires that the reaction left the actor without substantial capacity to appreciate the criminality of the conduct or to conform it to the law. A patient whose reaction produced only agitation or loosened inhibitions has no affirmative defense, although evidence of the reaction remains admissible to show that a required mental state was absent.⁶³ Students lose this issue when they treat a prescription as blanket protection, because the exclusion removes the self-induced label only for what the prescriber advised and does nothing for added alcohol or an extra dose. Pathological intoxication, taken up next, is a separate category defined by a reaction grossly excessive for the amount taken, to which the actor does not know he is susceptible, and it does not depend on medical advice.⁶⁴

Pathological Intoxication

The fourth kind of involuntary intoxication differs from the other three because nothing about the substance itself is hidden from the actor. The Code defines pathological intoxication as intoxication grossly excessive in degree, given the amount of the intoxicant, to which the actor does not know he is susceptible.⁶⁶ In the typical case the actor knows he is taking a drug and has a fair idea of how much, but the reaction is far out of proportion to the dose.⁶⁷ What distinguishes the category from the earlier ones is what is missing. Coerced intoxication depends on a threat, innocent or mistaken intoxication on ignorance of what is in the cup, and a medication reaction on medical advice, while here the only thing the actor lacks is knowledge of his own sensitivity.

The definition has two components, and each has its own logic. The first is a comparison between effect and dose: the intoxication must be grossly excessive for the amount taken, so the yardstick is what that quantity of that substance would ordinarily do. The reason for measuring against the dose is that a person who drinks accepts the risk the quantity ordinarily carries. An effect of ordinary size falls inside the risk he took, while an effect wildly beyond it falls outside. The second component is the actor's lack of knowledge that he is susceptible, and it does the work of fault. A person who knows he reacts badly to small amounts and takes the substance anyway has chosen to run the risk of that reaction, and the choice stays with him when the consequences arrive. A person who does not know of his own sensitivity has chosen nothing beyond the ordinary risk, which is why the law does not hold the surprise against him.

The structure of the Code explains why this category needs its own definition. An actor who knowingly takes a familiar intoxicant can satisfy the definition of self-induced intoxication, because he knowingly introduced the substance and knows its tendency to cause intoxication.⁶⁸ Taken alone, that classification would close the involuntary-intoxication defense to him. Subsection (4) therefore lists two separate gateways, intoxication that is not self-induced and intoxication that is pathological.⁶⁹ The second gateway exists for the actor who met every knowledge requirement of the self-induced definition and still could not have foreseen how severe the result would be.

The knowledge component is worded differently from the self-induced definition. The self-induced definition asks whether the actor knows or ought to know the substance's tendency to intoxicate, while the pathological definition asks only whether the actor does not know he is susceptible.⁷⁰ Read on its text, the inquiry is therefore what the actor actually knew about his own sensitivity. Proof usually comes from history: a first exposure to the substance or the absence of any earlier episode points toward ignorance, and a previous violent reaction to a small amount points toward knowledge.

Classification as pathological opens the capacity standard and goes no further. The affirmative defense exists only if, by reason of the intoxication, the actor at the time of his conduct lacks substantial capacity either to appreciate its criminality or to conform his conduct to the requirements of law.⁷³ A grossly excessive reaction will often produce such incapacity, but the two are separate questions, and a pathological reaction that left the actor's capacity substantially intact supports no affirmative defense. Its significance then is the one that governs intoxication generally: it matters to the extent that it negatives a mental-state element of the offense.⁷⁴ The same route is all that remains for the actor who knew of his susceptibility, because his intoxication is voluntary, and for voluntary intoxication the Code's recklessness rule adds that unawareness of a risk caused by self-induced intoxication is immaterial.⁷⁵ The plurality in Montana v. Egelhoff, which upheld a statute excluding voluntary intoxication from the mental-state inquiry, reproduced the Code's definition of pathological intoxication when it described how the Code limits the relevance of intoxication.⁷⁶

Students lose this issue when they treat any unexpected reaction as pathological. The definition asks whether the intoxication was grossly excessive for the amount, so a drinker who miscounts is outside it: a woman who believes she had two drinks but actually had six is intoxicated in proportion to what she consumed, and her surprise at the result does not make the result excessive. Nor does the category depend on how the actor came to take the substance. A reaction that follows a prescribed dose may fall under the medication rule, and one that follows a spiked drink under the innocent-intoxication rule, but pathological intoxication needs neither medical advice nor deception. It needs only a reaction out of proportion to the dose in a person who did not know he was prone to it.⁷⁷

Exam Analysis Steps

Because the definition has two components and the defense then has a capacity requirement, a spiked-reaction fact pattern is best run in order. The steps are these:

Compare the severity of the intoxication with the amount of the substance taken, and ask whether the effect was grossly excessive for that amount.
Ask what the actor actually knew about his own susceptibility, looking for any earlier reaction or warning that would show knowledge.
If the effect was grossly excessive and the actor did not know he was susceptible, ask whether the intoxication left him without substantial capacity to appreciate criminality or to conform his conduct to the law.
If either of the first two questions is answered the other way, treat the intoxication as voluntary and ask only whether it negatived a required mental state.