Possible defences related to substance misuse

Generally, the acute effects of having voluntarily taken drugs or alcohol are not a mitigating factor and it is argued that a drunken intent is still an intent. However, there are narrowly defined circumstances in which an altered mental state due to substance misuse can raise the question of a possible defence.


Amnesia is common after violent offending, and may relate to acute intoxication especially on alcohol or sedatives. In the absence of organic disease, amnesia carries no legal implications in England and Wales, and all common law jurisdictions have ruled that amnesia does not affect fitness to plead, (1.9 though it clearly complicates assessment of the perpetrator's mental state at the time of an offence.

Simple intoxication

Self-induced intoxication is generally no defence to a criminal charge. However, in England and Wales, case law has determined that crimes such as murder, wounding with intent, theft, and burglary, require a specific intent, for which self-induced intoxication on alcohol or drugs may be a defence, but only if it can be shown that the accused was so intoxicated as to be unable to form the necessary intent. The psychiatrist can only comment as to whether the accused had the capacity to form the specific intent. It is a matter for the jury to determine whether the specific intent was present or not. If the specific intent is not demonstrated, then the accused may still be convicted of a lesser offence, so that acquittal on a charge of murder may lead to a conviction for manslaughter. It is a matter of clinical judgement as to whether an individual was so intoxicated as to be unable to form a specific intent, and the degree of purposiveness before, during, and after the offence, may be a useful indication.

Other crimes such as manslaughter, rape, and unlawful wounding, require only a basic intent, which cannot be negated by intoxication. (19 For these offences, the recklessness of voluntary intoxication may provide the necessary mental guilt.


Alcohol or drug misuse may give rise to a psychotic illness, such as delirium tremens, which may meet the requirements of the McNaghten Rules, but the insanity defence is rarely used. In theory, consumption of drugs or alcohol could lead to a state of insane automatism, but the defence of insanity is not available if the consumption has been voluntary.

Diminished responsibility

In England and Wales, Section 2 of the Homicide Act 1957 provides a defence of diminished responsibility in a charge of murder. The defence has to demonstrate that an abnormality of mind arises from one of the causes specified in the Act and those of possible relevance to substance misuse are disease, injury, or inherent causes. An abnormality of mind due to intoxication is no defence. Alcohol dependence could meet criteria for disease, provided that the first drink of the day was shown to be involuntary. Diminished responsibility may become an issue when the effects of substance misuse interact with other factors such as organic brain damage, depression, or personality disorder. For legal purposes, the effect of intoxication has to be set aside and the defence must show that the associated condition was in itself severe enough to lead to an abnormality of mind.

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Beat The Battle With The Bottle

Beat The Battle With The Bottle

Alcoholism is something that can't be formed in easy terms. Alcoholism as a whole refers to the circumstance whereby there's an obsession in man to keep ingesting beverages with alcohol content which is injurious to health. The circumstance of alcoholism doesn't let the person addicted have any command over ingestion despite being cognizant of the damaging consequences ensuing from it.

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