1. Capacity defences of insanity and intoxication

2. Person has chosen to take alcohol, drugs or other substances e. g
Person has chosen to take alcohol, drugs or other substances e.g. glue-sniffing.
General rule - if a person is voluntarily intoxicated and commits a crime there is no defence.
Intoxication is relevant as to whether or not the defendant has the required mens rea for the offence.
If the defendant does not have the required mens rea because of his intoxicated state he may not be guilty, however this depends on whether the intoxication was voluntary or involuntary and whether the offence charged is one of specific or basic intent.

3. Voluntary intoxication and specific intent offences
These are crimes where intention is required in addition to the basic offence e.g. Section18 OAPA 1861 is GBH or malicious wounding with intention to do GBH.
Voluntary intoxication can negate the mens rea for a specific intent offence - if the defendant is so intoxicated that the mens rea for the offence is not formed, he is not guilty – DPP v Beard (1920)
Usually means the charge is reduced rather than escaping liability e.g. Lipman (1970) but also bear in mind AG for Northern Ireland v Gallagher (1963) where it was held that drunken intent is still an intent.

4. Voluntary intoxication and basic intent offences
DPP v Majewski (1977) – voluntarily becoming intoxicated is considered a reckless course of conduct and recklessness is enough to constitute the necessary mens rea in assault cases.
Fortheringham (1989).

5. Involuntary intoxication
Includes spiked drinks, prescribed drugs and soporific drugs.
Pearson (1835) – “If a party be made drunk by stratagem, or the fraud of another, he is not responsible.” – therefore may be defence for basic and specific intent crimes.
Soporific drugs – Hardie (1985).
Spiked drinks – Allen (1988).
However, note HOL decision in Kingston (1994) - drugged intent is still intent.

6. Intoxicated mistake
If the defendant makes a mistake due to intoxication then it will depend what the mistake was as to whether the defence is available.
Lipman (1970) - he had recklessly taken drugs so no defence.
O’Grady (1987).
Hatton (2005).
In all 3 cases, the charge was manslaughter which is a basic intent crime so, following Majewski, the defence is not available.

7. Problems with Intoxication
The Majewski decision is that a person is reckless if they get drunk and therefore guilty but this does not comply with the principle that the actus reus and mens rea of a crime must coincide.
Normally if recklessness is sufficient for the mens rea the defendant needs to be aware of the risk but this is not the case with intoxication.
Where there is a lesser offence the charge will be reduced to a basic intent crime, but where there is no lesser offence the defendant escapes liability.
See the Law Commission’s Report of Intoxication and Criminal Liability, for recommendations for reform of the law of intoxication.