R v Dietschmann [2003] UKHL 10

Court: House of Lords

Facts: D killed a friend while suffering from a combination of depression and intoxication. The court needed to determine the role of each factor in causing the killing.

Held: The House of Lords ruled that the jury must consider the causal link between the intoxication and the killing in determining diminished responsibility. Although this case was decided under the old law (pre-2009) it seems likely the outcome of this case would be the same today.

Key Judicial Statement: Lord Bingham clarified, "The jury must determine whether the mental disorder was a substantial cause of the killing, irrespective of the effect of intoxication."