“Epilepsy constitutes legal insanity despite being neurological, not psychiatric condition in medical terms.”
Sullivan suffered from psychomotor epilepsy and during a seizure kicked and injured an 80-year-old man. He was charged with assault and claimed automatism. The trial judge ruled that the evidence supported only the insanity defence, not automatism.
Whether epilepsy constitutes a disease of the mind under the M'Naghten Rules, and how to define 'disease of the mind' in legal rather than medical terms.
The House of Lords held that epilepsy constitutes a disease of the mind for legal purposes, even though it is not considered a mental illness medically.
This case establishes the authoritative definition of 'disease of the mind' in English criminal law and confirms the divergence between legal and medical concepts of mental disorder. It remains fundamental to understanding the insanity defence and its scope in modern criminal law.
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OSCOLA Citation
R v Sullivan [1984] AC 156
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