Diminished Responsibility

• Diminished Responsibility


  A partial defence to murder where the defendant is not acquitted but the charge of murder is reduced to manslaughter
• Diminished Responsibility


  • The defendant was suffering from an abnormality of mental functioning caused by a recognised medical condition which substantially impaired the defendant's ability:

  1. To understand the nature of their conduct or,

  ii) To form a rational judgement or,

  iii) To exercise self-control,

  And which provides an explanation for the defendant's conduct.
• Abnormality of mental functioning


  A state of mind so different from that of ordinary human beings that the reasonable man would think it abnormal
• Psychological conditions

  • Psychotic disorders (paranoia, depression, hallucinations, delusions, bipolar, schizophrenia)
  • Post-natal depression
  • Battered wife syndrome – pre-menstrual tension
  • Post-traumatic stress disorder (PTSD)
  • Autism
• Physical conditions


  • Epilepsy
  • Sleep disorder
  • Diabetes
• Substantially


  To a great extent
• Impair


  Have a negative effect on
• Ability impaired


  • To understand the nature of his conduct
  • To form a rational judgement
  • To exercise self-control
• There must be medical evidence at trial
• The abnormality of mental function should come from a recognised medical condition, not intoxication due to drugs or alcohol alone
• Defendant is suffering from an abnormality of mental functioning from a recognised medical condition and is intoxicated


  Intoxication should be disregarded by the jury, the recognised medical condition (RMC) must be significant on its own
• Alcohol dependency syndrome (ADS)


  Someone who is unable to control their alcohol consumption
• Defendant kills while suffering from ADS and is intoxicated

  The jury can consider the effect of the alcohol on causing the abnormality of mental functioning, and ADS and the intoxication are all part of the same condition