or diminished capacity
In law, doctrine that absolves an accused person of part of the liability for his criminal act if he suffers from such abnormality of mind as to substantially impair his responsibility in committing or being a party to an alleged violation.
The doctrine provides a mitigating defense in cases in which the mental disease or defect is not of such magnitude as to exclude criminal responsibility altogether. Diminished responsibility is most frequently asserted as a defense to murder charges that require proof of a particular mental state (e.g., premeditation). If diminished responsibility is shown, negating an element of the crime with which a defendant is charged, the defendant can be convicted only of a lesser offense that does not include the element. Although diminished responsibility is recognized as a defense in Britain, most other countries recognize only mental disease or abnormality of sufficient degree to sustain a defense of insanity .