Indian J. PsychiaL, 1994,36(1), 25-29. PLEA OF INSANITY AS A DEFENSE IN CRIMINAL CASES: AN UPDATE SAYEED AKHTAR, TUSHAR JAGAWAT Mc'Naughten Rule is die commonest formulation for plea of insanity in most countries. Althougjk assessment of the mental state at thetimeofoffence is difficult, few instruments have been devised for this purpose. In the USA., efforts are being made to abolish the insanity defense and in the United Kingdom, amendments in the provisions of insanity defense have been proposed. The authors have stressed the need for some changes in the relevant sections of Indian Penal Code to increase the credibility ofPsychiatric testimony in such cases. INTRODUCTION Plea of insanity is used as a defense in criminal cases and when successful the accused is acquitted of the charge on the ground of insanity. The term 'insanity' is not a medical term but a legal concept meaning that degree of mental disorder that relieves toe offender of the criminal responsibility for his action. In the Western countries, it is estimated that plea of insanity is used as a defense in 1-2% of the criminal cases (Pasewik & Craig, 1980). Not Guilty By Reason of Insanity (NGBRI) defendants tend to be older, married and un­ employed at the time of commission of the crime. Most of them have a prior psychiatric treatment history and there is a history of drug and alcohol abuse (Roger, 1987). Acquitees differed from those convicted, in being female (Roger, 1984), older and more educated, and more likely to be schizophrenic (Somasundaram, 1960 & 1974; Benezech et aL 1984). Li a study of 187 men found NGBRI (Taylor & London, 1982), 34% of the defendants using the insanity plea were patients with Bipolar Affective Disorder. A high concordance rate (88%) was found between psychiatric evaluation of insanity and the verdict of the court. It reflects the influence of the psychiatrist's recommendations in the court's decision of insanity plea. HISTORICAL BACKGROUND The defence of insanity has been recognized in English courts for over 700 years beginning from the reign of Edward HI in the fourteenth century, when complete madness was considered as a defense to a criminal charge (Simon, 1967). By 1518, it was well established that the lack of guilty mind and intellect meant a lack of criminal responsibility. Some 250 years ago an English judge, in the trial of Edward Arnold said, "in order to avail oneself of defense of insanity, a man must be totally deprived of under­ standing and memory that be is not to know what i x was doing, not more than an infant, brute or a wild beast (Simon, 1983). The "wild-beast" test along with determination of ability to distinguish between right and wrong remained the standard of judging criminal responsibility until the year 1800 A D . , when the landmark trial of Hadfield set a new stand­ ard (Whitlock, 1963). A former soldier. James Hadfield attempted as­ sassination of reigning English monarch, George m with the belief that be was the savior of mankind. He thought that in order to become popular he should sacrifice his life like Jesus Christ and for this he chose to carry out an act for which he would be hanged. The prosecution argued that the defendant's behavior (purchase of gunpowder, concealment of pistol etc.) clearly indicated that he was neither an idiot nor a madman, so "afflicted by absolute priva­ tion of reason". The jury acquitted him because he was insane at the time of commission of the crime. This decision was a landmark because it rejected two concepts previously held by the court. First, it is not necessary for acquittal on the ground of insanity that be must be completely deprived of his mental faculties; second, it severed the tie between insanity and ability to distinguish between right and wrong, MC'NAUGHTEN RULE Daniel Mc'Naughten was a Scottish woodcutter who assassinated Edward Drummond who was secretary to the Prime Minister Sir Robert Peel, in the mistaken belief that Drummond was the Prime Minister. Mc'Naughten was described by nine medical witnesses as 'an extreme paranoiac en­ tangled in an elaborate system of delusions' and be believed, albeit falsely, that the Prime Minister was responsible for all his financial and personal misfor­ tunes. His trial, acquittal and reference to the House of Lords led to the formulation of a popular set of rules for criminal responsibility which have come to »