RECONSIDERING THE INSANITY DEFENSE: BRIDGING THE GAP BETWEEN LEGAL DOCTRINE AND MODERN PSYCHIATRIC UNDERSTANDING
AUTHOR – PRATHIKSHA NAVEEN, STUDENT AT SCHOOL OF LAW, CHRIST (DEEMED TO BE UNIVERSITY)
BEST CITATION – PRATHIKSHA NAVEEN, RECONSIDERING THE INSANITY DEFENSE: BRIDGING THE GAP BETWEEN LEGAL DOCTRINE AND MODERN PSYCHIATRIC UNDERSTANDING, INDIAN JOURNAL OF LEGAL REVIEW (IJLR), 6 (3) OF 2026, PG. 36-46, APIS – 3920 – 0001 & ISSN – 2583-2344. DOI – https://doi.org/10.65393/RYBQ5368
Abstract
The intersection of criminal law and mental health has long been a contested domain, where legal principles often struggle to keep pace with medical science[1]. Among the doctrines at this intersection, the insanity defense occupies a uniquely controversial space. On one hand, it embodies a recognition that punishment presupposes responsibility, and responsibility presupposes the ability to choose between right and wrong[2]. On the other hand, its doctrinal rigidity and resistance to change reveal a legal system that has not meaningfully integrated the last century of advances in psychiatry and neuroscience.[3]
The defense, most famously articulated in the M’Naghten Rules of 1843[4], continues to dominate in many common law jurisdictions, including India under Section 84 of the Indian Penal Code (now Section 22 of the Bharatiya Nyaya Sanhita, 2023)[5]. These formulations prioritize cognitive capacity, whether the accused knew the nature of the act or that it was wrong over volitional or emotional impairments, which are equally central to psychiatric understandings of mental illness.[6] The persistence of such narrow tests has given rise to widespread criticism[7]. Scholars, judges, and psychiatrists alike have argued that the defense excludes many genuinely mentally ill defendants while at the same time being inconsistently applied.[8]
This paper examines whether the insanity defense, as currently structured in common law systems, adequately reflects the realities of psychiatric knowledge. It explores the defense’s historical evolution, its statutory and judicial interpretations, and the doctrinal inconsistencies that result from its outdated foundations. It also considers comparative perspectives from other jurisdictions and critiques the gap between law and medicine. The central argument advanced here is that the insanity defense, though rooted in humane principles, has become outdated, conceptually flawed, and ethically problematic. Reform is urgently needed to align legal doctrine with scientific knowledge, ensuring both fairness to mentally ill defendants and legitimacy for the criminal justice system.[9]
[1] Stephen J. Morse, Excusing the Crazy: The Insanity Defense Reconsidered, 58 S. Cal. L. Rev. 777, 777–78 (1985).
[2] H.L.A. Hart, Punishment and Responsibility: Essays in the Philosophy of Law 152–53 (2d ed. 2008).
[3] Michael L. Perlin, The Jurisprudence of the Insanity Defense 19–22 (1994).
[4] R v. M’Naghten (1843) 10 Cl. & Fin. 200, 8 Eng. Rep. 718 (H.L.).
[5] Indian Penal Code § 84 (1860); Bharatiya Nyaya Sanhita § 22 (2023).
[6] Alan A. Stone, The Insanity Defense on Trial, 69 A.B.A. J. 134, 135 (1983).
[7] Nigel Walker, Crime and Insanity in England: The Historical Perspective 72–73 (1968); Michael L. Perlin, The Symbolism, Mythology and Reality of the Insanity Defense, 82 Iowa L. Rev. 1375 (1997).
[8] Michael L. Perlin, Mental Disability and the Death Penalty: The Shame of the States 55–56 (2d ed. 2008) (discussion of inconsistent application).
[9] Andrew Ashworth & Jeremy Horder, Principles of Criminal Law 145–46 (8th ed. 2013) (on doctrine and reform).