Unsoundness Of Mind vs. Mental Retardation: Delhi High Court Explains Medical And Legal Differences

Medical Distinction

Justice Swarana Kanta Sharma observed that unsoundness of mind or mental illness generally refers to disorders that affect a person's thinking which impair their judgment, perception of reality, or ability to function in daily life. She added that such conditions are episodic or progressive in nature and may, in certain circumstances, be responsive to treatment.

Mental retardation or intellectual disability on the other hand, the Judge continued, is a separate condition which denotes developmental disability characterized by subaverage intellectual functioning, which originates during the developmental period.

“It is not considered a mental illness or unsoundness of mind per se, but rather a condition involving arrested or incomplete cognitive development, which is generally non-curable and not typically subject to fluctuation or relapse in the way mental illnesses are,” she added.

Legal Distinction

Given this medical distinction, the Court observed that in law, a person of unsound mind is exempted from criminal liability under Section 84 IPC if, at the time of committing the act, he was incapable of knowing the nature of the act.

“The relevant point of time for deciding as to whether the benefit of the defence available to an accused under this Section should be given or not, is the material time when the alleged offence takes place.”

However, mental retardation, being a static and developmental condition, is not per se referred to under Section 84 of IPC, the Court held.

Distinction In Trial

For cases involving unsoundness of mind, the Magistrate must consider the evidence on record, hear the advocate for the accused, and may discharge the accused and deal with him in the manner provided under Section 330 of CrPC (Release of lunatic pending investigation or trial), if no prima facie case is made out.

Detailed procedure under Section 330 CrPC can be read here.

If a prima facie case exists, the Magistrate is then to proceed in accordance with the procedure laid down under the proviso to Section 328(3) of CrPC, which sets out that the proceedings shall be postponed for such period, as in the opinion of the psychiatrist or clinical psychologist, is required for the treatment of the accused, and order the accused to be dealt with as provided under Section 330 of CrPC.

Section 329 of CrPC is almost similar to Section 328 but operates at a different stage ― during the trial of a person. It mandates that if during the trial, it appears to the Magistrate that such person is of unsound mind and consequently incapable of making his defence, the concerned Court has to first try the fact of such unsoundness and incapacity.

Conversely, if the accused is found to be suffering from mental retardation, Section 328(4) empowers the Magistrate to immediately order the closure of inquiry and proceed directly under Section 330 of CrPC.

Additionally, Section 328(3) allows the Magistrate, during the pendency of medical examination or inquiry, to pass appropriate orders under Section 330 of CrPC for dealing with the accused.

In the case at hand, since the accused was suffering with mental retardation, the High Court held that the Sessions Court ought to have complied with procedure under Section 330 CrPC, before ordering his release after discharge.

As such, the matter was remanded the matter back to the Sessions Court for passing an order afresh in compliance with Section 330.

Case title: State v. Neeraj

Citation: 2025 LiveLaw (Del) 610

Case no.: CRL.REV.P. 763/2017

Click here to read judgment