How to Prove Mental Illness, Such as Schizophrenia, in Court in India

To prove mental illness in an Indian court, a person must provide expert medical evidence such as psychiatric evaluations, testimony, and medical records and show how the illness is legally relevant. The law recognizes a narrow concept of "unsoundness of mind,"which is different from the broader medical definition of mental illness. In criminal cases, Section 84 IPC allows the defense of legal insanity, meaning the accused, due to unsoundness of mind, was incapable of understanding the nature or wrongfulness of the act at the time of the offense; this requires more than just a history of illness and must be proved through expert opinion, records, and circumstantial evidence. In civil cases, mental illness may be relevant for divorce (e.g., incurable unsoundness of mind making cohabitation unreasonable), guardianship and property management (where the court may hold an inquiry under the Mental Healthcare Act, 2017, and seek a Mental Health Review Board's opinion), or testamentary capacity (where a will is valid if made during a lucid interval with understanding of assets and beneficiaries). Across all contexts, courts rely on expert evidence under Section 45 of the Indian Evidence Act, medical records, and surrounding circumstances, while carefully distinguishing medical diagnoses from the legal test of unsoundness of mind, which ultimately determines responsibility or capacity in law.