Under the Hindu Marriage Act, 1955, unsoundness of mind as a ground for divorce requires:

Section 13(1)(iii) requires that the respondent "has been incurably of unsound mind, or has been suffering continuously or intermittently from mental disorder of such a kind and to such an extent that the petitioner cannot reasonably be expected to live with the respondent". No minimum period applies, and a certificate alone does not prove the ground.