You cannot get divorce because of medical grounds if her disease is curable. Section 13 of the Hindu Marriage Act does not permit to get divorce on curable illness. You are, as a husband, responsible to give her proper medical treatment. It is a misconception in the general public that any kind of mental illness is grounds for divorce.
Divorce on medical ground
Section 13 however, enumerates some grounds for divorce. The grounds are
- Incurably of unsound mind
- 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.
- Virulent and incurable form of leprosy.
- Venereal disease in a communicable form
Divorce on mental illness
Mental disorder of a wife however, is a ground of divorce but only when the husband cannot live with her due to such a mental disorder. If the wife is unable to understand what marriage and marital obligations are then the husband can get divorce. Abnormal behaviour of the wife due to mental disorder or schizophrenia is a ground of divorce.
If your wife is suffering from an arrested or incomplete development of mind, psychopathic disorder or any other disorder or disability of mind then you can get divorce. The gist of divorce on mental illness is that the husband cannot live a married life due to the incurable or grievous mental disorder of his wife.