Such an action may also be maintained by the person with a mental illness at any time after restoration to a sound mind; but in that case, the marriage should not be annulled if it appears that the parties freely cohabited as husband and wife after the person with a mental illness was restored to a sound mind. Where one of the parties to a marriage was a person with a mental illness at the time of the marriage, an action may also be maintained by the other party at any time during the continuance of the mental illness, provided the plaintiff did not know of the mental illness at the time of the marriage. Where no relative of the person with a developmental disability or person with a mental illness brings an action to annul the marriage and the person with a mental illness is not restored to sound mind, the court may allow an action for that purpose to be maintained at any time during the life-time of both the parties to the marriage, by any person as the next friend of the person with a mental illness or person with a developmental disability.
N.Y. Dom. Rel. Law § 140