Wife was treated for depression before marriage wants divorce

Wife being treated for depression is no basis of divorce in court of law. Court takes cognizance if the person is of such a medical condition that he/she may prove dangers for the life of the other spouse. However this behaviour has to continued and not limited to one or two odd instances.

Definitely you can file divorce case because it's a misrepresentation of fact by your in laws and in law have provision for this.
And as per the section 5 of HMA it's mandatory to represent everything if they try to skip something serious then, you can go for nullity of marriage as per section 11 or 12 of HMA

If a person is suffereing from depression that is not a ground for divorce unless she sufferes from insanity attacks. If you want divorce, talk to her. Why did you want to divorce her? Depression is curable. She needs care and attention of yours. Your wife is ill. You are acting like a narrow minded husband. What do you expect from her? If you cannot support your wife in times of her needs, I am sure in future if at all you get a defect free wife, you would not get the care and attention you longing.

You can file for annulment of marriage on the ground of not disclosing this fact at the time of before marriage. But it can not be filed after one year of marriage.
Depression itself is not a ground of divorce but affecting adversely mental capability is mental illness which is ground for divorce.