His wife has a mental disorder that he didn't know of at time of marriage
5-11-2013 | IslamWeb
Question:
I have married on 2nd june 2013, after that i observ she is suffering from mental problem for last 10 years but her parents suppressed the fact before begining matrimonial negotiation. Her behaviour is not tolerable. As she is suffering from mental disorder. I feel i cannot continue my life with her. Doctor also does not give any assurance regarding her cure.
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
First of all, we ask Allaah, The Almighty, to heal your wife and take away her illness, for He is the Healer, besides Whom there is no healer. We advise you to always ask Allaah to heal your wife from any affliction, for He responds to the supplication of the desperate person and removes harm. Allaah, The Almighty, says (what means): {Is He [not best] who responds to the desperate one when he calls upon Him and removes evil and makes you inheritors of the earth? Is there a deity with Allaah? Little do you remember.} [Quran 27:62]
We also advise you to seek treatment for her. One of the best means of treatment is the Ruqyah, which Muslims often neglect. For more benefit, please refer to Fataawa 92491, 88660and 82918.
If her illness is just a mental deficiency and does not reach the degree of insanity, then her guardian is not liable for concealing it, and you do not then have the choice of annulling the marriage. However, her guardian should have told you about her condition to avoid any causes for dispute.
On the other hand, if her illness reached the degree of insanity, then you have the choice of annulling the marriage, because insanity is one of the physical defects that are grounds for either spouse having the choice of annulling the marriage. Ibn Al-Qayyim 
states in Zaad Al-Ma'aad: “Ash-Shaafi‘i and Maalik said that marriage may only be annulled on grounds of insanity, vitiligo (skin depigmentation), leprosy, a blocked vagina, a severed penis or impotence.” [End quote]
It is a condition for the right of annulment that the husband did not know of the defect at the time of the marriage contract, and did not accept it when learning the facts.
Finally, if it is easy to get treatment for your wife, then all praise be to Allaah, The Almighty; and if not, then you can marry another one if you are able to be fair and fulfill your obligations towards both wives. But if you cannot marry another with her, then you can divorce her and marry another. Divorce is permissible, especially if there is a need for it.
Allaah Knows best.