If the husband pronounces one talaq does it occur 

In the name of Allah, the most Beneficent, the most Merciful.

Answer

For talaq to occur, one of the conditions is that the person issuing the talaq must be sane and mature.  Imam Kasani (RA) has said “And amongst the conditions of Talaq is that he be sane, literally and figuratively.  The talaq of an insane person is not effected, nor that of an immature boy, who is not of an understanding age.”   (Badaius Sanai p.179 v.4)

Therefore, in your situation, one talaq will occur.

The next issue here is whether you can get back together again with your wife. You can take your wife back if you revoke the talaq before the ending of her three menstrual periods (if she still menstruates) or three months. The choice of taking the wife back lasts only during this period. At the expiry of this time, the rujuu also expires. You can get back together again by redoing the marriage. You will require two male witnesses or one male and two female witnesses. Also a new dowry will have to be set. (Bahrur Raaiq p.50 v.4)

Only Allah Knows Best

Mohammed Tosir Miah

Darul Ifta Birmingham.