anxiety
"Not only was this medicine not helpful, it made me a zombie.  I took a quarter of a pill in the lowest dose available. Within 15 minutes I literally could not function and had to stop what I was in the middle of and go to bed. I woke up after a full nights rest and was still in a fog. As I drove to work, I was so out of it. I would snap back to reality for a second and be scared that I passed my exit, which was still miles away, because I just wasn't with it.  I also nearly missed an appointment because (despite reminding myself more than once during the day that I needed to get to this appointment) I completely forgot.  I stayed in a zombie like state all day."