... This was a drug to help me quit smoking but it caused a terrible chemical imbalance that made me think about suicide. Lexapro was a miracle for me. The only major side effects was the excessive weight gain. After two years, I decided it was time for me to come off the Lexapro. After 3 days of not taking it, I seem to be ok. Has anyone else out there quit Lexapro? If so, did you have any side effects from it?