My doc had me on Celexa, Respirdal and Wellbutrin, all at the same time. I don't know which drug is responsible for which side effect, but they include weight gain, insomnia, lethargy, inability to concentrate, loss of volition, hopelessness. I quit. I went cold turkey for 10 days, but realized this was a big mistake. Now I'm weaning myself off slowly. I feel out of control and scared. I hope this doesn't last too long.