depression
"I have been on this wonder drug for many years.  I find that if I forget to take my medicines for even one day I become sad and can cry very easily.  If I am off them for more than 3 days watch out.  So don't skip.  Take your medicines. I am 46 and find I am forgetting things. I have been on antidepressents for 20 years now.  6 or 7 of those years on this medicine. "