Lexapro, Abilify are most likely responsible for the weight gain. I would blame the Clonazepam for the memory loss, along with the Abilify. Wellbutrin usually causes people to lose weight, when I was on Wellbutrin I was underweight and my doctor was also concerned. As others have stated some people get memory loss from Lamictal as well, but when I've taken antipsychotics (seroquel) or benzodiazepines (xanax) I noticed lots of memory loss and just not being as sharp as usual in general. Always misspelling words and not thinking clearly. Its certainly something you should talk to your doctor about. I noticed dissociation with benzos is also common. They are really hard to come off of, so be sure to talk to your doctor before trying to adjust anything on your own.