I did use Abilify effectively with Pristiq but after about a year...it became less and less effective. I never had any of the oddball side effects many have with Abilify...ie...the super intense dreams...lol
Welbutrin is great because of the lack of sexual side effects...but made me kinda irritable and a cranky camper. lol
I do not know for sure if your Dr could use Abilify to "boost" Lexapro. But if its been working therapeutically for awhile...and you are just experiencing some "break thru symptoms"...I would think it might be great to try to keep with the Lexapro.