I was on it from November to May (until it pooped out on my hallucinations) it was had to say how long it started to work on my depression though as at the time I started I was also just starting on an antidepressant. But when it did kick in it worked on my depression especially after I stopped the antidepressant. When I stopped Latuda I was also starting Abilify so idk if I experienced any withdrawal from Latuda. And the only major side effect I really experienced was nausea and vomiting if I didn't take it with at least 350 calories.
Hope this helps you a little with your decision on Latuda.