I've been taking Risperdal for over two years now. When it was first prescribed I was off the wall manic and it started to take effect almost immediately. I actually have been trying to taper off my dosage (4mg) because of some side effects, mostly weight gain. That being said, Risperdal worked wonders for me in controlling my mania but not so much for my depression. I'm on Lamictal, Zoloft and Latuda for the depression.