My DS was put on Risperdal about 4 weeks ago (.25mg). I guess this is supposed to be helping his "impulsivity " according to the P-DR. By impulsivity I'm assuming he means his violent rages...my choice was to address the rages or the possible ADHD, obviously I chose the rages. My question is how long does it usually start to work. It's been 4 weeks and there's no change is his behavior or attitude. He's supposed to see his P-DR on 4/12, so not too long, but I'm just curious if my expectations are out of wack for thinking I should be seeing some improvements by this point.