I was recently diagnosed and have been taking Ritalin SR for about 2 weeks now. If all goes well your husband should see an immediate response to the medication. However, I've heard that it often takes a lot of trial and error to get the medication and does that works best for each individual. It's often a balance of effectivity and tolerating some of the side effects. Currently Ritalin isn't working so well. I felt a difference the first few days... then, my problems crept back. May just be a dosage increase is needed.. but I'm new to this too so I'm not sure.