All the medications are different for different kids, but any XR should not have rebound, that is why they came up with extended release. Stimulants, for the most part, kick in very quickly, and have no half life; once they are out of the system, they are out of the system. Some appitite issues will go away in a short time. There are non stimulant options so if this one does not work, or you think you can do better, do not get discouraged and ask for a change.
A couple of factors you should consider: make sure that you have a full, developmental, neurpsychological, educational and medical evaluation. If you do not yet have this, get it. A ratings scale in the pediatricians office and a school based evaluation are not enough, make an appointment with either a Develpmental Pediatrician or a Neuropsychologist/psychiatrist combo. You need to know exactly how he is effected, and exactly what you are looking to improve; progress is ultamately shown by the data. Data will also drive his treatment program, which should include some combination of: Medical intervention, Cognative Behavioral therapy, play therapy (find a new therapist or find a Cognative Behaviroarl therapist) social skills classes, speech, langauge, occupational, sensory, phsycial therapy-if the data indicates. Also, see a developmental Optomitrist, he may have 20-20 vision, but if he has handwriting issues, he may have some visual motor, visual perceptual, or occular motor issues that are often comorbid.
Use a Board Certified Child psychiatrist to prescribe these medications and case manage for your sons treatment program. Medication without therapy is not a good program.
Last, let go of your guilt about using modern medicine to treat a medical problem, which is what your son has. Brain dysfunction is no different (no more worthy of guilt and recrimination) than kidney dysfunction. Insert "pee" into all the symptoms you are concerned with, and you will realize that he is entitled to feel better, just like a child who has issues with his urine output. No guilt. His body has an issue either making enough neurotrasmitters or his body has damaged or dysfunctional neurotransmitter receptors; which is why medication is a good tool to help him benefit from his therapy and learn how to control impulses and learn other good strategies that will work for him. Increase the therapy and take advantage of his new ablity to process information and count on his brain to do so reliably.
M.