How stimulants reduce hyperactivity and why sometimes cause drowsiness? i'm not feeling better from taking ritalin (methylphenidate).with regards.

The basics: The basic issue with ad/adhd is thought to be the inability to screen out external stimulus form reaching the thinking processes. The stimulants "turn on" a better screening center to eliminate the distracting inputs and allow a greater ability to focus and/or control activity overflow.At higher doses this often slows the kids spontanious activity and makes them sleepy.