I checked out the website.
First, before I share some ideas, we must consider the nature of the problem. Unfortunately, the cause of the problem is embedded deeply into the core "programming" of the body, so I would not get your hopes up about any miracle cures

. However, there might be some things to help. You might try supplements that are known to address the hypothalmic-pituitary-adrenal axis (HPA), such as Panax ginseng root, Eleutherococcus senticosus root, Rhodiola root or Leuzea root (Rhamponticum carthomoides). These agents are generally quite safe, and have been shown to improve things like psychomotor performance (related to coordination/reaction time), memory, and physical strength and endurance. These agents may help maximize your childs ability to cope both physically and mentally in the modern world.
Omega-3 fatty acids are also quite safe and are essential for all body tissues. I've seen cases of so-called "ADD" improve with fish oil concentrate supplementation over time.
I'm curious, why do you have him on carnosine?