How is he sleeping at night? I also have a 5 year old, not diagnosed yet but I have ADHD and I see the signs. I am having him evaluated because his teacher did say he has a hard time focusing and starting his work. I started using melatonin at night to get him to fall asleep easier and it has been working well. I also cleaned up his diet tremendously (I always feel this works well for him), and started him on a vitamin regimen. I know for me if I don’t get enough sleep I am cranky and tired, but as an adult I am able to control how I feel outwardly. Hopefully some of this helps!