Can I ask about what he eats? When my daughter was about 5, and we were edging toward a diagnosis, we also did a food sensitivity panel, and found that she is very reactive to dairy and eggs. And we were giving her lots of protein in the form of hard boiled eggs, yogurt, cheese. Her sensitivities to dairy and eggs (NOT the same as allergy and WON’T show up on standard allergy testing) manifested in behaviors. General crankiness, misunderstanding social cues, anger, frustration, rage, lack of impulse control.
If you can, you might want to test your son for food sensitivities, and if the test identifies any, eliminate them from his diet.
(we also tried Intuniv for our daughter and helped somewhat. But, be careful about increasing the dosage too much, too soon. We did the introductory dosage, and before we even got to the full dose, she felt tired and lethargic–after all, it’s a medicine to lower blood pressure.)