There's a lot you can do on your own. First is diet (the most common culprits are sugar, caffeine, artificial food colors and flavors, egg whites, milk products and wheat).
A couple other things that I think are helpful (as a grandmother who needed to know this stuff 30+ years ago for my OWN kids!) are the child's temperament and 'love language'. There are tests online and you and he could even make a game of him helping you figure it out.
The temperaments are:
Sanguine (happy-go-lucky, life of the party, scatterbrained, enthusiastic but doesn't follow through.)
Choleric (strong ideas, pushy, leader, insentitive to other's feelings).
Melancholy (perfectionist, negative [sees the glass as half-empty], neat [sometimes O/C about it).
Phlegmatic (easy-going/laid back, pacifist/peacemaker, slow moving, stubborn/resistant to being 'bossed')
And some tests include a newer category, 'Supine' (serves others, can't express their thoughts/feelings). We're born with our temperament(s -- we're usually a blend of 2 or a little of 3).
The 5 love languages have been anayzed by Dr. Gary Chapman and include:
Acts of service (doing things for others and liking having things done for self)
Physical touch (any loving touch)
Words of affirmation (any complimentary, encouraging statements)
Quality time (just being together with someone) and
Gifts (giving and receiving)
Each of us have an innate need for a couple of these 'languages' being 'spoken' to us.
Bottom line is, your child is different from you. He'll have different learning styles, interests, personality, temperament, and abilities. Parent him according to this -- HIS natural 'bent' rather than yours, and you'll notice improvement. If our teaching style is rigid, it can cause rebellion and resistance (looking back, I can see that I parented at least one of our 4 terribly wrongly).
Hope this helps!!