google it. The program I use is from a company called Learning Technics. They have offices in a few cities, and there are some schools and residential programs who use it. I think they also have a program you can purchase and do yourself.

They are quite expensive. I paid $2700 when I used it for my son, which included an hour every week with their therapist and then about 45 minutes at home 5 days a week with me.

There are also some issues with medication for hyperactivity. The way the therapy works is it overloads the neural pathways, so if you are medicated to interfere with overload, the therapy is not as effective.

I'm not familiar with written expression disorder, but some of the interventions help with reversals, and some help with expressing language, so I think it would help, but you'd have to ask the person who will help you evaluate your child.

I heard of a program called Fast Forward. I looked into it for my son who is also developmentally delayed. It's supposed to be helpful for kids w/ processing problems and expressive language issues. It's very expensive as well, and it takes a lot of time and dedication. I wanted to do it w/ my son, but when he was tested on it, the therapist told me the program was too advanced for him. At the time my son was 4. I may try it again w/ him in the future. I've heard good things about how it helps children increase their processing speed and how it's made a difference for many children.

You said your son was diagnosed w/ ADHD at 4 yrs old. Are you still following up w/ his drs on a regular basis? We bring our son to a Developmental Pediatrician approx twice a yr. She has been very helpful in giving us pointers and advice through this whole process. My son doesn't have ADHD, but he does have focusing issues as well as other learning difficulties. The dr has been working w/ us in getting the school to give our son the services he needs.
Although our son is not on meds, we try to redirect his energy in other ways. He takes swimming classes, karate, and plays outside everyday. We're also looking into getting him a small trampoline that he can jump on. We find that if he releases that extra energy before doing his schoolwork, he's a lot better focused. For him, it's a sensory thing. He tends to get over-stimulated at times, and he often seeks input. You can try simple things like exercising or other physical activities to help your son release his energy. Also, avoid too much TV and computer time, and try to maintain a healthy diet for your son. Eliminating sugar from his diet can make a difference. We also give our son Omega 3 fish oil every day. This is proven to have many health benefits as well.
Stay on top of your sons needs. Often you have to try different things to keep a child interested and motivated. Find things your son enjoys doing, and avoid those things that are too difficult for him. He probably won't want to do them b/c they're difficult.
It's not always going to be perfect, but these are just a few things that have helped us and our son. Of course if the behavior problems persist or get worse, consult a dr. You may have to adjust your son's meds or try an alternative therapy. Speech, OT and PT have also been beneficial to our son. Talk to a dr to see if any of these therapies may be helpful to your son as well. Best of luck.

I'm wondering if any of the eye doctors that saw him specialized in vision therapy? It sounds like he might have convergence insufficiency or an oculomotor or accomodative problem. Those can be tested for, and are treatable. They're not usually found in school and an OT can't help-it has to be an optometrist (not opthalmologist) that's board certified in vision therapy.

I hope you've gotten some help or recommendations by now. I have specialized in helping children like this for around 20 years now. I did a lot of studying etc. because I found I had children growing up with the same problems and knew, as a teacher, that I had to have students facing the same difficulties. I have found that good tutors working with an Orton-Gillingham method are excellent at helping students facing these challenges. To me it sounds like among other things your child is working with the challenge of being dyslexic. A lot of schools and teachers don't like to hear the word, but it is very real and challenging to young and old alike.