I would get the neuropsych eval - it will give you a good idea of what exactly is up with your ds, which is important to have, particularly if you have any doubts about the ADHD diagnosis.
FWIW, my dd10 has multiple x multiple food allergies - back when she was 4-5 years old and we were still figuring out what her full list of foods she was allergic to was, she had a very tough time focusing. Allergies aren't her only challenge, she also had visual processing challenges and is very sensitive hearing, but the food allergies absolutely impacted her ability to concentrate... as well as... there are foods contained as inert ingredients in many medicines and she ultimately had to start having her meds compounded. Sooo.... just something to consider, do you think you're at that place yet where you really have a good idea of his full list of allergens or is there a chance that there might be something still in his diet that's impacting his ability to concentrate? I'd really want to know that before starting any kind of meds.
I also was wondering why your ds would have to sit by himself at lunch at school? Wouldn't the school be able to make arrangements such that he could have an allergen-free table and have other kids sit with him? Our dd has gone to public school since kindergarten and preschools before that. Advocating for kids with allergies can be a lot of work, but it's also something that you can usually advocate for successfully. There are more and more kids with multiple food allergies each year across the US.
Best wishes,
polarbear
