I have a five year old boy who is currently going through the diagnoses and testing for adhd, but who also displays mild asd symptoms as well. I decided about a month before we saw the specialists to try the failsafe way of eating, but I did not put him on the strict diet, I simply printed out the list of additives that are no-go and completely stopped buying anything with them in it.  Within two weeks his behaviour still needed (and still needs) a lot of work but has drastically improved.  - Anthea, by email (children who improve on an additive free diet may do even better if they reduce their salicylates and/or amine intake too - S).