My 8yr old son has very violent behaviour, was suggested he has, adhd, add, odd and gdd, but nothing actually diagnosed, why won't they diagnose him,

Frustrated: Not sure why. Take him to a child psychaitrist. It sounds like you are an empowered and educated parent. Some physicians and psychologists don't "like" to diagnose adhd because they feel "it condemns the child to medication." unfortunately, the alternative - an unmedicated child who is destructo-boy has its own issues. If the sxs are as clear as you say, diagnosis by someone competent is easy.

Behavioral Diagnoses: The neuro-behavioral sector has been redefining these disorders and applying stricter criteria to what used to be a common "catch all" diagnosis. If they are not "making the call, " it means that there are atypical features or overlapping features to your son's behavior. Be persistent in your quest for a diagnosis and a prescribed treatment plan, for your son"'s sake.

Ask for results of : Standardized tests of your son's iq, social/adaptive skills, & current academic levels. If significantly < average (<70), a diagnosis of intellectual disability warrants neurological & genetic evaluations for medical causes of id + adhd, aggression +/- autism to find the best medical, behavioral & educational management http://humanrights.Gov.Au/disability_rights/education/barriers_96.Html.