I am looking for a special needs school in Thailand, that specifically looks after and cares for children with the condition of ADHD.
Thankfully my son, eight years old, is actually not that bad. However the experience we have had to date, are that the regular schools are not trained or experienced to deal with such children.
I would be most grateful for any advise or recommendation please, of any schools that even might cater for this disability.

I highly doubt there are many schools here that fully cater for those needs. Generally, the internationals schools are organised and clued up on these types of things as you would expect. They usually have designated SENCOs and can provide staff to support the child or work with them at certain times. However, this comes at a high cost.