Bit of an update. My son has been on a medication called Concerta XL for the last 3 weeks and the difference in his behaviour is startling. It's like that bridge that wasn't there before, the bridge which failed in him being unable to do things off the cuff has been built, and he now thinks about things rather than just doing. That, for us, means a completely different way of living based on the things he was doing. He has had a couple of side effects, weight loss being the most concerning, but we've changed his diet since last Friday to build him back up again so hopefully he will get a more permanent prescription as at the moment it's all monitored every 2 weeks. I was all against medication at the start, but we were at a cross roads which meant we had no choice because of the disgusting way we were being treated by him, and it's made a massive, huge difference to us all - him obviously benefiting the most.
Fingers crossed it continues.