Hi Katy, Sounds just awful.

It's very difficult for me to know what to suggest with the situation so bad and knowing so little.

What happens at the hospital when you go there with him?

This type of behaviour is really not related to his tics/TS and because he's only currently diagnosed with TS and OCD, I'm at a loss to know what his treating Psychiatrist is thinking.

Have you had sit down meetings with the school staff at all, just you and hubby, and I also wondered if he's in a regular classroom setting?

I really can't say it more clearly than to say this sounds like CRISIS time and I'm wondering what type of support agencies there are in your area where you can get professional help to sort out so many of these concerns you have... like your concerns he is on Autism Spectrum. Because I'm not in the UK, I have no idea on how the system works but I wonder if you have access to centres where you can get some help and guidance. We can do that here where I live... either with private practitioners or in Youth and Mental Health Services which are often run out of major hospitals. You also might find that a Psychologist could be more helpful than a Psychiatrist in your son's situation. It's one thing to dish out medications but there's so much more that sounds as if it's being neglected.

Edited to add:
http://www.tourettes-action.org.uk/8-find-support.html
http://www.tourettes-action.org.uk/10-ta-groups.html
TS Support Groups - Eng, Wales and Northern Ireland

I also just found this link below on that AutismUK site I showed you earlier.
Even though you don't have an Autism diagnosis and that might not be what is going on for him at all, but considering your concerns about Autism, it wouldn't hurt to talk to someone from the support groups.
http://www.autism.org.uk/directory