Possible PDA?

Hello, i was wondering if anyone could give there experience's of PDA? After someone had mentioned PDA, i did some research and it sounds like my 9 year old boy so so much. 

I just dont know where to start because of how good he is at masking the challenging behaviour and all his other traits in school etc. I have tried talking to health visitors etc when he was younger , but they kept palming me off with parenting courses etc. However , i still feel he needs some help to manage certain traits . 

Thank you for any help and advice on this matter .