I have a suspicion that many of the young people I have worked with in the past have had PDA - that would explain a great deal of their behaviour.
I like this statement, it helps me make sense of it
It is their inability to cope with what they perceive as the stress of everyday demands that manifests itself differently according to their
Rather that me trying to justify my limited knowledge, it might be easier to read others' experiences
'Autistic;not naughty' is a blog written buy a parent of a PDA child and really gives a good insight into the difficulties of managing life with a child like this and trying to get support.
If you want to get some idea of what PDA is, take a look here