you can also contact the helpline run by the national autistic society on 0808 800 111011. programme, so stay with us. we will come back to talking about this in the next half—hour, so stay with us. let me read some messages. peter on facebook: "i worked for many years with young people with autism and severe aggression problems. the injuries we saw on almost a daily basis were horrendous. its so sad, and utterly heart breaking for parents and siblings and the young people themselves. the children ended up in our unit due to their aggression when parents became unable to cope at home." patricia on facebook: "my son has pda, some days are a living hell he is only six and honestly the violence is unbelievable there" is no local support at all, no help. helen on facebook: "it's great to see pda getting tv exposure. however a balanced view of the condition would be even better. its such a misunderstood wiring of the brain — the central feature isn't violence but demand avoidance. i realise i'm fortunate as a parent to have a little pdaer who's demand avoidance presents itself a