This is the post I tried to direct people to and since the poster placed it on an open forum I assume they won't mind me reproducing it here
"Yes. Doctors don't know what they're talking about. Teachers...well, we know everything.
Some of it is subjective. Not every diagnosis is correct. But that surely doesn't mean that we ignore or dispute all of them?
My son was misdiagnosed by an experienced, prominent psychiatrist who only diagnosed the ADHD.
When he got re-referred to CAMHS as things were worse at home and at school, we saw a new psychiatrist, who picked up the autism immediately. Testing confirmed her suspicions, but of course it's not an exact science.
I refused to believe that my son was autistic. He can't be, I said, because I've taught an autistic boy and he has no facial expressions and speaks in a monotone. My son has loads of facial expressions and is a very expressive speaker. He can't be autistic because he's nothing like that boy.
What did I know? Clearly nothing. I had had one half day training course in SEN when I was on my PGCE course. I'm not imagining that many mainstream teachers (or TAs) have had much more than me. So who are we to question the views of those who DO know? With a bit more education (I've read everything I can get my hands on about autism now), I can see that there are far more children with autism than are diagnosed with it. I can see that my son is absolutely autistic and I am ashamed not to have had the knowledge to have understood that before. But it made me aware of how complex SEN is and how school staff need to be led by the people who actually KNOW.
The original psychiatrist missed the autism because the ADHD hyperactivity masked the social difficulties and everything else, because he never stayed still long enough to have it picked up on.
Equally, we teachers miss difficulties that we should spot. I know of at least ten children at my school this year who range between 12 and 15 who have only just now been diagnosed with autism, Asperger's etc. These are children who've had quite significant behavioural and social problems throughout their school careers, and yet nobody has done anything about it until now.
They have been labelled by teachers and pupils as 'mad', 'freaks' and 'naughty', and it is unlikely that any help that we put in place now will undo the damage of those years.
Their parents didn't know and couldn't be expected to. Maybe teachers should have more training so they can recognise potential issues and, more importantly, offer the right support to those who have diagnosed conditions.
Ignorance is no excuse for refusing to accept professional diagnoses though. Yes, some doctors will get it wrong, but WE are not qualified to say that. "