School exclusions: 'I had low hopes at my old school'
Alternative education providers have raised concerns that mainstream schools are failing to spot ADHD and autism.
The rate of permanent exclusions in Wales have almost doubled between 2014 and 2017 to four in every 10,000 pupils.
When he was excluded from school 15-year-old Riley said he was worried he would not get his GCSEs.
"I was getting angry all the time - with the students, with the teachers. I just didn't like the school," he said.
But after starting at a specialist school for children kicked out of the classroom, Riley's behaviour improved.
The Welsh Government said permanent exclusion was a last resort and "should only be used where all other strategies for supporting the pupil have been exhausted".