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Children in and around Bristol are having to wait years for an autism assessment - and there has been a "dramatic increase" in referrals which could make things even worse.
The Bristol Autism Hub opened in September 2020, bringing together children awaiting a diagnosis in Bristol and South Gloucestershire and has since expanded to include North Somerset.
An autism diagnosis can help families access extra support and funding to help a child's development.
The most recent figures provided by Sirona Care & Health, which runs the hub, show 2,454 children on the waiting list. At the beginning of November, this was 1,364.
There is a triage system in place so, after they are referred, children are clinically prioritised. The average wait is 18 months but it could take up to two and a half years for some to be seen.
Emma Nickson says the situation has left her "feeling helpless". Her five-year-old son George has epilepsy and delayed development. He has been referred through a GP for an assessment.
Emma says George's behaviour can be worrying.
"I can't do chores on my own because it will trigger a massive meltdown," she said.
"He puts himself in danger because he'll really throw his body around if he's on a chair.
"We had an incident where we were on holiday and we were on a concrete thing and he threw himself back onto the floor and banged his head. So that's quite difficult to try and restrain and calm him down."
"I don't understand why it takes so long as we're under a lot of other specialists and their systems seem to work slicker and quicker."
Laura Manning says her son Zac's condition is becoming more apparent as he gets older.
His referral was sent in 2020. Despite a paediatrician saying they were confident he would get a full autism diagnosis - his family are still waiting for this to happen.
"It is huge, because without the knowledge of autism, it's not as easy," Laura said.
She continued: "Zac can't go to parents or aunties or siblings because no one is aware of his actual needs.
"Without that full diagnosis and without the information needed and support it's a very isolating place because Zac's not a naughty boy. He just has needs and he has a frustration of communication where he can't get his point across."
Local charity Bristol Autism Support want to see more assessors and staff at the hub or even a second facility created to deal with these waiting times.
"I think any amount of time you have to wait between being told your child may have autism and getting the answers is a long time. To be in that limbo is very hard. Ideally I would like to see it be about six months. We can't be too unreasonable but I think six months is long enough to wait."
The hub says it works hard with partners to ensure those in need have support while they wait for a formal assessment, but there are concerns the increase in referrals could lead to further delays.
In a statement Julie Sharma, interim Chief Executive for Sirona Care & Health, apologised.
She said: "We recognise that families are waiting too long for their children to receive an initial assessment for autism and we are really sorry that we do not have the capacity to reduce this.
"We are also reviewing our processes and criteria to ensure that those children with the highest needs can be seen more quickly and we will continue to work with our partners and our funders to identify ways of reducing the overall wait times for all families."