Melanie Berger, of Gawdy Close, Harleston, said it took four years to get her son, Ben, now aged eight, diagnosed with autistic spectrum disorder.

Part of her struggle to get an official recognition of her son's problems involved the whole family – mother and son, husband Steve and daughter Zoe, now aged five – spending six weeks at an in-patient residential unit in Cambridge while their parenting skills and Ben's behaviour were assessed.

"But even after that we still weren't given a diagnosis as we were told Ben could not be autistic because he was too sociable," she said.

Mrs Berger said autism is a lifelong developmental disability that affects the way a person communicates and relates to others around them.

People with autism have difficulties with everyday social interaction and a new report from The National Autistic Society has found many adults with the disability struggle to get the help they need and remain totally dependent on their families for support.

The society's recently-launched Think Differently About Autism campaign is aimed at highlighting the plight of adults with autism.

Mrs Berger is very worried about what will happen to Ben when he is older. At the moment, he is in mainstream schooling at Harleston Primary School and, although he has difficulty with writing, he is a bright boy who excels at maths and science.

But at times he displays an explosive temper and although he understands the importance of safety rules has trouble putting that knowledge into practice.

"He has great difficulty regulating his emotions and at times he has kicked and punched me and thrown things," said Mrs Berger.

Simply family activities such as going for a walk have to be meticulously planned to ensure Ben does not put himself in danger by rushing into the road, and shopping trips and holidays have to be kept to a minimum because he doesn't deal well with changes in his environment and can react in an impulsive and, at times, potentially life threatening manner.

"He once set a fire in the kitchen because he was mad about firemen at the time. He then put it out and very proudly came and told us what he had done. It was a big worry.