FIVE-year-old John doesn't fall asleep when he's tired like other little boys - he falls unconscious when his body cannot take his hyperactivity any more. His mum Janice is a sister on a hospital ward, so has demands on her care and attention all day, but when she gets home, her work-rate goes through the roof.

Her autistic son spends all evening jumping on the spot, hopping from one foot to another and generally creating mayhem, pushing his perpetually tired parents into a situation where they are on the edge of a nervous breakdown. He eventually crashes out in the early hours of the morning. This happens practically every day.

Janice's story is typical of the hundreds of mothers stretched to breaking point with the pressures of caring for a 'problem' child: one with autism or a physical or mental handicap. Taken to extremes, it also illustrates the strains that lead to a devoted single mother leaping off a viaduct in County Durham, cradling her 11-year-old autistic son as they plummeted to their deaths.

While social services are preparing to investigate the circumstances leading up to the tragic deaths of Helen Rogan and Mark Owen Young, parents of autistic children are questioning the amount of help available to them. Many - who probably wouldn't even class themselves as carers - are now asking themselves: "Who is caring for the carers?".

As Janice takes a rare break from John's attention-grabbing behaviour, she reflects on the pressures that, were it not for the help of her husband, could have also driven her to breaking point. Clearly enjoying her time off 'John duty', she says: "Each day is a trauma for me. I utterly empathise with what poor Helen Rogan went through. How I haven't flipped my lid yet I don't know. The pressures on me and my husband are almost constant and, for a single mother like her, it must have been twice as bad."

Her golden-haired little boy looks almost angelic to outsiders - there are no physical signs of disability in autistic children. But to Janice, looking after him can be hellish.

"It's not just the fight in the home to have some kind of normality that wears us down. The red tape and bureaucracy of trying to get social services care has been crippling, and ensuring his special educational needs are met has exhausted us," she says.

"We've had no help whatsoever from social services: they have refused to fund respite care that they initially agreed to. We are entitled to it and it would have given us maybe one hour off a week, but what a difference it would have made."

A lack of support, particularly respite care, is having a demoralising effect on the nation's army of carers, usually relatives, who are being choked by their responsibilities. According to Carers UK, three in five Britons are expected to have to sacrifice their jobs and social lives to care for sick or disabled relatives at some time in their lives. Carers UK estimates the number of carers will top nine million by 2037.

And, with many carers complaining of being sidelined or ignored by social services, campaigners claim that Tuesday's tragic events have brought into sharp focus a need for change.

The Government brought in the new Carers and Disabled Children's Act in April. This gives carers more rights to have their needs taken into account and places a duty on local authorities to meet those needs. But it's an Act that probably came into force too late for Helen Rogan.

Helen Geldard is all too familiar with the problems of looking after an autistic child. Her struggle to bring up her son Mark, locked in a world of his own and unable to communicate in a normal way, led the Spennymoor mum to found a self-help group, the County Durham Autistic Support Group, five years ago.

"I've had a non-stop stream of calls from worried parents wanting to talk since Tuesday. It really has hit a raw nerve with a lot of people who know what she was going through," she says. "I knew the family. My son goes to the same school as Mark did and we gave them all the help and support we could. But in many ways, that's just the problem: they had to come to the group for this because they didn't get it from anywhere else.

"And believe me, they need support. It is the simple things that take so long and are so difficult. You have to teach them to clean their teeth, explain the concept of sex education when they get older. There is no specific support for these everyday problems. I always liken it to a 24-hour, seven-days-a-week job that you didn't apply for."

Carers also complain that the authorities are more concerned with child protection than helping families with problem children.

Helen says: "I knew a family who had a huge lad, about 15-years-old I think, who was lashing out in the home. They had asked social services for help but had been turned down. He was tearing the house down and becoming a threat to his brother and sister, so his dad had to pin him to the floor. Within minutes the Child Protection Unit was called."

Rob Goffee, manager of the Derwentside Carers Centre, says that, while the child's needs are always paramount, those of the parents are often neglected.

"The focus is very much on children, as opposed to their parents," he says. "They are not really taken into the equation. For example, to my knowledge, there are only a couple of social workers dealing with autistic children's parents in County Durham, but there is a massive 20-strong Child Protection team based in Stanley.

"Basically, the general rule seems to be, unless a child is assessed for specific needs, their parents or carers are not assessed at all."

The psychological damage inflicted on the carer by their never-ending burden is one more cross to bear for the parent, according to Dr Michelle Turner, lecturer in psychology at Durham University. She says parents are often expected to shoulder this burden on top of their usual maternal and paternal responsibilities.

"Autistic children have no concept of safety, for instance. Imagine the strains of never, ever letting the child out of your sight because they can't learn about danger.

"Parenting can be challenging at the best of times but, with a developmental problem, it becomes exceptionally difficult. There are extreme and constant demands on the carer. With a 24-seven care situation, they must have some respite and, if they don't get this, it's not difficult to see how the pressure builds up."