How does a child vanish in plain sight? Our grandson, Christian, used to watch trucks drive by and name them all - “fire truck”, “mail truck” - until, suddenly, he had no more words. We used to go for walks on the beach until he could no longer tolerate the feeling of sand on his feet. Warm smiles were gone, too, replaced by eyes that would not connect with mine.

The boy who had brought so much joy and had been hitting all his developmental milestones was slipping away. At first, doctors told us it was because he had a new baby brother, or because boys are slower to develop. Our concern turned into panic as Christian became increasingly sick and disconnected.

Eventually, we learnt the real answer when Christian had autism diagnosed. We were stunned. Despite having spent decades in the media business, we knew little about the disorder, and although we had access to the best medical care, we were at a loss about what to do next. Christian's doctors told us “goodbye and good luck”. As we struggled to understand autism and help our grandson, our personal quest became a public crusade.

This crusade is very necessary: 1 per cent of the population in Britain - more than 500,000 people - suffer from autism spectrum disorder, yet it is still met with a mixture of ignorance, prejudice or indifference.

What is autism? For the person with autism, the world is a place of anxiety. It is a great swirl of people, places and events that make little, if any, sense. A person with autism can be terribly isolated from people around him or her, a stranger to the social skills we take for granted, of how to relate to other people or read their emotions.

Because it's a spectrum disorder, a person with autism can have anything from mild symptoms, such as a literal approach to language, making it impossible to follow the subtleties of conversation, to being unable to speak, living in a state of lonely despair and agitation. Some people with autism can lead independent lives, others may never be able to care for themselves.

We created Autism Speaks in the US in 2005 to change the future for all who struggle with autism. Our main objective was to raise awareness. We knew that once autism entered public consciousness, it would generate the funding necessary to drive research into the unanswered questions about what causes it and how we might alleviate its effects.

In three years of aggressive campaigning, we have made great progress in increasing awareness. We have raised more than $110 million for scientific research. With other organisations, we achieved passage of the Combating Autism Act 2006, a $900 million Bill that allocates funds directly for research and services.

Similar action is needed in Britain. That's why I was eager to accept an invitation from TreeHouse, the national charity for autism education, to give its annual lecture yesterday. We are eager to support TreeHouse's work. The need is particularly urgent in the UK - the incidence of autism is greater here than in the US (where it is 1 in 150), and is rapidly increasing. Not only is the disorder devastating the lives of British families, it is becoming a growing burden on the health system and the economy.

A study last year by the Foundation for People with Learning Disabilities calculated the lifetime cost to society of caring for someone with autism can be as much as £4.7 million per person. That includes everything from direct medical expenses and the provision of special education, to the hidden costs of childcare, adult care in later life, respite and family care, as well as the lost wages for carers who have to give up their careers.

But the numbers do not capture autism's overwhelming emotional burden. The study found that the stresses of caring for children with autism are much greater than the pressures of bringing up those with with other developmental disorders. The divorce rate, for instance, is much higher. Families can be ground down by the need to give constant attention to their child and struggle with a welfare or education system that is often unresponsive to their needs.

Despite these thousands of private tragedies, support is hard to come by. Less than 0.5 per cent of public medical funding goes to research, prevention and treatment of the disorder. This makes one of the fastest-growing and most prevalent childhood disorders in the UK, the country's least funded.

Awareness about autism and increased support for early intervention are the keys to changing this. As awareness grows among policymakers, doctors, carers, teachers and families, so will compassion for people and families living with autism. This will help the money-raising efforts that can fund research, early diagnosis and more consistent early intervention - which can lead to a more fulfilled adult life - and ultimately, successful treatments.

We can begin with the three-pronged approach of education, legislation and research that is working in the US: educate the general population as well as carers and teachers focused on young children; lobby government to increase funding for research; and demand and develop improved interventions for those with autism. We must ensure that people know about and use these tools to give children the best possible shot at living functional and rewarding lives. We know that early diagnosis (as early as the age of 1) coupled with immediate acute therapies (speech, occupational and behavioural) can allow up to half of children to start primary school with their peer group with some special help. Starting with diagnosis, every child with autism should have access to applied behavioural analysis (ABA), at present the only therapy regimen widely considered to be effective.

We must press for the passage of legislation, such as the Autism Bill, presented in Parliament this month, that will ensure that the needs of people with autism are not overlooked. The Combating Autism Act in the US creates a precedent that transcends party lines, which the UK should follow.

Finally, we must increase and improve information on the prevalence of autism in Britain. Not only will it provide more clues about the causes of the disorder and create opportunities to advance new therapies and treatments, but it will also drive funding and awareness.

We know it is possible to lighten the burdens of autism for individuals and families living with the disorder. But hope and progress can only come through public awareness, swift and substantial legislative action and more research into the mysteries of one of the most devastating childhood disorders of our time. Autism speaks. It's time for the world to listen.

Bob Wright is a former chairman of NBC. With his wife Suzanne, he is co-founder of Autism Speaks. For free resources to help everyone from teachers and medical professionals to families to cope with autism, go to www.autismspeaks.org

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