The campaign to keep in the headlines what has long been known about the mental health and well-being of children in the UK – that they appear to be declining – reached another trigger point today with the release of more opinion poll results by the Good Childhood Inquiry.

The clear gist of the latest anecdotal evidence about children’s health is that most adults think they had a happier childhood than their own offspring, and an alarmingly high number of teenagers say they feel bad or really bad – and under pressure to look good.

Two-thirds of those surveyed in the poll blamed computer games and television watching for preventing children from being more active; nine out of ten agreed children need more education about healthy diets. There was an overwhelming consensus among respondents that physical health plays a crucial role in mental health – nearly all agreeing “to some extent” that physical activities are an important element in promoting mental health.

All of which has enabled Bob Reitemeier, chief executive of the Good Childhood Inquiry’s sponsors, The Children’s Society, to point to “a growing recognition of the true cost of neglecting children’s mental health and well-being”.

“Too often,” he says “mental health and well-being have been dismissed as being of little importance, but there is now an understanding that if we want to give children a better childhood these matters must be addressed. We now need to translate this growing concern into action and investment in the necessary support services.”

However it is measured or explained, the 25-year decline has been widely commented upon and there is an increasingly robust body of evidence to suggest what should be done to correct it [see for example the Prevention Action stories Repairing children's mental health – through thick and thin, Children's futures and the big screen and Bringing children’s services out of the care closet.

The lack of connection between what has long been known and concerted action to remedy it has prompted Professor Stephen Scott of the Institute of Psychiatry, who is also an inquiry panel member, to add his voice to the Children’s Society campaign.

“Many respondents to the inquiry shared the belief that well-being depends on good relationships, especially within the family; on a sense of purpose and on freedom," he says.

“To achieve this, child mental health and well-being must be everybody’s business. Support for parents is crucial; schooling has a key part to play; and providing the effective treatments now available for children with mental health problems takes time, skill and resources.”

The Good Childhood Inquiry – the UK’s first independent national inquiry into childhood – is managed by The Children’s Society. Its final report and recommendations will be published in early 2009.

• For more about the Inquiry and a summary of the health evidence submitted to it, see Good Childhood: what you told us about health.