The numbers of young people suffering from depression in the last 10 years has risen worryingly, an expert says.
More and more teens are becoming depressed
Government statistics suggest one in eight adolescents now has depression.
Unless doctors recognise the problem, more could slip through the net, says Professor Tim Kendall of the National Collaborating Centre for Mental Health.
Guidelines on treating childhood depression will be published next year. Professor Kendall says a lot more needs to be done to treat the illness.
"We know that between 10 and 19 years old the third leading cause of death is now suicide, and suicide and depression tend to go hand in hand," he said.
Kirsty, 17, has suffered from depression since she was 13.
"It's not a nice problem to have. It's horrible. I think it's because people can't see it so you might appear bubbly and happy but inside you are feeling really unhappy," she said.
Beth, 18, was about 10 when her symptoms started and she became desperate.
Beth had severe depression
"There's just no point in being alive. There's no reason to exist really. It's a struggle to do the simplest of things. I can't get dressed in the morning, I can't feed myself. It's just awful," she said.
Professor Kendall warned: "If we don't recognise that children and adolescents are getting depressed then we are not going to realise those that are likely to kill themselves."
He said that GPs in particular, but psychiatrists as well, found it difficult to accept that children and adolescents get depressed.
"Unless we are prepared to make the investment in providing the right infrastructure and the right treatments for children we may be setting ourselves up for a much bigger problem later in their lives," he said.