The charity said the number of young people getting in touch because of problems like suicidal thoughts, bipolar and depression has risen by eight per cent during the last four years.
Rachael Newham, a Christian mental health expert who founded Think Twice, told Premier's News Hour: "It's really important that you have at least one person on the staff team or pastoral care team that knows the signs to look for in mental health, the people who can say 'Actually, I think you might to visit the doctor'.
"It's not that we become diagnosis experts but that we're able to spot signs and point people in the right direction."
Childline founder Dame Esther Rantzen warned young people are sometimes missing out on professional help because children's mental health services are "terribly overstretched".
She said: "It's striking how many more children seem to be suffering serious mental health problems today than when we launched Childline 30 years ago.
"So many desperately unhappy children seem to be suffering suicidal thoughts, self-harming, becoming anxious and depressed, with many of them turning to Childline because no other support is available."
The figures were compiled by the National Society for the Prevention of Cruelty to Children (NSPCC) and were released to mark the beginning of Children's Mental Health Week.
Rachael Newham told Premier's News Hour that Christian adults can set a positive example by opening up about how their dealing with mental health issues.
She went on say: "We need to be able to model healthy ways of coping with emotion and a real openness.
"It's not that we need to tell our children and young people every detail of our lives but we do need to be able to say 'Actually, I'm struggling with my mental health and here are some of the things that help me."
Click here to hear Rachael Newham speaking with Premier's Aaron James: