Primary school principals at Wellington have been invited for a seminar on child depression as Wellington's Central Regional Health School in the lower North Island raises alarm on the increasing number of children with depression problems.

In the seminar held on March 2012, the school coached local principals, Education Ministry staff, and Capital and Coast District Health Board staff on how to spot signs of mental health problems in pupils, which go way beyond moodiness.

Wellington's Central Regional Health School caters to 166 primary and secondary school pupils who are deemed too ill to attend mainstream schools.

Principal Ken McIntosh said that 10 years ago the school catered solely for children with physical illnesses. At present, 47 per cent of the pupils show signs of mental illness, a dramatic increase of about 20 per cent in the past few years.

"That's a reasonably significant jump. We want schools to be aware that they are able to work with students within their school early on, and when things do get past the normal, healthy anxiety and start to impact on kids they know the kinds of services that are available to help."

Mental Health Foundation Chief Executive Judi Clements also said adolescent mental health was a major concern.

"Growing up is a hard time. Young people have to deal with issues in school, in their home life, their emerging sexuality, developing friendships ... it's faster-moving than it used to be, there is more alcohol misuse and more cyber-bullying."

Evolve Wellington Youth Service Manager Kirsten Smith told Dominion Post the number of young people using the service had significantly increased in the past two years.

"It's a massive issue, and we've been seeing the same trend in the last couple of years - we've noticed a huge spike in mental health-related issues going on in young people."

Ms Smith blamed high unemployment among the youth for increasing depression and anxiety problems in older teenagers. She noted those who are unable to get a job suffer self-esteem issues leading to anxiety problems, insecurities, and questions on self-worth.

However, Pharmac figures show an average 10 per cent increase in prescriptions of mood-stabilising drugs for children aged five and over compared to five years ago, Dominion Post reported.

The most alarming increase is in anti-psychotic medication among 10 to 19-year-olds, which has risen 47 per cent since 2007 - with 3240 children taking the drugs in 2011, according to Dominion Post.

Massey University Psychology Professor Ian Evans said this could be due to the "overpathologising" of childhood behavior, with parents resorting quickly to medication when therapy would work just as well.

"There's a great willingness in society in general to give labels, and to attribute problems to some form of illness."

However, the combined stress of school, widening economic disadvantages and modern technology meant today's kids were struggling to cope, he said.