The rate of children diagnosed by a doctor with mental health conditions has almost doubled over the past five years.
A suicide prevention advocate has slammed the results as bad science and says the definition of a "normal child" has narrowed too far.
However, child psychology experts say the increasing rate could be a symptom of a more anxiety-driven society and improvements in the diagnosis of youngsters.
About 25,000 children have been diagnosed with behavioural and emotional problems, with anxiety the fastest growing condition, according to the Ministry of Health's latest children's health report.
Anxiety, ADHD and depression are the three most common disorders in children, and boys are twice as likely to be diagnosed with mental health problems.
Casper chief executive Maria Bradshaw said she was horrified to hear of babies now being diagnosed as depressed.
She founded suicide prevention group Casper after her teenage son took his life just two weeks after being prescribed prozac for depression.
"It really worries me how narrow the definition of normal is becoming. We used to accept a wide range of behaviour from 2-year-olds and talked about the terrible-twos.
"Now a lack of concentration is a conduct disorder. Parents are scared their children are not going to function at school so they accept these labels."
The percentage of children with diagnosed mental health conditions jumped from 1.8 per cent to 3.2 per cent since 2007-08. Increasing numbers of children with anxiety, such as phobias, drove the increase, according to the Ministry of Health report.
More than 15,500 children are diagnosed with anxiety, up from 2800 children five years ago.
Bradshaw said a subjective test of preschoolers' mental health could be behind the rise. Four-year-olds have been undergoing the Ministry of Health's B4 School checks since 2008.
It rates children as normal, abnormal or borderline, and produces a score indicating whether a child is likely to have a significant problem.
"It's a checklist of moods and feelings. These are not medical things. It's not like working out if your child has diabetes or not. That's science, but this is not."
There was a public outcry last year when Pharmac figures showed an average 10 per cent increase in mood-stabilising drug prescriptions for children aged 5 and over in the past five years.
There was also a 140 per cent increase in antidepressant prescriptions for up to 4-year-olds between 2009 and 2010.
Canterbury University associate professor Kathleen Liberty said New Zealand is not alone in experiencing rising rates of mental health conditions in children.
"Symptoms of anxiety and depression seem to be increasing in children in many developed countries."
This could be caused by a whole range of factors, including the effects of the Christchurch earthquakes on children, increasing violence in media, homes and communities, and the economic downturn.
"In difficult economic times, children's emotional problems can increase and this can be related to the stress in the family, such as unemployment."
The content of children's television has also become more violent and there is more reported bullying in schools, all of which can increase anxiety, she said.
It was important to diagnose children suffering from mental health conditions, she said.
"It is better to understand that the children might be worried about something rather than the child simply being naughty.
"It helps the parent have more understanding about possible sources of the child's behaviour."
Another expert on child psychology said the Ministry of Health figures have underestimated the rate of mental health problems in children.
Waikato University psychology senior lecturer Dr Carrie Barber said the rates of anxiety disorders in children alone would be 20 per cent higher.
This is because the survey does not take into account children with behavioural or emotional conditions who have not been assessed by experts.
The Ministry of Health survey asked about 12,000 adults whether their child had been diagnosed by a doctor with a mental health condition.
Barber said parents are recognising and seeking treatment more often for mental health disorders, which could be partly behind the rising rate.
"Sometimes those increases have much more to do with awareness and accessibility than increasing rates."
Whether a child was treated depends on how much the condition interfered with the child's life, she said.
A more serious anxiety disorder, if left untreated, could potentially develop into panic attacks by teenage years and lead to a person withdrawing from society, she said.
- © Fairfax NZ News
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