The prevalence of depression among 15-year-olds has more than doubled since the 1980s, according to a new study led by the University of Otago.
New data from the Dunedin Study revealed children whose parents have depression are also four times more likely to be depressed at age 15.
“The rise in the prevalence of depression has major consequences for the current generation of young people, but our findings also suggest that it could also affect the mental health of their children and subsequent generations,” co-author and professor Bob Hancox said.
“We found that parents who’d only had maybe one episode of depression during their life, their kids were not really at increased risk.
“But if their parents had depression that started early and became recurrent at many ages throughout their life, that really put their children at increased risk.”
Initially, researchers had only set out to find out whether depression had links over generations, he told Breakfast. What they didn’t expect to find was that 15-year-olds overall were 2.5 times more likely to have depression than their parents at the same age.
Data was collected from 612 children born to 375 members of the Dunedin Study. The children, at age 15, were asked the same questions that their parents were when they were that age.
Because the study spanned two generations, Hancox said it began to show a “genuine increase” in the prevalence of depression.
He said the findings were “concerning” and warned ineffective mental healthcare would increase depression for generations ahead.
“It is of further concern that the mental health and addiction inquiry, He Ara Oranga, found that our mental healthcare system is struggling to meet people’s needs.
“This research was conducted before the Covid-19 pandemic and it is likely that young people’s mental health problems are even worse now.”
Clinical psychologist Dougal Sutherland, who appeared on Breakfast after Hancox, said he wasn't surprised there had been an increase in the prevalence of depression among teens because he and other professionals had seen it during their practice.
Since Covid-19 lockdowns, Sutherland said he had seen a "groundswell" or referrals. He'd also seen an increase in the severity and complexity of youth's mental health concerns.
“I think we are better at identifying it, and young people … a silver lining in the cloud in a way is that young people are actually talking about this stuff more," he said.