The study comparing millennials with Generation Z found rates of depression among adolescents had surged from fewer than one in ten (nine per cent) to more than one in seven (16 per cent) in the 10 years between the two generations.
By contrast the proportion who had smoked in adolescence had almost halved from nine per cent to five per cent, while the number trying alcohol before the age of 14 dropped from 52 per cent to 48 per cent.
Generation Z were, however, more likely to be worried about their body image, and more likely to be overweight, according to the research by UCL’s Centre for Longitudinal Studies and Liverpool University. Lower self-worth and body confidence has been linked to increased social media use.
Born just as social media and the iphone were taking off, Generation Z also spent more time on social media and were more influenced by it than millennials.
Dr Praveetha Patalay, co-author of the research, said the study showed that while there was “good news” that Generation Z were spurning drink and cigarettes, those that did were more prone to depression than the earlier cohort of teenagers.
She said such a link was “concerning” and required urgent action by public health and clinical care planners.
Yvonne Kelly, Professor Lifecourse Epidemiology at UCL, said increased social media use among Generation Z could be linked to the rise in depression.
“That generation is spending more time engaging with social media and consuming information via those platforms. It could be to do with the content and context of that use,” she said.
“Social media could be a conduit but there is still a question mark over whether it is causally related to markers of wellbeing. “There are many many many influences on wellbeing and mental health: the pressures through education, the impact of Covid on particularly Generation Z’s schooling and youth unemployment.”
The research is one of the most in-depth comparisons of the state of mind and habits of the two groups of teenagers Data on the younger generation Z group was drawn from the millennium cohort study which has tracked more than 11,000 young people across the UK since they were born in 2000/02.
The older group of millennials consisted of more than 5,600 people who were born in the Bristol area in 1991/92 and are being followed by the Children of the 90s study.
While Generation Z spent three hours a day on social media, for millennials it was two and a half hours. They were also more likely to buy products from social media influencers and to purchase online.
The UCL researchers found that rates of obesity among young people had almost doubled over a decade, from four per cent to eight per cent.
Generation Z teenagers were also more likely to perceive themselves as being overweight or obese compared to their older counterparts at the same age (33 per cent versus 26 per cent).
Among generation Z, those who were overweight, obese or perceived themselves to have a high BMI were more likely to be depressed aged 14 compared to similar millennial adolescents a decade earlier.
There was however less evidence of anti-social behaviour among generation Z with rates of assault down eight per cent compared with millennials.
Co-author, Dr Suzanne Gage, of Liverpool university, said: “Substance use, antisocial behaviours, body image issues and depression tend to begin in adolescence, and have long lasting effects for individuals and society.
“This research reveals a closer link between these risky behaviours and poor mental health for more recent generations of teens.”
More than 52% of the millennials had tried alcohol by age 14, compared to less than 48% of those born a decade later, and, 9% of millennials had tried smoking cigarettes in adolescence, compared to 5% of generation Z.