One in 17-year-olds have tried hard drugs such as cocaine, ecstasy and ketamine, research by UCL has found.

The study, which explores engagement in substance use and antisocial behaviours among Generation Z as they reached late adolescence, found that one third of 17 year olds had tried cannabis with one in 10 trying harder drugs. More than half had engaged in binge drinking and 12% were regular smokers by the age of 17.

Co-author, Professor Emla Fitzsimons at the UCL Centre for Longitudinal Studies said: “To some extent, experimental and risk-taking behaviours are an expected part of growing up and, for many, will subside in early adulthood. Nevertheless, behaviours in adolescence can be a cause for concern as they can have adverse long-term consequences for individuals’ health and wellbeing, and their social and economic outcomes.”

“The prevalence of alcohol consumption in this study is very similar to that found in an English cohort born 12 years before, and which measured alcohol use around the same age. However, reports of cannabis use in our study suggest a decline compared to rates among this earlier born generation. It remains to be seen how the COVID-19 pandemic has affected engagement in these behaviours,” she added.

The researchers analysed new data collected from a nationally representative group of almost 10,000 teenagers who have been taking part in the Millennium Cohort Study (MCS) since they were born in 2000-02. In 2018-19, when study participants were age 17, they were asked about substance use – including drug taking, binge drinking and smoking – and antisocial behaviours – such as assault, shoplifting and vandalism.

The study, funded by the Economic and Social Research Council, revealed:

- 31% of young people had tried cannabis by age 17

- 10% had tried harder drugs by age 17

- More than half (53%) had engaged in binge drinking – drinking five or more drinks at a time

- 9% said they had done this on 10 or more occasions in the past year.

- More than two fifths (45%) had tried a cigarette

- 12% were regular smokers at age 17.

Rates had increased substantially for all these behaviours since participants were age 14, as would be expected. However, researchers noted differences in rates of substance use according to sex, parents’ education level and ethnicity.

- Males reported higher rates of cannabis use than females (34% vs 28%)

- Males reported higher rates of harder drug taking (12% vs 8%)

- Males also reported higher levels of binge drinking (56% vs 51%)

- Young people whose parents were highly educated – holding at least a degree – were more likely to report having tried alcohol than those whose parents had lower level qualifications (89% vs 82%).

- Young people whose parents were highly educated were also more likely to have engaged in binge drinking (59% vs 50%).

- Rates of drug use remained similar among young people, regardless of parents’ educational qualifications.

- White teenagers were much more likely to have experimented with substances than their ethnic minority peers.

- White teenagers were twice as likely to report taking harder drugs (11% vs 5%) and almost three times more likely to report binge drinking than ethnic minority teens (59% vs 21%).

As Generation Z approached adulthood, reports of antisocial behaviours mostly remained stable or declined compared to rates at age 14. Prevalence of assault – pushing, shoving, hitting, slapping or punching someone – decreased from 32% at age 14 to 25% at age 17, and levels of vandalism, graffitiing and use of a weapon were similar at both ages. However, reports of shoplifting increased from 4% in early adolescence to 7% a few years later.

Rates of certain antisocial behaviours differed by sex and parents’ education level.

- Males were almost three times more likely than females to report assaulting someone at age 17 (36% vs 13%).

- Young people whose parents were educated to degree level or higher reported higher rates of shoplifting than their peers whose parents had lower level qualifications (9% vs 5%).

- The prevalence of antisocial behaviours was similar among white teens and their ethnic minority counterparts.

Co-author, Dr Aase Villadsen, UCL Centre for Longitudinal Studies, added: “In relation to our finding for antisocial behaviours we might have expected to have seen a larger increase from the age of 14 to 17 in line with the well-established age-crime curve shown in previous research, whereby these behaviours worsen over adolescence, and then decline again in late adolescence and early adulthood.”

“This surprising finding could show that the peak in antisocial behaviours in this generation has been reached earlier than usual and rates have already started to come down by age 17. Or it may be because young people nowadays are engaging in a much lower level of offending than in the past; official figures have shown plummeting rates of youth offending in the last decade. This is a positive and will potentially help to improve the future social and economic prospects of Generation Z,” she concluded.

Substance use and antisocial behaviour in adolescence