The early 21st century decline in adolescent use of alcohol, tobacco and cannabis may have reached a plateau, and could reverse, researchers fear.
In a review summarising the latest evidence, a University of Otago team said substance use among 13 to 19-year-olds had peaked in the late 1990s or early 2000s.
It had then declined quickly, with prevalence now much lower than 20 years ago. But levels of adolescent binge-drinking in Aotearoa remained high by international standards, and disparities in tobacco and cannabis use by ethnicity and socioeconomic status were wide.
“Furthermore, evidence suggests we may again be at a turning point, with long-term declines stalling or reversing since about 2014–2016, and e-cigarette use emerging as a new risk,” the study, publicly released on Friday in the Journal of the Royal Society of New Zealand, said.
Lead author Dr Jude Ball, from the Department of Public Health at the University of Otago, Wellington, said she didn’t think a return to the adolescent substance use levels of the late 1990s was likely.
“Certainly not for smoking. It’s hard to imagine smoking coming back in a big way,” Ball said.
But concerns that alcohol use among adolescents could increase were justified. “Unlike tobacco, alcohol regulation is still very relaxed in New Zealand compared to lots of other countries. There are genuine concerns there.”
While smoking was at low levels, that was not the case for binge-drinking and cannabis use, with one survey of Year 10 students finding cannabis use was more common than smoking.
“Prevention is still a really important focus,” Ball said. “Young adults are at greater risk of harm. Starting any substance use at an early age you are more likely to become dependent, and have other long term problems.”
The review was concerned by anecdotal evidence that suggested black market producers were creating and selling vaping e-liquids that contained active cannabis ingredient THC.
The emergence of black market and homemade e-liquids in Aotearoa was concerning given the 2019 US outbreak of acute lung injury that killed 68 people and hospitalised thousands (mostly young men), was traced to black market THC e-liquids containing Vitamin E acetate, the review said.
The major changes in drinking, smoking, and cannabis use during the past 20 years were not unique to Aotearoa, rather they reflected patterns seen in almost all English-speaking and northern European countries.
This international decline in adolescent substance use was not fully understood, but several studies indicated that less unstructured in-person socialising was an important contributing factor, resulting in fewer opportunities for risk behaviours of all kinds, the review said.
Less permissive parental attitudes to adolescent alcohol use and improved parent–child relationships – may also have played a role.
Several indicators suggested declining substance use had positive effects on adolescent health, safety and wellbeing in this country, the review said.
The youth offending rate had declined by over 60% in the decade between 2009/10 and 2019/20, and by nearly 70% for Māori. While that decline had multiple causes, decreasing prevalence and frequency of adolescent binge-drinking was almost certainly one of them.
Declining rates of sexual activity, teenage pregnancy and sexually transmitted infections had run alongside the decline in substance use in adolescents, the review said.
The decline in substance use was also likely to have contributed to a fall in adolescent mortality since the late 1990s, since substance use was linked to the two leading causes of death in that age group – vehicle crashes and suicide.
The authors back up their findings and concerns with a wide range of data. Some of the key points include:
- past month drinking prevalence fell from 40% to 30% among 14–15-year-olds between 2012 and 2016
- the prevalence of past month binge-drinking (five or more drinks in a session) in secondary students declined from 36% to 22% between 2001 and 2019
- regular (at least monthly) smoking in Year 10 students (14-15 years) rose in the 1990s, peaking at 29% in 1999 before declining rapidly in the 2000s to a low of 4.7% in 2016, between 2016 and 2019 regular smoking rose slightly to 5.9%
- daily smoking among Year 10 students also rose in the 1990s, rapidly declined in the 2000s and was stable at 2% for the 2016–2019 period before reaching an all-time low of 1.3% in 2021
- for 15–17-year-olds, a daily smoking plateau from 2016/17 to–2019/20 was followed by a substantial decline from 3% to 1% between 2019/20 and 2020/21
- prevalence of at least monthly use of e-cigarettes increased from 3.5% (2015) to 12% (2019) in Year 10 students, and from less than 1% (2015/16) to 12% (2020/21) in a sample of 15–17-year-olds
- between 2015 and 2021 daily e-cigarette use increased from 1% to 10% among Year 10 students, and from less than 1% to 6% in the 15–17 years age group
- data show a decline in prevalence of 14 and 15-year-olds who have ever used cannabis from 19% (2012) to 14% (2014–2018), and in past month use from 10% (2012 and 2014) to 8% (2016 and 2018)
- in secondary school students (13–18 years), at least weekly cannabis use declined from 6.5% in 2001 to about 4% in 2012, with no significant change between 2012 and 2019
The review noted that one survey had found that since 2019 hazardous drinking – drinking patterns associated with acute and long-term risk – had increased in the15–17 age group.
“Although this finding should be treated with caution due the small sample size for this age band, it suggests the long-term decline in adolescent drinking may be over,” the review said.
When it came to vaping, the review said that while some evidence suggested e-cigarettes were attracting youth who would otherwise be smoke-free into nicotine use, some recent data provided the first local evidence that vaping may also be displacing smoking in older adolescents.
It also said cannabis use was now more prevalent than tobacco use in secondary school students, due to the dramatic decline in tobacco use.
While ethnic and socio-economic disparities among cannabis users had narrowed, a survey found the proportion of adolescents who used cannabis weekly or more often was still greater in high (5.4%) compared to low (3.3%) deprivation neighbourhoods, and greater in Māori (8.4%) than Pacific (3.6%), European (3.3%) or Asian (1.1%) students.
Michael Daly – Stuff – 2022-04-25.