Spotlight on the Groundbreaking GRiT Study from University of Canterbury

A groundbreaking new study published in the New Zealand Medical Journal (NZMJ) on February 27, 2026, has shed light on the alarming prevalence of vaping and nicotine dependence among high-risk teenagers in New Zealand. Conducted by researchers at the University of Canterbury's School of Health Sciences, the Gauging Risk and Resilience in Teenagers (GRiT) Study reveals stark disparities in vaping behaviours between vulnerable adolescents and their typically developing peers.

The longitudinal GRiT cohort, originally tracking children born to mothers receiving opioid substitution therapy during pregnancy, followed 135 late adolescents aged 16-19 years from Canterbury. High-risk participants, defined as those exposed to prenatal opioids and often facing ongoing socio-economic hardships, family instability, and health vulnerabilities, showed dramatically higher vaping rates compared to a matched comparison group.

Key statistics highlight the crisis: 87% of high-risk teens had ever vaped, and 64% vaped regularly (more than monthly), versus 55% and 30% in the comparison group. This places regular vaping in the high-risk group at over four times national averages for secondary students.

Defining High-Risk Teenagers and Their Vulnerabilities

High-risk teenagers in the GRiT Study are a unique cohort: children born to mothers prescribed methadone as part of opioid substitution treatment (OST) during pregnancy. These young people have navigated significant adversity, including parental substance use disorders, low family socioeconomic status (SES), housing instability, and limited access to supportive environments. Professor Lianne J. Woodward and her team at University of Canterbury emphasize that such backgrounds compound risks for substance use, mental health issues, and poor health outcomes.

While the study focuses on Canterbury, its findings resonate nationally, as similar inequities affect Māori and Pacific youth, who are over-represented in low-SES groups and showed higher regular vaping rates (31% vs 17% non-vapers). Logistic regression confirmed that high-risk status, rather than SES alone, drives these patterns, underscoring the need for targeted interventions.

Median vaping onset was 15 years across groups, with no significant sex differences, but regular use trended higher with age in the general sample.

Signs of Nicotine Dependence: A Path to Addiction

Among regular vapers, nicotine dependence was assessed using adapted DSM-IV and DSM-5 criteria, revealing troubling symptoms. Nearly 60% had unsuccessfully tried to quit or cut down, 52% couldn't go a day without vaping, and 46% faced concerns from others. High-risk teens reported significantly more symptoms overall (p=0.03), with 75% exhibiting two or more—compared to less than 50% in the comparison group (p=0.02).

Particularly alarming: 67% of high-risk regular vapers felt tense or irritable when unable to vape (2.2 times higher), and 61% craved a vape first thing in the morning (1.8 times higher). These hallmarks of dependence indicate a rapid 'path to addiction,' especially given most (over 75%) started vaping without prior cigarette use.

• Unsuccessful quit attempts: 59% high-risk vs 54% comparison
• Unable to abstain for a day: 52% vs 42%
• Cravings upon waking: 61% vs 33%
• Withdrawal irritability: 67% vs 30%

Regular vapers predominantly used high-nicotine products (50-60mg/ml salts pre-regulation, equivalent to 20-28.5mg/ml freebase post), amplifying addiction risks.

Broad Health Risks of Youth Nicotine Vaping

Nicotine, the primary addictive agent in vapes, disrupts adolescent brain development—the prefrontal cortex responsible for impulse control, decision-making, and learning remains plastic until the mid-20s. Dependence leads to withdrawal symptoms like irritability, anxiety, and concentration issues, disrupting school and daily life.

Beyond addiction, vaping poses respiratory risks (e.g., EVALI-like illnesses), cardiovascular strain, and oral health damage. Long-term, it may gateway to other substances or smoking, though GRiT shows most initiate with vapes. High-risk teens, already burdened by adversity, face compounded mental health impacts, widening inequities.

For context, New Zealand Health Survey 2024/25 data shows 13.6% daily vaping among 15-17-year-olds, highest among Māori (27.5%) and deprived areas.

Photo by Te Pania ♡ on Unsplash

National Trends: Declines Amid Persistent Concerns

While GRiT highlights vulnerabilities, broader surveys show progress. The ASH Year 10 Snapshot 2025 (31,000+ students aged 14-15) reports daily vaping at 7.1% (down from 10.1% peak), regular at 11.2%, ever-tried 31%—fourth year of declines post-regulations.

Māori rates remain high (daily 16.5%), low-SES 24.8% regular. Friends/family main sources (57%/17%).

Quit attempts: 59% daily vapers tried last year, but success low.

Disparities Exacerbating Health Inequities

Vaping disproportionately impacts Māori, Pacific, and low-SES youth. GRiT Māori over-representation in vapers tied to SES/high-risk. NZHS: deprived quintile 5 has 2.4x daily vaping odds. University research like Youth19 confirms 10% regular secondary vaping, nicotine-dominant.

Culturally responsive support essential, as high-risk unlikely to use standard GP/helplines.

Government Policies and Regulatory Responses

New Zealand's Smokefree Aotearoa 2025 goal drove amendments: mid-2023 bans on cartoons/flavors, nicotine caps; Dec 2024 Amendment Bill (No 2) prohibits disposables, displays, specialist shops near schools/marae, stricter penalties.

Despite, specialist retailers flout age verification. GRiT calls for enforcement, youth-access curbs.

Pathways to Cessation: Evidence-Based Solutions

Cessation vital: NZ's first youth quit vaping guidelines (2023) emphasize behavioral support, nicotine replacement therapy (NRT). Programs like 'Don't Get Sucked In' train educators; Quitline expanding vape support.

• Youth-friendly apps/helplines
• School-based interventions
• Cultural programs for Māori/Pacific
• NRT trials for dependent teens

University of Otago research shows strong cravings disrupt life; tailored support needed.

Photo by Mike Swigunski on Unsplash

Universities Leading the Charge in Vaping Research

NZ universities drive insights: UC's GRiT, UoA Youth19, Otago addiction studies. Explore careers advancing this work via university jobs or higher ed career advice.

Future: equity-focused trials, longitudinal impacts.

Future Outlook: Prevention, Equity, and Hope

Declining trends offer optimism, but high-risk crisis demands action: enforce regs, fund cessation, address roots (poverty, family support). With UC/Otago leading, NZ can curb teen vaping nicotine dependency.

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