Sources
All numbered references, what they measured, and who took part. Guidance documents and reviews draw on many studies; they do not have one surveyed population.
- The Teen Brain: 7 Things to Know
National Institute of Mental Health · 2023
Public-health guidance on adolescent brain development, the prefrontal cortex, learning, social context, sleep and resilience. It summarizes research rather than reporting one survey or an individual maturity deadline.
Who / what: General guidance about adolescents; no single surveyed population.
- A canonical trajectory of executive function maturation from adolescence to adulthood
Nature Communications · 2023
Combined four datasets containing 10,766 participants aged 8–35 and 23 measures from 17 executive-function tasks. It studied average changes in measured skills, not a universal age at which every brain is mature.
Who / what: 10,766 participants aged 8–35; two longitudinal and two cross-sectional datasets.
- The Promise of Adolescence: Realizing Opportunity for All Youth — Adolescent Development
National Academies of Sciences, Engineering, and Medicine · 2019
Consensus report reviewing biological, brain and social development, including plasticity and changing connections. It synthesizes many studies rather than surveying one group.
Who / what: Evidence synthesis about adolescence; no single surveyed population.
- Information about the Brain
NIH Curriculum Supplement Series · 2007
Educational background on neurons, synapses, plasticity and learning, including the formation and strengthening of connections. This is teaching material, not a new survey or a numerical model of learning speed.
Who / what: Educational synthesis; no single surveyed population.
- Risks of vaping
Health Canada · Public-health guidance
Summarizes nicotine delivery, dependence, developmental concerns, aerosol chemicals and other vaping risks. It provides guidance for youth and adults rather than findings from a single survey.
Who / what: General public, with a section on children and teens; no single surveyed population.
- Health Effects of Vaping
CDC · 2025
Public-health summary of vaping risks, nicotine dependence, withdrawal and effects on developing systems involved in attention, learning, mood and impulse control. It draws on multiple sources and does not calculate a teenager's individual damage percentage.
Who / what: General guidance with a youth section; no single surveyed population.
- New Biological Insights into Smoking Cessation
U.S. Surgeon General, Smoking Cessation report, chapter 3 · 2020
Reviews human and animal research on nicotine receptors, dopamine, dependence, withdrawal and learned cues. It explains general nicotine mechanisms rather than reporting one teenage vaping survey.
Who / what: Review of human and animal studies; no single sample.
- Nicotine Exposure during Adolescence Leads to Short- and Long-Term Changes in Spike Timing-Dependent Plasticity in Rat Prefrontal Cortex
Journal of Neuroscience · 2012
Experimental study measuring short- and long-term changes in prefrontal synaptic plasticity after adolescent nicotine exposure in rats. It used nicotine injections and brain recordings, not human vaping or a survey of teenagers.
Who / what: Laboratory rats; no human participants.
- Association Between E-Cigarettes, Cognition and Mood in Adolescents
Psychological Reports · 2024
Online survey of 432 Australian adolescents aged 11–18, including 88 who had used e-cigarettes. It measured self-reported mind-wandering, confidence about schoolwork and mood symptoms; the cross-sectional associations do not establish causation.
Who / what: 432 adolescents aged 11–18; 88 reported e-cigarette use.
- I quit for me
Health Canada · 2026
Practical youth guide for quitting tobacco use or vaping, including cravings, triggers, planning and support. It is a self-help resource, not a survey or a guarantee of a particular recovery timeline.
Who / what: Written for young people who want to quit; no single surveyed population.
- Searching for Signatures of Brain Maturity: What Are We Searching For?
Neuron · 2016
Research perspective examining what brain maturity means and why different measures develop on different timelines. It is not a new survey and does not establish one birthday as a universal maturity cutoff.
Who / what: Research perspective; no newly surveyed population.
- Attention-Deficit/Hyperactivity Disorder: What You Need to Know
National Institute of Mental Health · Public-health guidance
ADHD symptoms, individual differences, and established treatments (medication, psychotherapy, behavioural interventions); advises avoiding tobacco.
Who / what: Clinical education about children and adults with ADHD; no single surveyed population.
- Attention-Deficit/Hyperactivity Disorder Symptoms and Later E-Cigarette and Tobacco Use in US Youths
JAMA Network Open · 2025
Longitudinal study of later vaping starts and four screened ADHD symptoms. Observational associations do not establish causation or extra brain injury.
Who / what: 13,572 US participants, initially aged 12–17; 12,091 in the vaping-start analysis.
- 2025 National Youth Tobacco Survey results
FDA · 2025 survey; results released 2026
Measures recent vaping frequency. Among current vapers, 27.5% reported daily use and 41.2% use on at least 20 days; these groups overlap.
Who / what: US middle and high school students; the displayed figures concern current vapers.
- Use of vapes among young people in Great Britain, 2025
ASH / YouGov · 2025
March–April survey with 2,746 respondents aged 11–17 in Great Britain. The current-vaper subgroup had 231 respondents; its weighted 47% figure measures strong, very strong or extremely strong urges, not a clinical diagnosis or brain injury.
Who / what: Ages 11–17 in England, Scotland and Wales; current-vaper subgroup n=231.
- Alcohol and Drug Use among Students in Canada, 2023–24
Health Canada, Canadian Student Alcohol and Drugs Survey · 2023–24 survey; published 2025
Survey of 51,844 students in grades 7–12 across nine provinces; Quebec did not participate. Grade 12 past-month non-cannabis vaping was 27%, giving an approximately 73% complement; the measure includes nicotine, non-nicotine and unknown-content vapes.
Who / what: Grades 7–12 in nine Canadian provinces; the displayed 27%/73% comparison concerns Grade 12.
- Protecting Youth From the Harms of Vaping
CDC · 2024
Guidance on helping young people avoid or stop vaping, including nicotine dependence, withdrawal and developing-brain concerns. It is public-health advice, not a single survey or a dose-finding study establishing a safe teen exposure.
Who / what: Guidance for young people, caregivers and educators; no single surveyed population.
- Public Health Consequences of E-Cigarettes — Summary Annex: Report Conclusions by Level of Evidence
National Academies of Sciences, Engineering, and Medicine · 2018
Consensus evidence review of e-cigarettes. Conclusion 4-1 finds nicotine exposure varies with the device, liquid and how the device is operated; this is a synthesis of studies, not one surveyed population.
Who / what: Review of laboratory, clinical and population evidence; no single sample.
- Vaping and quitting smoking
Health Canada · 2026
Discusses complete switching from cigarettes, reduced exposure and risks, and why youth and people who do not smoke should not vape.
Who / what: Guidance for adults who smoke; evidence synthesis, not a single survey.
- Using e-cigarettes to stop smoking
NHS · Public-health guidance
Explains quitting smoking, complete switching, relative harms and remaining uncertainty.
Who / what: Guidance for adults who smoke; not one surveyed population.
- Advisory on E-cigarette Use Among Youth
U.S. Surgeon General · 2018
Describes youth e-cigarette use as an epidemic and reviews concerns about nicotine exposure.
Who / what: Advisory drawing on national US youth tobacco surveys and health evidence.
- Quitting smoking: Provincial and territorial services
Health Canada · Service information
Official directory of free, confidential provincial and territorial quit support; lists the toll-free quit-coach number 1-866-366-3667.
Who / what: Service information for people seeking quit support; not a research study.
- Smokers’ Helpline
Canadian Cancer Society · Service information
Free support for quitting smoking, vaping or both. The provider's service directory confirms iQuit to 123456 in Ontario, Manitoba and Saskatchewan, 1-877-513-5333, and the requested weekday phone hours.
Who / what: Quit-support service information; not a research study.
- Support to quit smoking
Government of Ontario · Service information
Ontario guidance on quitting, including Health811 and Smokers’ Helpline support. It is service information, not a survey.
Who / what: Ontario residents seeking health advice and quit support.
- Quash
Lung Health Foundation · Service information
App and program to help people quit smoking or vaping, developed with Health Canada funding. Health Canada's current youth guide links to Quash; this is a support resource, not a claim of guaranteed success.
Who / what: Young people seeking support to stop smoking or vaping.
- Kids Help Phone
Kids Help Phone · Service information
Youth support service in Canada. Its website confirms calling 1-800-668-6868 around the clock or texting CONNECT to 686868 for support.
Who / what: Young people in Canada; service information, not a research study.
- Single-use vapes ban: information for businesses
UK Government · Regulatory guidance
Confirms that the ban on sale and supply of single-use vapes took effect on 1 June 2025.
Who / what: UK rules; not a research study or survey.
- Changes to the regulation of vapes
Therapeutic Goods Administration, Australia · Regulatory guidance
Explains reforms implemented during 2024–25, including pharmacy access rules.
Who / what: Australian rules; not a research study or survey.
- Vaping products regulations
Health Canada · Regulatory guidance
Confirms a maximum nicotine concentration of 20 mg/mL for vaping products manufactured or imported for sale in Canada.
Who / what: Canadian regulations; not a research study or survey.
About the models: The brain map is schematic. The age slider contains no biological scoring. The learning network does not model a measured growth rate. Nicotine steps explain a mechanism, not dose-response or irreversible damage. The interactive lessons don't request or store any personal information. The contact form sends your message by email only; see Privacy. Source links require an internet connection.
Quiz sources
The sources used in the 13-question vaping quiz. Open a link to read the original evidence.
- Health Effects of Vaping
CDC · 2025
- Risks of vaping
Health Canada · 2026
- Vaping and quitting smoking
Health Canada · 2026
- Trading standards finds that one in eight ‘nicotine free’ vapes tested contain nicotine
Devon County Council · 2025
- Nicotine and other potentially harmful compounds in “nicotine-free” e-cigarette liquids in Australia
Medical Journal of Australia · 2019
- Nicotine Concentration in Vaping Products Regulations
Government of Canada · 2021
- Trends in US E-cigarette Sales and Prices by Nicotine Strength, Overall and by Product and Flavor Type, 2017–2022
Nicotine & Tobacco Research · 2023
- List of Health Warnings for Vaping Products
Health Canada · 2019
- Tobacco and Vaping Products Act
Government of Canada · 1997, as amended; checked 2026
- Vaping Compliance and Enforcement Report April 2024 – March 2025: Retail
Health Canada · 2026 (2024–25 inspections)
- Vapes confiscated from children contain unsafe levels of lead
The National, reporting the BBC’s test · 2023
- Outbreak of Lung Injury Associated with the Use of E-Cigarette, or Vaping, Products
CDC · 2020 (final update)
- Does stopping smoking improve mental health?
Cochrane · 2021
- Surgeon General’s Advisory on E-cigarette Use Among Youth
U.S. Surgeon General · 2018
- Product categories
British American Tobacco · Undated; checked 2026
- Regional variations and market share of FDA-authorised products for top-selling electronic cigarette brands in the USA: 2022–2024
Tobacco Control, listed by Penn State · 2025
- Electronic cigarettes and health outcomes: umbrella and systematic review of the global evidence
Medical Journal of Australia · 2023
- NJOY
Altria (ownership information only) · Undated; checked 2026