The "Gateway Drug" Theory Tested Across 17 Countries: It Does Not Hold Up
A WHO study across 17 countries found that the gateway drug sequence (tobacco/alcohol to cannabis to other drugs) partially reflects common causes like drug availability rather than causal effects of earlier drugs promoting later use.
Quick Facts
What This Study Found
Using data from WHO World Mental Health Surveys across 17 countries with widely varying drug use prevalence, researchers tested whether the standard gateway sequence (alcohol/tobacco to cannabis to other illicit drugs) reflects a causal chain or other factors.
The likelihood of progression from "gateway" substances to other illicit drugs varied based on the background prevalence of gateway substance use in each country. In countries where gateway substances were more commonly used, the conditional probability of progression was different.
Cross-country differences in substance use prevalence also corresponded to differences in the likelihood of non-normative sequences (people starting with "harder" drugs before "softer" ones).
The authors concluded that the gateway pattern at least partially reflects unmeasured common causes (like drug availability, cultural attitudes, and socioeconomic factors) rather than causal effects of specific drugs promoting subsequent use.
The implication: preventing use of specific gateway drugs may not lead to major reductions in later drug use.
Key Numbers
17 countries surveyed. Initiation sequence varied with background substance use prevalence. Non-normative sequences (skipping gateway drugs) were more common in some countries.
How They Did This
Cross-national analysis using WHO World Mental Health Surveys conducted in 17 countries with consistent instruments and procedures. Patterns and order of initiation of alcohol, tobacco, cannabis, and other illicit drug use were compared across populations with varying drug prevalence.
Why This Research Matters
The gateway theory has profoundly influenced drug policy for decades. This large cross-national study provided evidence that the theory oversimplifies the relationship between substance use progression, suggesting policy should focus on common underlying causes rather than specific gateway substances.
The Bigger Picture
Drug policy based on the gateway theory focuses on preventing initial cannabis use to prevent later hard drug use. If the gateway sequence reflects shared causes rather than causal chains, this policy approach may be misguided, and resources might be better directed at addressing underlying risk factors.
What This Study Doesn't Tell Us
Cross-sectional surveys rely on retrospective recall of drug initiation timing. The study could not directly test causal mechanisms. "Common causes" were inferred from patterns rather than measured directly.
Questions This Raises
- ?What are the common causes that drive the gateway sequence?
- ?Would addressing poverty, mental health, or drug availability be more effective than preventing cannabis use?
- ?Does the gateway theory hold for any substance-to-substance transition?
Trust & Context
- Key Stat:
- 17 countries: gateway sequence varied with drug prevalence, suggesting common causes, not causation
- Evidence Grade:
- Large cross-national study using standardized WHO survey methodology across diverse populations. Strong design for testing the gateway hypothesis, though unable to directly measure causal mechanisms.
- Study Age:
- Published in 2010. The gateway theory remains debated, but most researchers now agree that common underlying factors play a larger role than any causal chain between specific substances.
- Original Title:
- Evaluating the drug use "gateway" theory using cross-national data: consistency and associations of the order of initiation of drug use among participants in the WHO World Mental Health Surveys.
- Published In:
- Drug and alcohol dependence, 108(1-2), 84-97 (2010)
- Authors:
- Degenhardt, Louisa(11), Dierker, Lisa, Chiu, Wai Tat, Medina-Mora, Maria Elena, Neumark, Yehuda, Sampson, Nancy, Alonso, Jordi, Angermeyer, Matthias, Anthony, James C, Bruffaerts, Ronny, de Girolamo, Giovanni, de Graaf, Ron, Gureje, Oye, Karam, Aimee N, Kostyuchenko, Stanislav, Lee, Sing, Lépine, Jean-Pierre, Levinson, Daphna, Nakamura, Yosikazu, Posada-Villa, Jose, Stein, Dan, Wells, J Elisabeth, Kessler, Ronald C
- Database ID:
- RTHC-00406
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Is cannabis a gateway drug?
This study found that the sequence of drug use initiation varies across countries in ways consistent with common underlying causes (like drug availability) rather than cannabis itself causing progression. Most people who use cannabis never progress to other illicit drugs.
What are the "common causes" the study refers to?
Factors like drug availability, cultural attitudes toward drug use, socioeconomic conditions, mental health, and genetic vulnerability. These shared factors may independently increase the probability of using multiple substances, creating the appearance of a gateway sequence.
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Cite This Study
https://rethinkthc.com/research/RTHC-00406APA
Degenhardt, Louisa; Dierker, Lisa; Chiu, Wai Tat; Medina-Mora, Maria Elena; Neumark, Yehuda; Sampson, Nancy; Alonso, Jordi; Angermeyer, Matthias; Anthony, James C; Bruffaerts, Ronny; de Girolamo, Giovanni; de Graaf, Ron; Gureje, Oye; Karam, Aimee N; Kostyuchenko, Stanislav; Lee, Sing; Lépine, Jean-Pierre; Levinson, Daphna; Nakamura, Yosikazu; Posada-Villa, Jose; Stein, Dan; Wells, J Elisabeth; Kessler, Ronald C. (2010). Evaluating the drug use "gateway" theory using cross-national data: consistency and associations of the order of initiation of drug use among participants in the WHO World Mental Health Surveys.. Drug and alcohol dependence, 108(1-2), 84-97. https://doi.org/10.1016/j.drugalcdep.2009.12.001
MLA
Degenhardt, Louisa, et al. "Evaluating the drug use "gateway" theory using cross-national data: consistency and associations of the order of initiation of drug use among participants in the WHO World Mental Health Surveys.." Drug and alcohol dependence, 2010. https://doi.org/10.1016/j.drugalcdep.2009.12.001
RethinkTHC
RethinkTHC Research Database. "Evaluating the drug use "gateway" theory using cross-nationa..." RTHC-00406. Retrieved from https://rethinkthc.com/research/degenhardt-2010-evaluating-the-drug-use
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.