Evidence map›Paper›PMID 40590180›Full record

ArticleNeuropsychopharmacology reports2025

Revisiting the Gateway Drug Hypothesis for Cannabis: A Secondary Analysis of a Nationwide Survey Among Community Users in Japan.

Yuji Masataka, Munenori Katayama, Futaba Umemura, Takeshi Sugiyama, Naoko Miki, Yoshiyuki Akahoshi, Chihiro Oka, Takashi Asahi, Takashi Matsumori, Ichiro Takumi and 2 more

Abstract read
In one paragraph

Article in Neuropsychopharmacology reports, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

  1. Article
  2. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Yuji MasatakaDepartment of Neurosurgery, St. Marianna University School of Medicine, Kawasaki, Japan.ORCID https://orcid.org/0000-0003-1831-1512
Munenori KatayamaDepartment of Drug Dependence Research, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan.ORCID https://orcid.org/0000-0001-5614-0000
Futaba UmemuraGraduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
Takeshi SugiyamaGeneral Incorporated Association Green Zone Japan, Saitama, Japan.
Naoko MikiGeneral Incorporated Association Green Zone Japan, Saitama, Japan.
Yoshiyuki AkahoshiCollege of Bioresource Sciences, Nihon University, Fujisawa, Japan.
Chihiro OkaDepartment of Neurosurgery, Yokohama City University, Graduate School of Medicine, Yokohama, Japan.
Takashi AsahiDepartment of Neurosurgery, Kanazawa Neurosurgical Hospital, Nonoichi, Japan.
Takashi MatsumoriDepartment of Neurosurgery, St. Marianna University School of Medicine, Kawasaki, Japan.
Ichiro TakumiDepartment of Neurosurgery, St. Marianna University School of Medicine, Kawasaki, Japan.
Hidetoshi MurataDepartment of Neurosurgery, St. Marianna University School of Medicine, Kawasaki, Japan.
Toshihiko MatsumotoDepartment of Drug Dependence Research, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan.

Funding

Ministry of Health, Labour and Welfare 24CA2012the Japanese Clinical Association of Cannabinoids
6 · The paper itself

Abstract

aimCannabis has historically been used for medicinal and industrial purposes, but is strictly regulated worldwide due to the psychoactive effects of THC. In Japan, cannabis is frequently labeled a "gateway drug," yet strong causal evidence for progression to other substances is limited. This study investigates whether cannabis acts as a gateway drug among Japanese users.

methodsAn anonymous online survey was conducted in January 2021 with 3900 individuals reporting lifetime cannabis use in Japan. Participants were recruited via social media. The survey gathered data on demographics, cannabis and other substance use history, order of substance initiation, psychiatric background, and criminal records. A Sankey diagram visualized substance use progression, and odds ratios were calculated to assess the likelihood of using other substances following cannabis use.

resultsOf all respondents, 81.5% were male, with the largest age group being 20-24. Tobacco and alcohol were the most common initial substances, while cannabis was typically the third. Odds for subsequent use of alcohol, tobacco, methamphetamine, and other illicit drugs after cannabis use were 1.25, 0.77, 0.08, and 0.78, respectively, suggesting low probabilities of progression. Nearly half of those who reported cannabis as their third drug did not use other substances afterward.

conclusionCannabis use in Japan typically follows alcohol and tobacco, and rarely leads to further drug use. These findings challenge the gateway hypothesis in the Japanese context. Shared vulnerabilities and strict drug policies may shape these patterns. Further research is warranted to explore the impact of legal changes on drug use behavior. REGISTRY AND REGISTRATION NUMBER OF THE STUDY/TRIAL: Not applicable.

Indexed as

CannabisMarijuana UseAdolescentAdultAgedFemaleHumansIllicit DrugsJapanMaleMiddle AgedSubstance-Related DisordersSurveys and QuestionnairesYoung AdultIllicit Drugscannabisgateway drug hypothesisJapanmarijuanasubstance use

Identifiers

PMID40590180
PMCPMC12209865

What Socratic holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.