Sultan Lab for Mental Health Informatics

CASNY: Cannabis Access and Safety in New York

New York State legalized recreational cannabis in March 2021, establishing an adult-use program while maintaining a medical marijuana system that had operated since 2014. The first licensed recreational cannabis outlets opened in late 2022. Within months, the city went from having a handful of medical dispensaries to an explosion of cannabis storefronts -- the vast majority of which operated without state licenses. By some estimates, unlicensed cannabis retailers in New York City outnumber licensed ones by a factor of ten or more, creating an unprecedented natural experiment in the consequences of cannabis deregulation without adequate enforcement infrastructure.

The Cannabis Access and Safety in New York (CASNY) study, led by Dr. Ryan Sultan at the Sultan Lab for Mental Health Informatics, Columbia University Irving Medical Center, was designed to rigorously examine the public health implications of this rapid transformation. The study addresses three core questions: Can young people easily access cannabis from these retailers? Are cannabis products adequately labeled to inform consumers about what they are using? And do the actual chemical contents of cannabis products match what labels claim?

Study Phases

Phase I: Youth Access and Retail Practices (Secret Shopper Study)

The first phase of CASNY employed a secret shopper methodology to evaluate retail practices across the New York City cannabis landscape. The research team used Google Maps to create a comprehensive directory of 840 cannabis outlets across all five boroughs -- including licensed medical dispensaries, licensed recreational dispensaries, unlicensed dispensaries, and smoke shops. Of these 840 outlets, only 19 were licensed to sell cannabis products at the time of the study.

A 22-year-old research assistant, posing as an underage consumer, visited a random selection of 37 stores to evaluate three key dimensions: age verification practices, marketing strategies targeting youth, and product quality information.

Key Findings

"Regulation to restrict access in this age group is based on evidence that cannabis affects working memory, brain development, and increases addiction risk when used at an early age," Dr. Sultan stated in the study's press release. "High-potency cannabis, which is much more prevalent today, has also been linked to adverse effects on physical and mental health in adolescents."

The findings demonstrate that New York's cannabis legalization created conditions in which youth access to cannabis is largely unrestricted at the majority of retail outlets. While licensed dispensaries consistently followed age-verification regulations, the overwhelming numerical dominance of unlicensed retailers means that most cannabis transactions in the city occur in settings with minimal regulatory compliance.

Phase II: Product Labeling Analysis

The second phase of CASNY systematically analyzed the labeling and packaging of 88 cannabis products acquired from both licensed and unlicensed retailers during the secret shopper visits. Products included cannabis flower and vape pen samples. Each product was evaluated for the presence of essential consumer information, safety warnings, and child-oriented design elements.

Labeling Disparities

Products from unlicensed retailers were significantly less likely to include:

• Product identification as cannabis: Some products sold at unlicensed outlets could not be identified as cannabis products from packaging alone
• THC potency information: Without potency labeling, consumers cannot gauge the strength of what they are using, creating risk of overconsumption
• Standard dose indication: No guidance on what constitutes a single serving or dose
• Expiration date: No information about product freshness or degradation
• "Keep Away from Children" warnings: A basic safety notice absent from many unlicensed products
• Poison control information: No guidance for consumers in case of adverse reactions

Additionally, products from unlicensed retailers were more likely to feature child-oriented packaging elements, including cartoon characters and imagery designed to appeal to younger consumers -- a pattern directly analogous to the youth-targeting marketing practices that led to regulatory action against flavored tobacco and e-cigarette products.

Phase III: Chemical Analysis (Ongoing)

The third and most technically demanding phase of CASNY involves mass spectrometry analysis of cannabis product samples acquired during the secret shopper visits. Conducted in collaboration with Dr. Colin Nuckolls at Columbia University's chemistry department, this phase assesses:

• Actual THC potency: Whether the THC content of products matches what is stated on labels (where labels exist)
• Cannabinoid profiles: Full spectrum analysis of cannabinoid composition, including CBD, CBN, and other compounds
• Pesticide screening: Testing for the presence of agricultural chemicals that may pose health risks when inhaled or ingested
• Concordance analysis: Direct comparison of laboratory-measured chemical composition with retailer-reported metrics

This phase is particularly significant because it moves beyond what retailers claim about their products to what the products actually contain. Prior research in other states has revealed significant discrepancies between labeled and actual THC potency, with some products containing substantially more or less THC than stated, and others containing contaminants not disclosed on packaging.

FDA Presentation

In October 2024, the CASNY research team requested and participated in a listening session with the U.S. Food and Drug Administration to share early results from all three study phases. The presentation was led by Dr. Sultan and included:

• Dr. Ryan Sultan -- Background, study overview, youth access findings, and policy implications
• Dr. Timothy Becker -- Secret Shopper and Labeling study methodology and results
• Dr. Colin Nuckolls -- Chemical analysis methodology and preliminary findings

Invited FDA attendees included Dr. Gerald Dal Pan (Director, Office of Surveillance and Epidemiology), Carol Bennett, Dr. Marta Sokolowska (Deputy Director, Center for Drug Evaluation and Research), and Dr. Peter Stein. The presentation highlighted the unique perspective the CASNY team brings: expertise spanning child and adolescent psychiatry, epidemiology, and organic chemistry, combined with direct empirical data from the largest newly legalized cannabis market in the United States.

The NYC Cannabis Landscape Post-Legalization

New York City's experience with cannabis legalization represents a cautionary case study in what happens when deregulation outpaces enforcement. Several factors make the NYC market particularly consequential:

Scale of the Unlicensed Market

Unlike states such as Colorado or California where licensed dispensaries established a significant retail presence before legalization created room for unlicensed competitors, New York's rollout was plagued by licensing delays. The result was that unlicensed cannabis stores proliferated far faster than the state could issue licenses, creating an environment where the vast majority of cannabis retail occurs outside any regulatory framework.

Youth Vulnerability

New York City's density and the ubiquity of cannabis storefronts mean that adolescents encounter cannabis retail on a daily basis. The CASNY findings demonstrate that most of these encounters involve unlicensed outlets that do not verify age, price cannabis cheaply, and use marketing strategies that appeal to young consumers. This creates a scenario in which legalization has paradoxically made cannabis more accessible to youth than it was under prohibition -- the opposite of what legalization advocates promised.

Product Safety Vacuum

Licensed cannabis products in New York are subject to testing requirements, potency labeling standards, and child-resistant packaging mandates. Products sold at unlicensed outlets are subject to none of these protections. Consumers purchasing from unlicensed retailers -- who may not even realize their retailer is unlicensed -- face unknown risks from products of unverified potency, composition, and purity.

Connection to Sultan Lab Cannabis Research Program

CASNY is part of a broader program of cannabis research within the Sultan Lab:

NIDA K12-Funded Adolescent Cannabis Research

Dr. Sultan's cannabis research is supported by a NIDA K12 Substance Use Clinical Scientist Career Development Award (2021-2026, $670K), which has funded his training in bioinformatics and substance use research at Columbia and Mass General/Harvard. The CASNY study directly addresses the K12 award's focus on patterns and outcomes of adolescent substance use.

Nondisordered Cannabis Use (JAMA Network Open, 2023)

Dr. Sultan's groundbreaking 2023 study in JAMA Network Open revealed that 2.5 million U.S. adolescents use cannabis without meeting diagnostic criteria for cannabis use disorder -- a population he termed "nondisordered" users. These teens nonetheless face significantly elevated risks: 2 times higher rates of depression, 2 times higher suicidal ideation, and 4 times higher arrest rates compared to non-using peers. This finding established the importance of studying cannabis use below the threshold of addiction, directly informing CASNY's focus on access and exposure.

Pediatrics 2026: Adolescent Cannabis Use Patterns

A forthcoming 2026 paper in Pediatrics, co-authored with Drs. Levin, Wilens, Levy, Becker, Simon, Sethaputra, Huang, and Scott Levy, extends the investigation of cannabis use patterns among U.S. adolescents, further establishing the public health significance of CASNY's access and safety findings.

PAWS Digital Therapeutics Project

The PAWS (Pawsitive Companion) project, an NIH-funded UG3/UH3 digital therapeutic for cannabis use disorder in youth, represents the intervention arm of Dr. Sultan's cannabis research program. While CASNY identifies the scope of the problem -- how easily youth can access cannabis and how unsafe the products may be -- PAWS is developing a scalable solution for youth who develop problematic cannabis use.

Cannabis and Psychosis Research

The Sultan Lab is also conducting a pharmacoepidemiological study of cannabis use and new-onset psychosis using MarketScan data, examining whether cannabis legalization contexts moderate the risk of cannabis-associated psychotic disorders. CASNY's documentation of the unlicensed retail environment provides real-world context for understanding how legalization changes cannabis exposure patterns at the population level.

Policy Implications

The CASNY findings carry direct implications for cannabis policy at the local, state, and federal levels:

Research Team

Frequently Asked Questions

What is the CASNY study?

CASNY (Cannabis Access and Safety in New York) is a multi-phase research project led by Dr. Ryan Sultan at Columbia University that examines how cannabis legalization in New York affects youth access to cannabis products, the accuracy of product labeling, and the chemical safety of products sold at licensed versus unlicensed retailers. The study uses a secret shopper methodology to evaluate retail practices, laboratory analysis to assess product contents, and epidemiologic methods to study broader population-level patterns of cannabis use among adolescents.

What did the CASNY secret shopper study find about youth access to cannabis?

The CASNY secret shopper study, published in Pediatrics in 2025, found that all licensed cannabis dispensaries in New York City verified customer age with photo ID before permitting store entry, compared to only 10% of unlicensed outlets. Less than half of unlicensed outlets verified age at any point during the purchase process. Unlicensed retailers also sold cannabis at lower prices and used youth-friendly marketing practices including cartoon signage, and often sold cannabis alongside youth-appealing products like energy drinks and candy.

What labeling differences exist between licensed and unlicensed cannabis products?

The CASNY labeling study, published in the American Journal of Preventive Medicine in 2025, analyzed 88 cannabis products from licensed and unlicensed retailers. Products from unlicensed retailers were significantly less likely to provide essential consumer information including identification as a cannabis product, THC potency, standard dose, and expiration date. They were also less likely to include safety warnings such as "Keep Away from Children" or poison control information, and were more likely to feature child-oriented packaging elements such as cartoon imagery.

Has the CASNY research been presented to the FDA?

Yes, Dr. Sultan and the CASNY research team participated in a listening session with the FDA in October 2024 to share early results from all three phases of the CASNY study. The presentation team included Dr. Sultan, Dr. Timothy Becker, and Dr. Colin Nuckolls. Invited FDA staff included Dr. Gerald Dal Pan, Carol Bennett, Dr. Marta Sokolowska, and Dr. Peter Stein.

Related Resources

• Sultan Lab for Mental Health Informatics - Full lab overview
• Cannabis Research - Comprehensive cannabis research information
• Blog: Cannabis Labeling in NYC - Public-facing summary
• Cannabis Legalization Impact - Policy analysis
• Complete Publication List - Peer-reviewed research
• Research Grants & Funding - Grant details