Cannabis, Pediatrics / 12.05.2026
Adolescents View Cannabis as Less Harmful Than Alcohol and Tobacco — New California Survey Data
Editor's note: This piece discusses mental health issues. If you have experienced suicidal thoughts or have lost someone to suicide and want to seek help, you can contact the Crisis Text Line by texting "START" to 741-741 or call the Suicide Prevention Lifeline at 800-273-8255.
Prof. Shu-Hong Zhu[/caption]
Shu-Hong Zhu, Ph.D.
Professor of Family Medicine and Public Health and
Director of the Center for Research and Intervention in Tobacco Control (CRITC)
University of California, San Diego
MedicalResearch.com: What is the background for this study?
Response: Cannabis use in the U.S. has steadily increased over recent decades. As use rates increased, perceptions that cannabis use is harmful have trended in the opposite direction.
Declining harm perceptions in the broader population are concerning in part because of their influence on adolescents. Regular cannabis use during adolescents can negatively impact overall functioning, cognition, and educational achievement. It can lead to depression, psychosis, and suicidality. If young people don’t perceive cannabis as harmful, they are more likely to use it and suffer these effects.
The purpose of this study was to investigate the extent to which adolescents view the everyday and occasional use of cannabis as harmful, and to compare their perceptions of cannabis to their perceptions of alcohol, cigarettes, and nicotine vapes. It used data from over 160,000 students who took the 2019−2020 California Student Tobacco Survey and over 16,000 who took the 2024 California Youth Tobacco Survey.
Please note: Cannabis laws and regulations vary by state and locality. Cannabis use may have significant health risks, particularly for adolescents, pregnant individuals, and those with a history of mental health conditions. Cannabis has not been approved by the FDA for most uses and may interact with medications. Do not use cannabis as a substitute for medical treatment. The information in this post is for educational purposes only and does not constitute medical or legal advice. Always consult your physician or qualified healthcare provider before making decisions about cannabis use. Do not use cannabis products if pregnant, nursing or may become pregnant. Children should never be exposed to cannabis products.
MedicalResearch.com Interview with: [caption id="attachment_73658" align="alignleft" width="130"] Prof. Shu-Hong Zhu[/caption]
Shu-Hong Zhu, Ph.D.
Professor of Family Medicine and Public Health and
Director of the Center for Research and Intervention in Tobacco Control (CRITC)
University of California, San Diego
MedicalResearch.com: What is the background for this study?
Response: Cannabis use in the U.S. has steadily increased over recent decades. As use rates increased, perceptions that cannabis use is harmful have trended in the opposite direction.
Declining harm perceptions in the broader population are concerning in part because of their influence on adolescents. Regular cannabis use during adolescents can negatively impact overall functioning, cognition, and educational achievement. It can lead to depression, psychosis, and suicidality. If young people don’t perceive cannabis as harmful, they are more likely to use it and suffer these effects.
The purpose of this study was to investigate the extent to which adolescents view the everyday and occasional use of cannabis as harmful, and to compare their perceptions of cannabis to their perceptions of alcohol, cigarettes, and nicotine vapes. It used data from over 160,000 students who took the 2019−2020 California Student Tobacco Survey and over 16,000 who took the 2024 California Youth Tobacco Survey.
Response: We were broadly interested in discovering instances of bacterial genes that have been acquired by diverse animal genomes over millions of years of evolution by the process of horizontal gene transfer (HGT). Since these events are quite rare and most previous discoveries have been serendipitous, we developed computational methods to identify genes acquired by HGT in animals. One of the exciting discoveries from our work was that vertebrate IRBP appeared to have originated in bacteria and is now a critical component of the vertebrate visual cycle, so this paper focuses on that one discovery.
IRBP or interphotoreceptor retinoid binding protein is an important protein present in the space between two major cell types in our eyes, photoreceptor cells and RPE cells. Our ability to see involves an intricate set of steps where light is first sensed by causing a change (isomerization) in the chemical structure of molecules in the eye called retinoids. This sensing of light occurs in our photoreceptor cells. Following this change in the chemical structure, the retinoid needs to be recycled back to the chemical structure that can again sense light. This recycling occurs in RPE cells. IRBP performs the essential function of shuttling retinoids between the photoreceptors and the RPE cells, which allows the cycle of sensing and regeneration to work. Supporting its importance, mutations in IRBP (also known as retinol binding protein 3 or RBP3) can cause several severe human eye diseases.
Dr. Pierce[/caption]
Karen Pierce, Ph.D.
Professor, Department of Neurosciences, UCSD
Co-Director, Autism Center of Excellence, UCSD
MedicalResearch.com: What is the background for this study?
Response: The mean age of ASD diagnosis and eventual treatment remains at ~52 months in the United States1 - years beyond the disorder’s prenatal origins2, and beyond the age when it can be reliably diagnosed in many cases3.
Currently the only way to determine if a child has autism spectrum disorder (ASD) is to receive a developmental evaluation from an experienced clinician (usually a licensed clinical psychologist). There are often long waiting lists, and only a small number of clinicians have the experience required to make early-age (i.e., between 12-36 months) diagnoses of ASD. Thus, there are many places in the country as well as world wide wherein children wait months or years to receive a formal diagnosis due to a lack of available expertise. Moreover, diagnostic evaluations are expensive and usually cost the parent and/or insurance approximately ~$2,000 or more per evaluation. Finally, clinical evaluations usually take between 2-3 hours to complete and result in fatigue for both the parent and toddler.
Eye-tracking, which generates biologically-relevant, objective, and quantifiable metrics of both visual and auditory preference profiles in babies and toddlers in just minutes, is a technology that can dramatically change how ASD is diagnosed.
Dr. Leas[/caption]
Eric Leas PhD, MPH
Stanford Prevention Research Center
University of California, San Diego
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Recent research has demonstrated the importance that neighborhood context has on life opportunity, health and well-being that can perpetuate across generations. A strongly defining factor that leads to differences in health outcomes across neighborhoods, such as differences in chronic disease, is the concurrent-uneven distribution of modifiable risk factors for chronic disease.
The main goal of our study was to characterize inequities in smoking, the leading risk factor for chronic disease, between neighborhoods in America's 500 largest cities. To accomplish this aim we used first-of-its-kind data generated from the 500 Cities Project—a collaboration between Robert Wood Johnson Foundation and the US Centers for Disease Control and Prevention—representing the largest effort to provide small-area estimates of modifiable risk factors for chronic disease.
We found that inequities in smoking prevalence are greater within cities than between cities, are highest in the nation’s capital, and are linked to inequities in chronic disease outcomes. We also found that inequities in smoking were associated to inequities in neighborhood characteristics, including race, median household income and the number of tobacco retailers.
