Youth
April 29, 2024 - Recreational Cannabis Legalization, Retail Sales, and Adolescent Substance Use Through 2021. Several survey-based studies have looked at the effects of cannabis recreational legalization. This SAMMn research site includes numerous of them, with some studies showing a post-legalization increase in cannabis use among youth and some showing no change or decreased use.
This study by Coley and colleagues (Coley et al., 2024) analyzed several years (2011-2021) of Youth Risk Behavior Survey (TRBS) data (N= 898,271). Survey results from 21 states on the effects of both enactment of recreational legalization (RCL) and enactment of retail sales (RCR) were examined. As our readers know, there is a time interval often several months or years between the onset of legalization and the opening of retail markets.
The main finding pertaining to the enactment of legalization (RCL) was no significant changes in adolescents’ likelihood or frequency of cannabis use. Yet the effects of initiation of retail sales (RCR) showed a different pattern of use. RCR was associated with a 28% higher odds of no cannabis use but also a 26% higher frequency of use among those who were pre-RCR users.
The RCR finding is consistent with other adolescent cannabis survey findings in that post legalization has been shown to be associated with increases in the frequency of cannabis use among already-using youth.
Comment from this reviewer (KCW): There is a caveat about the use of YRBS data as a national gauge for adolescent cannabis use. These data are not nationally representative as schools self-select as to their participation in the YRBS program. By contrast, the NIH-funded annual Monitoring the Future Survey of high school students is designed to assess a nationally representative sample.
January 6, 2024 - Impact of Changing Cannabis Laws on Cannabis Use Disorders, Serious Mental Illness, and Mortality Outcomes in US Youth: A Narrative Review. The authors (Hammond et al. 2023) provide a narrative review of the “current scientific literature investigating the impact of changing cannabis policies on cannabis and other drug use, mental health, and mortality outcomes in US youth”. Impacts are separately discussed for medical and adult-use legalization, and for adolescents and young adults. (A narrative review is defined as an extensive description and interpretation of previously published research on a chosen topic.)
This sweeping review does not yield any definitive conclusions. Yet this writer (KCW) observed two themes that were frequently noted by the authors: (1) data are mixed with respect to linking legalization and changes in youth rates of cannabis and other health indices (which is not surprising given the complexity of determining the impact of any change in public policy on any public health issue); and (2) viewpoints on the intersection of cannabis legalization and youth health may change as more studies examine longer periods of post-legalization and include users of higher potency strains of cannabis.
November 25, 2023 - Perceived risk of weekly marijuana use among students participating in the National Survey on Drug Use and Health. The authors (Dunn & Klump, 2023) analyzed national survey data from 2020 (sample size +32,000) to identify factors linked to adolescent perception of risk of weekly cannabis use. Adolescents who more likely reported that using marijuana weekly was a risk behavior more commonly reported strong parental involvement/support, peer disapproval of marijuana use, low perception of peer use, no personal use of alcohol or illicit drugs and enjoyed school.
These findings are consistent with prior research on substance use risk perception by teens, yet the study is important in that it focuses on cannabis use risk with a large, contemporary sample.
October 23, 2023 - Appeal Rating and Visual Attention Associated with Youth-Appealing Cannabis Packaging: An Eye-Tracking Experiment. This pre-proof publication by Cooper and Shi (2023) about the impact of packaging labeling confirmed what is predictable when youth- appealing features are included in cannabis products.
A small sample of young adults were asked to rate the appeal of various edible packages and they also had their fixation duration measured with an eye tracking procedure.
The researchers found that edible packages containing a cartoon character, bubble font, berry flavor, or gummy bear shape received higher appeal ratings than packages with no youth-appealing attributes. Also, youth appealing attributes received longer fixation durations than non-youth-appealing attributes and reduced fixation durations on the warning label.
May 27, 2023 - Nondisordered Cannabis Use Among US Adolescents. This study addressed the issue of possible adverse consequences when adolescent use of cannabis occurs at a so-called "subclinical" level. The authors (Sultan et al., 2023) analyzed survey results from the nationally representative National Survey on Drug Use and Health database from 2015 to 2019. Participants were adolescents aged 12 to 17 years. Three distinct groups were created based on cannabis use: no recent cannabis use, recent cannabis use below diagnostic threshold (non-diagnostic), and those who recently met criteria for a Cannabis Use Disorder (CUD).
Among respondents, 10% met the definition of non-diagnostic cannabis use and 2.5% met criteria for CUD. Compared with nonusers, non-diagnostic cannabis users had approximately 2 to 4 times greater odds of all adverse psychosocial events examined, including major depression, suicidal ideation, slower thoughts, difficulty concentrating, truancy, low grade point average, arrest, fighting, and aggression. As expected, the prevalence of these adverse psychosocial events was the greatest for adolescents with CUD.
Additional note from this writer, KCW: Whereas these cross-sectional results do not directly inform causality, the findings from this study are consistent with longitudinal studies.
March 31, 2023 - Associations of Alternative Cannabis Product Use and Poly‑Use with Subsequent Illicit Drug Use Initiation during Adolescence. This study looked at the issue of whether specific cannabis products differentially increase risk of initiating non-cannabis illicit drug use during adolescence. That is, the researchers examined to what extent is the use of various cannabis products a “gateway drug” for subsequent use of non-cannabis illicit drugs. In-school survey data from Los Angeles high school students (N=2163) collected at baseline (spring, 11th grade) and at follow-up (fall and spring, 12th grade) were analyzed.
After adjustments for several baseline covariates and including only those in the analysis that reported no lifetime use of any non-cannabis illicit drug at baseline, the results indicated that each of the five different cannabis products (smoked, edible, vaporized, concentrates, and blunts) were associated with greater odds of later illicit drug use. The two cannabis variables particularly linked to elevated risk of later illicit drug use were using cannabis concentrates (almost a 6-fold increase) and being a poly-cannabis-product user (approximately a 4-fold increase).
Note from KCW: Does this study support the theory that cannabis is a gateway drug? It does from this perspective: Some cannabis users do subsequently initiate use of other illicit drugs.
March 31, 2023 - Cannabis Use Is Associated With Depression Severity and Suicidality in the National Comorbidity Survey - Adolescent Supplement. The researchers (Hinkley et al., 2023) investigated the association of cannabis use with major depression and suicidal behavior in adolescence. They analyzed data from the National Comorbidity Survey - Adolescent Supplement (N = 10,123), a nationally representative survey of adolescents aged 13 to 18 years.
Cannabis use is associated with higher odds of depression and depression severity in adolescence. Adolescents with lifetime cannabis use were found to have 2 times higher odds of mild/moderate depressive disorder and 3 times higher odds of severe major depressive disorder. As expected, depression was associated with higher odds of suicide attempt. Also, cannabis use was independently associated with higher odds of suicide attempt.
January 4, 2023 - Pediatric Edible Cannabis Exposures and Acute Toxicity: 2017–2021. Previous postings here have highlighted a consistent increase in pediatric edible cannabis exposures over recent years. This research report from Pediatrics (Tweet et al., 2023) takes a very rigorous look at this issue. The authors evaluated trends for the years 2017-2021 in pediatric cannabis edible ingestions in children younger than age 6 years with regard to toxicity, medical outcome, and health care utilization for the years 2017–2021.
Specifically, the authors analyzed data from the National Poison Data System for pediatric exposures to edible cannabis products in children less than 6 years. The analysis focused on incidence (that is, new cases), common clinical effects, medical outcomes, health care utilization, and changes in acute toxicity between the pre-COVID years (2017–2019) to the COVID years (2020–2021).
There were a total of 7,043 exposures reported during 2017–2021. A striking finding was that in 2017 there were 207 reported cases, but in 2021 there were 3,054 cases, an increase of 1,375.0% . Most exposures (97.7%) occurred in a home setting. Of all reported cases, 22.7% of child patients were admitted to the hospital, and for cases that were followed, 70% of the children were known to have suffered “central nervous system depression.”
As the authors note, this increase in pediatric edible cannabis exposures, with the potential for significant toxicity, is a major pediatric health issue.
December 16, 2022 - Trends in intentional abuse and misuse ingestions in school-aged children and adolescents. The authors (Hughes et al., 2022) examined data records of intentional misuse and abuse exposures in children, ages 6 through 18 years, that were reported to the National Poison Data System (NPDS) from January 1, 2000, through December 31, 2020.
The authors found that over 330,000 poison center cases (all sources of poisoning) were reported during the 20-year study period. Whereas over-the-counter medications, household products and pharmaceuticals commonly prescribed to youth are the substances most commonly misused/abused, the “study describes an upward trend in marijuana misuse/abuse exposures among youth, especially those involving edible products.
Marijuana exposure rates had the highest average monthly increase overall, with the most dramatic rise occurring from 2017 to 2020.
Of great relevance to us in Minnesota is that “edible marijuana preparations accounted for the highest increase in call rates compared with all other forms of marijuana.”
November 30, 2022 - Effects of Cannabis Legalization on Adolescent Cannabis Use Across 3 Studies (Bailey et al., 2022) The authors addressed the possible effects of legalizing cannabis for commercial sales on adolescent use in two states that have legalized (WA and CO) and included a control state (NY). Based on the analysis of longitudinal datasets from each state, the authors had two major conclusions. 1) A change in legalization status was not significantly related to change in the frequency of self-reported past-year cannabis use when cannabis use of individuals was tracked across time, as in use at time 1, use at time 2, etc. 2) When the comparison was between groups of youth based on how many years spent under legalization, those who spent more of their adolescence under legalization were no more or less likely to have used cannabis at age 15 years than adolescents who spent little or no time under legalization.
Commentary from this review, KCW: There are three significant research design concerns when interpreting the results of this paper. One issue is the reliance by the authors on a narrow dependent measure - past year frequency of use. It has been shown in numerous other published adolescent studies that post-legalization is associated with an uptick of heavy cannabis use and in the rate of those meeting criteria for a cannabis use disorder. Past year frequency of use would not be a sensitive index to detect these patterns and consequences of use. A second issue is that trend data does not examine cannabis use past age 15. Thus, the reported data may have capitalized on a floor risk effect, that is, early adolescence is a developmental period with much lower general risk of use of any substance, with the later adolescent years being a period with a much higher risk for use. The third problem is that the three samples were not based on a representative sample of youth in the participating states. For example, the WA state data were obtained from a large-scale prevention project, which means the data may reflect the positive effects of those prevention efforts.
November 29, 2022 - Recreational cannabis legalization alters associations among cannabis use, perception of risk, and cannabis use disorder treatment for adolescents and young adults. In this study researchers from Temple University analyzed two survey-related databases, NSDUH and TEDS-A, to determine whether legalization of cannabis changed teen and young adult perception of harm from cannabis use, prevalence of cannabis use, and rate of cannabis use disorder treatment admissions. The results indicate that legalization of cannabis will likely lead to increased use of cannabis by teens and young adults, particularly by those who perceive low harm from cannabis use, while reducing the rate of cannabis users seeking treatment for CUD.
Summary provided By Maria Poirier, MD
September 23, 2022 - Adolescents’ Use of Free Time and Associations with Substance Use from 1991 to 2019. For this study the authors analyzed data from the national Monitoring the Future (MFT) study, spanning years 1991-2019 (N=536,291). This yearly survey collects data from 8th, 10th and 12th grade students. The study’s main conclusion was that whereas alcohol, cigarette, and some other substance use have declined during the time period for each grade group, cannabis use and vaping are increasing for each group.
Note from this writer (KCW): The MTF data of 12th graders is necessarily limited in representativeness given that many youth have dropped-out of school by the time they would have been in the 12th grade.
September 11, 2022 - A scoping review of school-level risk and protective factors of youth cannabis use: An application of the socio-ecological model. The authors of this study (Butler et al., 2021) used a “scoping review methodology” to describe current research on the link between adolescent cannabis use and school-level risk and protective factors. Original research articles published between 2010-2020 that examined cannabis use as a main outcome of interest were identified; those that examined school-related variables for adolescents and that met pre-established criteria were analyzed. Four levels of risk and protective factors related to the school environment were identified (individual, interpersonal, community, and societal). Individual-level outcome variables, which are likely of the most interest from a public health perspective, were truancy, bullying experience, school sports participation, attitudes, and commitment towards school and/or academic performance.
Study results indicated that “a number of consistent themes were identified, however, findings were mixed and demonstrate the need for a more critical examination of research in order to understand which risk and protective factors are most influential among youth.”
Comment from this reviewer, KCW: The nature and extent of cannabis use and school-related variables is a very complex research endeavor. For those interested in this topic, it is best that you review the attached study by Butler and colleagues and draw your own assessment of the study findings. My own view is that there is an absence of longitudinal studies that adequately control for confounding variables, thus, making it very problematic to draw any firm conclusions as to how or to what extent adolescent cannabis use impacts school performance.
August 6, 2022 - Marijuana use in children: An update focusing on pediatric tetrahydrocannabinol and cannabidiol use. This paper provides a general overview of the current research literature regarding the impact of cannabis use on youth (children and adolescents). Research summaries of several topic areas are provided, with a focus on acute and long-term effects of cannabis use. The authors' main conclusions are these: “The perception that marijuana is 'safe' appears to be driven, in part, by legalization. The use of marijuana and cannabinoid products, in general, is not without harm, particularly in children, and the incidence of permanent neuropsychiatric sequelae demands action and increased preventative education.”
May 28, 2022 - Recreational Cannabis Legalization and Transitions in Cannabis Use: Findings from a Nationally Representative Longitudinal Cohort in the United States. As highlighted in a May 27, 2022 post by SAM (New study: Teen use up in legal states), a published research report in March 2022 by a prominent journal, Addiction, provides a rigorous comparison of cannabis use among youth and adults in legal (RCL) and non-legal states. Four large RCL states (CA, MA, ME and NV) were associated with increases in terms of several youth and adult cannabis use behaviors, compared to non-legal states. Pertaining to youth, the “association between RCL and greater odds of transition from non-users to users was seen in comparison with non-legalization states."
See summary at Teen cannabis use likelier in legalization states (axios.com)
Commentary from this writer (KW): This study's design is noteworthy for two reasons (1) the data examine change in a longitudinal sample by comparing pre-legalization cannabis use and post-legalization cannabis use, and (2) each legalization state had been “legal” for a significant number of years, which permits a more reliable view of the impact of a change in the legal status of cannabis on use behavior.
May 20, 2022 - Cannabis Vaping Among Youth and Young Adults: a Scoping Review. This literature review focuses on the research pertaining to vaping by adolescents and young adults. Nearly half of the studies (46%) address the specific health effects of vaping cannabis, particularly e-cig related lung injury. The remaining topics were risk factors, epidemiology, regulation and marketing. A sampling of the summary of findings:
Cannabis vaping is increasingly common among youth and young adults.
Vaping is more prevalent in settings where recreational use of cannabis for adults has been legalized.
Common risk factors: being male; onset during high school; and co-vaping of nicotine.
Marketing is prevalent, largely unregulated, and is an important risk factor for e-cigarette use among youth.
May 12, 2022 - Examining Trends in Youth Cannabis Use as a Function of U.S., State Legalization Status. The authors of this study focused on survey studies on cannabis use with respondents as adolescents or young adults (18-26 years old). Their search identified 33 research reports (22 with adolescent samples; 14 young adults). Among the 23 adolescent studies, ten studies reported no change in prevalence use associated with legalization, six reported a decrease, and seven reported an increase. For the 13 young adult studies, eight studies showed an increase in at least one prevalence measure, four showed no change, and one showed a decrease. Three studies examined changes in the prevalence of Cannabis Use Disorder; the two adolescent studies showed an increase, and the one young adult showed no change.
Caveats from the writer of this summary (KCW): (1) the legalization date was used rather than the dispensary opening date; some intervals were significant; and (2) survey data were not examined as a function of number of years of legalization; prior work shows that trend changes do not occur very soon after legalization.
March 1, 2022 - Associations of Cannabis Product Source and Subsequent Cannabis Use among Adolescents. This study examined the association of the source of obtaining cannabis and subsequent cannabis use (6-months later) among adolescents (N=835 high-schoolers). Most youth (72.1%) received cannabis for free, 50.9% bought cannabis from someone, 15.9% used a valid medical card at a brick-and-mortar dispensary, and 3.9% grew cannabis. Those who purchased cannabis illicitly from someone or from a brick-and-mortar dispensary using a valid medical card were more likely to be the heaviest users, compared to youth who obtained cannabis from other sources.
Commentary from this writer: This study is a reminder that medical cannabis use with a valid medical card is available in many states for underage youth. One wonders: For what disorders or ailments is cannabis being prescribed to adolescents?
February 22, 2022 - A Content Analysis of Cannabis Company Adherence to Marketing Requirements in Four States This study’s premise is that marketing messages can influence adolescents’ attitudes and behaviors toward cannabis use. The authors did a content analysis of one year of publicly displayed posts by retail cannabis companies on Facebook and Instagram from four states in which cannabis use was commercially legal for adults (Alaska, Colorado, Oregon, and Washington State). They limited the evaluation to these content areas: (a) business practices, such as discounts/promotions; (b) modeling cannabis use or overconsumption; (c) youth focused messaging; (d) health benefits; and (e) required warnings (limiting to legal age, avoiding impaired driving, and health risks). A total of 2,660 posts were evaluated from 14 businesses. The major findings:
· discounts/promotions were present in approximately 35% of all posts
· modeling overconsumption was present in 12% of posts; and
· required content warnings were absent in more than half of all social media posts.
February 1, 2022 - Changes in Brain Structure with low level use by Teens This study of 46 adolescents (age 14) presents evidence “suggesting structural brain and cognitive effects of just one or two instances of cannabis use in adolescence.” The authors further contend that their study is aligned with converging evidence suggesting a contributing role of the natural endocannabinoid system in these effects.
January 23, 2022 - Teen vaping of Cannabis Doubles. This meta-analysis of 17 epidemiological studies involving nearly 200,000 adolescents in the US and Canada found that the past 12-month prevalence of cannabis vaping across all school grades nearly doubled from 2013 (7.2%) to 2020 (13.2%), and the 30-day prevalence increased by about 4-fold (from 1.6% to 8.4% during the same period). The study also found some evidence that adolescents now prefer the more potent cannabis oil used in vaping devices (with typical THC levels at about 70%) over the dried herb.
December 3, 2021 - Swiss long term cannabis study. This longitudinal study of youth from Switzerland (N = 1482) collected several assessments from 2004 to 2018, from ages 7–20).
Substance use was assessed with self-reports between ages 13 and 20, and additional just at age 20, participants reported on psychopathology (psychotic symptoms, problematic substance use, aggression, and internalizing symptoms) and functional well-being (delinquency, financial difficulties, social exclusion, general well-being, and not being in education, employment, or training).
The results indicated that almost one in five adolescents had used cannabis frequently between ages 13 and 17 (26.6% of males, 9.8% of females). After adjusting nearly 20 potential confounders, frequent teenage cannabis use, compared to no cannabis use and occasional use, was associated at age 20 with these outcomes: problematic substance use; more delinquency; and poorer functional well-being. The authors conclude that “frequent teenage cannabis users could experience increased difficulties in mastering the transitions of young adulthood”.
December 3, 2021 - Vaping Cannabis by Teens. This systematic review and meta-analysis reviewed 17 unique studies from the US and Canada, with a total of 198 845 adolescents. The results indicated that lifetime prevalence of cannabis vaping doubled from 2013 to 2020 (6.1% to 13.6%), past 12-month use doubled from 2017 to 2020 (7.2% to 13.2%), and the 30-day prevalence of cannabis vaping increased 7-fold from 2013 to 2020 (1.6% to 8.4%). The authors speculate that the preference for cannabis products may be shifting from dried herb to cannabis oil.
July 28, 2021 - A Longitudinal Analysis of Escalating Cannabis Use and Motivation among Adolescents. This longitudinal study looked at the association of cannabis use and changes in motivation in a sample of 401 adolescents assessed at 5 time points. Several indices of motivation were examined. The results were mixed; not all measures of motivation changed across time as function of cannabis use. Yet one noteworthy finding: cannabis use measured cross-sectionally was associated with lower perceived value of school.
July 20, 2021 - Here is a link to the Abstract of the online pre-publication of a meta-analysis that looks at adolescent cannabis use and subsequent risk for psychosis. The authors conclude that “Adolescent cannabis use is associated with an increased risk for psychosis later in life.” They also cite these factors that are associated with the highest risk among adolescent cannabis users: initiating use early in the teen years; very frequent cannabis use; exposure to childhood trauma; concurrent use of other substances; and having genetic makeup associated with risk for psychosis.
July 12, 2021 - Pediatric acute cannabis intoxication: Canadian researchers report on the changes in Emergency Department (ED) visits associated with pediatric acute cannabis intoxication effects. The study design was a retrospective, single center cohort study at the Hospital for Sick Children, Toronto, over a 12-year period from January 1, 2008 to December 31, 2019. Patients, aged 0–18 years, were included if they presented to the Emergency Department (ED) with presenting symptoms attributed to acute cannabis intoxication. Two timeframes were defined: the pre legalization period – from January 2008 to April 12, 2017, and the peri-post legalization period – from April 13, 2017 (when the bill to legalize cannabis was introduced to the Canadian Parliament and the anticipated changes regarding the legalization were published) to December 31, 2019. Consistent with findings in U.S. cities that have tracked pre- and post-legalization effects on ED visits, the recreational cannabis legalization in Canada was found to be associated with increased rates of severe intoxications in children, primarily due to ingestion of edible products.
July 12, 2021 - Suicidality and marijuana use: For this study the authors analyzed survey data from more than 280,000 young adults (age 18-35) and found a strong association of increased risks of thoughts of suicide (suicidal ideation), suicide plan, and suicide attempt. These associations remained regardless of whether someone was also experiencing depression, and the risks were greater for women than for men. “While we cannot establish that cannabis use caused the increased suicidality we observed in this study, these associations warrant further research, especially given the great burden of suicide on young adults,” said NIDA Director Nora Volkow, M.D., senior author of this study (click here for source of quote)
July 12 2021 - Flavored cannabis: A research brief from a CDC publication (Preventing Chronic Disease) highlights the popularity of flavored cannabis (and tobacco) among youth. Students in 8 Northern and Central California public high schools (2019–2020) (N=1,423) were surveyed. Among students who indicated past 30-day cannabis use, it was common to use flavored cannabis, most often fruit-flavored, for smoked (48.1%) and vaped (58.0%) products. The results highlight that flavored cannabis products pose a risk of attracting adolescents to use cannabis.
Link: https://www.cdc.gov/PCD/issues/2021/21_0026.htm)
July 12, 2021 - Negative effects of combined alcohol and marijuana use: The researchers analyzed online surveys of 1,390 full-time college students ages 18 to 24 who had used alcohol and marijuana in the past year. The students were recruited from colleges in three states with different state laws regarding recreational marijuana use. Survey items also included whether the following negative consequences were associated with substance use: cognitive, academic, social, and self-care effects; blackouts; vomiting; risky behavior; driving under the influence; and physical dependence
The two major study results were the following: 1. respondents who used marijuana and alcohol simultaneously experienced more negative consequences than those who used both substances sequentially or when they used only or the other; and 2. respondents drank more alcohol on days when they also used marijuana than on days when they only drank alcohol.
July 12, 2021 - Brain imaging of teen marihuana use: This longitudinal brain imaging study was collected on 799 teens at two time points: baseline (no cannabis use yet) and follow-up, 5 years later (many had initiated cannabis use). The follow-up brain imaging data showed that among youth that had initiated cannabis use during adolescence, they showed altered neuro-development, particularly in the regions of the brain that are rich with cannabinoid receptors, when compared to those who did not use cannabis. And a dose-dependent relationship was found: the heavier the cannabis use, the greater the altered neurodevelopment.
This is a significant study because it compares brain development brain imaging data with a longitudinal sample collected at two time points: before any cannabis use and after cannabis use.
June 13, 2021 - Dual trajectories of cannabis and alcohol use among young adults in a state with legal nonmedical cannabis: The researchers in this study followed for 2-years a sample of young adults (n = 774) in Washington State after enactment of legalizing commercial sales of cannabis. The authors were not comparing pre and post legalization effects, rather they were looking at changes in alcohol and cannabis use over the study period. The main findings were that (1) there was a positive association between the average frequency of cannabis and alcohol use; (2) individuals who used cannabis more frequently on average also drank alcohol more frequently on average; and (3) change over time in cannabis use was positively associated with change in alcohol use. The authors' concluding statement is informative: “Overall, we found no evidence of substitution. Rather, the results suggest a complementary relationship between cannabis and alcohol use, such that the use of cannabis and alcohol rises and falls together.”
April 23, 2021 - Marijuana and the transition to other drugs: The researchers in this study used pooled samples of adolescent drug users (14–17 years old; n =10,644) from the National Survey on Drug Use and Health (2015–2018), and then constructed trajectories of adolescents’ illicit drug use history, based on the age of drug initiation (use of tobacco and alcohol was not included in the analysis). When initiation of a teen’s first illicit drug was marijuana or inhalants, which were the two most frequently first initiated illicit substances, there was a high likelihood of initiating use of an additional illicit drug. Comparatively, initiation of illicit substance was more likely for the inhalant initiates compared to the cannabis initiates.
March 30, 2021 - How addictive is cannabis: The earlier the age of first drug use has been shown to be associated with faster transition to substance use disorder (SUD). However, prevalence of specific SUDs as a function of time since first substance use among young people has not previously been investigated. This study examined the prevalence of specific SUDs since first drug use (including tobacco, alcohol, cannabis, cocaine, methamphetamine, opioids, stimulants, and tranquilizers and heroin) in adolescents aged 12 to 17 years and young adults aged 18 to 25 years. The results showed that among teens who initiated use of cannabis during their teenage years, within 12 months of initiation, 11% had developed a CUD; and within 36 months, 20% had met criteria for a CUD. In comparison: Among young adults who initiated cannabis use during ages 18-25, the CUD rate was about half that of the teenagers. These results support the principle that there is a faster transition to a cannabis use problem the younger the age of initiation of use.
March 10th, 2021 - Risks of teen vaping: This study investigated the associations of nicotine and cannabis vaping with bronchitic symptoms, wheeze, and shortness of breath among youth. Cross-sectional survey data on self-reported lifetime, 6-month, and 30-day vaping from 2553 young adults recruited from high schools in Southern California, collected from June 2018 to October 2019. Cannabis vaping at any level was associated with increased odds of bronchitic symptoms, and cannabis vaping 3 or more times in the last month was associated with increased odds of wheeze, even after simultaneously adjusting for nicotine vaping, cigarette smoking, and combustible cannabis use.
January 29, 2021 - Marijuana and drop in IQ: A new study found using marijuana regularly as a teen drops their IQ later in life. The authors conducted a meta-analysis (a statistical approach of pooling similar studies and drawing conclusions across them) to assess the effect of cannabis use during youth on intelligence. Only studies with pre- and post-exposure measures of IQ were included. Seven cohort studies met inclusion criteria, for a total of 808 cases (cannabis users) and 5308 controls (non-users). The results: There was found a significant effect for the association between frequent or dependent cannabis use in youth and an IQ change in the decline direction, Cohen’s d = −0.132 (95% CI −0.198 to −0.066) p < 0.001. This translates to an average decline of approximately 2 IQ points following exposure to cannabis in youth. However, the studies that followed youth for more years into adulthood typically found a much greater decline in IQ points.
August 12, 2019: Association Between Electronic Cigarette Use and Marijuana Use Among Adolescents and Young Adults. This meta-analysis found a significant increase in the odds of past or current an subsequent marijuana use in adolescents and young adults who used e-cigarettes.
June 12, 2019: Does liberalization of cannabis policy influence levels of use in adolescents and young adults? A systematic review and meta-analysis. The study concludes that “cannabis policy liberalization does not appear to result in significant changes in youths’ use, with the possible exception of legalization for recreational purposes that requires monitoring.
September 17, 2018: Prevalence of Cannabis Use in Electronic Cigarettes Among US Youth Shifts in social acceptability and access to cannabis could occur as several states consider legalized cannabis sales for adults. The National Academies of Sciences has found cannabis use among youth can adversely affect learning and memory and may impair later academic achievement and education. Thus, strategies to reduce cannabis use in e-cigarettes are critical for protecting young people from these potential health risks.
October 2015: High School Students’ Use of Electronic Cigarettes to Vaporize Cannabis E-cigarettes can be used to vaporize cannabis. This study presents rates of vaporizing cannabis among a sample of high school students.