The effects of the 4/20 cannabis holiday and adult-use cannabis legalization on medical cannabis sales and medical cannabis patient registration in Arizona.

BACKGROUND: This study examined whether the 4/20 cannabis holiday was associated with increases in medical cannabis sales from licensed dispensaries in Arizona from 2018-2021, and whether adult-use cannabis legalization (the vote in November 2020 and retail sales in January 2021) was associated with declines in medical cannabis sales and in the number of registered medical patients. METHODS: Data came from the Arizona Medical Marijuana Program monthly reports from January 2018-December 2021. The reports show daily sales from licensed medical cannabis dispensaries (i.e., the number of medical cannabis dispensary transactions and the amount of cannabis sold in pounds), which we averaged by week, and show the number of registered medical cannabis patients each month. Autoregressive integrated moving average models were used to test changes in these outcomes associated with the 4/20 cannabis holiday and with legalization of adult-use cannabis. RESULTS: During the week of the 4/20 cannabis holiday, medical cannabis dispensary transactions abruptly increased by an average of 2,319.4 transactions each day (95% CI: 1636.1, 3002.7), and the amount of medical cannabis sold increased by an average of 120.3 pounds each day (95% CI: 99.3-141.3). During the first week of adult-use cannabis sales in late January 2021, medical cannabis dispensary transactions abruptly decreased by an average of 5,073 transactions each day (95% CI: -5,929.5, -4216.7), and the amount of medical cannabis sold decreased by an average of 119.1 pounds each day (95% CI: -144.2, -94.0). Moreover, medical cannabis sales continued to gradually decline each week after the start of adult-use retail sales, with declines in sales preceding declines in registered patients. By December 2021, slightly over a year after the vote to legalize adult-use cannabis, the actual number of registered medical cannabis patients fell short of the forecasted number, had adult-use not been legalized, by 36.5%. Moreover, the number of medical dispensary transactions and the amount of medical cannabis sold fell short of expectations, had adult-use cannabis not been legalized, by 58% and 53%, respectively. CONCLUSIONS: Findings document the blurred boundary between medical and non-medical cannabis use and are consistent with the possibility that medical cannabis legalization contributes to increases in adult cannabis use and dependence.

Preparedness for healthy ageing and polysubstance use in long-term cannabis users: a population-representative longitudinal study.

BACKGROUND: Cannabis is often characterised as a young person's drug. However, people who began consuming cannabis in the 1970s and 1980s are no longer young and some have consumed it for many years. This study tested the preregistered hypothesis that long-term cannabis users show accelerated biological ageing in midlife and poorer health preparedness, financial preparedness, and social preparedness for old age. METHODS: In this longitudinal study, participants comprised a population-representative cohort of 1037 individuals born in Dunedin, New Zealand, between April, 1972, and March, 1973, and followed to age 45 years. Cannabis, tobacco, and alcohol use and dependence were assessed at ages 18 years, 21 years, 26 years, 32 years, 38 years, and 45 years. Biological ageing and health, financial, and social preparedness for old age were assessed at age 45 years. Long-term cannabis users were compared using independent samples t tests with five groups: lifelong cannabis non-users, long-term tobacco users, long-term alcohol users, midlife recreational cannabis users, and cannabis quitters. In addition, regression analyses tested dose-response associations for continuously measured persistence of cannabis dependence from age 18 years to 45 years, with associations adjusted for sex, childhood socioeconomic status, childhood IQ, low childhood self-control, family substance dependence history, and persistence of alcohol, tobacco, and other illicit drug dependence. FINDINGS: Of 997 cohort members still alive at age 45 years, 938 (94%) were assessed at age 45 years. Long-term cannabis users showed statistically significant accelerated biological ageing and were less equipped to manage a range of later-life health, financial, and social demands than non-users. Standardised mean differences between long-term cannabis users and non-users were large: 0·70 (95% CI 0·46 to 0·94; p<0·0001) for biological ageing, -0·72 (-0·96 to -0·49, p<0·0001) for health preparedness, -1·08 (-1·31 to -0·85; p<0·0001) for financial preparedness, and -0·59 (-0·84 to -0·34, p<0·0001) for social preparedness. Long-term cannabis users did not fare better than long-term tobacco or alcohol users. Tests of dose-response associations suggested that cannabis associations could not be explained by the socioeconomic origins, childhood IQ, childhood self-control, and family substance-dependence history of long-term cannabis users. Statistical adjustment for long-term tobacco, alcohol, and other illicit drug dependence suggested that long-term cannabis users' tendency toward polysubstance dependence accounted for their accelerated biological ageing and poor financial and health preparedness, although not for their poor social preparedness (ß -0·10, 95% CI -0·18 to -0·02; p=0·017). INTERPRETATION: Long-term cannabis users are underprepared for the demands of old age. Although long-term cannabis use appears detrimental, the greatest challenge to healthy ageing is not use of any specific substance, but rather the long-term polysubstance use that characterises many long-term cannabis users. Substance-use interventions should include practical strategies for improving health and building financial and social capital for healthy longevity. FUNDING: The National Institute on Aging and the UK Medical Research Council. The Dunedin Research Unit is supported by the New Zealand Health Research Council and the New Zealand Ministry of Business, Innovation and Employment.

Diminished Structural Brain Integrity in Long-term Cannabis Users Reflects a History of Polysubstance Use.

BACKGROUND: Cannabis legalization and use are outpacing our understanding of its long-term effects on brain and behavior, which is fundamental for effective policy and health practices. Existing studies are limited by small samples, cross-sectional measures, failure to separate long-term from recreational use, and inadequate control for other substance use. Here, we address these limitations by determining the structural brain integrity of long-term cannabis users in the Dunedin Study, a longitudinal investigation of a population-representative birth cohort followed to midlife. METHODS: We leveraged prospective measures of cannabis, alcohol, tobacco, and other illicit drug use in addition to structural neuroimaging in 875 study members at age 45 to test for differences in both global and regional gray and white matter integrity between long-term cannabis users and lifelong nonusers. We additionally tested for dose-response associations between continuous measures of cannabis use and brain structure, including careful adjustments for use of other substances. RESULTS: Long-term cannabis users had a thinner cortex, smaller subcortical gray matter volumes, and higher machine learning-predicted brain age than nonusers. However, these differences in structural brain integrity were explained by the propensity of long-term cannabis users to engage in polysubstance use, especially with alcohol and tobacco. CONCLUSIONS: These findings suggest that diminished midlife structural brain integrity in long-term cannabis users reflects a broader pattern of polysubstance use, underlining the importance of understanding comorbid substance use in efforts to curb the negative effects of cannabis on brain and behavior as well as establish more effective policy and health practices.

The anticipated effects of simultaneous alcohol and cannabis use: Initial development and preliminary validation.

Social learning theories suggest that outcome expectancies are strong determinants of behavior, and studies find that alcohol and cannabis expectancies are associated with negative substance use outcomes. However, there are no measures to date that assess expectancies for simultaneous alcohol and cannabis use (SAM), often referred to as SAM, despite strong links with negative consequences and rising time trends. The present study sought to provide initial validation of test scores for the Anticipated Effects of Simultaneous Alcohol and Cannabis Use Scale (AE-SAM), using a sample of past month college student simultaneous users (N = 434). Exploratory factor analysis and confirmatory factor analysis conducted in random half samples suggested five expectancy factors, representing high arousal positive, high arousal negative (alcohol driven), high arousal negative (cannabis driven), low arousal positive, and low arousal negative expectancies. The factor structure was invariant across sex, race/ethnicity, and simultaneous use frequency, and demonstrated convergent and discriminant validity with other alcohol/cannabis expectancy measures. AE-SAM high arousal positive expectancies were associated with simultaneous use frequency and heavier drinking/cannabis use, AE-SAM high arousal negative (cannabis driven) expectancies were associated with less frequent simultaneous use and more negative alcohol consequences, and AE-SAM low arousal negative expectancies were associated with less cannabis use. Effects of AE-SAM high arousal positive and high arousal negative (cannabis driven) expectancies remained, above and beyond other expectancy measures, suggesting that AE-SAM expectancies provide additional information beyond single substance expectancies. The results demonstrate the feasibility and utility of assessing simultaneous use expectancies, and lay groundwork for future research on simultaneous use expectancies in relation to alcohol and cannabis couse outcomes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Long-Term Cannabis Use and Cognitive Reserves and Hippocampal Volume in Midlife.

OBJECTIVE: Cannabis use is increasing among midlife and older adults. This study tested the hypotheses that long-term cannabis use is associated with cognitive deficits and smaller hippocampal volume in midlife, which is important because midlife cognitive deficits and smaller hippocampal volume are risk factors for dementia. METHODS: Participants are members of a representative cohort of 1,037 individuals born in Dunedin, New Zealand, in 1972-1973 and followed to age 45, with 94% retention. Cannabis use and dependence were assessed at ages 18, 21, 26, 32, 38, and 45. IQ was assessed at ages 7, 9, 11, and 45. Specific neuropsychological functions and hippocampal volume were assessed at age 45. RESULTS: Long-term cannabis users showed IQ decline from childhood to midlife (mean=-5.5 IQ points), poorer learning and processing speed relative to their childhood IQ, and informant-reported memory and attention problems. These deficits were specific to long-term cannabis users because they were either not present or were smaller among long-term tobacco users, long-term alcohol users, midlife recreational cannabis users, and cannabis quitters. Cognitive deficits among long-term cannabis users could not be explained by persistent tobacco, alcohol, or other illicit drug use, childhood socioeconomic status, low childhood self-control, or family history of substance dependence. Long-term cannabis users showed smaller hippocampal volume, but smaller hippocampal volume did not statistically mediate cannabis-related cognitive deficits. CONCLUSIONS: Long-term cannabis users showed cognitive deficits and smaller hippocampal volume in midlife. Research is needed to ascertain whether long-term cannabis users show elevated rates of dementia in later life.

Validating a brief screening measure for early-onset substance use during adolescence in a diverse, nationwide birth cohort.

The Loeber Risk Score (LRS) was developed to predict early-onset cannabis use in adolescence from late childhood, facilitating early identification. However, the LRS was developed in non-representative historical samples, leaving uncertain its generalizability to children/adolescents across the U.S. today. We externally validated the LRS in a diverse, nationwide cohort (N = 4,898) weighted to the composition of the U.S. Census. Participants in 20 cities completed assessments when youth were approximately 5, 9, and 15 years old. Parents completed the LRS at the age ∼5 and ∼9 interviews. At the age ∼15 interview, youth reported on the onset of alcohol/drug use before age 15, monthly drinking/binge drinking at ages 14-16, and use of cannabis multiple times per month at ages 14-16. First, we validated the LRS measured at age ∼9. Area under the receiver operating curve was 0.62 for onset of cannabis use before age 15, 0.68 for onset of cigarette use before age 15, and 0.62 for use of cannabis multiple times per month at ages 14-16. For drinking outcomes, LRS performance could not be distinguished from chance prediction. The recommended screening cutoff of LRS ≥ 2 identified 24% of children, among whom early-onset cannabis/cigarette use outcomes occurred 1.4-2.2 times more frequently than the general population. The LRS' performance did not vary significantly by sex, race, or ethnicity. When the LRS was measured at age ∼5, AUROC was significantly lower for some outcomes. Together, findings support the LRS measure as a potential tool for identifying children in early or late childhood at risk of early-onset drug use in adolescence.

Are recreational cannabis laws associated with declining medical cannabis program enrollment in the U.S.? An analysis of cardholder enrollment and demographic characteristics from 2013 to 2020.

BACKGROUND: There is speculation that enrollment in U.S. state medical cannabis programs differs depending on whether adult recreational cannabis use is legal. If true, this could have implications for public health and policy. METHODS: Using medical cannabis registry data from U.S. states with a mandatory registry between 2013 and 2020 (N = 23 states), this study examined time-trends in medical cannabis cardholder enrollment and tested whether enrollment trends differed depending on adult recreational cannabis legalization. RESULTS: Multilevel models showed that time-trends for registered active medical cardholders differed during years when adult recreational cannabis use was legal versus not legal (time*recreational cannabis law interaction: b = -0.004, p < 0.01, 95% CI = -0.005, -0.003). The population prevalence of registered active medical cardholders increased over time in years when recreational cannabis was not legal (i.e., medical-only years; b = 0.004, p < 0.001, 95% CI = 0.003, 0.004, corresponding to an increase of 380 cardholders per 100,000 people per year), and decreased in years when recreational cannabis was legal (i.e., recreational years; b = -0.001, p < 0.001, 95% CI = -0.002, -0.001, corresponding to a decrease of 100 cardholders per 100,000 people per year). Time-trends were similar for each sex (male, female) and age group (18-30/35, 30/35+), with each cardholder group showing increases in medical-only years and decreases in recreational years. In medical-only years, there were no differences in enrollment time-trends across sex, but older cardholder (30/35+) enrollment increased at a faster rate than younger cardholder enrollment (18-30/35) (F = 16.199, p < 0.001). In recreational years, male cardholder enrollment decreased at a faster rate than female cardholder enrollment (F = 7.347, p < 0.01), but there was no difference in trends across age. Three states, all with medical-only years, provided data on ethnicity/race. Results showed significant increases from 2016 to 2020 in enrollment of White, African-American, and Hispanic individuals. CONCLUSIONS: Findings suggest that recreational cannabis legalization is associated with decreasing enrollment in medical cannabis programs, particularly for males.

Cannabis use and psychosocial functioning: evidence from prospective longitudinal studies.

Cannabis legalization is expected to result in more frequent and compulsive use, potentially contributing to worsening psychosocial functioning among some cannabis users. This review evaluates associations between cannabis use and psychosocial functioning in recently published reports from prospective longitudinal studies and considers evidence for and against causation. Unlike previous reviews, studies of adolescents/emerging adults are considered separately from studies that followed adolescents well into adulthood, in part because of vast differences in cumulative cannabis exposure. Infrequent adolescent cannabis use is associated with poorer psychosocial functioning in some domains in emerging adulthood, whereas chronic, frequent adult use, regardless of adolescent-onset versus adult-onset, is associated with poorer psychosocial functioning in many domains. Associations are likely attributable to a combination of causal and non-causal mechanisms, with causal mechanisms likely to be social, not neurotoxic, in nature.

Adolescent executive cognitive functioning and trait impulsivity as predictors of young-adult risky drinking and alcohol-related problems.

Executive cognitive functioning (ECF) and trait impulsivity have long been implicated in risky drinking and alcohol-related problems. However, research on these constructs has developed independently. The present study tested whether two subdomains of adolescent ECF (updating and response inhibition) and adolescent trait impulsivity, considered separately and together, predicted young-adult risky drinking and alcohol-related problems. Data came from the Adolescent/Adult Family Development Project-a longitudinal study of the intergenerational transmission of alcohol use. Alcohol-naïve youth ages 11-17 (N = 249) completed three tasks tapping ECF subdomains of updating (letter-number sequencing, matrix span task) and inhibition (immediate memory task) and a self-reported measure of trait impulsivity (UPPS-P). Approximately 7 years later (ages 18-25), participants reported on their drinking behavior (maximum drinks in a day, heavy episodic drinking, alcohol-related problems). We tested whether adolescent ECF and trait impulsivity predicted young-adult drinking outcomes, separately and together. Results showed that poorer adolescent ECF (a latent factor) predicted more maximum drinks in a day (Incidence Rate Ratios [IRR] = 1.27, p = .001) but not young-adult heavy episodic drinking and alcohol-related problems. In contrast, adolescent trait impulsivity predicted all three outcomes: maximum drinks in a day (IRR = 1.34, p < .001), heavy episodic drinking (ß = 0.27, p < .001), and alcohol-related problems in young adulthood (IRR = 1.60, p = .001). Results were similar when adolescent ECF and trait impulsivity were considered together in the same model. Findings suggest that adolescent trait impulsivity is a robust predictor of young-adult risky drinking and alcohol-related problems. Adolescent ECF, and specifically response inhibition, may add predictive value over and above trait impulsivity for some alcohol outcomes. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The Anticipated Effects of Cannabis Scale (AECS): Initial development and validation of an affect- and valence-based expectancy measure.

Prior research suggests that cannabis expectancies are related to cannabis misuse and problems. Although there are established measures of cannabis expectancies, existing measures have psychometric limitations and/or are lengthy. Existing measures typically have a two-factor structure of positive and negative expectancies, but recent conceptualizations of alcohol expectancies support a valence- (positive vs. negative) and arousal-based (high vs. low arousal) structure. Thus, the present study sought to test a similar structure for cannabis. Cannabis expectancy items underwent 2 preliminary studies, assessing item valance/arousal (n = 233) and relevance to cannabis (n = 124). A final pool of 76 items underwent exploratory factor analysis (n = 303), and remaining items underwent confirmatory factor analysis in a separate sample (n = 469). Lastly, an additional sample (n = 435) examined validity. Results suggested a 3-factor structure (general positive, high arousal negative, low arousal negative) for the 17-item Anticipated Effects of Cannabis Scale (AECS), which was invariant across cannabis use frequency, sex, and race/ethnicity. Positive expectancies were strongly associated with cannabis use, whereas low arousal negative expectancies were protective against cannabis frequency; high arousal negative expectancies were strongly associated with more negative consequences and dependence symptoms. In addition, the proposed interpretation of AECS test scores showed evidence of incremental validity relative to another abbreviated measure. The current study provides initial support for the AECS, a brief, psychometrically sound cannabis expectancies measure. The AECS captures the full range of cannabis effects and may be suited to test discrepancies between cannabis expectancies and subjective response. Additional research is needed to validate its structure and predictive utility. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

A within-person comparison of the subjective effects of higher vs. lower-potency cannabis.

BACKGROUND: Cannabis concentrates have much higher concentrations of THC than marijuana (flower) and are quickly gaining popularity in the United States. One hypothesis is that use of higher-THC cannabis (concentrates) might result in greater intoxication and more severe acute negative effects than lower-THC cannabis (marijuana), but few studies have compared the subjective effects of concentrates and marijuana. METHODS: Current (past-year) cannabis users were recruited online to complete a survey about their cannabis use. Cannabis users who reported using both marijuana and concentrates (n = 574) answered questions about the subjective effects of marijuana and, subsequently, the subjective effects of concentrates. Subjective effects were obtained for the following domains: affect, cognitive function, psychotic-like experiences, physiological effects, and reduced consciousness. RESULTS: Participants reported using marijuana between 5-6 times per week and concentrates slightly more than once per month. Within-person comparisons of the subjective effects of marijuana and concentrates showed that marijuana was rated as producing greater overall positive effects (Marijuana: M = 5.6, Concentrates: M = 4.5; Cohen's d = 0.75, paired t(561) = 14.67, p < .001), including greater positive affect and enhanced cognitive function. Negative effects of both marijuana and concentrates were minimal. Marijuana was selected over concentrates as the 'preferred type' of cannabis by 77.5 % of participants. CONCLUSIONS: The main difference in the subjective effects of marijuana and concentrates is in terms of their positive effects, with marijuana producing greater positive effects than concentrates. Negative effects of marijuana and concentrates were small, suggesting that extreme negative effects are unlikely for regular cannabis users.

Associations between Recent and Cumulative Cannabis Use and Internalizing Problems in Boys from Adolescence to Young Adulthood.

This study tested whether increases in recent and cumulative cannabis use were each associated with increases in internalizing problems from adolescence to young adulthood. Participants were boys from a community sample that was assessed annually from ~age 15-26 (N = 506). Boys reported on their cannabis use, depression symptoms, and anxiety/depression problems each year. Exposures were frequency of cannabis use in a given year (no use, < weekly use, weekly or more frequent use) and cumulative prior years of weekly cannabis use. Outcomes were depression symptoms and anxiety/depression problems in a given year. Analyses examined within-person associations between changes in exposures and outcomes over time, which eliminated "fixed" (unchanging) individual differences as potential confounds. Analyses also accounted for time-varying factors as potential confounds (other substance use, externalizing problems, subclinical psychotic symptoms). Results showed that increases in recent cannabis use and cumulative prior years of weekly cannabis use were each associated with increases in depression symptoms and anxiety/depression problems. After controlling for time-varying covariates, increases in cumulative prior years of weekly cannabis use, but not recent cannabis use, remained associated with increases in depression symptoms and anxiety/depression problems. Specifically, each additional year of prior weekly cannabis use was associated with a small increase in depression symptoms (b = 0.012, p = .005) and anxiety/depression problems (b = 0.009, p = .001). Associations did not vary systematically across time. There was also no evidence of reverse causation. As boys engaged in weekly cannabis use for more years, they showed increases in internalizing problems, suggesting the importance of preventing chronic weekly cannabis use.

Associations between cannabis use and retinal vessel diameter in young adults.

Cannabis appears to have vascular effects that may have implications for cerebrovascular function, but no studies have directly visualized the microvasculature in living cannabis users. The current study used retinal imaging, a tool taken from ophthalmology, to visualize the small retinal microvessels in cannabis users. We compared retinal arteriolar (small arteries) and venular (small veins) diameters in 55 frequent cannabis users and 51 comparison individuals with a mean age of 19.25 years (SD = 2.43). Results indicated that mean arteriolar diameter was statistically significantly wider for cannabis users (M = 157.98, SE = 1.42) than for comparison individuals (M = 153.56, SE = 1.46; F(1,103) = 4.67, p = .033), even after controlling for a variety of covariates and after excluding from analyses cannabis users who had used cannabis in the past 24 h. There was no statistically significant difference in retinal venular diameter between cannabis users and comparison individuals. Findings suggest that frequent cannabis use is associated with wider retinal arterioles, which might represent a residual vasodilatory effect of recent cannabis use or impaired autoregulation resulting from chronic cannabis use. Retinal imaging is a non-invasive, cost-effective tool for visualizing the microvasculature in living individuals and can be combined, in future research, with neuroimaging and other measures of retinal vascular function to better understand the acute and longer-term effects of cannabis use on the microvasculature.

Cannabis Concentrate Use in Adolescents.

BACKGROUND: Cannabis concentrates, which are cannabis plant extracts that contain high concentrations of Δ-9-tetrahydrocannbinol (THC), have become increasingly popular among adults in the United States. However, no studies have reported on the prevalence or correlates of cannabis concentrate use in adolescents, who, as a group, are thought to be particularly vulnerable to the harms of THC. METHODS: Participants are a racially and ethnically diverse group of 47 142 8th-, 10th-, and 12th-grade students recruited from 245 schools across Arizona in 2018. Participants reported on their lifetime and past-month marijuana and cannabis concentrate use, other substance use, and risk and protective factors for substance use problems spanning multiple life domains (ie, individual, peer, family, school, and community). RESULTS: Thirty-three percent of all 8th-, 10th-, and 12th-graders reported lifetime cannabis use, and 24% reported lifetime concentrate use. Seventy-two percent of all lifetime cannabis users had used concentrates. Relative to adolescent cannabis users who had not used concentrates, adolescent concentrate users were more likely to use other substances and to experience more risk factors, and fewer protective factors, for substance use problems across numerous life domains. CONCLUSIONS: Most adolescent cannabis users have used concentrates. Based on their risk and protective factor profile, adolescent concentrate users are at higher risk for substance use problems than adolescent cannabis users who do not use concentrates. Findings raise concerns about high-risk adolescents' exposure to high-THC cannabis.

Associations between adolescent cannabis use frequency and adult brain structure: A prospective study of boys followed to adulthood.

BACKGROUND: Few studies have tested the hypothesis that adolescent cannabis users show structural brain alterations in adulthood. The present study tested associations between prospectively-assessed trajectories of adolescent cannabis use and adult brain structure in a sample of boys followed to adulthood. METHODS: Data came from the Pittsburgh Youth Study - a longitudinal study of ˜1000 boys. Boys completed self-reports of cannabis use annually from age 13-19, and latent class growth analysis was used to identify different trajectories of adolescent cannabis use. Once adolescent cannabis trajectories were identified, boys were classified into their most likely cannabis trajectory. A subset of boys (n = 181) subsequently underwent structural neuroimaging in adulthood, when they were between 30-36 years old on average. For this subset, we grouped participants according to their classified adolescent cannabis trajectory and tested whether these groups showed differences in adult brain structure in 14 a priori regions of interest, including six subcortical (volume only: amygdala, hippocampus, nucleus accumbens, caudate, putamen, and pallidum) and eight cortical regions (volume and thickness: superior frontal gyrus; caudal and rostral middle frontal gyrus; inferior frontal gyrus, separated into pars opercularis, pars triangularis, and pars orbitalis; lateral and medial orbitofrontal gyrus). RESULTS: We identified four adolescent cannabis trajectories: non-users/infrequent users, desisters, escalators, and chronic-relatively frequent users. Boys in different trajectory subgroups did not differ on adult brain structure in any subcortical or cortical region of interest. CONCLUSIONS: Adolescent cannabis use is not associated with structural brain differences in adulthood.

Associations Between Cannabis Use and Cardiometabolic Risk Factors: A Longitudinal Study of Men.

OBJECTIVE: This study tested longitudinal associations between cannabis use and cardiometabolic risk factors that underlie the development of cardiovascular diseases. METHODS: Participants were men from the youngest cohort of the Pittsburgh Youth Study who were followed prospectively from approximately age 7 to 32 years (N = 253). Frequency of cannabis use was assessed yearly from approximately ages 12 to 20 years and again at approximately ages 26, 29, and 32 years. The following cardiometabolic risk factors were assessed during a laboratory visit at approximately age 32 years: body mass index (BMI), waist-hip ratio, high- and low-density lipoprotein cholesterol, triglycerides, fasting glucose, insulin resistance, blood pressure, interleukin 6, and C-reactive protein. RESULTS: Greater cannabis exposure was associated with relatively lower BMI (ß = -0.31, p < .001), smaller waist-hip ratio (ß = -0.23, p = .002), better high- (ß = 0.14, p = .036) and low-density lipoprotein cholesterol (ß = -0.15, p = .026), lower triglycerides (ß = -0.17, p = .009), lower fasting glucose (ß = -0.15, p < .001) and insulin resistance (ß = -0.21, p = .003), lower systolic (ß = -0.22, p < .001) and diastolic blood pressure (ß = -0.15, p = .028), and fewer metabolic syndrome criteria (ß = -0.27, p < .001). With exception of BMI, cannabis users' mean levels on cardiometabolic risk factors were generally below clinical cutoffs for high risk. Most associations between cannabis use and cardiometabolic risk factors remained after adjusting for tobacco use, childhood socioeconomic status, and childhood health. However, after adjusting for adult BMI, these associations were no longer apparent, and mediation tests suggested that cannabis users' relatively lower BMI might explain their lower levels of risk on other cardiometabolic risk factors. CONCLUSIONS: Cannabis use is associated with lower BMI, and lower BMI is related to lower levels of risk on other cardiometabolic risk factors.

Comparison of the locations where young adults smoke, vape, and eat/drink cannabis: Implications for harm reduction.

BACKGROUND: Cannabis vaping and edible use are increasingly popular methods of cannabis use. These discreet methods could increase risk of cannabis-related problems by facilitating cannabis use in a wider range of settings. METHODS: A sample of 1018 college students were recruited to complete a survey about their health and behavior. Participants who used cannabis in the past year (35.1%, n = 357) answered questions about their cannabis use, including where they were the last time they smoked, vaped, or ate/drank cannabis, and their experience of cannabis-related problems. RESULTS: Compared with cannabis smoking, participants were more likely to have vaped cannabis (15.8% smoked vs. 24.6% vaped; X2 = 4.59, p = .032), and were slightly, but not statistically significantly, more likely to have used cannabis edibles (17.5% smoked vs. 24.2% used edibles; X2 = 3.57, p = .059), in locations other than a private residence. For example, participants were more likely to have vaped cannabis in a car than to have smoked cannabis in a car (8.8% vaped vs. 3.5% smoked; X2 = 4.26, p = .039). More frequent cannabis vaping was associated with driving while high on cannabis, even after accounting for overall frequency of cannabis use and other covariates (OR = 1.22, p = .047). More frequent cannabis vaping and edible use were associated with various cannabis-related problems, but, in general, these associations became statistically non-significant after accounting for overall frequency of cannabis use. CONCLUSIONS: Cannabis vaporizers and edibles facilitate cannabis use in locations that require discretion. Increased availability of cannabis vaporizers and edibles could increase risk of cannabis-related problems by enabling use in more settings.

Associations between adolescent cannabis use and neuropsychological decline: a longitudinal co-twin control study.

AIMS: This study tested whether adolescents who used cannabis or met criteria for cannabis dependence showed neuropsychological impairment prior to cannabis initiation and neuropsychological decline from before to after cannabis initiation. DESIGN: A longitudinal co-twin control study. SETTING AND PARTICIPANTS: Participants were 1989 twins from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative birth cohort of twins born in England and Wales from 1994 to 1995. MEASUREMENTS: Frequency of cannabis use and cannabis dependence were assessed at age 18. Intelligence quotient (IQ) was obtained at ages 5, 12 and 18. Executive functions were assessed at age 18. FINDINGS: Compared with adolescents who did not use cannabis, adolescents who used cannabis had lower IQ in childhood prior to cannabis initiation and lower IQ at age 18, but there was little evidence that cannabis use was associated with IQ decline from ages 12-18. For example, adolescents with cannabis dependence had age 12 and age 18 IQ scores that were 5.61 (t = -3.11, P = 0.002) and 7.34 IQ points (t = -5.27, P < 0.001) lower than adolescents without cannabis dependence, but adolescents with cannabis dependence did not show greater IQ decline from age 12-18 (t = -1.27, P = 0.20). Moreover, adolescents who used cannabis had poorer executive functions at age 18 than adolescents who did not use cannabis, but these associations were generally not apparent within twin pairs. For example, twins who used cannabis more frequently than their co-twin performed similarly to their co-twin on five of six executive function tests (Ps > 0.10). The one exception was that twins who used cannabis more frequently than their co-twin performed worse on one working memory test (Spatial Span reversed; ß = -0.07, P = 0.036). CONCLUSIONS: Short-term cannabis use in adolescence does not appear to cause IQ decline or impair executive functions, even when cannabis use reaches the level of dependence. Family background factors explain why adolescent cannabis users perform worse on IQ and executive function tests.

The intergenerational transmission of cannabis use: Associations between parental history of cannabis use and cannabis use disorder, low positive parenting, and offspring cannabis use.

Parental cannabis use disorder (CUD) and low positive parenting (monitoring, support, and consistency) are risk factors for adolescent cannabis use. However, it is unclear whether parental cannabis use without CUD is sufficient to increase risk for low positive parenting and adolescent cannabis use. Additionally, parents may not treat each of their adolescents the same, and risk for adolescent cannabis use may increase as a result of low levels of positive parenting in families or low positive parenting unique to each adolescent. The current study prospectively tested low positive parenting as a mediator of the relation between parental cannabis use history (with parental cannabis use and CUD considered separately) and adolescent cannabis use at the family level and individual level. Participants were 363 adolescents from a multigenerational longitudinal study who reported on positive parenting when they were ages 9-16 (M = 11.6, SD = 1.40) and on cannabis use when they were ages 13-19 (M = 16.3, SD = 1.84). Parents reported on their own cannabis use and CUD. Results showed that parental CUD was associated with adolescent cannabis use (OR = 3.62, p = .047) but parental cannabis use without CUD was not, and only parental CUD predicted low positive parenting (B = -0.28, p < .05). Average levels of low positive parenting within a family partially mediated the association between parental CUD and offspring cannabis use. These findings suggest parental cannabis use alone may not impair parenting, but parental use that meets criteria for CUD does impair parenting. Additionally, average levels of positive parenting in families may be a mechanism underlying the intergenerational transmission of cannabis use. (PsycINFO Database Record

Associations between butane hash oil use and cannabis-related problems.

BACKGROUND: High-potency cannabis concentrates are increasingly popular in the United States, and there is concern that use of high-potency cannabis might increase risk for cannabis-related problems. However, little is known about the potential negative consequences of concentrate use. This study reports on associations between past-year use of a high-potency cannabis concentrate, known as butane hash oil (BHO), and cannabis-related problems. METHODS: A sample of 821 college students were recruited to complete a survey about their health and behavior. Participants who had used cannabis in the past year (33%, n=273) completed questions about their cannabis use, including their use of BHO and cannabis-related problems in eight domains: physical dependence, impaired control, academic-occupational problems, social-interpersonal problems, self-care problems, self-perception, risk behavior, and blackouts. RESULTS: Approximately 44% (n=121) of past-year cannabis users had used BHO in the past year. More frequent BHO use was associated with higher levels of physical dependence (RR=1.8, p<0.001), impaired control (RR=1.3, p<0.001), cannabis-related academic/occupational problems (RR=1.5, p=0.004), poor self-care (RR=1.3, p=0.002), and cannabis-related risk behavior (RR=1.2, p=0.001). After accounting for sociodemographic factors, age of onset of cannabis use, sensation seeking, overall frequency of cannabis use, and frequency of other substance use, BHO use was still associated with higher levels of physical dependence (RR=1.2, p=0.014). CONCLUSIONS: BHO use is associated with greater physiological dependence on cannabis, even after accounting for potential confounders. Longitudinal research is needed to determine if cannabis users with higher levels of physiological dependence seek out BHO and/or if BHO use increases risk for physiological dependence.