Correlates of intentions to use cannabis among US high school seniors in the case of cannabis legalization

Exploring Twitter chatter to assess the type and availability of cannabis-related products in Thailand

Cannabis-related tweets were collected between January and April 2022 to estimate the availability and characteristics of cannabis products advertised on Twitter amid the legalization of recreational cannabis in Thailand. The Twitter API was called using the tweepy Python library to collect cannabis-related tweets in the Thai language. A total of 185,558 unique tweets were collected over the duration of the data collection period based on 83 search terms. Twenty thousand random tweets were manually coded by four Thai native speakers to assess the volume and characteristics of tweets proposing cannabis. 72.6% of collected tweets from the 20,000 random samples were coded as relevant to the study. 54.6% of relevant tweets were advertising cannabis products, 29.8% were personal communications, and 15.6% were related to news or media content. Among the tweets that advertised cannabis products, 94.4% proposed cannabis flower, 2.4% cannabis edibles and 1.8% cannabis concentrates. Consumption of potent forms of cannabis such as cannabis edibles and concentrates increase the risk of harmful side-effects, especially in a population with limited knowledge about these products. Our findings call for additional monitoring efforts and for increasing the public awareness on potent cannabis products emerging in Thailand.

Perinatal Tetrahydrocannabinol Compromises Maternal Care and Increases Litter Attrition in the Long-Evans Rat

The marijuana legalization trend in the U.S. will likely lead to increased use by younger adults during gestation and postpartum. The current study examined the hypothesis that delta-9-tetrahydrocannabinol (THC) would disrupt voluntary maternal care behaviors and negatively impact offspring development. Rat dams were gavaged with 0, 2, 5, or 10 mg/kg THC from the 1st day of gestation through the 21st postnatal day. Somatic growth and developmental milestones were measured in the offspring, and maternal pup retrieval tests were conducted on postnatal days 1, 3, and 5. THC did not affect body growth but produced transient delays in the righting reflex and eye opening in offspring. However, there was significant pup mortality due to impaired maternal care. Dams in all THC groups took significantly longer to retrieve their pups to the nest and often failed to retrieve any pups. Serum levels of THC and metabolites measured at this time were comparable to those in breastfeeding women who are chronic users. Benchmark doses associated with a 10% reduction of pup retrieval or increased pup mortality were 0.383 (BMDL 0.228) and 0.794 (BMDL 0.442) mg/kg THC, respectively. The current findings indicate that maternal care is an important and heretofore overlooked index of THC behavioral toxicity and should be included in future assessments of THC's health risks.

Perceptions, Attitudes, and Knowledge of Cannabis and its Use: A Qualitative Study among Herbal Heart Study Young Adult Cannabis Consumers in South Florida

Growing cannabis use among young adults in the United States surpasses research and public understanding, raising health concerns despite potential benefits. Limited research focuses on their knowledge, attitudes, risks, and motivations, especially in states with limited legalization. This study explores cannabis knowledge and attitudes among healthy young adult cannabis consumers to understand their risk and benefit perceptions. Data include a subsample of participants in the Herbal Heart Study, a cohort to examine subclinical cardiovascular risk among healthy young adult (18-35 years old) cannabis consumers and non-consumers. A qualitative thematic analysis of the interviews was performed using a deductive approach driven by the theory of the Health Belief Model to generate categories and codes. Dedoose was used to organize transcripts and coding. A total of 22 young adult cannabis consumers (M age = 25.3, SD = 4.4) were interviewed between May 5, 2021- September 23, 2022. Participants were predominantly female (n = 13) and Hispanic (n = 9) or non-Hispanic Black (n = 7). Five themes were identified: perceived health benefits and risks associated with cannabis use, motivation for cannabis use, knowledge of cannabis, and perceived barriers to cannabis use. Participants discussed knowledge, positive/negative attitudes toward cannabis, and perceived risks/benefits based on personal experience and gathered information. Some showed knowledge deficits, and most wanted more health-related cannabis research. Given the current climate of rising cannabis legalization, availability of novel cannabis products, and societal acceptance, further research and evidence-based cannabis literacy for young adults are essential to keep pace with liberalization trends.

Gone with the weed: incidents of adolescent marijuana use in the United States, 1976-2021

PURPOSE

This study sought to examine grouped and right-censored (GRC) counts of adolescent marijuana use and estimate its temporal trajectories and sociodemographic disparities over almost half a century.

METHODS

After compiling 46 waves of nationally representative data from the Monitoring the Future (MTF) study from 1976 to 2021 (sample size = 491,348), we utilized an innovative modified Poisson (mixture) approach to analyze past-year marijuana use quantified by GRC counts.

RESULTS

The overall reduction in incidence rates of marijuana use was attributable to an almost 40% reduction in the risk of marijuana use (with the proportion of at-risk adolescents at 51.36% in 1979 and 31.53% in 2021). Despite substantial changes over the study period, the recent incidence rates for at-risk individuals were similar to those in the early 1980s. Living in an intact family was a protective factor against adolescent marijuana use over time.

CONCLUSIONS

The incidence rates of marijuana use among at-risk students, especially those from disadvantaged families, remained high over the study period. The modified Poisson (mixture) approach serves as the preferred tool for modeling GRC responses. It is essential to distinguish among risk, at-risk incidence, and overall incidence when assessing substance use and other risky behaviors.

Correlates of adolescent sole-, dual- and poly-use of cannabis, vaped nicotine, and combusted tobacco

BACKGROUND

Compared to single substance use, adolescents' use of multiple substances is associated with more severe dependence, cessation outcomes, and health risks. This study examined correlates of use and co-use of e-cigarettes, combusted tobacco, and cannabis among high school-aged (9th-12th grade, approximately aged 14-18) adolescents.

METHODS

We analyzed the 2019 Massachusetts Youth Health Survey (MYHS) data to calculate the weighted means of any past 30-day sole-use of e-cigarettes, sole-use of combusted tobacco, sole-use of cannabis, dual-use of two of the above substances, and poly-use of all three substances. We then used weighted multinomial logistic regression to examine the associations between demographic, social and behavioral factors and sole-, dual-, and poly-use (vs. no use) of these substances.

RESULTS

Among N = 1614 respondents, any past 30-day dual-use of e-cigarettes and cannabis was the most prevalent (17.2%, SE: 1.3%). Sole-use of combusted tobacco was less than 1%, whereas 4.5% (SE: 0.7%) of respondents reported poly-use of e-cigarettes, cannabis, and combusted tobacco. Lower academic grades and self-reported depression (1 item on persistent feelings of sadness or hopelessness) were associated with increased odds of dual-use of e-cigarettes and cannabis and poly-use (vs. sole-use of any substance). Adolescents who self-reported having "any long-term emotional problems or learning disabilities" had greater odds of poly-use.

CONCLUSION

Different sets of correlates were associated with sole-, dual-, and poly-use, suggesting that certain adolescents may be more vulnerable than others to multiple substance use. Future research should examine potentially modifiable upstream influences, such as the home environment and socioeconomic factors that may affect the relationship between adolescent mental health, school performance, and multiple addictive substance use.

"There must be something good": Fair balance and ad appeal of marijuana brands' website

Ever since medical and nonmedical marijuana became legal in parts of the United States in 2012, scholars have cited concerns regarding marijuana advertising's impact on adolescents. The current study aimed to explore how online marijuana websites are utilizing their advertising strategies amid the lack of centralized regulation by qualitatively analyzing 141 websites of marijuana brands in the United States. We found that the common themes they employed were high, professionalism, natural, and adventurous. There was no fair balance between benefit and risk information because most of the brands did not communicate the risk. The use of animated characters was found, along with other appeals that could potentially influence underage users. Areas of concern that need imminent attention from the regulatory body are discussed.

Can global or national disability weights represent provincial level?

BACKGROUND

A universal set of disability weights(DWs) is mainly based on the survey of North America, Australia and Europe, whereas the participants in Asia was limited. The debate hasn't yet settled whether a universal DW is desirable or useful.The focus of the debate is its representativenes-s.After all, the DWs come from people's subjective evaluation of pain, and they may vary according to cultural background.The differences of the DWs could have implications for the magnitude or ranking of disease burdens.The DWs of Anhui Province has not been completely presented.This paper aims to obtain the DWs suitable for the general population of Anhui Province of China, and attempts to explore the differences between different DWs by comparing the DWs with the similar-cultural background and the DWs with cross-cultural background.

METHODS

A web-based survey was conducted to estimate the DWs for 206 health states of Anhui province in 2020. Paired comparison (PC) data were analyzed and anchored by probit regression and fitting loess model. We compared the DWs in Anhui with other provinces in China and those in Global burden of disease (GBD) and Japan.

RESULTS

Compared with Anhui province, the proportion of health states which showed 2 times or more differences ranged from 1.94% (Henan) to 11.17% (Sichuan) in China and domestic provinces. It was 19.88% in Japan and 21.51% in GBD 2013 respectively. In Asian countries or regions, most of the health states with top 15 DWs belonged to the category of mental, behavioral, and substance use disorders. But in GBD, most were infectious diseases and cancer. The differences of DWs in neighboring provinces were smaller than other geographically distant provinces or countries.

CONCLUSION

PC responses were largely consistent across very distinct settings,but the exceptions do need to be faced squarely.The differences of DWs among similar-cultural regions were smaller than cross-cultural regions. There is an urgent need for relevant gold standards.

Impacts of recreational cannabis legalization on use and harms: A narrative review of sex/gender differences

Legalization of cannabis use for non-medical (recreational) purposes is changing the global cannabis landscape. As attitudes toward cannabis use become more positive and prevalence of use increases in complex ways, concerns emerge about the potential for increased cannabis-attributable harms. Understanding the who, why, and when of this likely increase in cannabis-attributable harms is thus an important public health priority. Both sex and gender contribute to variability in the use, effects, and harms of cannabis and thus sex/gender considerations are important when evaluating the impacts of cannabis legalization. The goal of this narrative review is to broadly discuss sex/gender differences in attitudes toward and prevalence of cannabis use, whether there are sex/gender differences in the impacts of cannabis legalization, and why these sex/gender differences might exist. One of our strongest conclusions is that men have always been more likely to use cannabis than women, yet the sex/gender gap in prevalence of cannabis use has narrowed over time, and this might be partly due to cannabis legalization. The existing evidence suggests that there have also been sex/gender differences in the impacts of legalization on cannabis-attributable harms such as cannabis-involved motor vehicle collisions and hospitalizations, though these results are more variable. The body of literature reviewed has focused almost exclusively on samples of cisgender research participants, and thus future research should encourage inclusion of transgender and gender-diverse participants. More consideration of sex- and gender-based analysis in research evaluating long-term impacts of cannabis legalization is a clear research priority.

Effects of Cannabis Legalization on Road Safety: A Literature Review

BACKGROUND

Legalizing medical and recreational cannabis and decriminalizing this substance may have unanticipated effects on traffic safety. The present study aimed to assess the impact of cannabis legalization on traffic accidents.

METHODS

A systematic review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) declaration of the articles included in the Web of Science (WoS) and Scopus databases. The number of papers included in the review was 29.

RESULTS

The results show that in 15 papers, there is a relationship between the legalization of medical and/or recreational cannabis and the number of traffic accidents, while in 5 papers, no such relationship is observed. In addition, nine articles indicate a greater number of risk behaviors related to driving after consumption, identifying young, male, and alcohol consumption together with cannabis as the risk profile.

CONCLUSIONS

It can be concluded that the legalization of medical and/or recreational cannabis has negative effects on road safety when considering the number of jobs that affect the number of fatalities.

Cannabis use, self-perceived risk, perceived peer approval and parental attitudes among youth at clinical high-risk for psychosis

AIM

Cannabis use is associated with greater likelihood of psychosis. The relationship between attitudes about cannabis and use has not been examined in youth at clinical high-risk (CHR) for psychosis. Additionally, the shifting legal landscape can provide a valuable context for evaluating use and related attitudes.

METHODS

This study included 174 participants (44 CHR, 43 healthy control [HC] youth-parent dyads). Youth completed measures of self-reported cannabis use confirmed with a urinalysis, self-perceived risk and perceived peer attitudes. Parents reported attitudes about youth use. Legalization occurred halfway during a 5-year study in Colorado, providing an opportunity to cross-sectionally examine its role in use and attitudes.

RESULTS

Frequency of youth reporting cannabis use was significantly higher in CHR (69%) than control group (30%). Use in CHR group was associated with higher perceived peer approval (r = .57), increased parental permissiveness (r = .28) and lower self-perceived risk (r = -.26). Comparing samples participating pre and post-legalization, use remained stable within each group. Group differences in parental permissiveness shifted; trend toward decrease in permissiveness in CHR group (η²_partial  = .07) and a significant increase in HCs (η²_partial  = .16) were observed. Post-legalization, use in CHR group correlated with higher perceived peer approval (r = .64), lower self-perceived risk (r = -.51) and higher parental permissiveness (r = .35, trend).

CONCLUSIONS

Taken together, results indicate a relationship between self and peer/parental attitudes about cannabis and use in youth at CHR for psychosis. These factors are important to consider within the legalization context given the changes in parental attitudes and a stronger association between use and attitudes in this group post-legalization.

Marijuana knowledge, confidence in knowledge, and information efficacy as the protective and risk factors of marijuana use among college students

Objective This study explored the relationships between marijuana knowledge, confidence in knowledge, and information efficacy and marijuana use. Furthermore, the effects of the knowledge-related variables were examined on intention to use, resistance efficacy, and intention to vote for legalization. Participants: Undergraduate students (N = 215) were surveyed in Fall 2018. Methods: Data were collected online and analyzed through a series of regression analyses. Results: Higher knowledge was related to less use via higher perceived risk whereas higher confidence in knowledge was related to more use. Marijuana use was related to higher future intention to use, lower resistance self-efficacy, and intention to vote for legalization. Information efficacy was related to intention to vote for legalization only. Conclusions: Students with more knowledge were less likely to use marijuana, whereas students who considered themselves well-informed were more likely to use it. Future intervention efforts will benefit from counteracting students' misplaced confidence in their knowledge.

Occipital neural dynamics in cannabis and alcohol use: independent effects of addiction

Alcohol and cannabis use disorder (AUD/CUD) are two of the most common addictive disorders. While studies are beginning to understand the neural changes related to acute and chronic use, few studies have examined the independent effects of AUD and CUD on neural oscillatory activity. We examined 45 adults who reported current use of both cannabis and alcohol. Participants underwent the SCID-V to determine whether they met criteria for AUD and/or CUD. Participants also completed a visual-spatial processing task while undergoing magnetoencephalography (MEG). ANCOVA with a 2 × 2 design was then used to identify the main effects of AUD and CUD on source-level oscillatory activity. Of the 45 adults, 17 met criteria for AUD, and 26 met criteria for CUD. All participants, including comparison groups, reported use of both cannabis and alcohol. Statistical analyses showed a main effect of AUD, such that participants with AUD displayed a blunted occipital alpha (8-16 Hz) response. Post-hoc testing showed this decreased alpha response was related to increased AUD symptoms, above and beyond amount of use. No effects of AUD or CUD were identified in visual theta or gamma activity. In conclusion, AUD was associated with reduced alpha responses and scaled with increasing severity, independent of CUD. These findings indicate that alpha oscillatory activity may play an integral part in networks affected by alcohol addiction.

Density of medical and recreational cannabis outlets: racial/ethnic differences in the associations with young adult intentions to use cannabis, e-cigarettes, and cannabis mixed with tobacco/nicotine

BACKGROUND

Differences in access to medical versus recreational cannabis outlets and their associations with intentions to use cannabis have not yet been examined among young adults. This study compares the associations between densities of medical versus recreational cannabis outlets and young adults' intentions to use cannabis, electronic cigarettes, and cannabis mixed with tobacco/nicotine products. Racial/ethnic differences in these associations were examined.

METHODS

Young adults ages 18-23 (mean age = 20.9) in Los Angeles County were surveyed online in 2018 after the legalization of recreational cannabis (n = 604). Multiple linear regressions were estimated for the entire sample and stratified by race/ethnicity. Outcomes were intentions to use cannabis, electronic cigarettes, and cannabis mixed with tobacco/nicotine in the next 6 months. Density was measured as the number of medical cannabis dispensaries (MCDs), recreational cannabis retailers (RCRs), and outlets of any type within 5 miles of respondents' homes.

RESULTS

Living near more outlets of any type was not significantly associated with intentions to use in the full sample, adjusting for individual- and neighborhood-level characteristics. However, race/ethnicity-stratified models indicated that living near more outlets of any type and more RCRs were significantly associated with stronger co-use intentions among white young adults. Higher MCD density was marginally associated with stronger co-use intentions among Asian young adults. However, higher MCD density was significantly associated with lower intentions to use e-cigarettes among Hispanic young adults.

CONCLUSIONS

The results suggest racial/ethnic differences in the impact of living near cannabis outlets on intentions to use. Prevention efforts targeting young adults who live near more cannabis outlets may be especially beneficial for white and Asian young adults.

Alcohol substitution during one month of cannabis abstinence among non-treatment seeking youth

OBJECTIVE

Cannabis and alcohol use are correlated behaviors among youth. It is not known whether discontinuation of cannabis use is associated with changes in alcohol use. This study assessed alcohol use in youth before, during, and after 4 weeks of paid cannabis abstinence.

METHODS

Healthy, non-treatment seeking, cannabis users (n = 160), aged 14-25 years, 84% of whom used alcohol in the last month, were enrolled for a 4-week study with a 2-4 week follow-up. Participants were randomly assigned to 4 weeks of either biochemically-verified cannabis abstinence achieved through a contingency management framework (CB-Abst) or monitoring with no abstinence requirement (CB-Mon). Participants were assessed at baseline and approximately 4, 6, 10, 17, 24, and 31 days after enrollment. A follow-up visit with no cannabis abstinence requirement for CB-Abst was conducted after 2-4 weeks.

RESULTS

Sixty percent of individuals assigned to the CB-Abst condition increased in frequency and quantity of alcohol consumption during the 4-week period of incentivized cannabis abstinence. As a whole, CB-Abst increased by a mean of 0.6 drinking days and 0.2 drinks per day in the initial week of abstinence (p's < 0.006). There was no evidence for further increases in drinking frequency or quantity during the 30-day abstinence period (p's > 0.53). There was no change in drinking frequency or quantity during the 4-week monitoring or follow-up periods among CB-Mon.

CONCLUSIONS

On average, 4 weeks of incentivized (i.e., paid) cannabis abstinence among non-treatment seeking youth was associated with increased frequency and amount of alcohol use in week 1 that was sustained over 4 weeks and resolved with resumption of cannabis use. However, there was notable variability in individual-level response, with 60% increasing in alcohol use and 23% actually decreasing in alcohol use during cannabis abstinence. Findings suggest that increased alcohol use during cannabis abstinence among youth merits further study to determine whether this behavior occurs among treatment seeking youth and its clinical significance.

Suicidal Behavior and Club Drugs in Young Adults

Psychoactive drugs play a significant role in suicidality when used for intentional overdose or, more frequently, when the intoxication leads to disinhibition and alterations in judgment, thereby making suicide more likely. In this study, we investigated suicidality prevalence among drug users and evaluated the differences in suicide ideation, taking into account the substance categories and the association of suicide ideation intensity with other psychiatric symptoms. Subjects admitted to the Can Misses Hospital's psychiatry ward in Ibiza were recruited during summer openings of local nightclubs for four consecutive years starting in 2015. The main inclusion criterium was an intake of psychoactive substances during the previous 24 h. The Columbia Suicide Severity Rating Scale (C-SSRS) was used to assess the suicide risk. Suicidality was present in 39% of the study cohort. Suicide Ideation Intensity overall and in the previous month was higher in users of opioids and in general of psychodepressors compared to psychostimulants or psychodysleptics. Suicidality was not correlated with alterations in any of the major psychopathological scales employed to assess the psychiatric background of the study subjects. The presence of high levels of suicidality did not specifically correlate with any major symptom indicative of previous or ongoing psychopathological alterations. These findings suggest that impulsivity and loss of self-control may be determinants of the increased suicidality irrespectively of any major ongoing psychiatric background.

Cannabis use among Norwegian university students: Gender differences, legalization support and use intentions, risk perceptions, and use disorder

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Past year cannabis use was fairly common in a sample of Norwegian college students.

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About 6% of users possibly met criteria for use disorder, function of use frequency.

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Legalization attitudes and risk perceptions were associated with cannabis use risk.

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Intentions to use cannabis if legal were evident even among some current non-users.

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Many non-users expressed uncertainty in legalization attitudes and risk perceptions.

Aims

We explored past-year cannabis use and associated characteristics, focusing on legalization attitudes, use intentions, risk perceptions, and possible dependence among Norwegian university/college students.

Methods

We examined a nation-wide sample of Norwegian university/college students (N = 49,688; 67% female) who participated in the Students’ Health and Wellbeing Study (SHoT-study) in 2018. Participants reported past-year substance use, support for cannabis legalization, intent to use cannabis if legal, and perceived risks of weekly use. Past-year cannabis use (including use frequency) was examined in relation to these indicators. Legalization support, use intentions, and risk perceptions were examined in relation to use and gender. Potential cannabis use disorder was assessed with the Cannabis Abuse Screening Test (CAST) and examined in relation to use frequency and gender.

Findings

Past-year use was reported by 15.3% (11.8% women; 22.9% men). Majority of current users (roughly 90%) used no more than 50 times past year, and 6% (3.8% women; 8.5% men) met CAST use disorder criteria. Legalization support, use intentions, and no/low risk perceptions were significantly associated with greater odds of use, and greater use frequency among current users in both crude and adjusted models. Legalization support (23.0%), use intentions (14.0%), and perceptions of no/low risk (29.2%) were also relatively common even among current non-users, especially men. Male gender and more frequent use were associated with greater CAST scores and greater odds of use disorder.

Conclusions

Cannabis use was relatively common in this student sample. In addition to targeting frequent use, interventions may focus on cannabis-related attitudes and risk perceptions among uncertain/uninformed students.

Effects of cannabis on visual function and self-perceived visual quality

Cannabis is one of the most used drugs of abuse in the world. The objective of this study was to analyze the effects of smoking cannabis on vision and to relate these to those perceived by the user. Thirty-one cannabis users participated in this study. Visual function assessment was carried out in a baseline session as well as after smoking cannabis. We evaluated static visual acuity, contrast sensitivity, stereoacuity, accommodative response, straylight, night-vision disturbances (halos) and pupil size. The participants were also divided into two groups depending on whether they perceived their vision to have worsened after smoking cannabis. A logistic regression analysis was employed to identify which visual test could best predict self-perceived visual effects. The study found that smoking cannabis has significant adverse effects on all the visual parameters analyzed (p < 0.05). Self-perceived visual quality results revealed that about two thirds of the sample think that smoking cannabis impairs their vision. Contrast sensitivity, specifically for the spatial frequency 18 cpd, was identified as the only visual parameter significantly associated with self-perceived visual quality (Odds Ratio: 1.135; p = 0.040). Smoking cannabis is associated with negative effects on visual function. Self-perceived visual quality after smoking cannabis could be related to impaired contrast sensitivity.

Implications of Medical and Recreational Marijuana Laws for Neuroscience Research: a Review

Purpose of Review

Review of US medical and recreational marijuana laws (MML and RML), their effects on cannabis potency, prevalence of non-medical cannabis use and cannabis use disorder (CUD) in adolescents and adults, and implications for neuroscience research, given what is known about the relationship of cannabis to neurocognitive impairments and underlying brain functioning.

Recent Findings

Cannabis potency may be increasing faster in states with MML or RML than in other states. MML and RML have not impacted prevalence in adolescents but have consistently been shown to increase rates of adult non-medical use and CUD.

Summary

Recent neurocognitive or neuroimaging studies may be more impacted by cannabis than studies conducted when MML and RML were less common. Neurocognitive or neuroimaging studies conducted in MML or RML states should carefully test potential participants for recent cannabis use. More research is needed on cannabis and cognition in medical marijuana patients.

The Influence of Co-Occurring Substance Use on the Effectiveness of Opiate Treatment Programs According to Intervention Type

This systematic review describes the influence of co-occurring substance use on the effectiveness of opiate treatment programs. MEDLINE/PubMed, Embase, PsychINFO, and the Cumulative Index to Nursing and Allied Health Literature were searched from database inception to November 28, 2018, to identify eligible opioid treatment studies in the United States that assessed the relationship between co-occurring substance use and treatment outcome (i.e., opioid abstinence and treatment retention). A total of 34 eligible studies were included. Overall, co-occurring substance use was associated with negative treatment outcomes regardless of intervention type. However, patterns varied by substance and intervention type. In particular, co-occurring use of cocaine or marijuana with opioids was associated with reduced treatment retention and opioid abstinence regardless of intervention type. Co-occurring use of amphetamines, compared with no use or reduced use of amphetamines, decreased treatment retention. Co-occurring use of alcohol was both positively and negatively associated with treatment outcomes. One study reported a significant positive association between sedative use and opioid abstinence. Generally, findings suggest that combined interventions reported better health outcomes compared with pharmacological or behavioral intervention studies alone. The findings of this review emphasize the need to comprehensively study and address co-occurring substance use to improve opiate treatment programs.

How many more young Australians say that they would use cannabis if it were legal?

INTRODUCTION AND AIMS

The potential for increased cannabis use by young people after legalisation remains a key concern of opponents of legalisation. This study used survey data to estimate how many young Australians may be prepared to use cannabis if it became legally available.

DESIGN AND METHODS

The study included 3052 youths (adolescents aged 12-17 and young adults aged 18-25 years) in Australia who participated in the 2016 National Drug Strategy Household Survey. Incident cases were estimated by multiplying the prevalence and estimated population sizes from the Australian Bureau of Statistics.

RESULTS

It was estimated that 17% of adolescents would try (13%) or use (4%), and 32% of young adults would try (15%) or use (17%) cannabis if it were legal. Among those who reported an intention to try it, 85% of adolescents and 59% of young adults had never used cannabis. These translate to 199 000 and 238 000 potential initiators, respectively. Among those with an intention to use cannabis, 21% of adolescents and 3% of young adults had never used cannabis. These translate to 14 000 adolescents and 12 000 young adults who intended to use cannabis if it were legal.

DISCUSSION AND CONCLUSIONS

A substantial minority of young Australians say that they would use cannabis for the first time if it were legalised. A proportion of young people who have used cannabis also expressed an interest in increasing their use. Both would warrant special attention if cannabis were legalised.

Adolescent treatment admissions for marijuana following recreational legalization in Colorado and Washington

INTRODUCTION

There is concern that recreational marijuana legalization (RML) may lead to increased cannabis use disorder (CUD) among youth due to increased marijuana use. This study investigates whether adolescent substance use disorder treatment admissions for marijuana use increased in Colorado and Washington following RML.

METHODS

Annual data on 2008-2017 treatment admissions for marijuana use from the SAMHSA TEDS-A dataset for adolescents age 12-17 were used to model state treatment admissions trends. Difference-in-differences models were used to investigate whether treatment admissions increased following RML in Colorado/Washington compared to non-RML states, after adjusting for socioeconomic characteristics and treatment availability.

RESULTS

Over all states in the analysis, the rate of adolescent treatment admissions for marijuana use declined significantly over the study period (β=-3.375, 95 % CI=-4.842, -1.907), with the mean rate falling nearly in half. The decline in admissions rate was greater in Colorado and Washington compared to non-RML states following RML, though this difference was not significant (β=-7.671, 95 % CI=-38.798, 23.456).

CONCLUSION

Adolescent treatment admissions for marijuana use did not increase in Colorado and Washington following RML. This may be because youth marijuana use did not increase, CUD did not increase (even if use did increase), or treatment seeking behaviors changed due to shifts in attitudes and perceptions of risk towards marijuana use.

Trends of poly-substance use among Canadian youth

INTRODUCTION

Poly-substance use, increasingly understood as a behaviour with uniquely adverse consequences, is on the rise among Canadian youth. High levels of e-cigarette vaping and the recent legalization of recreational cannabis use may result in an acceleration of this trend. The aim of this work was to characterise changes in youth poly-substance use over time, generate baseline data for future investigations, and highlight areas of interest for policy action.

METHODS

Descriptive statistics and regression models explored patterns and trends in concurrent use of multiple substances (alcohol, cigarettes, cannabis, and e-cigarettes) among Canadian high school students taking part in the COMPASS prospective cohort study during Y2 (2013/2014; n = 45,298), Y3 (2014/2015, n = 42,355), Y4 (2015/2016; n = 40,436), Y5 (2016/2017; n = 37,060), and Y6 (2017/2018; n = 34,879).

RESULTS

Poly-substance use increased significantly over time, with over 50% of students who used substance reporting past-year use of multiple substances by 2017/2018. Male and Indigenous students were significantly more likely to report poly-substance use than female and white students respectively. E-cigarette vaping doubled from Y5 to Y6 and was included in all increasingly prevalent substance use combinations.

CONCLUSIONS

Youth poly-substance use, rising since 2012/2013, saw a particularly steep increase after 2016/2017. Differential effects were observed for distinct demographic subpopulations, indicating tailored interventions may be required. E-cigarette vaping surged in parallel with the observed increase, suggesting a key role for this behaviour in shaping youth poly-substance use.

Cessation of cannabis use: A retrospective cohort study

Given recent findings of a worldwide increase in cannabis use, a better understanding of the factors associated with cannabis use is needed. Most previous studies have focused on factors that predict the initiation of cannabis use, but less is known about factors associated with cessation. The present study is a retrospective cohort study of 6467 current or former cannabis users aged 15 to 46 years (mean age 22.5, SD = 4.8). Data were collected via an online survey advertised in social media. All analyzed participants had used cannabis for at least three years. Approximately 16.3% (n = 1055) of the sample population had not used cannabis in the previous 12 months and were classified as quitters; all others (83.7%, n = 5412) reported at least monthly use. Cessation was predicted by older current age, being female, nonmigrant status, less sensation seeking, using psychological treatment, more peer cannabis use during youth and more negative first experience with cannabis. An additional predictor was a nonincrease in the frequency of cannabis use in the first three years of use, indicating that trajectories of cannabis use are set early on and might be used to identify risk groups for early preventive measures.

Cannabis Prevalence and National Drug Policy in 27 Countries: An Analysis of Adolescent Substance Use

Prior research that assesses the relationship between cannabis policy and prevalence rates has yielded mixed results, perhaps due to the varying rigor of these investigations. Addressing some of these issues in rigor and informed by a rational choice theory (RCT), we hypothesize that those policies on the more punitive end of McDonald and colleagues' classification will be most effective. Examining legislation in 27 countries utilizing the Second International Self-Report Delinquency Study (ISRD-2) through hierarchical linear modeling (HLM) models with both individual- and country-level controls, we find little support for these hypotheses. Instead, results from our analysis largely indicate that the variation in country prevalence rates from 2005 to 2007 was not significantly related to cannabis control policy. We comment on possible policy implications for these preliminary results.

Association of Marijuana, Mental Health, and Tobacco in Colorado

OBJECTIVES

Marijuana's evolving legality may change marijuana use patterns in adults. Co-use of marijuana and tobacco are strongly associated, and populations with mental health disorders are disproportionately likely to use either substance, but neither association has been assessed in the context of legal recreational marijuana. We assessed the associations of tobacco smoking with marijuana use and with mental health disorders in Colorado in 2015.

METHODS

Data came from a population-based survey of adults (n = 8023). Multiple logistic regressions were used with current tobacco smoking as the primary outcome. Past 30-day marijuana use and mental health status were the independent variables of interest. Covariates included age, sex, ethnicity, poverty level, and education.

RESULTS

Adults who used marijuana in the past 30 days had 3.4 (95% confidence interval [CI] 2.7, 4.2) greater odds of currently smoking tobacco compared to adults who had not recently used marijuana, after adjusting for sociodemographic and economic factors. A mental health disorder was independently associated with tobacco smoking (adjusted odds ratio [OR] 1.7, 95% CI 1.4, 2.1). Prevalence of co-use among adults self-reporting a mental health disorder was significantly higher compared those without a mental health disorder (11.1% vs 4.3%; P < 0.0001).

CONCLUSIONS

This study examined the associations between mental health, marijuana use, and tobacco smoking after the legalization of recreational marijuana in Colorado. Adults using marijuana and/or self-reporting a mental health disorder were more likely to smoke tobacco and should be targeted for cessation interventions.

Prelegalisation patterns and trends of cannabis use among Canadian youth: results from the COMPASS prospective cohort study

OBJECTIVE

Canada federally legalised recreational cannabis use among adults in October 2018. The impact this will have on Canadian youth is cause for concern. The current study examined changes in youth cannabis use over the time prior to legalisation to explore the impact of the beginning federal discourse around legalisation during the 2016/2017 school year.

DESIGN

COMPASS, a prospective cohort study based on annual self-administered questionnaires.

SETTING

Ontario and Alberta during the first 6 years of the COMPASS study (2012/2013 to 2017/2018).

PARTICIPANTS

Canadian grade 9-12 students attending secondary schools participating in COMPASS. In total, 2 30 404 questionnaires were included in the analysis (Y1: 2012/2013, n=24 173; Y2: 2013/2014, n=45 298; Y3: 2014/2015, n=42 355, Y4: 2015/2016, n=40 436; Y5: 2016/2017, n=37 060; Y6: 2017/2018, n=34 897).

PRIMARY AND SECONDARY OUTCOME MEASURES

Lifetime cannabis use, past-year cannabis use, weekly cannabis use, ease of access to cannabis and age at first cannabis use.

RESULTS

Cannabis never-use decreased between Y5 and Y6. Changes in age at first cannabis use mirrored this trend, with male students consistently starting younger. Cannabis access rates increased from Y4, mainly led by female students. Lifetime and past-year use rates were lowest in Y4 then increased in Y5 and Y6 due to a rise in the occasional use more common among female students, who reported use increases first. Non-white students were more likely use cannabis, with black and Aboriginal students the only two groups consistently reporting more weekly than occasional use, though with opposing trajectories. Overall, Aboriginal students had the highest odds of reporting lifetime, past-year and weekly use among the demographic groups examined.

CONCLUSION

After a steady decrease in patterns of cannabis among youth over several years, it appears that there has been a gradual increase in cannabis use among youth following the start of discourse around cannabis legalisation, with some populations of youth being at greater risk.

Factors associated with cannabis use change in youth: Evidence from the COMPASS study

INTRODUCTION

Harmful effects of cannabis use in youth scale with frequency. In the context of approaching legalization in Canada, understanding the distinctions between youth who change and who maintain their cannabis use is essential for designing interventions and policy. A substantial number of characteristics may play a role. This study assessed whether and how youth who change their cannabis use differ from those who do not.

METHODS

Cannabis use was reported by 8375 Canadian high school students participating in the COMPASS study. GEE multiple logistic regressions were then used to establish impact of 13 baseline demographic and behavioural exposure variables on the likelihood of membership in four frequency change groups at follow-up a year later: reduction, cessation, escalation, and maintenance.

RESULTS

Groups were found to differ in several ways. Cessation group members (19.4% of users) were less likely to binge drink (OR 0.82), vape (OR 0.82), or attend class without completing homework (OR 0.72) than maintainers. Students who reduced their use (14.6% of users) were more likely to binge drink (OR 1.36), smoke (OR 1.20), and skip class (OR 1.21). Those who escalated (29.5% of users) were more likely to be male (OR 1.35) and to vape (OR 1.22).

CONCLUSIONS

Students who change their cannabis use differ in several demographic and behavioural characteristics. The results raise further concerns about the impact of e-cigarettes and the role of poly-substance use in high-risk trajectories. Distinct classes of cannabis users, essential for policy and intervention development, can be identified in high school populations.

Associations between state-level policy liberalism, cannabis use, and cannabis use disorder from 2004 to 2012: Looking beyond medical cannabis law status

BACKGROUND

Medical cannabis laws (MCL) have received increased attention as potential drivers of cannabis use (CU), but little work has explored how the broader policy climate, independent of MCL, may impact CU outcomes. We explored the association between state-level policy liberalism and past-year cannabis use (CU) and cannabis use disorder (CUD).

METHODS

We obtained state-level prevalence of past-year CU and CUD among past year cannabis users for ages 12-17, 18-25, and 26+ from the 2004-2006 and 2010-2012 National Surveys on Drug Use and Health. States were categorized as liberal, moderate, or conservative based on state-level policy liberalism rankings in 2005 and 2011. Linear models with random state effects examined the association between policy liberalism and past-year CU and CUD, adjusting for state-level social and economic covariates and medical cannabis laws.

RESULTS

In adjusted models, liberal states had higher average past-year CU than conservative states for ages 12-17 (+1.58 percentage points; p = 0.03) and 18-25 (+2.96 percentage points; p = 0.01) but not for 26+ (p = 0.19). CUD prevalence among past year users was significantly lower in liberal compared to conservative states for ages 12-17 (-2.87 percentage points; p = 0.045) and marginally lower for ages 26+ (-2.45 percentage points; p = 0.05).

CONCLUSION

Liberal states had higher past-year CU, but lower CUD prevalence among users, compared to conservative states. Researchers and policy makers should consider how the broader policy environment, independent of MCL, may contribute to CU outcomes.

ADOLESCENTS´ PERCEPTION OF HARMS, BENEFITS AND INTENTION TO USE MARIJUANA WITHIN THE CONTEXT OF REGULATORY CHANGES IN BELIZE

ABSTRACT Objective: to evaluate the perception of harm and benefits from using marijuana in adolescents’, to determine lifetime, past year and past month prevalence of marijuana use; and to analyze the relationship between marijuana use and the perception of harm and benefits from using marijuana. Methods: multi-centric, quantitative cross sectional survey design method was utilized for this research. Data was collected using structured standardized approved questionnaire. A total of 273 students from three high schools in two cities of the country of Belize participated in the survey conducted in 2015. Results: lifetime prevalence of marijuana use of 41.4% (39.2% past year, 24.9% past 30 days), and average age of onset of 12 years. First time prevalence of marijuana use among students by sex indicated 53.1% male students used marijuana as compared to 46.9% female students with no significant (p>0.05) statistical difference seen between genders. Participants reported that their friends use marijuana (45.1%); while 68.1% of the marijuana users had some friends that use marijuana. 51% of the students surveyed stated that they would not use marijuana, even if it were legally available. The majority (70%) perceived no risk to using marijuana occasionally. Statistical analysis revealed that a high perception of benefits, a low risk perception and friends’ use of marijuana was associated with individual use as well as intention to use in a hypothetical context of regulatory changes. Conclusion: the Belizean school-aged adolescents are more than likely to smoke marijuana because of friends’ influence, low perception of risks and if marijuana is legally available and accessible to them.

Heterogeneous Patterns of Marijuana Use Motives Using Latent Profile Analysis

Background: Given that marijuana use is often associated with detrimental physical and mental health problems, research examining motives for its use is critical for effective remedial and preventive treatment. To date, the majority of research on marijuana use motives has used variable-centered analyses, which overlooks potentially meaningful heterogeneous response patterns and the associations of those patterns with other risk/protective factors. Methods: To address this gap, in the current study, we conducted a person-centered analysis (latent profile analysis) to identify subgroups of participants based on endorsed marijuana use motives, and examined the construct validity of the optimal class solution (covariates included sociodemographic (e.g., age), psychiatric (e.g., depression), and marijuana-use indices (e.g., use-frequency, use-related problems). Participants were 898 college students (M_age = 20.93, SD_age = 3.10; 68.9% female) who completed an anonymous online survey examining substance use and psychological well-being, were 18 years or older, and endorsed lifetime marijuana use. Data were collected November 2016 through February 2018. Results: Results identified four unique classes of coping, conformity, social, and enhancement marijuana use motives: (a) "Low Motives" (37.6%), (b) "High Conformity" (4.9%), (c) "Low Conformity" (45.8%), and (d) "High Motives" (11.7%). In terms of covariates, higher motive classes tended to report more frequent and problematic use. The two classes uniquely characterized by conformity motives only differed on past-month marijuana use frequency. Conclusions/Importance: The current findings provide evidence that specific classes of motives were not only associated with marijuana use frequency and problems but other risk and protective factors, such as anxiety sensitivity and social support.

PERCEPTION OF DAMAGE AND BENEFITS ASSOCIATED TO THE USE OF MARIJUANA IN ADOLESCENTS, VIÑA DEL MAR, CHILE

ABSTRACT Objective: analyze the perception of harm and benefits, and its association with the use of marijuana in high school students, as well as the intention to use it in a context of regulatory changes. Method: a quantitative, exploratory, cross-sectional study was designed, applying a self-administered questionnaire to 268 high school students. Results: The results showed that the declared consumption in the sample is higher than that obtained in previous studies in Chile, which had already warned of the increase in prevalence, compared to previous measurements. There is a low perception of risk associated with consumption and insecurity regarding benefits. In the framework of regulatory changes, no change was observed in the intention of use. Adolescent consumers would continue to do so as before, while those who have not consumed it, 25% would try it, and 60% would still not use it. Conclusions: The current discussion in the country has focused on the effect that the change in the law would have, by itself, on adolescent consumption, however, it is relevant to direct efforts towards the perceptions of risk and benefits that they have, in order to stop the observed increasing in consumption in the country, in the latest studies.

PERCEPTION OF HARM AND BENEFITS OF MARIJUANA AND ITS RELATIONSHIP WITH THE INTENTION OF USE AND CONSUMPTION IN COLOMBIAN ADOLESCENTS

ABSTRACT Objective: analyze the relationship between the perception of harm and benefits associated with the use of marijuana and its relation to real consumption, as well as the intention to use it in a context of regulatory changes, in young students, between 15 and 17 years old, of a public school in Bogota Colombia. Method: a quantitative, cross-sectional survey was carried out. 268 students in grade 9th to 11th from a public school in the city of Bogotá, Colombia participated of the study. Results: results reveled that there is an association between the perception of benefits and the consumption of marijuana. In addition, how a low perception of risk is associated with an intention to use in a context of legalization. Conclusion: this is one of the first studies in Colombia which explores the intention to use (at age 18) in a context of regulatory changes, as well as the attitude of young people towards the legalization of marijuana for medicinal and recreational use.

A Systematic Review of the Efficacy of Cannabinoid Agonist Replacement Therapy for Cannabis Withdrawal Symptoms

BACKGROUND

About 30% of regular cannabis users report withdrawal symptoms on cessation of prolonged use, such as irritability, insomnia, decreased appetite, depressed mood, anxiety, and restlessness. However, among highly dependent and/or in-treatment users, the incidence of withdrawal can be even higher, reaching up to 50-95% of individuals. This syndrome was only recognized by the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) as a diagnosis with specific criteria in 2013. The treatment options are poor, with high rates of relapse and non-responders. In this scenario, agonist replacement therapy with cannabinoids has demonstrated potential as a promising therapeutic intervention, with a series of studies having been carried out in recent years.

OBJECTIVE

This review sought to summarize trials with cannabinoid agonist replacement therapy for cannabis withdrawal symptoms with the aim of evaluating the efficacy of this pharmacological intervention.

DATA SOURCES

We entered the following search terms on the PubMed, Web of Science and PsycINFO databases: (marijuana OR marihuana OR cannabis OR THC OR tetrahydrocannabinol OR hashish OR pot) AND (treatment OR medication) AND (withdrawal OR abstinence) AND (dronabinol OR nabilone OR nabiximols OR sativex OR cesamet OR synthetic cannabinoid). The date of the most recent search was September 2017.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

Original trials, published in English, performed on humans and dealing with cannabis users who were treated for cannabis withdrawal symptoms using synthetic cannabinoids were all included in the present systematic review. Quality and risk of bias across studies were assessed using a Cochrane tool.

STUDY APPRAISAL AND SYNTHESIS METHODS

The first, second, and last authors read the abstracts of all studies found in the search (n = 243). The inclusion and exclusion criteria were applied, and 233 articles were excluded. The first and second authors independently developed a data extraction sheet based on the included articles.

RESULTS

The present review included ten original articles. Despite the limited number of studies and methodological differences, our findings demonstrate that the use of dronabinol, nabilone, or nabiximols, either alone or in combination with other drugs, shows promise in reducing cannabis withdrawal symptoms, probably with a dose-dependent effect. This has also been considered a safe group of medications with good tolerability and few adverse effects.

LIMITATIONS

No method of handling data and combining results of studies was carried out, representing a limitation of the review.

CONCLUSIONS AND IMPLICATION OF THE KEY FINDINGS

Cannabinoids appear to be a promising group of drugs for the treatment of cannabis withdrawal symptoms. These medications may help decrease the rate of relapse in the treatment of cannabis dependence due to withdrawal symptoms occurring within the first few weeks of treatment.

SYSTEMATIC REVIEW REGISTRATION

The protocol for this review has been registered in the PROSPERO International prospective register of systematic reviews (PROSPERO 2014:CRD42014014118).

The Impact of Recreational Marijuana Legislation in Washington, DC on Marijuana Use Cognitions

BACKGROUND

There is little published research that tests the effect of recreational marijuana legislation on risk-related cognitions and how individuals respond immediately after legislative approval.

OBJECTIVES

The objective was to test whether learning about the passage of Initiative 71, a voter referendum that legalized recreational use of marijuana in the District of Columbia, would lead individuals to adopt more favorable marijuana cognitions than they had before the Initiative was passed.

METHODS

Undergraduate students (N = 402) completed two web-based questionnaires in 2014. The first questionnaire was completed prior to the referendum vote and the follow-up questionnaire was completed after voters approved Initiative 71. Attitudes, perceived norms, intentions, prototypes, and willingness were measured at time 1 and time 2. Study hypotheses were tested using repeated-measures analysis of covariance.

RESULTS

Results showed that attitudes, intentions, perceived norms, and willingness to use marijuana were more favorable after Initiative 71 was passed. However, the increase in attitudes and willingness was moderated by past experience with marijuana whereby the increases were statistically significant only among those with the least experience. The increase in perceived norms was also moderated by past experience whereby increases were statistically significant among those who were moderate or heavy users. The passage of Initiative 71 had no effect on favorable prototypes. Conclusion/Importance: Legalization may have the unintended outcome of leading to more favorable intentions to use marijuana and might lead abstainers or experimental users to become more frequent users of marijuana via more positive attitudes and willingness towards marijuana use.

Contemporary Patterns of Marijuana Use and Attitudes Among High School Seniors: 2010-2016

PURPOSE

The goal of this study was to examine changes in contemporary patterns of marijuana use and attitudes over time. Given shifts in state-by-state marijuana legislation, there is a reason to believe that the patterns of high school seniors' marijuana use behavior and attitudes about use have changed from 2010 to 2016.

METHODS

Data are from high school seniors in the 2010-2016 waves of Monitoring the Future, a nationally representative, cross-sectional survey in the United States. Latent class analysis was used to determine underlying patterns of marijuana use and related attitudes. Differences in latent class membership were examined across years, and gender and race/ethnicity were also examined.

RESULTS

Five latent classes were identified: Intolerant Nonusers (49% of the sample), Tolerant Nonusers (12%), Disapproving Users (7%), Experimenters (6%), and Marijuana Enthusiasts (26%). Class prevalences remained relatively stable from 2010 to 2013; beginning in 2014 a significant decrease in prevalence was observed for Intolerant Nonusers and significant increases in prevalence were observed for Tolerant Nonusers and Marijuana Enthusiasts. Membership in the Marijuana Enthusiasts class was consistently more likely for males; Hispanic and black adolescents were more likely to be Disapproving Users.

CONCLUSIONS

Contemporary patterns of marijuana use and attitudes have remained consistent over time, however, significant shifts in class prevalence emerged in 2014. Findings also suggest that a substantial subgroup of adolescents would benefit from prevention and intervention efforts targeting marijuana use and attitudes.

Simultaneous Alcohol and Marijuana Use Among Young Adult Drinkers: Age-Specific Changes in Prevalence from 1977 to 2016

BACKGROUND

The overall prevalence of U.S. young adult alcohol use has decreased, but little is known about historical change in related behaviors such as simultaneous alcohol and marijuana (SAM) use that may increase alcohol-related risks and societal costs. The purpose of this paper was to examine historical change in SAM use prevalence among U.S. young adult alcohol users from 1977 to 2016, and consider the extent to which observed historical change in SAM use among alcohol users reflects co-occurring change in marijuana use during these years.

METHODS

Data on past 12-month alcohol, marijuana, and SAM use at up to 6 modal ages (19/20, 21/22, 23/24, 25/26, 27/28, and 29/30) were collected from 11,789 individuals (45.0% men) participating in the Monitoring the Future panel study. Annual prevalence estimates within modal age group were obtained; historical SAM use trends among alcohol and marijuana users were estimated.

RESULTS

From 2014 to 2016, SAM use was reported by approximately 30% of alcohol users aged 19/20 and 21/22, and 20 to 25% of alcohol users aged 23/24 through 29/30. Since the mid-1990s, age-specific historical trends in SAM use prevalence among alcohol users followed 1 of 4 patterns: significant increase followed by oscillating increases/decreases (at modal age 19/20), consistent and significant increases (at modal ages 21/22, 23/24, and 25/26), stability followed by increase (at modal ages 27/28), or stability (at modal ages 29/30). In contrast, SAM use trends among marijuana users primarily reflected stability, with some evidence of a decrease across time at modal ages 19/20 and 23/24. Historical change in SAM prevalence among alcohol users was strongly and positively correlated with changes in overall marijuana use prevalence.

CONCLUSIONS

A growing proportion of early and mid-young adult alcohol users reported SAM use, with the highest risk among those in the early years of young adulthood. Young adult SAM use may continue to increase in proportion to the degree that young adult marijuana use continues to increase.

Contrast sensitivity and motion discrimination in cannabis users

RATIONALE

Cannabis use impairs visual attention; however, it is unclear whether cannabis use also impairs low level visual processing or whether low level visual deficits can be related to lower dopaminergic functioning found in cannabis users.

OBJECTIVES

To investigate whether spatiotemporal contrast sensitivity and motion discrimination under normal and low luminance conditions differ in cannabis users and non-users.

METHODS

Control (n = 20) and cannabis (n = 21) participants completed a visual acuity test, a saliva test and self-report measures. Spatial and temporal contrast thresholds, motion coherence thresholds for translational and radial motion and the spontaneous eye blink rate were then collected.

RESULTS

Cannabis users showed decreased spatial contrast sensitivity under low luminance conditions and increased motion coherence thresholds under all luminance levels tested compared to non-users. No differences in temporal contrast sensitivity were found between the groups. Frequency of cannabis use correlated significantly and negatively with contrast sensitivity, both spatial and temporal, in the cannabis group and higher motion coherence thresholds for radial motion were also associated with more frequent cannabis use in this group. The eye blink rate was significantly lower in cannabis users compared to non-users.

CONCLUSIONS

The present study shows that cannabis use is associated with deficits in low level visual processing. Such deficits are suggested to relate to lower dopamine, in a similar manner as in clinical populations. The implications for driving safety under reduced visibility (e.g. night) in abstaining cannabis users are discussed.

Reefer madness or much ado about nothing? Cannabis legalization outcomes among young adults in the United States

In 2012, Colorado became one of the first two U.S. States to legalize cannabis for recreational use for adults 21 and older. Given that cannabis use holds potential physical and mental health risks, particularly among adolescent users, concerns have grown regarding changes in use following this change in policy. Studies examining medical cannabis legalization have found inconsistent changes in cannabis use and prevalence of dependence following medical implementation. However, recreational legalization holds potential unique changes, such as increased availability and social acceptance, as well as decreased price and perceived harm of use. There also may be increased interest in moving to Colorado related to the changes in cannabis laws. Based on past literature, two hypotheses were made for this study. First, college student cannabis use would increase after recreational legalization, however just for those 21 years old and older. Second, there would be a positive relation between the influence of cannabis legislation on out-of-State student's decision to attend a Colorado university and their cannabis use. Data from 5241 undergraduate students was available to test study hypotheses using Pearson's Chi-square, negative binomial regressions, and path analysis. Results indicated that cannabis use increased since recreational legalization for all students, but more so for those over 21 years. No differences in past month use frequency were found between pre- and post-legalization. Influence of cannabis laws on non-resident student's decision to attend a Colorado college predicted lifetime and past 30-day use. Additionally, out-of-State students reported higher past 30-day use than in-State students. These findings may help inform other States considering recreational legalization of potential outcomes, as well as potential interventions.

A Qualitative Investigation Comparing Psychosocial and Physical Sexual Experiences Related to Alcohol and Marijuana Use among Adults

Alcohol and marijuana are two of the most prevalent psychoactive substances and each may result in distinct psychosocial and physical sexual experiences and different sexual risk behaviors. With marijuana becoming more accepted in the US along with more liberal state-level policies, it is important to examine and compare users' psychosocial and physical sexual experiences and sexual risk behavior associated with these drugs. In this study, we interviewed 24 adults who recently used marijuana before sex. Participants were 50 % female and all self-identified as heterosexual and HIV-negative. Using thematic analysis, we compared self-reported psychosocial and physical sexual experiences of alcohol and marijuana. Participants described differences between drugs with regard to psychosocial (e.g., partner interactions and contexts before sex, partner choice, perceived attractiveness of self and others, disinhibition, and feelings of regret after sex) and physical sexual experiences (e.g., sexual dysfunction, dose effects, sensations of body/sex organs, length and intensity of sex, and orgasm). Alcohol use was commonly associated with social outgoingness and use facilitated connections with potential sexual partners; however, alcohol was more likely than marijuana to lead to atypical partner choice or post-sex regret. Both alcohol and marijuana had a variety of negative sexual effects, and the illegality of marijuana reportedly facilitated intimate encounters. While sexual experiences tended to be similar across males and females, we did find some variation by gender. Results can inform prevention and harm reduction programming that will allow us to design more realistic programs and to craft interventions, which guide potential users to make safer choices.

Trajectories of cannabis-related associative memory among vulnerable adolescents: Psychometric and longitudinal evaluations

Indirect tests of memory associations relevant to cannabis have been shown to be useful in explaining and predicting adolescent cannabis use habits. This study sought to increase the understanding of adolescent cannabis-related associative memory and cannabis use behavior over time. A longitudinal sample of alternative high school students (N = 775) was assessed yearly for 3 years. The study first conducted extensive longitudinal measurement analyses of the cannabis-related word association test (WAT) applying contemporary psychometric models. Second, the study examined the longitudinal trajectories of cannabis-related associative memory and cannabis use and their contemporaneous and longitudinal relationships. Results showed that the cannabis-related WAT provided strong evidence of sound psychometric properties. Longitudinal change in cannabis-related associative memory was best described by modeling either a linearly decreasing trajectory or two separate trajectories: During middle adolescence, levels of cannabis-related associative memory were highest and stable but then gradually decreased toward late adolescence. Moreover, cannabis-related associative memory was contemporaneously predictive of cannabis use within ages 15 to 19 while controlling for the underlying growth process of cannabis use and time-invariant covariates (TICs) of gender and lifetime concurrent use of alcohol and cigarettes. Partial support of longitudinal prediction of cannabis use was also obtained from age 17 to 18 and age 19 to 20 while adjusting for growth in cannabis use and the TICs. These results demonstrated that predictive effects of cannabis-related memory associations on cannabis use were detected within some of the 1-year age spans and were consistent within ages across adolescent years. (PsycINFO Database Record

Pregnant Women's Current and Intended Cannabis Use in Relation to Their Views Toward Legalization and Knowledge of Potential Harm

OBJECTIVES

The objective of this study was to investigate pregnant women's current use of cannabis and their intended patterns of use with relation to their views on the legalization of cannabis and their knowledge of potential harms.

METHODS

A voluntary, anonymous survey regarding patterns of use of cannabis and views on legalization was distributed to a convenience sample of pregnant women presenting for prenatal care at an outpatient university clinic. Chi-square and Fischer's exact tests were used for analysis using STATA.

RESULTS

Of 306 surveys returned, 35% of women reported currently using cannabis at the time of diagnosis of pregnancy and 34% of those women continued to use. Seventy percent of respondents endorsed the belief that cannabis could be harmful to a pregnancy. Fifty-nine percent of respondents believed that cannabis should be legalized in some form and 10% reported that they would use cannabis more during pregnancy if it were legalized. Those who continued to use cannabis during pregnancy were less likely than those who quit to believe that cannabis use could be harmful during pregnancy (26% vs 75%, P < 0.001). The most common motivation for quitting cannabis use in pregnancy was to avoid being a bad example (74%); in comparison, only 27% of respondents listed a doctor's recommendation as a motivation to quit.

CONCLUSIONS

Cannabis use during pregnancy is relatively common and persistent, despite knowledge of the potential risks of harm. Views toward legalization vary among pregnant women and may impact cannabis use during pregnancy. In a changing legal climate, there is a need for clear messaging on the effects of cannabis use during pregnancy.

Marijuana use among youths in Mississippi, United States

Background Increased use of marijuana among youths in Mississippi, United States is of great concern to Public Health in the 21st century. This study examined the prevalence of marijuana use according to gender, race and ethnicity. Method The data for this study was obtained from Youth Risk Behavior Surveillance System (YRBSS) for 2015, a cross-sectional survey of the Mississippi High School Students, which examined the prevalence and trends in the use of marijuana according to gender, race and ethnicity. The trends in the percentage of students that reported the use of marijuana and its product was examined by univariate t-test statistical analysis at p < 0.05. The frequency distribution was used to determine the percentage differences in the groups. Results The students that ever used marijuana was 39.4% in Blacks, 39.1% in Hispanics and 31.0% in Whites. A total of 13.7% male and female (4.8%) used marijuana before 13 years of age. In addition, the students currently using marijuana include Blacks (10.9%), Hispanic (13.7%) and Whites (7.2%). Approximately 9.7% of students ever used the synthetic product, which was higher in Hispanic (18.7%) when compared to Blacks (8.8%) and Whites (9.1%). Conclusion The use of marijuana is significantly higher among the male youth in Mississippi than females, which is a major public health concern. Furthermore, there was higher rates of smoking marijuana in Hispanics and Blacks when compared to White youth.

US Epidemiology of Cannabis Use and Associated Problems

This review provides an overview of the changing US epidemiology of cannabis use and associated problems. Adults and adolescents increasingly view cannabis as harmless, and some can use cannabis without harm. However, potential problems include harms from prenatal exposure and unintentional childhood exposure; decline in educational or occupational functioning after early adolescent use, and in adulthood, impaired driving and vehicle crashes; cannabis use disorders (CUD), cannabis withdrawal, and psychiatric comorbidity. Evidence suggests national increases in cannabis potency, prenatal and unintentional childhood exposure; and in adults, increased use, CUD, cannabis-related emergency room visits, and fatal vehicle crashes. Twenty-nine states have medical marijuana laws (MMLs) and of these, 8 have recreational marijuana laws (RMLs). Many studies indicate that MMLs or their specific provisions did not increase adolescent cannabis use. However, the more limited literature suggests that MMLs have led to increased cannabis potency, unintentional childhood exposures, adult cannabis use, and adult CUD. Ecological-level studies suggest that MMLs have led to substitution of cannabis for opioids, and also possibly for psychiatric medications. Much remains to be determined about cannabis trends and the role of MMLs and RMLs in these trends. The public, health professionals, and policy makers would benefit from education about the risks of cannabis use, the increases in such risks, and the role of marijuana laws in these increases.

Visual attention to motion stimuli and its neural correlates in cannabis users

Attention to motion stimuli and correct motion perception are vital for road safety. Although cannabis use has been associated with increased road crash risks, there is limited research on attentional processing of moving stimuli in cannabis users. This study investigated the neural correlates of the three-stimulus oddball task in cannabis users (n = 18) and non-users (n = 23) in response to moving stimuli. Stimulus contrast was under 16% against a low luminance background (M luminance < 16 cd/m² ). The two groups did not differ in accuracy or in N2 peak amplitude; however, N2 latency was longer for target and standard stimuli in the cannabis group than in the control group. The cannabis group also showed a significantly reduced P3b amplitude in response to target stimuli. The AUDIT score was added as a random factor to the anova to rule out the effects of uneven alcohol consumption in the two groups. A significant group effect was found for N2 latency in response to target and standard stimuli and a significant interaction between the group, and the AUDIT score was found for the P3b peak amplitude for the distractor and standard stimuli, but not for the target stimuli. The results of this study suggest that cannabis use relates to reduced neural activity underlying attention to motion stimuli. Implications for regular early-onset cannabis use road safety are discussed.

Running Out of Options: Rhabdomyolysis Associated with Cannabis Hyperemesis Syndrome

Cannabis hyperemesis syndrome (CHS) is a condition in which some patients with long-term, frequent use of cannabis paradoxically develop recurrent episodes of nausea and vomiting. The pathophysiology underlying this condition is poorly understood, as is the explanation for its common association with patients' discovery that hot-water bathing alleviates symptoms. We describe the case of a 24-year-old male with daily marijuana use and a history of CHS who was found to have rhabdomyolysis induced by a period of 15 h of continuous jogging after he discovered that this activity helped to alleviate his symptoms. To our knowledge, this is the first reported case of exercise-alleviated CHS symptoms, and we propose that this case provides support to the theory of redistribution of enteric blood flow as the mechanism behind the learned hot-water bathing behavior seen so commonly in CHS.