Socio-economic differentials in cannabis use trends in Australia

Patterns of problematic cannabis use in Canada pre- and post-legalisation: Differences by neighbourhood deprivation, individual socioeconomic factors and race/ethnicity

INTRODUCTION

The legalisation of cannabis in Canada in 2018, and subsequent increase in prevalence of use, has generated interest in understanding potential changes in problematic patterns of use, including by socio-demographic factors such as race/ethnicity and neighbourhood deprivation level.

METHODS

This study used repeat cross-sectional data from three waves of the International Cannabis Policy Study web-based survey. Data were collected from respondents aged 16-65 prior to cannabis legalisation in 2018 (n = 8704), and post-legalisation in 2019 (n = 12,236) and 2020 (n = 12,815). Respondents' postal codes were linked to the INSPQ neighbourhood deprivation index. Multinomial regression models examined differences in problematic use by socio-demographic and socio-economic factors and over time.

RESULTS

No evidence of a change in the proportion of those aged 16-65 in Canada whose cannabis use would be classified as 'high risk' was noted from before cannabis legalisation (2018 = 1.5%) to 12 or 24 months after legalisation (2019 = 1.5%, 2020 = 1.6%; F = 0.17, p = 0.96). Problematic use differed by socio-demographic factors. For example, consumers from the most materially deprived neighbourhoods were more likely to experience 'moderate' vs 'low risk' compared to those living outside deprived neighbourhoods (p < 0.01 for all). Results were mixed for race/ethnicity and comparisons for high risk were limited by small sample sizes for some groups. Differences across subgroups were consistent from 2018 to 2020.

DISCUSSION AND CONCLUSIONS

The risk of problematic cannabis use does not appear to have increased in the 2 years following cannabis legalisation in Canada. Disparities in problematic use persisted, with some racial minority and marginalised groups experiencing higher risk.

Illicit drug use and exposure in disadvantaged neighborhoods in Czechia: policy representations and evidence

This study examines the lifetime prevalence of illicit drug use and illicit drug exposure in disadvantaged ("Roma") and more affluent neighborhoods in Czechia. The results of a survey among populations of both types of neighborhoods suggest no statistically significant difference between the two in terms of the overall lifetime prevalence of illicit drug use; however, lifetime prevalence of methamphetamine use proved higher in disadvantaged neighborhoods. The population of disadvantaged neighborhoods has also lower chances to use LSD during their lifetime. Further differences were identified in drug exposure, with the population of more affluent neighborhoods being more frequently exposed to illicit drugs than the population of disadvantaged neighborhoods. The predictors of drug use and drug exposure were partially different for both populations. In the disadvantaged population, drug use was revealed, among other predictors, to be associated with housing conditions.

Prenatal cannabis use disorders and offspring primary and secondary educational outcomes

BACKGROUND AND AIMS

Cannabis use is increasing among women of reproductive age, warranting a greater understanding of the impact of prenatal cannabis use on offspring developmental outcomes. We tested for a potential relationship between prenatal cannabis use disorders (CUD) and offspring educational outcomes across primary and secondary school.

DESIGN

Data were drawn from the New South Wales (NSW) Perinatal Data Collection, which included all live births in the Australian state of NSW between January 2003 and December 2005. These were linked with the NSW Admitted Patient Data collection for mothers and offspring, and the NSW National Assessment Program-Literacy and Numeracy (NAPLAN).

SETTING

New South Wales, Australia.

PARTICIPANTS

A total of 189 558 offspring who completed the NAPLAN in grades 3, 5 and 7 (resulting in 568 674 examination periods).

MEASUREMENTS

The exposure variable was ICD-10 cannabis use disorders (CUD = F13.0-F13.9). The study included five outcome variables measured at three time-points as not meeting the minimum national standards for: (i) numeracy, (ii) reading, (iii) spelling, (iv) writing and (v) grammar and punctuation.

FINDINGS

In unadjusted analyses, prenatal CUD was associated with an increased risk for not meeting the national minimum standard of all outcomes [odds ratios (OR) ranging from 3.42 (95% confidence interval (CI) = 2.94, 3.99) to 4.17 (95% CI = 3.55, 4.91)], with no evidence for an interaction across time. However, the associations attenuated greatly after exact matching by covariates, with reading and numeracy no longer associated with prenatal CUD, while the increased risk of the other outcomes ranged from OR = 1.31 (95% CI = 1.09, 1.57) to OR = 1.40 (95% CI = 1.17, 1.68).

CONCLUSION

Socio-economic status appears to confound the association between prenatal cannabis use disorder and poor educational performance in offspring.

Association of Breast Tumour Expression of Cannabinoid Receptors CBR1 and CBR2 with Prognostic Factors and Survival in Breast Cancer Patients

Cannabinoid receptors (CBR) are potential therapeutic targets for breast cancer. However, the role of CBR in breast cancer survival remains poorly understood. Data from a prospective cohort of 522 women diagnosed with invasive breast cancer between 2010 and 2012 were analysed. Clinical and pathological features were retrieved from electronic medical records. CBR expression was measured by immunohistochemistry. Adjusted partial Spearman correlations and multivariate Cox models were used to estimate associations with breast cancer prognostic factors and survival, respectively. The median follow-up was 92.0 months (range 7.0-114.0). CBR expression was heterogenous in tumours. Cytoplasmic expression of CBR1 was positively correlated with lymph node invasion (r_s = 0.110; p = 0.0155) and positive status of the human epidermal growth factor receptor 2 (HER2) (r_s = 0.168; p = 0.0002), while nuclear CBR2 was negatively correlated with grade (r_s = -0.171; p = 0.0002) and positively correlated with oestrogen receptor and progesterone receptor-positive status (r_s = 0.173; p = 0.0002 and r_s = 0.121; p = 0.0084, respectively). High cytoplasmic expression of CBR2 was associated, with 13% higher locoregional and distant recurrences (HR = 1.13 [0.97-1.33]), though this association did not reach statistical significance. Although the few events occurring during follow-up may have limited the detection of significant associations, these results indicate that CBR expression in breast cancer deserves further investigation.

Trends in cannabis use and attitudes toward legalization and use among Australians from 2001-2016: an age-period-cohort analysis

BACKGROUND AND AIMS

Changes in cannabis legalization and availability in Australia necessitate monitoring use and attitudes. We estimated age-period-cohort effects of past-year cannabis use and attitudes toward criminalization and legalization.

DESIGN

Analysis of six waves of the Australian National Drug Strategy Household Survey (NDSHS) every 3 years (2001-2016).

SETTING AND PARTICIPANTS

The study was nationally representative of Australian households using multistage random sampling, totaling 145 168 respondents 18-79 years old. Data were collected using telephone, face-to-face, and drop-and-collect. Sample sizes per analysis varied based on data availability (~107 000-127 000 per model).

MEASUREMENTS

Six waves of data for past-year cannabis use (by sex and education), attitudes toward criminalization and legalization.

FINDINGS

Past-year cannabis use decreased in young adults ages 18-35 from 2001-2016 (25.1%-18.6%) and increased in middle adults ages 36-55 (8.6%-10.1%) and older adults ages 56-79 (0.6%-3.0%). We observed a positive period effect and negative cohort effect for recent cohorts for past-year use (e.g. 1955 cohort had 1.41 (95% CI: [1.11, 1.70]) increased log odds vs. 1998 cohort had -2.86 (95% CI: [-3.17, -2.55]) increased log odds) compared with the mean across years. Results were consistent by sex and varied by education. We observed a negative period effect for criminalization favorability (0.14 (95% CI: [0.003, 0.28]) increased log odds in 2001 vs. -0.31 (95% CI: [-0.45, -0.17]) increased log odds in 2016) and positive cohort effect for recent cohorts. Last, we observed a positive period effect for legalization support (-0.03 (95% CI: [-0.20, 0.14]) increased log odds in 2001 vs. 0.38 (95% CI: [0.22, 0.55]) increased log odds in 2016) and negative cohort effect for recent cohorts.

CONCLUSION

Cannabis use appears to be increasing in Australia among adults over 35, while decreasing among adolescents and young adults. Legalization support also appears to have been increasing since 2007, signaling discordance between use and attitudes among adolescents and young adults, and potentially predicting increases in use over time.

The association between legalization of cannabis use and traffic deaths in Uruguay

BACKGROUND AND AIMS

While cannabis use has been found to impair motor vehicle driving, the association between cannabis legalization and motor vehicle fatalities is unclear. In Uruguay in December 2013, cannabis for recreational purposes was legalized. This study assessed the association between implementation of this law and changes in traffic fatality rates.

DESIGN

Interrupted time-series analysis of traffic fatality rates of light motor vehicle drivers and motorcyclists in urban and rural settings. Changes are reported as step and trend effects against modeled trends in the absence of legalization.

SETTING

Uruguay, Montevideo and four rural provinces (Colonia, Florida, Río Negro and San José) from 1 January 2012 to 31 December 2017. Cases and measurement Weekly traffic fatalities of light motor vehicle drivers and motorcyclists per type of vehicle. Data were gathered from the National Road Safety Agency of Uruguay and the Ministry of Transport and Public Works, respectively.

RESULTS

Cannabis legalization was associated with a 52.4% immediate increase [95% confidence interval (CI) = 11.6, 93.3, P = 0.012] in the light motor vehicle driver's fatality rate. However, no significant change in the motorcyclists' fatality rate was observed. In Montevideo the legislation was associated with an absolute increase in its light motor vehicle driver's fatality rate by 0.06 (95% CI = 0.01, 0.11, P = 0.025), but no significant associations were observed in rural settings.

CONCLUSIONS

In Uruguay, the 2013 legislation legalizing recreational cannabis consumption may have been associated with an increase in fatal motor vehicle crashes, particularly in light motor-vehicle drivers and urban settings.

The costs and benefits of cannabis control policies

As is the case for most drugs, cannabis use has costs and benefits, and so do the policies that attempt to minimize the first and maximize the second. This article summarizes what we know about the harmful effects of recreational cannabis use and the benefits of medical cannabis use under the policy of prohibition that prevailed in developed countries until 2012. It outlines three broad ways in which cannabis prohibition may be relaxed, namely, the depenalization of personal possession and use, the legalization of medical use, and the legalization of adult recreational use. It reviews evidence to date on the impacts of each of these forms of liberalization on the costs and benefits of cannabis use. It makes some plausible conjectures about the future impacts of the commercialization of cannabis using experience from the commercialization of the alcohol, tobacco, and gambling industries. Cannabis policy entails unavoidable trade-offs between competing social values in the face of considerable uncertainty about the effects that more liberal cannabis policies will have on cannabis use and its consequences for better or worse.
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Adolescent cannabis use, cognition, brain health and educational outcomes: A review of the evidence

We review the findings of systematic reviews and meta-analyses of case-control studies that examine brain functioning and cognitive correlates of adolescent cannabis use using structural and functional neuroimaging tools and standardised neuropsychological tests. We also examine prospective epidemiological studies on the possible effects of adolescent and young adult cannabis use on cognitive performance in adult life and the completion of secondary education. We summarize the findings of studies in each of these areas that have been published since the most recent systematic review. Systematic reviews find that adolescent cannabis use is inconsistently associated with alterations in the structure of prefrontal and temporal brain regions. Meta-analyses reveal functional alterations in the parietal cortex and putamen. Differences in the orbitofrontal cortex predate cannabis use; it is unclear if they are affected by continued cannabis use and prolonged abstinence. Longitudinal and twin studies report larger declines in IQ among cannabis users than their non-using peers but it is unclear whether these findings can be attributed to cannabis use or to genetic, mental health and environmental factors. Several longitudinal studies and a meta-analysis of cross-sectional studies suggest that there is some cognitive recovery after abstinence from cannabis. Longitudinal studies and some twin studies have found that cannabis users are less likely to complete secondary school than their non-using controls. This association might reflect an effect of cannabis use and/or the social environment of cannabis users and their cannabis using peers. Cognitive performance is altered in some domains (e.g. IQ, verbal learning) in young people while they are regularly using cannabis. There are two important messages to adolescents and young adults: First, cannabis has potentially detrimental effects on cognition, brain and educational outcomes that persist beyond acute intoxication. Second, impaired cognitive function in cannabis users appears to improve with sustained abstinence.

Non-medical use of pharmaceutical opioids with and without other illicit substances in Australia: Prevalence and correlates

INTRODUCTION AND AIMS

To estimate the prevalence of non-medical use of pharmaceutical opioids and examine the socio-demographic, psychological, health and behavioural correlates and type of opioids used.

DESIGN AND METHODS

Data from the Australian National Drug Strategy Household Survey 2016 was used. The sample consisted of. 23 448 participants aged over 14 years (54% female). The key measure was opioid use status in the past year. Based on participants' responses to questions about their substance use in the past 12 months, they were grouped into four opioid use status: (i) No illicit substance use (ISU) and no non-medical use of pharmaceutical opioids (NMUPO); (ii) ISU but no NMUPO; (iii) NMUPO but no ISU; and (iv) NMUPO and ISU.

RESULTS

The prevalence non-medical pharmaceutical opioid use was 3.56%. Two-thirds of them engaged in NMUPO but no ISU; one-third engaged in NMUPO and ISU. Younger people were more likely to use pharmaceutical opioids in addition to other illicit drugs, while older people were more likely to only use pharmaceutical opioids. Alcohol risk and daily smoking were associated with using pharmaceutical opioids and other illicit drugs, but not with pharmaceutical opioids only. Those who reported only using pharmaceutical opioids were more likely to use over-the-counter codeine products.

DISCUSSION AND CONCLUSIONS

Over 700 000 Australian used pharmaceutical opioids for non-medical purpose. Among users, two-thirds used only opioids and one-third used opioids in addition to other illicit drugs. Profile of these two types of users were substantially different. Future prevention efforts targeting different type of opioids users may need to be optimised based on their profiles.