Bianca Calabria

The global epidemiology and contribution of cannabis use and dependence to the global burden of disease: results from the GBD 2010 study.

Aims Estimate the prevalence of cannabis dependence and its contribution to the global burden of disease. Methods Systematic reviews of epidemiological data on cannabis dependence (1990-2008) were conducted in line with PRISMA and meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Culling and data extraction followed protocols, with cross-checking and consistency checks. DisMod-MR, the latest version of generic disease modelling system, redesigned as a Bayesian meta-regression tool, imputed prevalence by age, year and sex for 187 countries and 21 regions. The disability weight associated with cannabis dependence was estimated through population surveys and multiplied by prevalence data to calculate the years of life lived with disability (YLDs) and disability-adjusted life years (DALYs). YLDs and DALYs attributed to regular cannabis use as a risk factor for schizophrenia were also estimated. Results There were an estimated 13.1 million cannabis dependent people globally in 2010 (point prevalence0.19% (95% uncertainty: 0.17-0.21%)). Prevalence peaked between 20-24 yrs, was higher in males (0.23% (0.2-0.27%)) than females (0.14% (0.12-0.16%)) and in high income regions. Cannabis dependence accounted for 2 million DALYs globally (0.08%; 0.05-0.12%) in 2010; a 22% increase in crude DALYs since 1990 largely due to population growth. Countries with statistically higher age-standardised DALY rates included the United States, Canada, Australia, New Zealand and Western European countries such as the United Kingdom; those with lower DALY rates were from Sub-Saharan Africa-West and Latin America. Regular cannabis use as a risk factor for schizophrenia accounted for an estimated 7,000 DALYs globally. Conclusion Cannabis dependence is a disorder primarily experienced by young adults, especially in higher income countries. It has not been shown to increase mortality as opioid and other forms of illicit drug dependence do. Our estimates suggest that cannabis use as a risk factor for schizophrenia is not a major contributor to population-level disease burden.

What data are available on the extent of illicit drug use and dependence globally? Results of four systematic reviews

BACKGROUND We systematically reviewed availability and quality of data on the prevalence of use and dependence on meth/amphetamine, cannabis, cocaine and opioids. METHODS Multiple search strategies: (a) peer-reviewed literature searches (1990-2008) using methods recommended by the Meta-analysis of Observational Studies in Epidemiology (MOOSE) group; (b) systematic searches of online databases; (c) Internet searches to find other published evidence of drug use; (d) repeated consultation and feedback from experts around the globe; (e) a viral email sent to lists of researchers in the illicit drug and HIV fields. Data were extracted and graded according to predefined variables reflecting quality of data source. RESULTS Qualitative evidence of illicit drug use and dependence was found for most countries, which hold over 98% of the worlds population aged 15-64 years. Countries where use was identified but prevalence estimates had not been made (evidence of drug supply, trafficking, reports of use, treatment data) were mainly from Asia, Africa, the Middle East, and Oceania. Estimates of the prevalence of use were located in 77 countries for meth/amphetamine, 95 for cannabis, 86 for cocaine and 89 for opioids. Dependence prevalence estimates existed in very few countries; 9 meth/amphetamine dependence estimates, 7 cannabis dependence estimates, 5 cocaine dependence estimates, and 25 opioid dependence estimates were located. CONCLUSIONS Data on the extent of meth/amphetamine, cannabis, cocaine and opioid use and dependence must be improved in quality and coverage. Dependence estimates are lacking even in high income countries that have required resources. Responses to illicit drug dependence require better estimates of its scale.

Does cannabis use increase the risk of death?: Systematic review of epidemiological evidence on adverse effects of cannabis use

ISSUES To conduct a comprehensive search of the peer-reviewed literature to assess risk of cannabis-related mortality. APPROACH Systematic peer-reviewed literature searches were conducted in Medline, EMBASE and PsycINFO to identify data on mortality associated with cannabis use. Search strings for cannabis and mortality were used. Searches were limited to human subjects and the publication timeframe of January 1990 to January 2008. Reference lists of review articles and of specific studies deemed important by colleagues were searched to identify additional studies. A list of the selected articles was emailed to experts in the field asking for comment on completeness. KEY FINDINGS There is insufficient evidence, particularly because of the low number of studies, to assess whether the all-cause mortality rate is elevated among cannabis users in the general population. Case-control studies suggest that some adverse health outcomes may be elevated among heavy cannabis users, namely, fatal motor vehicle accidents, and possibly respiratory and brain cancers. The evidence is as yet unclear as to whether regular cannabis use increases the risk of suicide. CONCLUSIONS There is a need for long-term cohort studies that follow cannabis using individuals into old age, when the likelihood of any detrimental effects of cannabis use are more likely to emerge among those who persist in using cannabis into middle age and older. Case-control studies of cannabis use and various causes of mortality are also needed.

Epidemiology of alcohol-related burden of disease among Indigenous Australians

Objective: To compare the burden of alcohol‐related harm and underlying factors of this harm, by age and sex, for Indigenous and general population Australians.

Should Burden of Disease Estimates Include Cannabis Use as a Risk Factor for Psychosis

Louise Degenhardt and colleagues discuss the evidence and the debate about whether Global Burden of Disease estimates should include cannabis use as a risk factor for psychosis.

A systematic and methodological review of interventions for young people experiencing alcohol-related harm

AIMS This review identified published studies evaluating interventions delivered outside educational settings, designed for young people with existing alcohol use problems, or who participate in behaviour that places them at high risk of alcohol-related harm, critiqued their methodology and identified opportunities for new interventions. METHODS A systematic search of the peer-reviewed literature interrogated 10 electronic databases using specific search strings, limited to 2005-09. No additional studies were found by a librarian searching other collections and clearing-houses, or by hand-searching review paper reference lists. The 1697 articles identified were reviewed against criteria from the Dictionary for the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies. RESULTS The methodological quality of existing studies is variable, and needs to be both more rigorous and more consistent. Particular problems include the lack of blinding outcome assessors, a reliance solely on self-report measures, highly variable consent and follow-up rates, infrequent use of intention-to-treat analyses and the absence of any economic or cost analyses. The range of interventions evaluated is currently limited to individually focused approaches, almost exclusively implemented in the United States. CONCLUSIONS There is a great need for more intervention trials for young people at high risk of experiencing alcohol-related harm that are both methodologically rigorous and have a broader community focus, to complement the psychological interventions that currently dominate the relevant literature. Such trials would improve outcomes for high-risk young people themselves and would improve the evidence base, both in their own right and by facilitating future meta-analyses.

Are adolescents who moderate their cannabis use at lower risk of later regular and dependent cannabis use

AIMS To examine whether moderation of cannabis use among adolescent cannabis users is associated with reductions in cannabis use frequency and risk of dependence in young adulthood. DESIGN Ten-year representative cohort study with six surveys in adolescence (mean age 14.9-17.4 years) and two in young adulthood (mean age 20.7 and 24.1 years). PARTICIPANTS Inception cohort of 1943 Victorian secondary school students (96% response rate), with 1520 (78% of adolescent participants) interviewed in the final wave. MEASUREMENTS Participants were classified into six groups according to the maximum level of adolescent use and the extent of subsequent moderation in such use: non-users, occasional to abstinence, occasional persisting, weekly to abstinence, weekly to occasional and weekly persisting. Outcome measures were weekly+ cannabis use and DSM-IV cannabis dependence at 20 and 24 years. FINDINGS Thirty-one per cent reported cannabis use during adolescence. Most adolescent users had moderated their use: from occasional to abstinence (71% of occasional users), weekly to abstinence or weekly to occasional (28% and 48% of weekly+ users, respectively). By age 24, both occasional use groups were at similar, elevated risk of regular and dependent cannabis use compared to non-users. Weekly+ adolescent users were at greatest risk of these outcomes, although the weekly to abstinence group exhibited lower risk than those in the weekly persisting and weekly to occasional groups, who were at similar risk. CONCLUSIONS While many young people have dynamic cannabis use patterns, a pattern of moderating adolescent cannabis

Identifying Aboriginal-specific AUDIT-C and AUDIT-3 cutoff scores for at-risk, high-risk, and likely dependent drinkers using measures of agreement with the 10-item Alcohol Use Disorders Identification Test

BackgroundThe Alcohol Use Disorders Identification Test (AUDIT) is a 10-item alcohol screener that has been recommended for use in Aboriginal primary health care settings. The time it takes respondents to complete AUDIT, however, has proven to be a barrier to its routine delivery. Two shorter versions, AUDIT-C and AUDIT-3, have been used as screening instruments in primary health care. This paper aims to identify the AUDIT-C and AUDIT-3 cutoff scores that most closely identify individuals classified as being at-risk drinkers, high-risk drinkers, or likely alcohol dependent by the 10-item AUDIT.MethodsTwo cross-sectional surveys were conducted from June 2009 to May 2010 and from July 2010 to June 2011. Aboriginal Australian participants (N = 156) were recruited through an Aboriginal Community Controlled Health Service, and a community-based drug and alcohol treatment agency in rural New South Wales (NSW), and through community-based Aboriginal groups in Sydney NSW. Sensitivity, specificity, and positive and negative predictive values of each score on the AUDIT-C and AUDIT-3 were calculated, relative to cutoff scores on the 10-item AUDIT for at-risk, high-risk, and likely dependent drinkers. Receiver operating characteristic (ROC) curve analyses were conducted to measure the detection characteristics of AUDIT-C and AUDIT-3 for the three categories of risk.ResultsThe areas under the receiver operating characteristic (AUROC) curves were high for drinkers classified as being at-risk, high-risk, and likely dependent.ConclusionsRecommended cutoff scores for Aboriginal Australians are as follows: at-risk drinkers AUDIT-C ≥ 5, AUDIT-3 ≥ 1; high-risk drinkers AUDIT-C ≥ 6, AUDIT-3 ≥ 2; and likely dependent drinkers AUDIT-C ≥ 9, AUDIT-3 ≥ 3. Adequate sensitivity and specificity were achieved for recommended cutoff scores. AUROC curves were above 0.90.

The acceptability to Aboriginal Australians of a family-based intervention to reduce alcohol-related harms.

INTRODUCTION AND AIMS Cognitive-behavioural interventions that use familial and community reinforcers in an individuals environment are effective for reducing alcohol-related harms. Such interventions have considerable potential to reduce the disproportionately high burden of alcohol-related harm among Aboriginal Australians if they can be successfully tailored to their specific needs and circumstances. The overall aim of this paper is to describe the perceived acceptability of two cognitive-behavioural interventions, the Community Reinforcement Approach (CRA) and Community Reinforcement and Family Training (CRAFT), to a sample of Aboriginal people. DESIGN AND METHODS Descriptive survey was administered to 116 Aboriginal people recruited through an Aboriginal Community Controlled Health Service and a community-based drug and alcohol treatment agency in rural New South Wales, Australia. RESULTS Participants perceived CRA and CRAFT to be highly acceptable for delivery in their local Aboriginal community. Women were more likely than men to perceive CRAFT as highly acceptable. Participants expressed a preference for counsellors to be someone they knew and trusted, and who has experience working in their local community. CRA was deemed most acceptable for delivery to individuals after alcohol withdrawal and CRAFT for people who want to help a relative/friend start alcohol treatment. There was a preference for five or more detailed sessions. DISCUSSION AND CONCLUSIONS Findings of this study suggest that CRA and CRAFT are likely to be acceptable for delivery to some rural Aboriginal Australians, and that there is potential to tailor these interventions to specific communities.

The perceived health risks of cannabis use in an Australian household survey

INTRODUCTION AND AIMS Perceived risks of cannabis use have rarely been researched in Australia. This paper reports on the beliefs about the adverse effects of cannabis use on health, social well-being, driving, mental health and changes in cannabis over time. DESIGN AND METHODS Survey of 918 Australian adults was conducted as part of a quarterly omnibus self-report survey of an established panel. RESULTS Respondents believed that cannabis use can cause health and social problems, can adversely affect a persons ability to drive a car, can be addictive, and can lead to use of other illicit drugs. They were uncertain as to whether cannabis can cause schizophrenia and depression, and whether cannabis had become more potent over time. IMPLICATIONS Prevention efforts should focus on educating the Australian people about the nature of cannabis-related harms.