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Background: Australia introduced a prescription only policy for e-cigarettes in 2011 to prevent uptake among youth while allowing smokers to access e-cigarettes for cessation. This is one of the restrictive forms of regulation for e-cigarettes recommended by the World Health Organisation., Aims: To assess whether the policy has prevented e-cigarette youth uptake and facilitated smokers' access to e-cigarettes for cessation; and to examine a proposed toughening of the policy., Methods: An analysis of survey and administrative data on e-cigarette use and smoking and a critical analysis of the contents of submissions to parliamentary inquiries into the policy., Results: E-cigarette use among youth and young adults has increased steeply since 2016 but very few of these products have been obtained through the prescription system, because medical authorities discourage their use. A policy change in 2021 to increase the prescription of e-cigarettes has not reduced e-cigarette use among youth and only marginally increased rates of prescribing. Australian policy makers have nonetheless tightened the prescription system by banning any use of e-cigarettes unless prescribed by a doctor and dispensed by a pharmacist., Implications: Australia's tightened prescription policy for e-cigarettes may reduce adolescent vaping but at the risk of reducing smokers' access to e-cigarettes and increasing the size of the illicit market for combustible cigarettes and e-cigarettes. A more effective policy would allow vapes to be sold as consumer products by licensed tobacconists under regulations that require prior product approval, plain packaging, bans on their promotion and enforced age restrictions on purchases., (© 2024 The Author. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Randomized controlled trials (RCTs) are considered the gold standard for causal inference. With a sufficient sample size, randomization removes confounding up to the time of randomization and allows the treatment effect to be isolated. However, RCTs may have limited generalizability and transportability and are often not feasible in addiction research due to ethical or logistical constraints. The importance of observational studies from real-world settings has been increasingly recognized in research on health. This paper provides an overview of modern approaches to designing observational studies that enable causal inference. It illustrates three key techniques, Directed Acyclic Graphs (DAGs), modified Disjunctive Cause Criterion and Target Trial Emulation, and discusses the strengths and limitations of their applications., (© 2024 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Background and Aims: Heated tobacco products (HTPs) are electronic devices that heat process tobacco to release an aerosol containing nicotine and other chemicals. Limited data exist on world-wide HTP use prevalence. This meta-analytic review estimated the prevalence of HTP use by country, World Health Organization (WHO) region, year, sex/gender and age., Methods: Five databases (Web of Science, Scopus, Embase, PubMed and PsycINFO) were searched between January 2015 and May 2022. Included studies reported the prevalence of HTP use in nationally representative samples post-modern HTP device market entry (2015). A random-effects meta-analysis was used to estimate overall prevalence for life-time, current and daily HTP use., Results: Forty-five studies (n = 1 096 076) from 42 countries/areas from the European Region (EUR), Western Pacific Region (WPR), Region of the Americas (AMR) and African Region (AFR) met inclusion criteria. Estimated pooled prevalence for life-time, current and daily HTP use was 4.87% [95% confidence interval (CI) = 4.16, 5.63], 1.53% (95% CI = 1.22, 1.87) and 0.79% (95% CI = 0.48, 1.18), respectively, across all years (2015-22). Life-time HTP use prevalence significantly increased by 3.39% for WPR [0.52% (95% CI = 0.25, 0.88) in 2015 to 3.91% (95% CI = 2.30, 5.92) in 2019] and 5.58% for EUR [1.13% (95% CI = 0.59, 1.97) in 2016 to 6.98% (95% CI = 5.69, 8.39) in 2020]. Current HTP use increased by 10.45% for WPR [0.12% (95% CI = 0, 0.37) in 2015 to 10.57% (95% CI = 5.59, 16.88) in 2020] and 1.15% for EUR [0% (95% CI = 0, 0.35) in 2016 to 1.15% (95% CI = 0.87, 1.47) in 2020]. Meta-regression revealed higher current HTP use in WPR [3.80% (95% CI = 2.88, 4.98)] compared with EUR [1.40% (95% CI = 1.09, 1.74)] and AMR [0.81% (95% CI = 0.46, 1.26)] and for males [3.45% (95% CI = 2.56, 4.47)] compared with females [1.82% (95% CI = 1.39, 2.29)]. Adolescents had higher life-time HTP use prevalence [5.25% (95% CI = 4.36, 6.21) than adults [2.45% (95% CI = 0.79, 4.97)]. Most studies scored a low risk of sampling bias due to their nationally representative sampling., Conclusion: The prevalence of HTPs use increased in the EUR and WPR between 2015 and 2020, with nearly 5% of the included populations having ever tried HTP and 1.5% identifying as current users during the study period., (© 2023 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Background and Aims: Cannabis withdrawal is a well-characterized phenomenon that occurs in approximately half of regular and dependent cannabis users after abrupt cessation or significant reductions in cannabis products that contain Δ 9 -tetrahydrocannabinol (THC). This review describes the diagnosis, prevalence, course and management of cannabis withdrawal and highlights opportunities for future clinical research., Methods: Narrative review of literature., Results: Symptom onset typically occurs 24-48 hours after cessation and most symptoms generally peak at days 2-6, with some symptoms lasting up to 3 weeks or more in heavy cannabis users. The most common features of cannabis withdrawal are anxiety, irritability, anger or aggression, disturbed sleep/dreaming, depressed mood and loss of appetite. Less common physical symptoms include chills, headaches, physical tension, sweating and stomach pain. Despite limited empirical evidence, supportive counselling and psychoeducation are the first-line approaches in the management of cannabis withdrawal. There are no medications currently approved specifically for medically assisted withdrawal (MAW). Medications have been used to manage short-term symptoms (e.g. anxiety, sleep, nausea). A number of promising pharmacological agents have been examined in controlled trials, but these have been underpowered and positive findings not reliably replicated. Some (e.g. cannabis agonists) are used 'off-label' in clinical practice. Inpatient admission for MAW may be clinically indicated for patients who have significant comorbid mental health disorders and polysubstance use to avoid severe complications., Conclusions: The clinical significance of cannabis withdrawal is that its symptoms may precipitate relapse to cannabis use. Complicated withdrawal may occur in people with concurrent mental health and polysubstance use., (© 2021 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Aim: To test if there was a reduction in alcohol consumption in wastewater samples in the Northern Territory of Australia after the implementation of a minimum unit alcohol price policy (MUP) in October 2018., Design, Setting, Cases: Between August 2016 and February 2020, wastewater samples were collected across 66 sites in the Northern Territory and all other states and territories in Australia. Samples were collected every 2 months in capital cities and every 4 months in regional places during this period. Overall, 4917 samples were taken (2816 before MUP and 2101 after)., Measurements: The number of standard drinks per 1000 people per day in the respective catchment areas was estimated based on the concentration of an alcohol-specific metabolite, ethyl sulphate in the samples (using the excretion factor of ethyl sulphate, the flow of wastewater entering the wastewater treatment plants and the population of each wastewater catchment)., Findings: Results from a linear mixed model showed that there was a large drop in alcohol consumption immediately after the MUP in Northern Territory [estimated drop = 1231, 99% confidence interval (CI) = 830, 1633; 38.75%]. There was no significant drop in all other states/territories except for Queensland, which showed a significant but much smaller drop (estimated drop: 310; 99% CI = 114, 550). One year after the MUP, the drop narrowed to 520 (99% CI = 189, 851) and was no longer statistically significant in February 2020 (15 months after MUP; estimated drop = 283, 99% CI = -114, 681)., Conclusions: Per-capita consumption of alcohol appears to have decreased substantially in the Northern Territory of Australia immediately after the implementation of a minimum unit price but consumption steadily recovered and almost returned to the pre-MUP consumption level after 15 months., (© 2021 Society for the Study of Addiction.)

Background and Aims: Studies have consistently found a longitudinal association between e-cigarette use (vaping) and cigarette smoking. Many have interpreted such association as causal. This systematic review and meta-analysis evaluated the plausibility of a causal interpretation by (1) estimating the effect of adolescent vaping on smoking initiation, adjusted for study quality characteristics, (2) evaluating the sufficiency of adjustment for confounding based on the social development model (SDM) and the social ecological model (SEM) and E-value analyses and (3) investigating sample attrition and publication bias., Methods: Systematic review and meta-analysis of longitudinal studies that examined the association between e-cigarette use at baseline and smoking at follow-up. Participants were non-smokers aged < 18 at baseline., Results: Meta-analysis of 11 studies showed a significant longitudinal association between vaping and smoking [adjusted odds ratio (aOR) = 2.93, 95% confidence interval (CI) = 2.22, 3.87]. Studies with sample sizes < 1000 had a significantly higher odds ratio (OR = 6.68, 95% CI = 3.63, 12.31) than studies with sample sizes > 1000 (OR = 2.49, 95% CI = 1.97, 3.15). Overall, the attrition rate was very high (median = 30%). All but one study reported results from complete sample analysis, despite those dropping out having higher risk profiles. Only two studies comprehensively adjusted for confounding. The median E-value was 2.90, indicating that the estimates were not robust against unmeasured confounding., Conclusions: There is a longitudinal association between adolescent vaping and smoking initiation; however, the evidence is limited by publication bias, high sample attrition and inadequate adjustment for potential confounders., (© 2020 Society for the Study of Addiction.)

Background and Aims: Studies have linked adolescent alcohol use with adverse consequences in adulthood, yet it is unclear how strong the associations are and to what extent they may be due to confounding. Our aim was to estimate the strength of association between different patterns of adolescent drinking and longer-term psychosocial harms taking into account individual, family and peer factors., Design: Participant-level data were integrated from four long-running longitudinal studies: Australian Temperament Project, Christchurch Health and Development Study, Mater Hospital and University of Queensland Study of Pregnancy and Victorian Adolescent Health Cohort Study., Setting: Australia and New Zealand., Participants: Participants were assessed on multiple occasions between ages 13 and 30 years (from 1991 to 2012). Number of participants varied (up to n = 9453) by analysis., Measurements: Three patterns of alcohol use (frequent, heavy episodic and problem drinking) were assessed prior to age 17. Thirty outcomes were assessed to age 30 spanning substance use and related problems, antisocial behaviour, sexual risk-taking, accidents, socio-economic functioning, mental health and partner relationships., Findings: After covariate adjustment, weekly drinking prior to age 17 was associated with a two- to threefold increase in the odds of binge drinking [odds ratio (OR) = 2.14; 95% confidence interval (CI) = 1.57-2.90], drink driving (OR = 2.78; 95% CI = 1.84-4.19), alcohol-related problems (OR = 3.04; 95% CI = 1.90-4.84) and alcohol dependence (OR = 3.30; 95% CI = 1.69-6.47) in adulthood. Frequency of drinking accounted for a greater proportion of the rate of most adverse outcomes than the other measures of alcohol use. Associations between frequent, heavy episodic and problem drinking in adolescence and most non-alcohol outcomes were largely explained by shared risk factors for adolescent alcohol use and poor psychosocial functioning., Conclusions: Frequency of adolescent drinking predicts substance use problems in adulthood as much as, and possibly more than, heavy episodic and problem drinking independent of individual, family and peer predictors of those outcomes., (© 2018 Society for the Study of Addiction.)

Aims: Failure to complete high school predicts substantial economic and social disadvantage in adult life. The aim of this study was to determine the longitudinal association of mid-adolescent polydrug use and high school non-completion, relative to other drug use profiles., Design: A longitudinal analysis of the relationship between polydrug use in three cohorts at grade 9 (age 14-15 years) and school non-completion (reported post-high school)., Setting: A State-representative sample of students across Victoria, Australia., Participants: A total of 2287 secondary school students from 152 high schools. The retention rate was 85%., Measurements: The primary outcome was non-completion of grade 12 (assessed at age 19-23 years). At grade 9, predictors included 30-day use of eight drugs, school commitment, academic failure and peer drug use. Other controls included socio-economic status, family relationship quality, depressive symptoms, gender, age and cohort., Findings: Three distinct classes of drug use were identified-no drug use (31.7%), mainly alcohol use (61.8%) and polydrug use (6.5%). Polydrug users were characterized by high rates of alcohol, tobacco and cannabis use. In the full model, mainly alcohol users and polydrug users were less likely to complete school than non-drug users [odds ratio (OR) = 1.54, 95% confidence interval (CI) = 1.17-2.03) and OR = 2.51, 95% CI = 1.45-4.33), respectively, P < 0.001]. These effects were independent of school commitment, academic failure, peer drug use and other controls., Conclusions: Mid-adolescent polydrug use in Australia predicts subsequent school non-completion after accounting for a range of potential confounding factors. Adolescents who mainly consume alcohol are also at elevated risk of school non-completion., (© 2015 Society for the Study of Addiction.)

Aims: To estimate the prevalence and burden of disease attributable to opioid dependence globally, regionally and at country level., Methods: Multiple search strategies: (i) peer-reviewed literature searches; (ii) systematic searches of online databases; (iii) internet searches; (iv) consultation and feedback from experts. Culling and data extraction followed protocols. DisMod-MR, the latest version of the generic disease modelling system, a Bayesian meta-regression tool, imputed prevalence by age, year and sex for 187 countries and 21 regions. Disability weight for opioid dependence was estimated through population surveys and multiplied by prevalence data to calculate the years of life lived with disability (YLDs). Opioid dependence premature mortality was computed as years of life lost (YLLs) and summed with YLDs to calculate disability-adjusted life years (DALYs)., Results: There were 15.5 million opioid-dependent people globally in 2010 [0.22%, 95% uncertainty interval (UI) = 0.20-0.25%]. Age-standardized prevalence was higher in males (0.30%, 95% UI = 0.27-0.35%) than females (0.14%, 95% UI = 0.12-0.16%), and peaked at 25-29 years. Prevalence was higher than the global pooled prevalence in Australasia (0.46%, 95% UI = 0.41-0.53%), western Europe (0.35%, 95% UI = 0.32-0.39) and North America (0.30%, 95% UI = 0.25-0.36). Opioid dependence was estimated to account for 9.2 million DALYs globally (0.37% of global DALYs) in 2010, a 73% increase on DALYs estimated in 1990. Regions with the highest opioid dependence DALY rates were North America (292.1 per 100,000), eastern Europe (288.4 per 100,000), Australasia (278.6 per 100,000) and southern sub-Saharan Africa (263.5 per 100,000). The contribution of YLLs to opioid dependence burden was particularly high in North America, eastern Europe and southern sub-Saharan Africa., Conclusion: Opioid dependence is a substantial contributor to the global disease burden; its contribution to premature mortality (relative to prevalence) varies geographically, with North America, eastern Europe and southern sub-Saharan Africa most strongly affected., (© 2014 Society for the Study of Addiction.)

Aims: Debate continues about whether the association between cannabis use in adolescence and common mental disorders is causal. Most reports have focused on associations in adolescence, with few studies extending into adulthood. We examine the association from adolescence until the age of 29 years in a representative prospective cohort of young Australians., Design: Nine-wave, 15-year representative longitudinal cohort study, with six waves of data collection in adolescence (mean age 14.9-17.4 years) and three in young adulthood (mean age 20.7, 24.1 and 29.1 years)., Participants: Participants were a cohort of 1943 recruited in secondary school and surveyed at each wave when possible from mid-teen age to their late 20s., Setting: Victoria, Australia., Measurements: Psychiatric morbidity was assessed with the Revised Clinical Interview Schedule (CIS-R) at each adolescent wave, and as Composite International Diagnostic Interview (CIDI)-defined ICD-10 major depressive episode and anxiety disorder at 29 years. Frequency of cannabis use was measured in the past 6 months in adolescence. Cannabis use frequency in the last year and DSM-IV cannabis dependence were assessed at 29 years. Cross-sectional and prospective associations of these outcomes with cannabis use and dependence were estimated as odds ratios (OR), using multivariable logistic regression models, with the outcomes of interest, major depressive episode (MDE) and anxiety disorder (AD) at 29 years., Findings: There were no consistent associations between adolescent cannabis use and depression at age 29 years. Daily cannabis use was associated with anxiety disorder at 29 years [adjusted OR 2.5, 95% confidence interval (CI):< 1.2-5.2], as was cannabis dependence (adjusted OR 2.2, 95% CI: 1.1-4.4). Among weekly+ adolescent cannabis users, those who continued to use cannabis use daily at 29 years remained at significantly increased odds of anxiety disorder (adjusted OR 3.2, 95% CI: 1.1-9.2)., Conclusions: Regular (particularly daily) adolescent cannabis use is associated consistently with anxiety, but not depressive disorder, in adolescence and late young adulthood, even among regular users who then cease using the drug. It is possible that early cannabis exposure causes enduring mental health risks in the general cannabis-using adolescent population., (© 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.)

Aims: To stimulate debate by examining ethical issues raised by Project Prevention, a US-based organization that offers $US300 to addicted individuals who agree to either undergo surgical sterilization or use long-acting forms of contraception., Method: An analysis of key ethical questions raised by Project Prevention., Results: The important issues for debate are: (i) what are the reproductive rights of drug-using women; (ii) does a substantial cash incentive undermine the ability of addicted women to make free and informed decisions about long-term contraception; and (iii) how can we best assist addicted women to access good reproductive health care and obtain treatment for their addiction?, Conclusions: We need more research on ways in which small non-cash incentives for reversible methods of contraception could be used in a morally acceptable and effective way to promote the sexual, reproductive and general health of addicted women., (© 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.)

Aims: We used epidemiological modelling to assess whether nicotine vaccines would be a cost-effective way of preventing smoking uptake in adolescents., Design, Setting, Participants and Measurements: We built an epidemiological model using Australian data on age-specific smoking prevalence; smoking cessation and relapse rates; life-time sex-specific disability-adjusted life years lived for cohorts of 100,000 smokers and non-smokers; government data on the costs of delivering a vaccination programme by general practitioners; and a range of plausible and optimistic estimates of vaccine cost, efficacy and immune response rates based on clinical trial results. We first estimated the smoking uptake rates for Australians aged 12-19 years. We then used these estimates to predict the expected smoking prevalence in a birth cohort aged 12 in 2003 by age 20 under (i) current policy and (ii) different vaccination scenarios that varied in cost, initial vaccination uptake, yearly re-vaccination rates, efficacy and a favourable vaccine immune response rate., Findings: Under the most optimistic assumptions, the cost to avert a smoker at age 20 was $44,431 [95% confidence interval (CI) $40,023-49,250]. This increased to $296,019 (95% CI $252,307-$355,930) under more plausible scenarios. The vaccine programme was not cost-effective under any scenario., Conclusions: A preventive nicotine vaccination programme is unlikely to be cost-effective. The total cost of a universal vaccination programme would be high and its impact on population smoking prevalence negligible. For these reasons, such a programme is unlikely to be publicly funded in Australia or any other developed country., (© 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.)

Aims: This paper models the predicted impact of tobacco price increases proposed in the United States and Australia during 2009 on smoking prevalence in 2010 while taking account of the effects of financial stress among smokers on cessation rates., Methods: Two models of smoking prevalence were developed for each country. In model 1, prevalence rates were determined by price elasticity estimates. In model 2 price elasticity was moderated by financial stress. Each model was used to estimate smoking prevalence in 2010 in Australia and the United States., Results: Proposed price increases resulted in a 1.89% and 7.84% decrease in smoking participation among low socio-economic status (SES) groups in the United States and Australia, respectively. Model 1 overestimated the number of individuals expected to quit in both the United States (0.13% of smokers) and Australia (0.36% of smokers) by failing to take account of the differential effects of the tax on financially stressed smokers. The proportion of low-income smokers under financial stress increased in both countries in 2010 (by 1.06% in the United States and 3.75% in Australia)., Conclusions: The inclusion of financial stress when modelling the impact of price on smoking prevalence suggests that the population health returns of increased cigarette price will diminish over time. As it is likely that the proportion of low-income smokers under financial stress will also increase in 2010, future population-based approaches to reducing smoking will need to address this factor., (© 2010 The Authors, Addiction © 2010 Society for the Study of Addiction.)

Aims: To describe the prevalence, phenomenology and correlates of 'impulse control disorders' (ICDs) in patients with Parkinson's disease (PD) treated with dopamine replacement therapy (DRT); to assess the strength of the evidence that DRT plays a contributory causal role in these disorders; and to highlight the implications of these disorders for research in the addiction field., Methods: PubMed and Web of Science databases were searched and the reference lists of papers examined., Results: The prevalence of ICDs in Parkinson's patients using DRT varied between 3.5% and 13.6%, depending on the severity and range of disorders assessed. PD patients with ICDs were: generally younger; had an earlier onset of PD; had a personal or family history of substance abuse or an ICD; and were more likely to be treated with dopamine receptor agonists (DA agonists) than levodopa (l-dopa). There is reasonable evidence that dopaminergic medications play a causal role in ICDs in that they occur at a higher rate in an otherwise low-risk population of adults, begin after initiation of DA agonist therapy and cease upon its discontinuation. A causal relationship is biologically plausible, but the role of other factors (such as concurrent mood disorders) remain to be clarified by better-controlled studies., Conclusions: Impulse control disorders among patients with Parkinson's disease receiving dopamine replacement therapy may provide a unique opportunity for addiction researchers to study the neurobiology of impulsive forms of behaviour (such as problem gambling) that appear to be caused, in part, by the therapeutic use of dopamine receptor agonists., (© 2010 The Authors, Addiction © 2010 Society for the Study of Addiction.)

Aims: To examine trends in patterns of cannabis use and related harm in the Australian population between 1993 and 2007., Design: Analysis of prospectively collected data from: (1) the National Drug Strategy Household Survey (NDSHS) and Australian Secondary Student Alcohol and Drug Survey (ASSADS); (2) the National Hospital Morbidity Database (NHMD); and (3) the Alcohol and Other Drug Treatment Services National Minimum Dataset (AODTS-NMDS)., Participants: Australians aged 14 years and over from the general population; students aged 12-17 years; public and private hospital in-patients; public and private in-patients and out-patients attending for drug treatment., Measurement: Prevalence of 12-month cannabis use among the general population and secondary students. Proportions in the general population by age group reporting: daily cannabis use; difficulties in controlling cannabis use; and heavy cannabis use on each occasion. Number of hospital and treatment presentations for cannabis-related problems., Findings: Prevalence of past-year cannabis use has declined in the Australian population since the late 1990s. Among those reporting past-year use, daily use is prevalent among 40-49-year-olds, while heavy patterns of use are prevalent among 14-19-year-olds. Hospital presentations for cannabis-related problems reflect similar trends. Past-year cannabis use has decreased among the 10-19-year age group, but those who are daily users in this age group report using large quantities of cannabis., Conclusions: Despite declines in the prevalence of cannabis use, continued public health campaigns warning of the harms associated with cannabis use are essential, aimed particularly at users who are already experiencing problems. The increasing demand for treatment for cannabis problems in Australia suggests the need for more accessible and more effective interventions for cannabis use disorders.

Aims: The aims of this study were to: examine the number and characteristics of patients entering and re-entering opioid replacement treatment between 1985 and 2006, to examine select demographic and treatment correlates of leaving treatment between 1985 and 2000, and to compare retention rates in methadone and buprenorphine maintenance treatment from 2001 to 2006., Design: A retrospective cohort study using register data from the Pharmaceutical Drugs of Addiction System., Setting: Opioid substitution treatment in New South Wales (NSW), Australia., Participants: A total of n = 42 690 individuals prescribed opioid replacement treatment between 1985 and 2006 in NSW., Measurements: Client characteristics over time, retention in days in first treatment episode, number of episodes of treatment and proportion switching medication., Findings: Overall, younger individuals were significantly more likely to leave their first treatment episode than older individuals. In 2001-06, after controlling for age, sex and first administration point, the hazard of leaving treatment was 1.9 times for those on buprenorphine relative to those on methadone. Retention in treatment varied somewhat across historical time, with those entering during 1995-2000 more likely to leave at an earlier stage than those who entered before that time., Conclusions: Retention in treatment appears to fluctuate in inverse proportion to the availability of heroin. Individuals in contemporary treatment are older users with a lengthy treatment history. This study has provided population-level evidence to suggest that retention in methadone and buprenorphine differ in routine clinical practice. Future work might investigate ways in which patient adherence and retention may be improved.

Aims: To evaluate the utility of using predictive genetic screening of the population for susceptibility to smoking., Methods: The results of meta-analyses of genetic association studies of smoking behaviour were used to create simulated data sets using Monte Carlo methods. The ability of the genetic tests to screen for smoking was assessed using receiver operator characteristic curve analysis. The result was compared to prediction using simple family history information. To identify the circumstances in which predictive genetic testing would potentially justify screening we simulated tests using larger numbers of alleles (10, 15 and 20) that varied in prevalence from 10 to 50% and in strength of association [relative risks (RRs) of 1.2-2.1]., Results: A test based on the RRs and prevalence of five susceptibility alleles derived from meta-analyses of genetic association studies of smoking performed similarly to chance and no better than the prediction based on simple family history. Increasing the number of alleles from five to 20 improved the predictive ability of genetic screening only modestly when using genes with the effect sizes reported to date., Conclusions: This panel of genetic tests would be unsuitable for population screening. This situation is unlikely to be improved upon by screening based on more genetic tests. Given the similarity with associations found for other polygenic conditions, our results also suggest that using multiple genes to screen the general population for genetic susceptibility to polygenic disorders will be of limited utility.

Aims: To describe the formulation of a National Cannabis Strategy in Australia in 2006 and discuss the contribution that research evidence has made to its development., Methods: A description of trends in cannabis use in Australia and policy responses to it from the early 1970s to the present, with an analysis of the evidence and arguments that have been used to support competing policies towards cannabis use., Results: In 1977 an Australian Senate Committee recommended that a national cannabis policy should be developed that removed criminal penalties for personal possession and use. The arguments for the recommendation echoed those used to support similar earlier recommendations made in Canada, the Netherlands, the United Kingdom and the United States in the late 1960s and early 1970s. They were reiterated by a National Cannabis Task Force in 1994, but a national cannabis strategy was not developed until 2006. By default, the strategy supported continued prohibition on the production and sale of cannabis, and left penalties for cannabis use to state governments. It advocated public education campaigns to discourage young people, especially those at high risk, from initiating cannabis use, and to reduce the progression to regular use among young people who had used cannabis. It also supported efforts to reduce the availability of cannabis and to improve treatment for problem cannabis users. The research evidence which was cited as motivating the development of a national cannabis policy was epidemiological data on rising rates of use among young people, and emerging evidence from longitudinal studies in Australian and New Zealand that some adolescent cannabis users experienced harm as a result of their use., Conclusions: The impact that research evidence has had on Australian cannabis policy over the past three decades has, as in many comparable countries, been constrained by the limited policy options under consideration, and by the fact that interpretation of the evidence has been contested by advocates of the limited policy options under debate.

Aim: To assess the promise and risks of technological applications of genetic research on liability to develop nicotine dependence., Methods: We reviewed (i) the evidence on the genetics of nicotine dependence; (ii) the technical feasibility of using genetic information to reduce smoking uptake and increase cessation; and (iii) policy and ethical issues raised by the uses of genetic information on addiction liability., Results: (i) Despite evidence from twin studies that genes contribute to addiction susceptibility, research to date has not identified commonly occurring alleles that are strongly predictive of developing nicotine addiction. Nicotine addiction is likely to involve multiple alleles of small effect that interact with each other and with the environment. (ii) Population screening for susceptibility alleles is unlikely to be effective or cost-effective. Tailoring of smoking cessation treatments with genetic information is more plausible but results to date have been disappointing. Population health strategies such as increased taxation and reduced opportunities to smoke are more efficient in reducing cigarette smoking. Tobacco harm reduction policies applied to populations may also play a role in reducing tobacco-related harm. (iii) Future uses of genomic information on addiction risk will need to assess the risks of medicalising addiction (e.g. pessimism about capacity to quit) and community concerns about genetic privacy., Conclusions: Nicotine genomics is a very new and underdeveloped field. On the evidence to date, its advocates would be wise to avoid extravagant claims about its preventive applications.

Objective: To examine changes in age of tobacco experimentation and progression to daily smoking in men and women between birth cohorts that differ in exposure to public health programmes that aim to discourage smoking., Design: Analysis of national cross-sectional household surveys of smoking patterns, conducted in Australia in 2001 and 2004. SETTING AND PARTICIPANTS Australian adults aged 22 years and over in 2001 and 2004 who responded to the National Drug Strategy Household Survey., Main Outcome Measures: Prevalence of tobacco experimentation and progression to daily smoking by age 21, estimated by sex and birth cohort. Odds of tobacco experimentation and progression to daily smoking by age 21 estimated by sex for each birth cohort, with corrections for the effects of 'forward telescoping' in recalling age of use., Results: Sex differences in smoking prevalence are smaller in younger birth cohorts. Tobacco experimentation has increased among women, while progression to daily smoking has decreased among men., Conclusions: Sex differences in smoking experimentation and progression to daily smoking have decreased in younger birth cohorts. However, a significant proportion of younger males and females continue to experiment with tobacco and become daily smokers despite strong public health efforts to discourage smoking. More research is needed to determine why sex differences in smoking behaviour are not evident in younger birth cohorts.

Aims: To examine the long-term impact of brief and early interventions for hazardous and harmful alcohol consumption., Design: A 9-month and 10-year follow-up of subjects recruited into a randomized controlled trial of a range of alcohol-related brief interventions., Setting: General practices, the outpatient or acute care services of a major city hospital, and a privately run health screening programmeme., Participants: The cohort of 554 (non-dependent) hazardous and harmful drinkers recruited into the Australian arm of the Phase II World Health Organization collaborative project on identification and treatment of persons with harmful alcohol consumption., Intervention: The effectiveness of three forms of intervention, ranging from 5 to 60 minutes in duration, were compared with a no-treatment control condition., Measurements: Included drinking behaviour and biological markers of alcohol use. In addition, at 10 years subjects were asked about symptoms of diagnosable alcohol use disorders and their experience of alcohol-related psychological, social and physical harm. Mortality was also assessed., Findings: Results provide further evidence for the short-term effectiveness of alcohol-related brief interventions. In comparison to controls, subjects offered intervention: (1) report significantly lower consumption; and (2) less unsafe drinking at 9-month follow-up. The intensity of intervention was not related to the amount of change in drinking behaviour. Analysis at 10 years failed to find any differences in outcomes between intervention and control groups in median consumption, mean reduction in consumption from baseline to follow-up, mortality and ICD-10 diagnoses of alcohol dependence or harmful alcohol use., Conclusions: This study failed to find evidence that brief advice and counselling without regular follow-up and reinforcement can sustain significant long-term reductions in drinking behaviour at 10-year follow-up.