Adolescent tobacco-related associative memory: a cross-sectional and contextual analysis

Tobacco use is prevalent in adolescents, and understanding factors that contribute to its uptake and early development remains a critical public health priority. Implicit drug-related memory associations (DMAs) are predictive of drug use in older samples, but such models have little application to adolescent tobacco use. Moreover, extant research on memory associations yields little information on contextual factors that may be instrumental in the development of DMAs. The present study examined (a) the degree to which tobacco-related memory associations (TMAs) were associated with concurrent tobacco use and (b) the extent to which TMAs mediated the association of peer and self-use. A sample of 210 Australian high school students was recruited. Participants completed TMA tasks and behavioral checklists designed to obscure the tobacco-related focus of the study. Results showed that TMAs were associated with peer use, and TMAs predicted self-use. We found no evidence that TMAs mediated the association of peer and self-use. Future research might examine the emotive valence of implicit nodes and drinking behavior. The results have implications for testing the efficacy of consciousness-raising interventions for adolescents at risk of tobacco experimentation or regular use.

Alcohol use and risk taking among regular ecstasy users

We examine alcohol use in conjunction with ecstasy use and risk-taking behaviors among regular ecstasy users in every capital city in Australia. Data on drug use and risks were collected in 2004 from a national sample of 852 regular ecstasy users (persons who had used ecstasy at least monthly in the preceding 6 months). Users were grouped according to their typical alcohol use when using ecstasy: no use, consumption of between one and five standard drinks, and consumption of more than five drinks (binge alcohol use). The sample was young, well educated, and mainly working or studying. Approximately two thirds (65%) of the regular ecstasy users reported drinking alcohol when taking ecstasy. Of these, 69% reported usually consuming more than five standard drinks. Those who did not drink alcohol were more disadvantaged, with greater levels of unemployment, less education, higher rates of drug user treatment, and prison history. They were also more likely than those who drank alcohol when using ecstasy to be drug injectors and to be hepatitis C positive. Excluding alcohol, drug use patterns were similar between groups, although the no alcohol group used cannabis and methamphetamine more frequently. Binge drinkers were more likely to report having had three or more sexual partners in the past 6 months and were less likely to report having safe sex with casual partners while under the influence of drugs. Despite some evidence that the no alcohol group were more entrenched drug users, those who typically drank alcohol when taking ecstasy were as likely to report risks and problems associated with their drug use. It appears that regular ecstasy users who binge drink are placing themselves at increased sexual risk when under the influence of drugs. Safe sex messages should address the sexual risk associated with substance use and should be tailored to reducing alcohol consumption, particularly targeting heavy alcohol users. The study's limitations are noted.

Canadian heroin supply and the Australian 'heroin shortage'

No Abstract

Changes in the initiation of heroin use after a reduction in heroin supply

Increasing heroin use in Australia over the past 30 years has been associated with a decline in the age of initiation to heroin use. The 2001 Australian heroin shortage was used to assess the effects of a reduction in heroin supply on age of initiation into heroin injecting. Data collected from regular injecting drug users (IDU) over the period 1996-2004 as part of the Australian Illicit Drug Reporting System were examined for changes in self- reported age of first heroin use after the onset of the heroin shortage. Estimates were also made of the number of young people who may not have commenced injecting heroin during the heroin shortage. The proportion of IDU interviewed in the IDRS who were aged

Dissecting the causal anatomy of the link between cannabis and other illicit drugs

No Abstract

Documenting the heroin shortage in New South Wales

Australian heroin markets have recently undergone dramatic change, sparking debate about the nature of such markets. This study aimed to determine the onset, peak and decline of the heroin shortage in New South Wales (NSW), using the most appropriate available methods to detect market level changes. The parameters of the heroin shortage were determined by reviewing: reports of heroin users about availability and price (derived from the existing literature and the Illicit Drug Reporting System); qualitative interviews with injecting drug users, and health and law enforcement professionals working in the illicit drug field; and examining data on heroin seizures over the past decade. There was a marked reduction in heroin supply in NSW in early 2001. An increase in the price of heroin occurred in 2001, whereas it had decreased steadily since 1996. A reduction in purity also occurred, as reported by drug users and heroin seizures. The peak period of the shortage appears to have been January to April 2001. The market appears to have stabilised since that time, although it has not returned to pre- 2001 levels: heroin prices have decreased in NSW for street grams, but not to former levels, and the price of `caps' (street deals) remain elevated. Heroin purity in NSW has remained low, with perhaps a 10% increase above the lowest recorded levels. These data support the notion that the heroin market in NSW underwent significant changes, which appear to have involved a lasting shift in the nature of the market.

Is cannabis use a contributory cause of psychosis?

Objective: To assess whether cannabis use in adolescence and young adulthood is a contributory cause of schizophreniform psychosis in that it may precipitate psychosis in vulnerable individuals. Method: We reviewed longitudinal studies of adolescents and young adults that examined the relations between self-reported cannabis use and the risk of diagnosis with a psychosis or of reporting psychotic symptoms. We also reviewed studies that controlled for potential confounders, such as other forms of drug use and personal characteristics that predict an increased risk of psychosis. We assessed evidence for the biological plausibility of a contributory causal relation. Results: Evidence from 6 longitudinal studies in 5 countries shows that regular cannabis use predicts an increased risk of a schizophrenia diagnosis or of reporting symptoms of psychosis. These relations persisted after controlling for confounding variables, such as personal characteristics and other drug use. The relation did not seem to be a result of cannabis use to self-medicate symptoms of psychosis. A contributory causal relation is biologically plausible because psychotic disorders involve disturbances in the dopamine neurotransmitter systems with which the cannabinoid system interacts, as demonstrated by animal studies and one human provocation study. Conclusion: It is most plausible that cannabis use precipitates schizophrenia in individuals who are vulnerable because of a personal or family history of schizophrenia.

Is cannabis use psychotogenic?

No abstract

Minimising research censorship by government funders

No abstract

Number and type of substances in alcohol and drug-related completed suicides in an Australian sample

Background: The association between substance use and suicide is well-established, but evidence is scant regarding the relationship between the number, type, and level of substances and other risk factors in completed suicide across the lifespan. Aims: To examine the relationship between social/demographic characteristics and the number, type, and level of drugs present in an unrestricted age sample of completed suicides in Australia. Method: An analysis was undertaken of 893 substance-related suicides using data from the Government Statistician's Office for the years 1989-1992. Results: The number and type of substances present in suicide victims was related to the individual's gender, age, marital status, employment status, and method of suicide. Blood alcohol level was significantly different between the methods of suicide, but was unrelated to demographic characteristics of the individual. The level of antidepressants and minor tranquilizers in the individuals was also unrelated to demographic characteristics. Conclusion: Examination of the type and number of substances present in completed suicides is an important component in creating profiles of potential suicide victims.

The consumption of alcohol by Australian adolescents: A comparison of revenue and expenditure

Aims: To estimate (i) Australian government taxation revenue collected from the consumption of alcohol by adolescents and (ii) the amount spent by the government on interventions aimed at educating adolescents about the potential dangers of alcohol use. Design: Secondary data analysis. Setting: Australia. Findings: Australian adolescents (aged between 12 and 17 years, inclusive) spent approximately $217 million on alcoholic beverages in 2002, netting the Australian government approximately $112 million in tax revenue. This resulted in an average of $195 earned in tax per adolescent drinker. It is estimated that the Government spent approximately $17 million on adolescent drinking interventions in 2002, equating to an expenditure of about $10.51 per adolescent on the delivery of alcohol interventions. For every dollar spent on alcohol interventions aimed at adolescents, it is estimated that the government receives around $7 in alcohol tax revenue. Conclusions: A substantial disparity exists between the amount of tax revenue received by the Australian Government from adolescent drinkers and the overall amount spent in attempting to prevent and relieve some of the problems associated with adolescent problem drinking. (c) 2006 Elsevier Ltd. All rights reserved.

Prevalence of injecting drug use and associated risk behavior among regular ecstasy users in Australia

Background: The aim of the study was to investigate the prevalence of injecting drug use and associated risk behaviour among a sentinel sample of ecstasy users. Methods: Cross-sectional surveys were conducted with regular ecstasy users as part of an annual monitoring study of ecstasy and related drug markets in all Australian capital cities. Results: Twenty-three percent of the sample reported having ever injected a drug and 15% reported injecting in the 6 months preceding interview. Independent predictors of lifetime injection were older age, unemployment and having ever been in prison. Completion of secondary school and identifying as heterosexual was associated with a lower likelihood of having ever injected. Participants who had recently injected typically did so infrequently; only 9% reported daily injecting. Methamphetamine was the most commonly injected drug. Prevalence of needle sharing was low (6%), although half (47%) reported sharing other injecting equipment in the preceding 6 months. Conclusions: Ecstasy users who report having injected a drug at some time appear to be demographically different to ecstasy users who have not injected although neither are they typical of other drug injectors. The current investigation suggests that ongoing monitoring of injecting among regular ecstasy users is warranted. (c) 2005 Elsevier Ireland Ltd. All rights reserved.