Search PubMed⌕ Search

Biomedical subjects

Wayne Hall

Publications and source records attributed to Wayne Hall.

At least 37 records · Page 2Linked to original sources
PubMed2005

The impact of changes to heroin supply on blood-borne virus notifications and injecting related harms in New South Wales, Australia.

BACKGROUND: In early 2001 Australia experienced a sudden and unexpected disruption to heroin availability, know as the 'heroin shortage'. This 'shortage has been linked to a decrease in needle and syringe output and therefore possibly a reduction in injecting drug use. We aimed to examine changes, if any, in blood-borne viral infections and presentations for injecting related problems related to injecting drug use following the reduction heroin availability in Australia, in the context of widespread harm reduction measures. METHODS: Time series analysis of State level databases on HIV, hepatitis B, hepatitis C notifications and hospital and emergency department data. Examination of changes in HIV, hepatitis B, hepatitis C notifications and hospital and emergency department admissions for injection-related problems following the onset of the heroin shortage; non-parametric curve-fitting of number of hepatitis C notifications among those aged 15-19 years. RESULTS: There were no changes observed in hospital visits for injection-related problems. There was no change related to the onset heroin shortage in the number of hepatitis C notifications among persons aged 15-19 years, but HCV notifications have subsequently decreased in this group. No change occurred in HIV and hepatitis B notifications. CONCLUSION: A marked reduction in heroin supply resulted in no increase in injection-related harm at the community level. However, a delayed decrease in HCV notifications among young people may be related. These changes occurred in a setting with widespread, publicly funded harm reduction initiatives.

Adolescent↗
PubMed2005

Was an increase in cocaine use among injecting drug users in New South Wales, Australia, accompanied by an increase in violent crime?

BACKGROUND: A sharp reduction in heroin supply in Australia in 2001 was followed by a large but transient increase in cocaine use among injecting drug users (IDU) in Sydney. This paper assesses whether the increase in cocaine use among IDU was accompanied by increased rates of violent crime as occurred in the United States in the 1980s. Specifically, the paper aims to examine the impact of increased cocaine use among Sydney IDU upon police incidents of robbery with a weapon, assault and homicide. METHODS: Data on cocaine use among IDU was obtained from the Illicit Drug Reporting System (IDRS). Monthly NSW Police incident data on arrests for cocaine possession/use, robbery offences, homicides, and assaults, were obtained from the Bureau of Crime Statistics and Research. Time series analysis was conducted on the police data series where possible. Semi-structured interviews were conducted with representatives from law enforcement and health agencies about the impacts of cocaine use on crime and policing. RESULTS: There was a significant increase in cocaine use and cocaine possession offences in the months immediately following the reduction in heroin supply. There was also a significant increase in incidents of robbery where weapons were involved. There were no increases in offences involving firearms, homicides or reported assaults. CONCLUSION: The increased use of cocaine among injecting drug users following the heroin shortage led to increases in violent crime. Other States and territories that also experienced a heroin shortage but did not show any increases in cocaine use did not report any increase in violent crimes. The violent crimes committed did not involve guns, most likely because of its stringent gun laws, in contrast to the experience of American cities that have experienced high rates of cocaine use and violent crime.

Cocaine-Related Disorders↗
PubMed2005

The impact of a reduction in drug supply on demand for and compliance with treatment for drug dependence.

BACKGROUND: In early 2001, Australia experienced a sudden, dramatic and sustained decrease in heroin availability that was accompanied by sharp increases in price and decreases in street level purity--the so-called "heroin shortage". These unprecedented changes occurred in a context of widespread treatment availability, which made it possible for the first time to examine the impact of a sharp reduction in heroin supply in New South Wales (NSW) on entry to and adherence with treatment for heroin dependence. Given the evidence of drug substitution by some users, the current paper also examines the effects of the shortage on entry to treatment for other forms of drug dependence. METHODS: Interrupted time-series analysis of the number of persons entering opioid pharmacotherapy and other treatment modalities in NSW for heroin dependence and for the treatment for other types of drug dependence. FINDINGS: The heroin shortage was associated with a reduction in the number of younger persons entering opioid pharmacotherapy. There was a dramatic decrease in the number of persons entering heroin withdrawal or "assessment only" treatment episodes. There appear to have been small improvements in adherence to and retention in heroin treatment after the reduction in heroin supply. Relatively small increases were observed in numbers being treated for cocaine dependence. CONCLUSIONS: In the context of good treatment provision, a reduction in heroin supply appeared to produce modest improvements in intermediate outcomes. Supply and demand reduction measures, when both are implemented successfully, may be complementary.

Cocaine↗
PubMed2005

Cannabinoids and cancer: causation, remediation, and palliation.

This review discusses three different associations between cannabinoids and cancer. First, it assesses evidence that smoking of cannabis preparations may cause cancers of the aerodigestive and respiratory system. There have been case reports of upper-respiratory-tract cancers in young adults who smoke cannabis, but evidence from a few epidemiological cohort studies and case-control studies is inconsistent. Second, there is mixed evidence on the effects of THC and other cannabinoids on cancers: in some in vitro and in vivo studies THC and some synthetic cannabinoids have had antineoplastic effects, but in other studies THC seems to impair the immune response to cancer. As yet there is no evidence that THC or other cannabinoids have anticancer effects in humans. Third, Delta(9)-tetrahydrocannabinol (THC) may treat the symptoms and side-effects of cancer, and there is evidence that it and other cannabinoids may be useful adjuvant treatments that improve appetite, reduce nausea and vomiting, and alleviate moderate neuropathic pain in patients with cancer. The main challenge for the medical use of cannabinoids is the development of safe and effective methods of use that lead to therapeutic effects but that avoid adverse psychoactive effects. Furthermore, medical, legal, and regulatory obstacles hinder the smoking of cannabis for medical purposes. These very different uses of cannabinoids are in danger of being confused in public debate, especially in the USA where some advocates for the medical use of cannabinoids have argued for smoked cannabis rather than pharmaceutical cannabinoids. We review the available evidence on these three issues and consider their implications for policy.

Analgesics↗
PubMed2005

Evaluating explanations of the Australian 'heroin shortage'.

AIMS: In this paper we outline and evaluate competing explanations for a heroin shortage that occurred in Australia during 2001 with an abrupt onset at the beginning of 2001. METHODS: We evaluated each of the explanations offered for the shortage against evidence from a variety of sources: government reports, police and drug law enforcement documents and briefings, key informant (KI) interviews, indicator data and research data. RESULTS: No similar shortage occurred at the same time in other markets (e.g. Vancouver, Canada or Hong Kong) whose heroin originated in the same countries as Australia's. The shortage was due most probably to a combination of factors that operated synergistically and sequentially. The heroin market had grown rapidly in the late 1990s, perhaps helped by a decline in drug law enforcement (DLE) in Australia in the early 1990s that facilitated high-level heroin suppliers in Asia to establish large-scale importation heroin networks into Australia. This led to an increase in the availability of heroin, increasingly visible street-based drug markets, increased purity and decreased price of heroin around the country. The Australian heroin market was well established by the late 1990s, but it had a low profit margin with high heroin purity, and a lower price than ever before. The surge in heroin problems led to increased funding of the Australian Federal Police and Customs as part of the National Illicit Drug Strategy in 1998-99, with the result that a number of key individuals and large seizures occurred during 1999-2000, probably increasing the risks of large-scale importation. The combination of low profits and increased success of law enforcement may have reduced the dependability of key suppliers of heroin to Australia at a time when seized heroin was becoming more difficult to replace because of reduced supplies in the Golden Triangle. These factors may have reduced the attractiveness of Australia as a destination for heroin trafficking. CONCLUSIONS: The Australian heroin shortage in 2001 was due probably to a combination of factors that included increased effectiveness of law enforcement efforts to disrupt networks bringing large shipments of heroin from traditional source countries, and decreased capacity or willingness of major traffickers to continue large scale shipments to Australia.

Australia↗
PubMed2005

Effects of a sustained heroin shortage in three Australian States.

BACKGROUND: In early 2001 in Australia there was a sudden and dramatic decrease in heroin availability that occurred throughout the country that was evidenced by marked increases in heroin price and decreases in its purity. AIM: This study examines the impact of this change in heroin supply on the following indicators of heroin use: fatal and non-fatal drug overdoses; treatment seeking for heroin dependence; injecting drug use; drug-specific offences; and general property offences. The study was conducted using data from three Australian States [New South Wales (NSW), Victoria (VIC) and South Australia (SA)]. METHODS: Data were obtained on fatal and non-fatal overdoses from hospital emergency departments (EDs), ambulance services and coronial systems; treatment entries for heroin dependence compiled by State health departments; numbers of needles and syringes distributed to drug users; and data on arrests for heroin-related incidents and property-related crime incidents compiled by State Police Services. Time-series analyses were conducted where possible to examine changes before and after the onset of the heroin shortage. These were supplemented with information drawn from studies involving interviews with injecting drug users. RESULTS: After the reduction in heroin supply, fatal and non-fatal heroin overdoses decreased by between 40% and 85%. Despite some evidence of increased cocaine, methamphetamine and benzodiazepine use and reports of increases in harms related to their use, there were no increases recorded in the number of either non-fatal overdoses or deaths related to these drugs. There was a sustained decline in injecting drug use in NSW and VIC, as indicated by a substantial drop in the number of needles and syringes distributed (to 1999 levels in Victoria). There was a short-lived increase in property crime in NSW followed by a sustained reduction in such offences. SA and VIC did not show any marked change in the categories of property crime examined in the study. CONCLUSIONS: Substantial reductions in heroin availability have not occurred often, but in this Australian case a reduction had an aggregate positive impact in that it was associated with: reduced fatal and non-fatal heroin overdoses; reduced the apparent extent of injecting drug use in VIC and NSW; and may have contributed to reduced crime in NSW. All these changes provide substantial benefits to the community and some to heroin users. Documented shifts to other forms of drug use did not appear sufficient to produce increases in deaths, non-fatal overdoses or treatment seeking related to those drugs.

Adolescent↗
PubMed2004

Neuroscience research on the addictions: a prospectus for future ethical and policy analysis.

The increasing evidence that many addictive phenomena have a genetic and neurobiological basis promises improvements in societal responses to addiction that raise important ethical and social policy issues. One of the major potential benefits of such research is improved treatment of drug addiction, but in order to do the research required to realize this promise, it will be necessary to address ethical doubts raised about the capacity of addicted persons to give free and informed consent to participate in studies that involve the administration of drugs of dependence. Neuroscience research on addiction promises to transform the long running debate between moral and medical models of addiction by providing a detailed causal explanation of addiction in terms of brain processes. We must avoid causal models of addiction being misinterpreted as supporting simple-minded social policies, e.g., that we identify the minority of the community that is genetically and biologically vulnerable to addiction and hence can neglect social policy options for reducing addiction, including drug control policies. Causal accounts of addiction supplied by neuroscience and genetic research may also be seen to warrant the use of pharmacotherapies and drug vaccines under legal coercion. Neuroscientists also need to anticipate the ethical issues that may arise if the knowledge that they produce delivers interventions that enhance human cognitive and other capacities. Advances in neuroimaging that enable us to identify "addicts" or predict future risk of addiction will raise concerns about invasion of privacy, third-party use of neuroimaging data, the powers of courts to coerce defendants to undergo such tests, and consumer protection against the overinterpretation of test results. Given the strong public and media interest in the results of their research, neuroscientists and geneticists have a moral obligation, and a professional interest, to minimize popular misunderstandings of their work in the media that may rebound to its detriment.

Animals↗
PubMed2004

Cannabis use and psychotic disorders: an update.

This paper evaluates three hypotheses about the relationship between cannabis use and psychosis in the light of recent evidence from prospective epidemiological studies. These are that: (1) cannabis use causes a psychotic disorder that would not have occurred in the absence of cannabis use; (2) that cannabis use may precipitate schizophrenia or exacerbate its symptoms; and (3) that cannabis use may exacerbate the symptoms of psychosis. There is limited support for the first hypothesis. As a consequence of recent prospective studies, there is now stronger support for the second hypothesis. Four recent prospective studies in three countries have found relationships between the frequency with which cannabis had been used and the risk of receiving a diagnosis of schizophrenia or of reporting psychotic symptoms. These relationships are stronger in people with a history of psychotic symptoms and they have persisted after adjustment for potentially confounding variables. The absence of any change in the incidence of schizophrenia during the three decades in which cannabis use in Australia has increased makes it unlikely that cannabis use can produce psychoses that would not have occurred in its absence. It seems more likely that cannabis use can precipitate schizophrenia in vulnerable individuals. There is also reasonable evidence for the third hypothesis that cannabis use exacerbates psychosis.

Australia↗
PubMed2004

The contribution of research to Australian policy responses to heroin dependence 1990-2001: a personal retrospection.

Periodic public concern about heroin use has been a major driver of Australian drug policy in the four decades since heroin use was first reported. The number of heroin-dependent people in Australia has increased from several hundreds in the late 1960s to around 100,000 by the end of the 1990s. In this paper I do the following: (1) describe collaborative research on heroin dependence that was undertaken between 1991 and 2001 by researchers at the National Drug and Alcohol Research Centre; (2) discuss the contribution that this research may have made to the formulation of policies towards the treatment of heroin dependence during a period when the policy debate crystallized around the issue of whether or not Australia should conduct a controlled trial of heroin prescription; and (3) reflect on the relationships between research and policy-making in the addictions field, specifically on the roles of investigator-initiated and commissioned research, the interface between researchers, funders and policy-makers; and the need to be realistic about the likely impact of research on policy and practice.

Australia↗
PubMed2003

A randomised controlled trial of methadone maintenance treatment versus wait list control in an Australian prison system.

OBJECTIVES: The aim was to determine whether methadone maintenance treatment reduced heroin use, syringe sharing and HIV or hepatitis C incidence among prisoners. METHODS: All eligible prisoners seeking drug treatment were randomised to methadone or a waitlist control group from 1997 to 1998 and followed up after 4 months. Heroin use was measured by hair analysis and self report; drugs used and injected and syringe sharing were measured by self report. Hepatitis C and HIV incidence was measured by serology. RESULTS: Of 593 eligible prisoners, 382 (64%) were randomised to MMT (n=191) or control (n=191). 129 treated and 124 control subjects were followed up at 5 months. Heroin use was significantly lower among treated than control subjects at follow up. Treated subjects reported lower levels of drug injection and syringe sharing at follow up. There was no difference in HIV or hepatitis C incidence. CONCLUSIONS: Consideration should be given to the introduction of prison methadone programs particular where community based programs exist.

Adult↗
PubMed2003

Testing hypotheses about the relationship between cannabis use and psychosis.

AIM: To model the impact of rising rates of cannabis use on the incidence and prevalence of psychosis under four hypotheses about the relationship between cannabis use and psychosis. METHODS: The study modelled the effects on the prevalence of schizophrenia over the lifespan of cannabis in eight birth cohorts: 1940-1944, 1945-1949, 1950-1954, 1955-1959, 1960-1964, 1965-1969, 1970-1974, 1975-1979. It derived predictions as to the number of cases of schizophrenia that would be observed in these birth cohorts, given the following four hypotheses: (1) that there is a causal relationship between cannabis use and schizophrenia; (2) that cannabis use precipitates schizophrenia in vulnerable persons; (3) that cannabis use exacerbates schizophrenia; and (4) that persons with schizophrenia are more liable to become regular cannabis users. RESULTS: There was a steep rise in the prevalence of cannabis use in Australia over the past 30 years and a corresponding decrease in the age of initiation of cannabis use. There was no evidence of a significant increase in the incidence of schizophrenia over the past 30 years. Data on trends the age of onset of schizophrenia did not show a clear pattern. Cannabis use among persons with schizophrenia has consistently been found to be more common than in the general population. CONCLUSIONS: Cannabis use does not appear to be causally related to the incidence of schizophrenia, but its use may precipitate disorders in persons who are vulnerable to developing psychosis and worsen the course of the disorder among those who have already developed it.

Adult↗