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Biomedical subjects

W Hall

Publications and source records attributed to W Hall.

At least 73 records · Page 4Linked to original sources
PubMed1999

Prevalence of illicit drug use among youth: results from the Australian School Students' Alcohol and Drugs Survey.

OBJECTIVE: To estimate the prevalence of illicit drug use among Australian secondary school students. METHOD: Data was collected as part of the Australian School Student's Alcohol and Drugs Survey, a national survey of 29,447 secondary school students. RESULTS: Of all students aged 12-17 years, 39.9% (44.1% of males and 35.9% of females) reported having used at least one illicit drug in their lifetime. Cannabis was the most widely used illicit drug with 36.4% of all students reporting having used cannabis. Substantially fewer students reported using other drugs: hallucinogens (8.6%), amphetamines (6.1%), cocaine (3.6%), ecstasy (3.6%), opiates (3.7%) and steroids (1.8%). There were clear gender and age differences in the prevalence of illicit drug use: more males than females reported illicit drug use and the lifetime prevalence of illicit drug use increased with age. Most of those who reported illicit drug use had used drugs on relatively few occasions although there was a small minority of the sample who reported more frequent use. Finally, there were strong association between regular cannabis use and the use of other illicit drugs in the past year, and moderate associations between illicit drug use and the extent of both tobacco and alcohol use. CONCLUSIONS: The findings of this, the first national survey of illicit drug use among Australian school students, indicate a high prevalence of illicit drug use. Comparisons with previous regionally based surveys suggest there may have been a recent increase in the prevalence of cannabis use and highlight the need for further monitoring of and prevention efforts aimed at reducing illicit drug use among students.

Adolescent↗
PubMed1999

The 12-month prevalence of substance use and ICD-10 substance use disorders in Australian adults: findings from the National Survey of Mental Health and Well-Being.

AIMS: To present the prevalence of substance use and ICD-10 substance use disorders in the adult Australian population using data from the National Survey of Mental Health and Well-Being (NSMHWB). DESIGN: A cross-sectional survey assessing substance use and ICD substance use disorders (harmful use and dependence). SETTING AND PARTICIPANTS: A household survey of a nationally representative sample of 10,641 Australian adults (aged 18 years or older). MEASUREMENTS: Trained survey interviewers administered a structured interview based on the Composite International Diagnostic Interview (CIDI). FINDINGS: In the past 12 months 6.5% of the sample had an ICD-10 alcohol use disorder (95% CI: 6.2, 6.9), and 2.2% had another drug use disorder (95% CI: 2.0, 2.4). More males than females had substance use disorders: 9.5% of males (95% CI: 8.5, 10.5) and 3.6% of females (95% CI: 3.2, 4.0) met criteria for an alcohol use disorder, and 3.2% of males (95% CI: 2.8, 3.6) and 1.3% of females (95% CI: 0.9, 1.7) met criteria for another drug use disorder within the past 12 months. The prevalence of substance use disorders decreased with increasing age: 10.5% of respondents aged 18-34 years met criteria for an alcohol use disorder and 4.8% met criteria for a drug use disorder. The rates of these disorders among those aged 55 years or older were 1.8% and 0.1%, respectively. Substance use disorders were more prevalent among the unemployed, those who had never married and those who were Australian-born. CONCLUSIONS: The prevalence of substance use disorders in the Australian population is comparable to that in other English-speaking countries.

Adult↗
PubMed1998

Adverse effects of cannabis.

Cannabis is the most widely used illicit drug in many developed societies. Its health and psychological effects are not well understood and remain the subject of much debate, with opinions on its risks polarised along the lines of proponents' views on what its legal status should be. An unfortunate consequence of this polarisation of opinion has been the absence of any consensus on what health information the medical profession should give to patients who are users or potential users of cannabis. There is conflicting evidence about many of the effects of cannabis use, so we summarise the evidence on the most probable adverse health and psychological consequences of acute and chronic use. This uncertainty, however, should not prevent medical practitioners from advising patients about the most likely ill-effects of their cannabis use. Here we make some suggestions about the advice doctors can give to patients who use, or are contemplating the use, of this drug.

Adolescent↗
PubMed1998

Trends in opiate overdose deaths in Australia 1979-1995.

AIMS: To determine if there had been an increase in the rate of opioid overdose deaths between 1979 and 1995, and to describe the characteristics of persons who died of an opioid overdose. METHOD: Opioid overdose deaths were defined according to ICD-9 as deaths due to drug dependence (codes 304.0 and 304.7) and accidental opiate poisoning (code E850.0). Data were obtained from a national register of deaths compiled by the Australian Bureau of Statistics on: age at death, sex and jurisdiction of all such deaths between 1979 and 1995 inclusive. Mortality rates were calculated for each sex for the 15-24, 25-34 and 35-44 age groups. RESULTS: The number of opioid overdose deaths rose from 70 in 1979 to 550 in 1995. The rate (per million of the population aged 15-44) increased from 10.7 to 67.0. The increase was more marked among males than females, increasing 6.8 times among males (from 15.3 in 1979 to 104.6 in 1995) and 4.7 times among females (from 5.9 in 1979 to 27.9 in 1995). New South Wales consistently accounted for around a half of all male overdose fatalities and its overdose mortality rate was almost twice that in Victoria, and three times that in the remaining states. The average age at death for males increased from 24.5 years in 1979 to 30.6 years in 1995. The increase in overdose mortality was greatest among men and women aged 35 to 44 years, and 25 and 34 years. An analysis by birth cohort showed that 46% of male overdose deaths and 50% of female overdose deaths in the period occurred among those born between 1960 and 1969. Deaths among persons born between 1950 and 1959 accounted for 38% of male and 33% of female deaths. CONCLUSIONS: There has been a statistically significant increase in opioid overdose mortality between 1979 and 1995, most of it occurring among persons who initiated heroin use in the late 1970s and early 1980s. Recent initiations of heroin use among those born between 1970 and 1979 have begun to be reflected in an increased rate of opioid overdose deaths. If their mortality experience replicates that of earlier birth cohorts then opioid overdose mortality will continue to increase.

Adolescent↗
PubMed1998

A mathematical model of HIV transmission in NSW prisons.

A mathematical model was developed to estimate HIV incidence in NSW prisons. Data included: duration of imprisonment; number of inmates using each needle; lower and higher number of shared injections per IDU per week; proportion of IDUs using bleach; efficacy of bleach; HIV prevalence and probability of infection. HIV prevalence in IDUs in prison was estimated to have risen from 0.8 to 6.7% (12.2%) over 180 weeks when using lower (and higher) values for frequency of shared injections. The estimated minimum (and maximum) number of IDU inmates, infected with HIV in NSW prisons was 38 (and 152) in 1993 according to the model. These figures require confirmation by seroincidence studies.

Databases, Factual↗
PubMed1998

Choosing a diagnostic cut-off for cannabis dependence.

AIM: While cannabis dependence has been increasingly recognized, there is little research on the measurement issues involved in operationalizing the dependence syndrome for this drug. This paper aimed to investigate the diagnostic utility and appropriate diagnostic cut-offs of three short dependence measures among long-term cannabis users. SETTING AND PARTICIPANTS: Two hundred long-term, regular cannabis users were recruited and interviewed in Sydney, Australia. MEASUREMENTS: Receiver Operating Characteristic analyses compared the diagnostic performance of the short University of Michigan CIDI, a measure of ICD-10 dependence and the Severity of Dependence Scale against the "gold standard" of moderate or more severe DSM-III-R cannabis dependence, as diagnosed by the Substance Abuse Module of the CIDI. FINDINGS: The measures were of equal utility in diagnosing at least moderate DSM-III-R cannabis dependence. While the optimal diagnostic cut-offs for the short University of Michigan CIDI and the ICD-10 dependence measure remained unchanged from those conventionally applied, a more liberal cut-off was optimal for the Severity of Dependence Scale. The amended prevalence of cannabis dependence was 77% using the short University of Michigan CIDI, 72% by the ICD-10 measure and 62% by the Severity of Dependence Scale. CONCLUSIONS: The three instruments were able to diagnose cannabis dependence at levels substantially better than chance. They were generally robust in terms of the optimal diagnostic cut-off in a population of long-term cannabis users. This paper provides guidelines for choosing optimal cut-offs within different contexts.

Adolescent↗
PubMed1998

Long-term cannabis use: characteristics of users in an Australian rural area.

AIM: To investigate the characteristics and patterns of cannabis and other drug use among long-term cannabis users in an Australian rural area. DESIGN: Cross-sectional survey of a "snowball" sample of long-term cannabis users. SETTING: The North Coast of New South Wales is an area with high levels of cannabis cultivation and use, and many long-term users. PARTICIPANTS: The study involved 268 long-term cannabis users who had regularly used cannabis for at least 10 years. MEASUREMENTS: A structured interview schedule obtained information on: demographics, social circumstances, patterns of cannabis and other drug use, contexts of use, perceptions about cannabis and legal involvement. FINDINGS: The mean age of the sample was 36 years and 59% were made. The median length of regular cannabis use was 19 years. Most (94%) used two or more times a week and 60% used daily, with a median of two joints per day. Two-thirds (67%) used cannabis in social settings and two-thirds grew cannabis for their own use. The most common reasons for using cannabis were for relaxation or relief of tension (61%) and enjoyment or to feel good (27%). The most commonly reported negative effects were feelings of anxiety, paranoia, or depression (21%), tiredness, lack of motivation and low energy (21%) and effects of smoke on the respiratory system (18%). The majority drank alcohol (79%) and over one-third were drinking at hazardous levels. Most were current (64%) or ex-tobacco smokers (24%). One-quarter (25%) had been charged with possession of cannabis, 11% for cultivation and 6% for supply, with non-drug offences low (8%or less). Overall, three-quarters (72%) believed that the benefits of cannabis use outweighed the risks, 21% felt there was an even balance, and 7% said cannabis had done them more harm than good. CONCLUSIONS: Among long-term cannabis users in this Australian rural area, cannabis use was an integral part of everyday life and it was primarily used in social situations for the same reasons that alcohol use is used in the wider community.

Adult↗
PubMed1998

Patterns and correlates of cannabis dependence among long-term users in an Australian rural area.

AIM: To examine prevalence and correlates of cannabis dependence among long-term cannabis users. DESIGN: A cross-sectional survey of patterns and experiences of cannabis use and dependence. SETTING AND PARTICIPANTS: A snowball sample of 243 long-term cannabis smokers, who were currently smoking 3-4 times a week, were recruited from the New South Wales North Coast, an area long associated with cannabis cultivation and use. MEASUREMENTS: A structured interview was administered, incorporating the following dependence measures: an approximation to a life-time DSM-III-R diagnosis, an approximation to a 12-month ICD-10 diagnosis, and the Severity of Dependence Scale (SDS). FINDINGS: Prevalence of a life-time DSM-III-R diagnosis of cannabis dependence was 57%, while 57% received an ICD-10 dependence diagnosis for the last year. Substantially fewer (15%) of the sample were diagnosed as dependent according to the Severity of Dependence Scale (SDS). Only 26% believed they had a problem with cannabis at least sometimes. There was general concordance between DSM-III-R and ICD-10 measures, but not between these and the SDS. ICD-10 and DSM-III-R dependence diagnoses were modestly correlated with age, life-time illicit drug use and quantity of cannabis use. Principal components analyses of the dependence measures provided little evidence for a unidimensional dependence syndrome for ICD-10 and DSM-III-R criteria. There was strong support for unidimensionality of the SDS. CONCLUSIONS: Symptoms of cannabis dependence were common among these long-term users but only one-quarter perceived that they had a cannabis problem. There was no strong evidence for a unidimensional cannabis dependence syndrome.

Cross-Sectional Studies↗
PubMed1998

An evaluation of Cloninger's typology of alcohol abuse.

AIMS: To evaluate Cloninger's typology of "alcoholism" using the Alcohol Symptom Scale (Gilligan et al., 1987). PARTICIPANTS: A sample of 300 Australian men and women with a life-time diagnosis of DSM-III-R alcohol abuse/dependence. MEASURES: The Alcohol Dependence Scale, the Short Alcoholism Screening Test, the Composite International Diagnostic Interview (CIDI) Substance Abuse Module, the Brief Symptom Inventory, the CIDI core modules, the Family History Questionnaire and the Sensation Seeking Scale. FINDINGS: The Alcohol Symptom Scale classified only 18% of the sample into either type 1 or type 2. There was mixed support for the hypothesized differences between type 1 and type 2 problem drinkers in pattern of alcohol abuse, gender, personality characteristics and familial aggregation of alcohol abuse. More women than men were classified as type 1 (19% vs. 6%) but, contrary to expectations, similar numbers were classified as type 2 problem drinkers (7% vs. 4%). As predicted, type 2 problem drinkers had more symptoms of antisocial personality disorder, more social consequences of drinking and higher sensation-seeking scores than type 1 problem drinkers. CONCLUSIONS: Cloninger's typology failed to classify two types of problem drinkers and it did not predict gender differences in symptoms of alcohol dependence, family history or personality. Schuckit, Irwin & Mahler's (1990) hypothesis that type 2 problem drinkers are more likely to have primary ASPD was supported.

Adult↗
PubMed1998

Nursing's metaparadigm concepts: disimpacting the debates.

Theoretical advances in nursing have been complicated by polarization and extreme positions regarding nursing's approach to its main metaparadigm concepts: person, health, environment and nursing. In this paper, the authors deconstruct some of the central arguments that are used to further this polarization. Using a critical interpretive approach, they explain some of the logical implications imposed by various extreme positions for the larger project of nursing's health and social mandate, and consider the effects of such polarization. On the basis of an appreciation of the serious difficulties inherent in certain philosophical and theoretical positions currently evident within nursing's literature, the authors argue for a less extreme and more integrated reference point for nursing's theory and practice.

Disease↗
PubMed1998

Cohort trends in age of initiation to heroin use.

This paper examines gender differences and trends over time in the age of initiation to heroin use. Data from two large surveys: the Sydney component of the ANAIDUS, conducted in 1989, and the ASHIDU, conducted in 1994, were used to examine this issue. Together, these studies contained information on 1,292 individuals who identified themselves as heroin users. Results indicated that, while there were no significant gender differences in age of initiation to heroin use, there was a significant (p < 0.001) time trend in the mean age at which heroin was first used. Specifically, the mean age of first heroin use among individuals born during the interval 1940-1949 was 20.5 years while among those born during 1970-1979 the mean age of first heroin use was 16.5 years. These findings were confirmed by analyses of the National Household Survey. Further analysis of the ASHIDU data indicated that younger age of initiation to heroin use was associated with polydrug use, overdose and crime after the effects of duration of heroin use had been statistically controlled. These findings suggest that there has been both an increase in the willingness of young people to experiment with heroin and an increased availability of the drug over this time. In combination with evidence that there has been an increase in the amount of heroin being imported into Australia, and an increased demand for treatment for opiate dependence, these data suggest that Australia is experiencing an increase in the use of heroin, particularly among youth.

Journal Article↗
PubMed1998

Cannabis use and psychosis.

This paper reviews evidence on two hypotheses about the relationship between cannabis use and psychosis. The first hypothesis is that heavy cannabis use may cause a "cannabis psychosis"-a psychosis that would not occur in the absence of cannabis use, the symptoms of which are preceded by heavy cannabis use and remit after abstinence. The second hypothesis is that cannabis use may precipitate schizophrenia, or exacerbate its symptoms. Evaluation of these hypotheses requires evidence of an association between cannabis use and psychosis, that is unlikely to be due to chance, in which cannabis use precedes psychosis, and in which we can exclude the hypothesis that the relationship is due to other factors, such as other drug use, or a personal vulnerability to psychosis. There is some clinical support for the first hypothesis. If these disorders exist they seem to be rare, because they require very high doses of THC, the prolonged use of highly potent forms of cannabis, or a pre-existing (but as yet unspecified) vulnerability. There is more support for the second hypothesis, in that a large prospective study has shown a linear relationship between the frequency with which cannabis has been used by age 18 and the risks over the subsequent 15 years of a diagnosis of schizophrenia. It is still unclear whether this means that cannabis use precipitates schizophrenia, whether it is a form of "self-medication", or whether the association is due to the use of other drugs, such as amphetamines, which heavy cannabis users are more likely to use. There is stronger evidence that cannabis use can exacerbate the symptoms of schizophrenia. Mental health services should identify patients with schizophrenia who use alcohol, cannabis and other drugs and advise them to abstain or to greatly reduce their drug use.

Journal Article↗
PubMed1998

Jurisdictional trends in opioid overdose deaths, 1988-96.

This report analysed data on opioid overdose mortality between 1988 and 1996 to: examine differences between jurisdictions in the rate of fatal opioid overdose and the rate of increase in overdose; and estimate the proportion of all deaths which were attributed to opioid overdose. Australian Bureau of Statistics (ABS) data were obtained on the number of deaths attributed to opioid dependence (ICD 9 codes 304.0, 304.7) and accidental opioid poisoning (ICD 9 codes E850.0, E850.1). The highest rate of fatal overdose occurred in NSW, followed by Victoria. The standardised mortality rate among other jurisdictions fluctuated quite markedly. While the rate of opioid overdose has increased throughout Australia, the rate of increase has been greater in some of the less-populous states and territories than it has in NSW or Victoria. In 1996, approximately 6.5% of all deaths among people aged 15-24 years and approximately 10% of all deaths among those aged 25-34 were due to opioid overdose. During the interval from 1988 to 1996, the proportion of deaths attributed to opioid overdose increased. From 1988 to 1996, the proportion of deaths attributed to opioid overdose among individuals aged 25-34 years was approximately one-third that attributed to suicide, but this proportion had increased to approximately one-half by 1996. The rate of increase in the proportion of deaths attributed to opioid overdose was higher than the rate of increase in the proportion of deaths attributed to suicide.

Adolescent↗
PubMed1998

Characteristics of long-term cannabis users in Sydney, Australia.

Two hundred long-term cannabis users (58% male) were interviewed on their characteristics and experience of use. Respondents had been regularly using cannabis for an average of 11 years and more than half used daily (56%). The most common route of administration was in a waterpipe, and nearly all (93%) smoked the flowering heads ot the plant. One in 5 (21%) had a cannabis-related conviction. The benefits of use were perceived to be its relaxing, mood-enhancing effects, and its ability to alter consciousness. The most commonly cited negative aspects of use were cost, negative psychological effects and legal status. Polydrug use was common, with alcohol and tobacco almost universally used on a regular basis. More than half the drinkers in the sample were consuming alcohol at hazardous or harmful levels.

Adolescent↗
PubMed1998

Factor structure of psychopathy among methadone maintenance patients.

The proposed two-factor structure of the Psychopathy Checklist (Revised) was assessed by confirmatory factor analyses on a sample of 376 community and prison based methadones maintenance patients. Confirmatory factor analyses indicated that the two-factor model proposed by previous researchers did not fit well with the data from this population. Exploratory analyses extracted five interpretable factors, three psychological factors (glibness/manipulative, callousness, irresponsibility), and two behavioral factors (criminal behaviors, promiscuity), which accounted for 61% of the variance. The data provided support for the psychometric reliability of the PCL-R, as indicated by a Chronbach's alpha of 0.83, weighted kappas for concordance between raters ranging from 0.51 to 1.00, and 100% agreement on diagnoses of psychopathy between raters. The data indicate that a two-factor structure does not adequately capture the dimensions of psychopathy in this population. While the factors do fall into distinct psychological and behavioral dimensions, more than two general factors are required to describe the dimensions of psychopathy.

Adult↗