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Biomedical subjects

S Darke

Publications and source records attributed to S Darke.

At least 37 records · Page 2Linked to original sources
PubMed1998

Antisocial personality disorder, psychopathy and injecting heroin use.

Two hundred community-based methadone patients (CM); 200 prison inmates enrolled in prison methadone programs (PM); and 150 prison inmates with no history of heroin use (PNH) were interviewed to obtain diagnoses of antisocial personality disorder (ASPD) and Psychopathy Checklist-defined psychopathy. Large proportions of subjects in all three groups met the criteria for a diagnosis of ASPD (CM 44%, PM 65%, PNH 31%), with the two methadone groups having significantly higher proportions of ASPD diagnoses than non-heroin users. There were no differences between groups in the proportions diagnosed as psychopathic (CM 4%, PM 9%, PNH 4%). For each group, the proportions diagnosed as ASPD were significantly higher than the proportions diagnosed as psychopathic. Implications for the diagnosis of ASPD are discussed.

Adolescent↗
PubMed1998

Self-report among injecting drug users: a review.

The use of behavioural self-reports of drug users is widespread among studies of illicit drug use. Despite widespread use, concerns about the accuracy of these reports continue to be raised. The current paper critically reviews the literature on the reliability and validity of self-reported drug use, criminality and HIV risk-taking among injecting drug users. The literature shows respectable reliability and validity of self-reported behaviours when compared to biomarkers, criminal records and collateral interviews. It concludes that the self-reports of drug users are sufficiently reliable and valid to provide descriptions of drug use, drug-related problems and the natural history of drug use.

Crime↗
PubMed1998

Experience of non-fatal overdose among heroin users in Adelaide, Australia: circumstances and risk perceptions.

AIMS: To ascertain the prevalence and risk factors for non-fatal overdose among heroin users to assist in the development of an effective intervention. DESIGN: Cross-sectional design. SETTING: Community setting, principally metropolitan Adelaide. PARTICIPANTS: Current heroin users (used heroin in the previous six months). MEASUREMENTS: A structured questionnaire including the Severity of Dependence Scale. FINDING: Of 218 current South Australian heroin users interviewed in 1996, 48% had experienced at least one non-fatal overdose their life-time (median: two overdoses), and 11% had overdosed in the previous 6 months. At some time, 70% had been present at someone else's overdose (median: three overdoses). At the time of their own most recent overdose, 52% had been using central nervous system depressants in addition to heroin, principally benzodiazepines (33%) and/or alcohol (22%). The majority of overdoses occurred in a private home (81%) and in the presence of other people (88%). Unrealistic optimism regarding the risk of overdose was evident across the sample. Despite almost half the sample reporting having had an overdose, and the belief expressed by respondents that on average about 50% of regular heroin users would overdose during their life-time 73% had, during the previous 6 months, "rarely" or "never" worried about possibly overdosing. Optimism regarding the possibility of future overdose was reduced in those with recent experience of overdose in comparison to the rest of the sample. A targeted intervention aimed at the reduction of overdose among heroin users is outlined.

Adolescent↗
PubMed1998

Drug use and injection risk-taking among prison methadone maintenance patients.

AIMS: To examine the drug use and injection risk-taking among incarcerated methadone maintenance (MM) patients; to determine the impact of a diagnosis of antisocial personality disorder (ASPD) on prison-based MM treatment; to compare incarcerated patients with community patients. DESIGN: Structured interview. SETTINGS: New South Wales (NSW) prisons and community methadone maintenance (MM) units. PARTICIPANTS: One hundred incarcerated MM patients and 183 community MM patients. MEASUREMENTS: Subjects were interviewed about drug use and needle risk-taking in the previous 6 months, and assessed for a diagnosis of ASPD. FINDINGS: Heroin had been used by 38% of prison MM patients in the 6 months prior to interview, on a median of 4.5 days. Forty-four per cent of prison patients had injected a drug in the preceding 6 months. A third (32%) of prison subjects had borrowed used injecting equipment within the preceding 6 months, and 35% had lent used injecting equipment to others. Community patients were more likely to have injected a drug in the preceding 6 months (84% vs. 44%), to have used heroin (72% vs. 38%) and to have done so more frequently (20 vs. 4.5 days). Prisoners, however, were more likely to have borrowed (32% vs. 15%) and lent (35% vs. 21%) injecting equipment in that time. While injecting at lower rates than their community counterparts, the injecting occasions of prisoners were of much higher levels of risk. A diagnosis of ASPD was unrelated to both drug use and needle risk-taking. CONCLUSIONS: Incarcerated patients injected less frequently than community patients, but had higher levels of needle risk-taking.

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↗
PubMed1997

The applicability of the dependence syndrome to amphetamine.

While current psychiatric taxonomies recognise a classification of amphetamine dependence, derived from the notion of an alcohol dependence syndrome, little research has validated that such a condition exists for this drug. Current amphetamine users (N = 331), were interviewed using the World Health Organization operationalisation of DSM-III-R substance dependence criteria, and a measure of the psychological components of dependence. Structural analyses indicated that a unidimensional dependence syndrome as assessed by DSM-III-R and DSM-IV criteria exists for amphetamine, and that physiological, psychological and behavioural indicators were all important in accounting for the variance in responses. It was demonstrated that the concept of a dependence syndrome is applicable to amphetamine, and that the inclusion of the amphetamine dependence syndrome in DSM-III-R and DSM-IV is valid.

Adult↗
PubMed1997

Polydrug dependence and psychiatric comorbidity among heroin injectors.

The prevalence of diagnoses of substance dependence, anxiety disorders and depressive disorders were estimated in a sample of 222 heroin injectors, using the Composite International Diagnostic Interview. Subjects had a median of three lifetime substance diagnoses and two current diagnoses. A total of 60% met the criteria for a lifetime anxiety disorder, and 51% had a current anxiety disorder. A depressive disorder was diagnosed in 41% of subjects, with 30% having a current diagnosis. There were significant positive correlations between the number of lifetime drug dependence diagnoses and the number of lifetime anxiety and affective disorders (r = 0.41), and the number of current drug dependence diagnoses and the number of current comorbid diagnoses (r = 0.32). After controlling for other variables, the only significant independent predictor of the number of lifetime and current dependence diagnoses was the number of comorbid diagnoses.

Adolescent↗
PubMed1997

A comparison of blood toxicology of heroin-related deaths and current heroin users in Sydney, Australia.

Blood toxicology results for deaths attributed to heroin overdose during 1995 in the South Western Sydney (SWS) region (n = 39) were compared with those of a sample of 100 current SWS heroin users who had injected within the preceding 24 h. Heroin-related deaths had a higher median concentration of morphine than current heroin users (0.35 versus 0.09 mg/l). However, there was substantial overlap between the blood morphine concentrations of the two groups, ranging from 0.08-1.45 mg/l. This range incorporated 90% of heroin-related deaths. A third of current users had morphine concentrations over twice the toxic blood morphine concentration employed by the analytical laboratories, and 7% had morphine levels higher than the median recorded for fatal cases. Alcohol was detected in 51% of fatal cases (median = 0.10 g/100 ml) compared with 1% of current heroin user. There was a significant negative correlation among fatal cases between blood morphine and blood alcohol concentrations (r2 = -0.41). There was no significant difference between groups in the proportions of subjects positive for blood benzodiazepines. The results raise questions about the mechanisms of death in what are termed overdoses, and about the role of alcohol in these fatalities.

Adolescent↗
PubMed1997

Transitions between routes of benzodiazepine administration among heroin users in Sydney.

A sample of 312 heroin users were interviewed regarding their benzodiazepine use. The majority (94%) had used benzodiazepines, 72% in the 6 months prior to interview. Benzodiazepine injecting was common, with 28% of the sample having injected these drugs, 13% in the 6 months preceding interview. Current benzodiazepine injectors showed greater polydrug use, injection-related HIV risk-taking behaviour, criminal involvement, psychological distress and injection-related health problems, as well as poorer general health, and an increased risk of having overdosed, than other users of benzodiazepines. Of those subjects who had injected benzodiazepines, 55% were no longer current benzodiazepine injectors. Concern for general health emerged as the most common reason for having made a transition away from injecting, and for being likely to make such a transition.

Administration, Oral↗
PubMed1997

The distribution of naloxone to heroin users.

Overdose deaths are a major contributor to excess mortality among heroin users. It has been proposed that opioid overdose morbidity and mortality could be reduced substantially by distributing the opioid antagonist naloxone to heroin users. The ethical issues raised by this proposal are evaluated from a utilitarian perspective. The potential advantages of naloxone distribution include the increased chance of comatose opioid users being quickly resuscitated by others present at the time of an overdose, naloxone's safety and its lack of abuse potential. The main problems raised by the proposal are: the medico-legal complications of medical practitioners prescribing a drug that is most likely to be administered to and by people other than the one for whom it is prescribed; the economic costs of distributing naloxone sufficiently widely to have an impact on overdose morbidity and mortality; and the potentially greater cost-effectiveness of simpler educational interventions. Given the possible benefits of naloxone distribution, it may be worthwhile considering a controlled trial of naloxone distribution to high-risk heroin users.

Decision Making↗
PubMed1996

Prevalence and correlates of the injection of methadone syrup in Sydney, Australia.

A sample of 312 heroin users was interviewed on their injection of methadone syrup. Methadone injecting was widespread, with 52% of subjects having injected methadone syrup, 29% in the preceding six months. Males and females were equally likely to report methadone injecting. Forty per cent of current methadone injectors reported weekly or more frequent methadone injecting over the preceding six months. A history of methadone injecting was associated with abscesses and infections in injection sites, having been diagnosed with a venous thrombosis and a history of heroin overdose. Current methadone injectors were in poorer general health, had more injection-related symptoms, higher levels of psychological distress, were more likely to have recently passed on used injecting equipment and to have recently committed criminal acts. Implications for the reduction in the prevalence of methadone injecting and associated harm are discussed.

Adolescent↗
PubMed1996

Heroin-related deaths in New South Wales, 1992: toxicological findings and circumstances.

OBJECTIVE: To describe the circumstances of death and toxicological findings in all heroin-related deaths in New South Wales in 1992. DESIGN: Coronial files of all cases of heroin-related deaths were reviewed. A standardised form was used to collect information on sociodemographics, history of drug use, circumstances of death, and results of toxicological analysis for each case. RESULTS: 152 heroin-related deaths were identified. Subjects had a mean age of 29.7 years, 82% were male, and 98% were not enrolled in a methadone treatment program at the time of their deaths. Deaths occurred in the home environment in 68% of cases and in the company of at least one other person in 58%. There was intervention before the subject's death in only 21% of cases. Two or more drug classes were detected in 71% of subjects; alcohol was detected in 45%, with a mean blood alcohol concentration of 0.14 g/100mL. CONCLUSIONS: Fatal heroin overdose is potentially preventable. Educating users about the risks of co-administering alcohol and other depressant drugs with heroin, the comparative safety of injecting heroin in the company of others and the need to call for intervention sooner may reduce the frequency of heroin-related deaths.

Adolescent↗
PubMed1996

Fatal heroin 'overdose': a review.

The current paper examines critically the literature on deaths attributed to heroin overdose, and examines the characteristics and circumstances of such deaths. In particular, the dominance of the widely held belief that heroin-related fatalities are a consequence of overdose is challenged. Deaths attributed to overdose represented in the literature are typically older, heroin-dependent males not in drug treatment at the time of death. Fatalities involving only heroin appear to form a minority of overdose occasions, the presence of other drugs (primarily central nervous system depressants such as alcohol and benzodiazepines) being commonly detected at autopsy. Furthermore, deaths attributed to overdose are likely to have morphine levels no higher than those who survive, or heroin users who die from other causes. It is concluded that the term overdose is, in many cases, a misleading term, since it implies the same mechanism of death in all cases, an implication that is neither clinically useful nor consistent with published data. Implications for the prevention of heroin-related deaths are discussed.

Adult↗
PubMed1996

Psychological morbidity and route of administration among amphetamine users in Sydney, Australia.

A sample of 301 amphetamine users were interviewed about their experiences of psychological symptoms prior to, and subsequent to, their initiation of amphetamine use. Psychological morbidity was common, with 44% scoring greater than a conservative cut-off of 8 on the General Health Questionnaire. The most commonly reported symptoms subsequent to the onset of amphetamine use were depression (79%), anxiety (76%), paranoia (52%), hallucinations (46%) and violent behaviour (44%). All these symptoms increased in prevalence after the onset of amphetamine use. Route and frequency of amphetamine administration were significant independent predictors of overall psychological morbidity, while route of administration was related to the experience of hallucinations, violent behaviour and paranoia. The avoidance of injection as a route of administration and the use of amphetamines less than weekly are recommended as steps that users can take to reduce the psychological sequelae of amphetamine use.

Adult↗
PubMed1996

Overdose among heroin users in Sydney, Australia: II. responses to overdose.

A sample of 329 heroin users were interviewed about their experiences at other peoples' heroin overdoses. The overwhelming majority (86%) had witnessed a heroin overdose, on a median of six occasions. Heroin users were reluctant to seek medical attention, with an ambulance being called on only half (56%) of the most recent overdose occasions. At only 17% of most recent overdoses was calling an ambulance the first action taken. Males reported taking significantly longer than females to call an ambulance. Nearly half (44%) of subjects reported that there were factors that had delayed or stopped them seeking medical assistance, the most common impediment being a fear of police involvement. The importance of interventions to encourage help-seeking at overdoses are discussed.

Adolescent↗
PubMed1996

Characteristics of admissions to residential drug treatment agencies in New South Wales, 1988-92: I. Illicit drug problems.

The Clients at Residential Agencies (CARA) database of the New South Wales Drug and Alcohol Directorate was analysed for trends in admissions of clients with illicit drug problems over the years 1988-92. The mean age of admissions rose from 26.8 years to 27.9 years over the study period. There was a small increase in the proportion of male admissions to agencies (66.5% in 1988 to 69.9% in 1992). The proportion of admissions reporting opiates as their primary drug problem declined from 81% to 65%, while the proportion of admissions for stimulant problems doubled in that period (8% to 16%), as did those for cannabis (3.6% to 8.7%). There was a significant increase in the proportions of admissions who had drug problems of 10 or more years' standing (34.9-41.3%). The proportion of admissions that had never been in treatment decreased from 51% to 15% over the study period. Admissions with prior methadone experience rose from 37% to 69% between 1988 and 1992.

Journal Article↗
PubMed1996

Characteristics of admissions to residential drug treatment agencies in New South Wales, 1988-92: II. Alcohol problems.

The Clients at Residential Agencies (CARA) database of the New South Wales Drug and Alcohol Directorate was analysed for trends in admissions of clients with alcohol problems over the years 1988-92. There were no changes in the mean age and sex ratio of admissions, with the treatment population in all years predominantly males in their mid-thirties. There was a decrease in the proportion of clients who were employed full-time (25.1-16.4%), and an increase in admissions with criminal histories (45.7-59.3%). More than half of admissions in all years had alcohol problems of greater then 10 years' standing. The percentage of people who had never been in treatment before decreased from 44.4% in 1988 to 18.7% in 1992.

Journal Article↗