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Biomedical subjects

S Darke

Publications and source records attributed to S Darke.

At least 55 records · Page 3Linked to original sources

Benzodiazepine use among heroin users in Sydney: patterns of use, availability and procurement.

A sample of 210 heroin users who had used benzodiazepines during the preceding 6 months were interviewed about their benzodiazepine use. Forty-one percent of the sample reported having used benzodiazepines more than once a week during the 6 months preceding interview. Forty-eight percent had injected benzodiazepines, with 17% having done so during the preceding 6 months. Eleven percent of the sample reported having experienced convulsions when attempting detoxification from benzodiazepines. The majority of subjects (86%) indicated that benzodiazepines are easy or very easy to obtain. Only a third of the sample reported obtaining benzodiazepines exclusively through a doctor in the last 6 months. Over a half of the sample indicated that they had given or sold benzodiazepines to someone during that time. Diazepam was considered by subjects to be the easiest benzodiazepine to procure. Doctors should avoid the prescription of benzodiazepines to injecting drug users, particularly the more readily injectable drug temazepam. Given the widespread use of benzodiazepines by injection, research needs to examine the harm associated with the parenteral use of these drugs.

Journal Article↗

Anti-social personality disorder and response to methadone maintenance treatment.

A sample of 183 current methadone maintenance patients were interviewed on their drug use history, criminal history, current drug use, and symptoms of Anti-social Personality Disorder (ASPD). Thirty-nine percent of patients met the DSM-III-R criteria for a diagnosis of ASPD. ASPD patients had an earlier onset of drug use, drug injecting, heroin use, had wider polydrug using histories and had been arrested earlier and more frequently than other patients. Despite the different pretreatment histories of ASPD and other patients, there were no differences between the two groups in retention in treatment, methadone dosage or heroin use. It is concluded that heroin-dependent ASPD patients can be successfully retained in methadone treatment, on similar methadone doses and with similar in-treatment drug use patterns as those of non-ASPD heroin dependent patients.

Journal Article↗

Overdose among heroin users in Sydney, Australia: I. Prevalence and correlates of non-fatal overdose.

A sample of 329 heroin users were interviewed regarding their personal experience of non-fatal heroin overdose. Experience of overdose was widespread, with two-thirds of subjects (68%) reporting having overdosed. The median number of life-time overdoses was three, with males and females equally likely to have overdosed. The majority (62%) of most recent heroin overdoses occurred in conjunction with the consumption of other central nervous system depressants (alcohol, benzodiazepines and other opioids). Logistic regression analyses indicated three independent factors associated with having overdosed: longer heroin using careers, greater heroin dependence and higher levels of alcohol consumption. Implications for the reduction in the prevalence and frequency of overdose are discussed.

Adolescent↗

Levels and correlates of polydrug use among heroin users and regular amphetamine users.

Data from a sample of 329 primary heroin users and from a sample of 301 regular amphetamine users were analysed in order to determine the extent and correlates of polydrug use among illicit drug users. Both samples exhibited high levels of polydrug use, with means of 5.2 (heroin) and 6.3 (amphetamines) drug classes used in the preceding 6 months. Multi-variate analyses indicated that being younger, being male, not being in treatment, being an injector, having recently borrowed injecting equipment and being from the regular amphetamine using sample were independently associated with higher levels of polydrug use. Rather than increasing levels of polydrug use being associated with age, illicit drug users appear to reduce their range of drugs as they get older. The 'pure' heroin or amphetamine user was extremely rare. It is concluded that to characterise drug users as 'heroin' or 'amphetamine' users misses the context in which these drugs are used.

Adolescent↗

The Severity of Dependence Scale (SDS): psychometric properties of the SDS in English and Australian samples of heroin, cocaine and amphetamine users.

The Severity of Dependence Scale (SDS) was devised to provide a short, easily administered scale which can be used to measure the degree of dependence experienced by users of different types of drugs. The SDS contains five items, all of which are explicitly concerned with psychological components of dependence. These items are specifically concerned with impaired control over drug taking and with preoccupation and anxieties about drug use. The SDS was given to five samples of drug users in London and Sydney. The samples comprised users of heroin and users of cocaine in London, and users of amphetamines and methadone maintenance patients in Sydney. The SDS satisfies a number of criteria which indicate its suitability as a measure of dependence. All SDS items load significantly with a single factor, and the total SDS score was extremely highly correlated with the single factor score. The SDS score is related to behavioural patterns of drug taking that are, in themselves, indicators of dependence, such as dose, frequency of use, duration of use, daily use and degree of contact with other drug users; it also shows criterion validity in that drug users who have sought treatment at specialist and non-specialist agencies for drug problems have higher SDS scores than non-treatment samples. The psychometric properties of the scale were good in all five samples, despite being applied to primary users of different classes of drug, using different recruitment procedures in different cities in different countries.

Adult↗

Injecting and sexual risk-taking behaviour among regular amphetamine users.

A sample of 301 regular amphetamine users were interviewed regarding injecting and sexual risk-taking behaviours. Two-thirds of subjects were injecting the drug, with males being 1.8 times more likely to do so. Nearly half (41%) of injectors had shared injecting equipment in the preceding month. Females were twice as likely as males to report recent needle sharing. Having a regular sexual partner who injects amphetamines, using benzodiazepines and experiencing higher levels of psychopathology were independently associated with needle sharing. The number of sexual partners in the preceding six months was independently associated with having had paid sex in that period, and higher levels of polydrug use.

Adolescent↗

Drug replacement treatments: is amphetamine substitution a horse of a different colour?

Advocates of amphetamine substitution therapy argue that needle sharing by amphetamine users, and associated infectious disease risk, outweigh the risks associated with oral dexamphetamine substitution prescribing, and that substitution can allow stabilization and gradual withdrawal of patients, or maintenance. Others note that amphetamine users are not generally physically dependent, dexamphetamine prescribing can lead to increased drug use and psychosis, and that there are possible neurotoxic effects from prolonged chronic exposure to amphetamines. Research on the impact of amphetamine and cocaine prescribing on drug use, injecting, social adjustment and criminal involvement is lacking apart from a small number of retrospective case reports. Early experience in the United Kingdom leads to the view that amphetamine maintenance was a therapeutic failure. More recently, clinicians have expressed confidence that the approach has merit, and while their claims should not be discounted there remains no empirical basis to support them. Although dexamphetamine substitution therapy has been heralded as an important intervention to reduce injecting behaviour and associated infectious disease risk, there is very little research which attests to its success in reaching this goal. Indeed, what is known regarding patterns of amphetamine use and the effects of prolonged use of the drug raise serious doubts as to the efficacy of amphetamine maintenance. There is an urgent need for randomized or case-controlled trails of the efficacy of these procedures. Until such empirical comparative research is available, the benefits to be gained from dexamphetamine substitution therapy remain speculative and opinion-based.

Journal Article↗

Prevalence, symptoms and correlates of antisocial personality disorder among methadone maintenance clients.

A sample of 222 methadone maintenance (MM) clients were tested for a diagnosis of antisocial personality disorder (ASPD). The majority (60.8%) of clients qualified for a lifetime diagnosis of ASPD, 25.7% received a current diagnosis of ASPD, and a conduct disorder of childhood was diagnosed for 68.5% of subjects. The most common symptoms of ASPD among MM clients were unlawful behaviours, aggressiveness and recklessness. Lack of remorse was reported by less than a third of subjects with a lifetime diagnosis of ASPD. Subjects with a current diagnosis of ASPD had been retained in treatment as long as other clients, and were no more likely to be currently injecting or sharing injecting equipment. It is concluded that clients with ASPD can be retained in MM treatment, and can respond to MM treatment as well as other clients.

Adolescent↗

Geographical differences in risk-taking among Sydney methadone maintenance patients: a comparison of inner city and outer south western methadone maintenance patients.

The study compared the demographic profiles, treatment factors, current drug use, injecting behaviour and psychological functioning of inner city (ICS) and south-west Sydney (SWS) methadone patients. A total of 104 patients from two clinics in the inner city, and 118 patients from two clinics in the outer south-western suburbs of Sydney were interviewed using a structured interview. SWS patients were more likely to be married or de facto, to have a regular sexual partner who was an injecting drug user, and to have children in their care. While they were no more likely to have recently injected, SWS patients were twice as likely to have recently shared a needle. While SWS patients were more likely to have had sex in the month preceding interview, ICS patients were more likely to have had more than one partner in that period. Patients from the south-western clinics were twice as likely to receive a diagnosis of antisocial personality disorder, and had poorer social functioning. The clinical implications of these differences are discussed.

Journal Article↗

The use of benzodiazepines among injecting drug users.

Benzodiazepine use among injecting drug users (IDUs) presents a major clinical and public health problem that may increase in importance. The current paper examines the research on the extent of benzodiazepine use among IDUs and the harmful consequences associated with such use. Numerous studies have found benzodiazepine use to be widespread among IDUs, and to be associated with greater levels of risk-taking and polydrug use, and poorer psychosocial functioning than other IDUs. The injection of benzodiazepines has also been reported, and presents problems in itself. The implications of existing research for both clinical practice and research are discussed.

Journal Article↗

Prevalence, severity and correlates of psychological morbidity among methadone maintenance clients.

A sample of 222 methadone maintenance clients was tested for levels of depression, anxiety, and anti-social personality disorder. The prevalence of each type of psychopathology was high. There were large proportions of subjects exhibiting extremely severe depression, anxiety and a majority were classified as "psychiatric cases". Depression and anxiety were strongly related, but anti-social behaviour was unrelated to personal distress. Personal distress levels were predicted by benzodiazepine use, poorer social functioning and poorer health. Anti-social personality disorder was predicted by younger age, being male, poorer social functioning, and current criminality.

Adolescent↗

Predictors of injecting and injecting risk-taking behaviour among methadone-maintenance clients.

A sample of 222 methadone maintenance clients were interviewed regarding current injecting and needle risk-taking in order to ascertain factors associated with these behaviours. Just over half (55%) of subjects had injected in the month preceding interview. Current injecting was associated with being female, having a regular sexual partner who was a current injecting drug user, polydrug use and higher levels of global psychopathology. Approximately 15% of subjects had shared needles in the month preceding interview, predominantly with one other person. Needle sharing was associated with having a regular sexual partner who was a current injecting drug user, current criminality and injecting at places other than home. Needle-sharing episodes in the study period were considered safe by practically all sharers. The implications of these findings are discussed.

Adolescent↗

Transitions between routes of administration of regular amphetamine users.

A sample of 301 regular amphetamine users was interviewed regarding transitions between routes of administration of amphetamines. Use of amphetamines by injecting was widespread, with two-thirds (67%) of subjects having injected the drug during the preceding 6 months. Needle-sharing was common, with 41% of injectors having shared a needle in the month preceding interview. A transition to regular amphetamine injecting from other routes of administration was reported by 40% of subjects, with males being twice as likely to report such a transition. The median number of such transitions was one. The main reasons given by subjects for the transition to injecting were liking the "rush" from injecting, and seeing it as a more economical and a healthier way to use. A small proportion of subjects (9%) reported a transition away from injecting amphetamines, with a median of one such transition. The most common reason given for abandoning injecting was concern about vascular damage. Interventions to encourage safer use of amphetamines need to address the misconceptions that injecting is more economical and more healthy, and to emphasize the vascular problems associated with injecting.

Adolescent↗

The use of benzodiazepines among regular amphetamine users.

The relationship between benzodiazepine and regular amphetamine use was examined in a sample of 301 regular amphetamine users. Benzodiazepine use was widespread, with 37% of subjects having used them in the month preceding interview, and 55% in the preceding 6 months. Injectors of amphetamines were more likely to have ever used, and to be currently using, benzodiazepines. Comparisons of benzodiazepine users with other subjects indicated that benzodiazepine users had higher levels of polydrug use and psychopathology, as well as poorer health and social functioning than non-users. The odds of benzodiazepine using injectors having injected with a borrowed used needle in the preceding month were 3.8 times of those of non-benzodiazepine-using injectors. These results are consistent with studies of other groups of illicit drug users, such as heroin users, in indicating that benzodiazepine use is associated with greater levels of risk and psycho-social dysfunction.

Adolescent↗

Patterns of drug use and risk-taking among injecting amphetamine and opioid drug users in Sydney, Australia.

Data are presented on the patterns of drug use and HIV risk-taking of daily amphetamine and opioid injectors among 1245 injecting drug users who were interviewed in Sydney in 1989. About one-third of the sample had injected amphetamines during a typical month of injecting, and 12% were using amphetamines on a daily basis. Daily amphetamine injectors were younger, less well educated, and less likely to have engaged in drug treatment, but they were no more likely than daily opioid users to have shared injection equipment or to have engaged in other behaviour likely to transmit HIV. Although there seemed to be no special cause for concern about HIV risk-taking among amphetamine injectors, there was nonetheless a high prevalence of sharing injecting equipment, with over half of daily amphetamine and heroin injectors having shared in the past several months. In addition, approximately a third of amphetamine injectors were injecting on a daily basis, a pattern of use which increases the risk of developing a severe dependence syndrome, and of experiencing an amphetamine-induced psychosis.

Adolescent↗