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Aims: To document the geographical injection locations of IDU, and the factors and harms associated with injecting in public places., Design: Cross-sectional survey., Setting: Sydney, Australia., Participants: Two hundred injecting drug users., Findings: Nearly all subjects (96%) had injected in a public place, and 89% had done so in the preceding 6 months. Large proportions had injected in all locations studied, including cars (90%), public toilets (81%), the street (80%) and trains (55%). Injecting in public places also occurred frequently, with 53% of subjects having injected often in at least one public location during the preceding 6 months. Twenty-seven per cent of subjects had injected often in the street over the preceding 6 months, 22% had injected often in cars and 17% had injected often in public toilets. Frequent injectors in public places were more likely to be male, and to have overdosed in the preceding 6 months, injected significantly more drug classes in the preceding 6 months, injected in more bodily injecting sites in the preceding 6 months and had more current injection-related problems than other IDU., Conclusions: Injecting in public places was practiced by the overwhelming majority of the sample, and a pattern of increased harm was associated with frequent public injecting. In attempting to quantify the harm associated with injecting, and to reduce such harm, the locations injections take place in are of major importance.

The aim of this pilot study was to determine the potential of maintenance with clobazam in patients on methadone who we also benzodiazepine dependent. Five individuals we recruited and four were maintained on clobazam for a minimum of 3 months prior to reduction. Three subjects we abstinent from other benzodiazepines at 3 months. Clobazam was given as a single daily dose and was reported by the clients as less sedating than diazepam There is potential for clobazam to be used as a maintenance benzodiazepine., (2000 Australasian Professional Society on Alcohol and other Drugs.)

Aims: To determine the extent to which heroin users meet criteria for benzodiazepine dependence, to examine the appropriateness of these criteria for assessing benzodiazepine dependence among this population, and to assess what other substance use, depressive and anxiety disorders are associated with benzodiazepine dependence., Design: Cross-sectional survey., Setting: Sydney, Australia., Participants: Two hundred and twenty-two heroin injectors recruited through advertisements, needle exchanges, methadone maintenance clinics and by word of mouth., Findings: Twenty-six per cent (52/202) of those who had used benzodiazepines received a life-time diagnosis of benzodiazepine dependence, with 22% of current benzodiazepine users being dependent. A principal components analysis revealed that a unidimensional construct underlies the benzodiazepine dependence syndrome. Those respondents with life-time benzodiazepine dependence were more likely than others to meet criteria for anxiety or depressive disorders., Conclusions: The inclusion of the benzodiazepine dependence syndrome in DSM-III-R (and DSM-IV) is justified. A disturbingly high proportion of heroin users meet the criteria for benzodiazepine dependence, a condition that should be regarded as a significant marker for co-morbidity among this group.

The coronial files of all heroin-related fatalities that occurred in New South Wales (NSW) over the period 1992-1996 were inspected. There were 953 heroin-related fatalities in NSW over the study period. There was a substantial, statistically significant increase in heroin-related fatalities over the study period, from 152 deaths in 1992 to 226 during 1996. The mean age of cases was 31.0 years, 85% were male, and 85% were classified as dependent on heroin at the time of death. There was a significant increase in the age of cases over the study period and the proportion of cases that were employed. Fatalities predominantly occurred in home settings (61%). No intervention occurred in 79% of cases. Fifty deaths (5%) occurred in the month following release from prison, 16 of which occurred the first 24 hours after release. Morphine concentrations rose from 0.24 mg/l in 1992 to 0.38 mg/l in 1996. Seventy six percent of cases involved heroin in combination with other drugs: alcohol (46%), benzodiazepines (27%), antidepressants (7%) and cocaine (7%). In only 24% of cases was morphine the sole drug detected. Males were significantly more likely to have alcohol detected at autopsy (49 vs. 24%), while females were more likely to have benzodiazepines detected (41 vs. 17%). The median blood morphine concentration among cases in which alcohol was detected was significantly lower than other cases (0.27 vs. 0.39 mg/l). It is concluded that heroin-related deaths continued to rise throughout the study period, and that deaths were predominantly among older, untreated males. Despite the rise in blood morphine concentrations, polydrug use remained the predominant toxicological pattern.

Background: Vascular services' delivery has been criticised, and re-organisation based on a 600,000 population model suggested. We assessed the feasibility of this model in three geographically disparate English regions., Methods: Surgical arterial activity by Trust was analyzed using 1994/95 data from Hospital Episode Statistics. A postal survey of acute Trusts was used to assess vascular facilities and personnel. Distances between hospitals and enumeration districts were mapped using a Geographical Information System., Main Outcome Measures: Number (proportion) of Trusts performing over 100 arterial procedures a year. Number (proportion) of Trusts with a vascular on-call rota. Proportion of population likely to live more than 40 km away (equivalent to 1 h blue-light ambulance travel time) from a vascular unit under the proposed model., Results: Twelve of the 32 Trusts (38%) performed over 100 arterial procedures annually; 23 Trusts completed the survey. Of these, five (22%) had a vascular on-call rota. Under the 600,000 model, in East Anglia a further 16.5% of the population would live > 40 km from a vascular unit. In Wessex, a further 0.4% of the population would live > 40 km from a vascular unit. Impact on access in North West Thames was negligible., Conclusions: A 600,000 population model could be feasible in urbanized regions, but not in geographically remote ones.

Aims: To compare the cognitive performance of methadone maintenance patients (MMPs) and a matched sample of non-heroin-using control subjects, and to ascertain risk factors for poorer cognitive performance., Design: Matched control study., Setting: Sydney, Australia., Participants: Thirty MMPs and 30 non-heroin using controls, matched for age, gender and education., Findings: The MMP group had significantly higher rates than controls of alcohol dependence, heroin overdose and head injury. There was no difference between the groups on pre-morbid functioning. The MMP group performed significantly poorer than controls on all of the neuropsychological domains measured: information processing, attention, short-term visual memory, delayed visual memory, short-term verbal memory, long-term verbal memory and problem solving. A life-time diagnosis of alcohol dependence and the number of non-fatal heroin overdoses were independent significant predictors of poorer cognitive performance., Conclusions: In addition to high rates of psychiatric morbidity, MMPs also show cognitive deficits compared to matched controls. A history of alcohol dependence and repeated exposure to overdose increase the likelihood of cognitive impairment. The current study does not rule out the possibility of other factors, that were not measured, that may contribute to cognitive impairment among this MMPs.

Aims: To document cases of fatal heroin overdose in New South Wales by non-injecting routes of administration, and to compare the characteristics and toxicology of these cases with injecting fatalities., Design: Examination of coronial files., Setting: New South Wales, Australia., Participants: All fatal heroin overdose cases in NSW between 1992 and 1996., Findings: There were 10 cases of death resulting from non-injecting routes of heroin administration between 1992 and 1996, representing 1% of cases. In three cases the route of administration was by inhalation, in five cases by nasal administration and in two cases by swallowing. The mean age of cases was 29.6 years, and nine of the cases were male. The median blood morphine concentration of non-injectors was 0.31 mg/l (range 0.06-0.99 mg/l). Drugs other than morphine were also detected in seven cases., Conclusions: Heroin overdose deaths are not restricted to the injection of heroin. While injection may constitute a greater overdose risk-factor, there is no safe, overdose-free way to use heroin.

Aims: To ascertain the prevalence and patterns of antidepressant use among IDU in Sydney and to determine any harm associated with antidepressant use., Design: Cross-sectional survey., Setting: Sydney, Australia., Participants: Two hundred and one Sydney injecting drug users (IDU) recruited through advertisements, needle exchanges, methadone maintenance clinics and by word of mouth., Findings: Forty per cent of subjects had used antidepressants, 21% in the preceding 6 months. Similar proportions of subjects had used tricyclics (26%) and selective serotonin reuptake inhibitors (SSRIs) (24%), with 8% reporting use of a monoamine oxidase inhibitor. Recent use favoured the SSRIs; however, there was still widespread use of tricyclics. The injection of antidepressants was rare, with only three subjects reporting ever having injected the drugs. Antidepressant use was associated with higher levels of polydrug use, poorer health, higher levels of psychiatric distress and a greater risk of heroin overdose. The excess risk of overdose was specifically associated with tricyclics, rather than SSRIs., Conclusions: The study confirmed that, like other pharmaceutical products, the use of antidepressants was common among IDU in Sydney. The prescription of tricyclics to heroin users would appear to increase their risk of overdose. If it is considered appropriate to prescribe antidepressants to IDU, it would appear safer to prescribe SSRIs.

The standard management of primary lower limb varicosities (stripping of the long saphenous vein (LSV) with avulsion of the varicosities) is based on the assumption that the disease originates from primary valvular insufficiency and incompetent perforating veins. It has recently been suggested that the LSV may be spared in patients with superficial varicosities without incompetence of this vein, i.e., early disease. However, pre-operative identification of suitable patients for conservative surgery has proved difficult. In this study, we employed selective duplex scanning in cases with primary varicosity in whom sapheno-femoral and sapheno-popliteal incompetence had been excluded both clinically and with the hand-held Doppler (52 limbs [10% of new referrals]). We found that the varicosities in these limbs were of 3 types: (a) those arising independent of superficial vein incompetence (Type 1); (b) those associated with segmental LSV incompetence (Type 2); (c) those in whom incompetence of the sapheno-femoral junction and LSV was missed (Type 3). We therefore suggest that long saphenous varicosity may progress from Type 1 through to Type 3 with each type representing an increase in severity of the disease. We suggest that selective use of duplex scanning will assist in identifying those patients with early stages of the disease who can then be treated effectively with LSV-sparing surgery.

Primary lower limb varicosities classically arise from incompetence of the junction of the superficial and the deep venous systems with retrograde flow into the saphenous veins. However, some patients with superficial varicosities have no demonstrable incompetence of the saphenofemoral or saphenopopliteal junctions. In this study, we examined 52 limbs with primary varicose disease in whom saphenofemoral and saphenopopliteal incompetence had been excluded (clinically and with the hand-held Doppler) using a duplex ultrasound scan. Seventeen (33%) of the limbs had superficial varicosities despite normal long and short saphenous veins. The varicosities in 12 of these legs originated from groin veins, while those in the remaining 5 limbs communicated directly with normal deep veins. In this latter group of limbs, the superficial varicosities were found on the lateral aspect of the thighs only. Primary varicosities arising from normal deep venous systems have not been previously described, and are relatively rare (1.0% of patients referred to our clinic). As this complex venular anatomy was only detected on duplex scanning, we conclude that this study provides further evidence of the need for this imaging modality in patients with varicose disease of uncertain origin and/or those with an unusual distribution of superficial varicosities.

An investigation into whether or not the level of harm associated with injecting drug use varies depending on the drug that is injected was conducted among 151 primary heroin injectors and 145 primary amphetamine injectors. Compared to primary amphetamine injectors, primary heroin injectors were more dependent on their primary drug, had poorer social functioning, and had recently exhibited a higher degree of criminal behaviour. There were no differences between the two groups in terms of the prevalence of needle sharing, their health, or their psychological functioning, despite the amphetamine users being significantly younger and having used less frequently. It is concluded that while there are some harms that are attributable to injecting per se, the type of drug that is injected does play a mediating role in the relationship between injecting drug use and its associated harm.

Aims: To assess in current injecting heroin and amphetamine users to what extent their history of injecting represents a transition from amphetamine to heroin., Design: Cross-sectional survey., Setting: Sydney, Australia., Participants: One hundred and fifty-one primary heroin injectors and 145 primary amphetamine injectors recruited through advertisements, needle exchanges, methadone maintenance clinics and by word of mouth., Findings: Six major transition patterns were detected: heroin-heroin (n = 61), amphetamines-heroin (n = 60), heroin-amphetamines-heroin (n = 30), amphetamines-amphetamines (n = 80), amphetamines-heroin-amphetamines (n = 41) and heroin-amphetamines (n = 24). A logistic regression analysis predicting presence or absence of a transition from the original primary drug indicated that length of injecting career, years of education and original drug injected were independent predictors. Thus, the longer the injecting career, the greater the likelihood of a transition. If the original drug injected was amphetamine, the greater the likelihood of transition; and the more prior years of education, the lower the chances of a transition., Conclusions: While there was a small preponderance of movement from primary amphetamine injecting to primary heroin injecting, there was also movement in the other direction. Heroin use is not necessarily a stable endpoint for injecting careers.

Objective and Design: in 1978 Sheppard described using a flap of pectineus fascia in an attempt to reduce the further development of neovascularised veins at the saphenofemoral junction. The perceived benefits of this manoeuvre have not been tested by a prospective randomised trial., Materials and Methods: consecutive patients with symptomatic recurrent varicose veins referred to a single consultant were examined for evidence of further reflux from the saphenofemoral junction. This was subsequently confirmed in forty limbs (thirty-seven patients) by descending venography. All had features of a neovascularised segment. These patients were treated by complete exposure and ligation of the recurrences arising from the common femoral vein, with or without the placement of a flap of pectineus fascia (prospectively randomised). The patients were assessed a minimum of eighteen months later by both clinical examination and duplex ultrasound scanning., Results: six patients were lost to follow-up. This left seventeen limbs remaining in each half of the study. The characteristics in each group were broadly matched., Conclusions: this study failed to demonstrate any apparent benefit from the application of a flap of pectineus fascia. Most patients showed evidence of re-recurrence arising from the common femoral vein., (Copyright 1999 Harcourt Publishers Ltd.)

This study compares the findings of conventional computed tomography (CT) and ultrasound (US) imaging in the preoperative evaluation of patients with abdominal aortic aneurysm (AAA). It also assesses the impact of preoperative CT-derived information on operative strategy. A prospective study was conducted of 96 patients who were considered for aortic aneurysm surgery, and the operative notes and US and CT reports were analyzed to assess correlation of findings and influence of CT on operative tactics. Agreement between CT and US in sizing the aneurysm was generally good. CT was more accurate than US for defining the upper and lower extent of the aneurysm (75% and 83%, respectively, with CT, compared to 47% and 41% with US), although it had a high false positive rate (48%) for juxtarenal disease. Its advantage over US in regard to showing other intraabdominal pathology was only marginal, and it predicted an inflammatory reaction in only two of the five cases. Its influence on operative strategy was minimal: Of the 25 cases where a juxtarenal aneurysm was predicted by CT, only 2 patients did not have surgery as a result. CT is a relatively expensive and time-consuming procedure, and its ionizing radiation, however small, and potential side effects from contrast material hypersensitivity cannot be ignored. In light of the above findings, we suggest that CT scanning need not be routinely employed in the preoperative workup of elective aortic aneurysm repair but should be used only in selected cases.

In order to determine the role played by heroin purity in fatal heroin overdoses, time series analyses were conducted on the purity of street heroin seizures in south western Sydney and overdose fatalities in that region. A total of 322 heroin samples were analysed in fortnightly periods between February 1993 to January 1995. A total of 61 overdose deaths occurred in the region in the study period. Cross correlation plots revealed a significant correlation of 0.57 at time lag zero between mean purity of heroin samples per fortnight and number of overdose fatalities. Similarly, there was a significant correlation of 0.50 at time lag zero between the highest heroin purity per fortnight and number of overdose fatalities. The correlation between range of heroin purity and number of deaths per fortnight was 0.40. A simultaneous multiple regression on scores adjusted for first order correlation indicated both the mean level of heroin purity and the range of heroin purity were independent predictors of the number of deaths per fortnight. The results indicate that the occurrence of overdose fatalities was moderately associated with both the average heroin purity and the range of heroin purity over the study period.

The extent to which the onset of criminality with respect to heroin use accounts for heterogeneity within a heroin-using population was investigated among 400 community and incarcerated methadone maintenance patients. Those for whom crime preceded heroin use (primary antisocials) were younger and more likely to be male than those for whom heroin use preceded crime (secondary antisocials). Primary antisocials were also more likely to have committed violent crime and to qualify for a diagnosis of antisocial personality disorder (ASPD). It is concluded that taking the order of onset of heroin use and criminality into account may reduce the risk of overdiagnosing ASPD among this population and help clarify the relationship between drug use and crime.

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.

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.

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.

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.

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.

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.

Objectives: To compare the findings of continuous wave Doppler (CWD) with duplex ultrasound in the assessment of primary and uncomplicated varicose veins, and to determine how their relative roles might be best applied., Materials and Methods: One hundred consecutive limbs were studied in 73 patients with primary (no previous surgery) and uncomplicated (no significant skin change) varicose veins. CWD was employed by a single observer; followed by duplex scanning performed "blind" and independently., Results: There were 87 limbs with long saphenous incompetence on duplex; all but four of which were correctly identified by CWD, by which technique there were no false positives. (Sensitivity 95%, specificity 100%.) There were 21 limbs with short saphenous incompetence on duplex, all but two of which were recognised on CWD. However, CWD incorrectly diagnosed reflux at the saphenopopliteal junction in five limbs (false positives) with what was, in fact, segmental reflux in the long saphenous trunk on duplex (sensitivity 90%, specificity 93%.) This would have led to inappropriate exploration of the saphenopopliteal junction had surgery proceeded without checking with duplex., Conclusions: CWD is adequate for long saphenous incompetence. All "reflux" demonstrated on CWD in the popliteal fossa (about 25% of cases) should be checked by duplex. If this policy had been followed, all the patients in this study would have undergone the correct procedure. The only "errors" would have been missing coexistent short saphenous incompetence in two limbs undergoing appropriate long saphenous exploration.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Objectives: The primary aim of this prospective multi-centre study involving patients undergoing elective abdominal aortic aneurysm (AAA) surgery was to investigate the relationship between intraoperative intravenous heparinisation, blood loss during surgery and thrombotic complications., Methods: Two hundred and eighty-four patients were randomised to receive intravenous heparin (n = 145) or no heparin (n = 139). Groups were evenly matched for age, sex, weight, aneurysm size, haemoglobin concentration, platelet counts and distal occlusive disease measured by ankle/brachial systolic pressure., Results: There were no statistically significant differences in blood loss (median 1400 ml vs. 1500 ml; z = 0.02, p = 0.98, 95% C.I. = -200 to 200), blood transfused (4.0 units vs. 4.0 units; z = 1.09, p = 0.28, 95% C.I. = -1 to 0) or distal thrombosis between the two groups. However, analysis of the clinical outcome revealed that 5.7% of the non-heparin group but only 1.4% of the heparinised patients suffered a fatal perioperative myocardial infarction (MI); p < 0.05. All MI, including non fatal events, affected 8.5% and 2% respectively (p = 0.02)., Conclusions: Heparin does not increase blood loss or the need for blood transfusion during surgery. Heparin is not necessary to prevent distal thrombosis when the aorta is cross clamped. The results of the study are consistent with the known mechanisms leading to intraoperative MI and strategies for its prevention. Intravenous heparin, given before aortic cross clamping, is an important prophylaxic against perioperative MI in relation to AAA surgery.

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.

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.

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.

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.

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.

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.

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.

Objectives: To determine the extent and patterns of benzodiazepine use among heroin users, and whether preferences for different benzodiazepines exist among this group., Subjects and Methods: 210 heroin users who were current users of benzodiazepines volunteered for the study and completed a structured questionnaire., Results: Heroin users had used a median of five different benzodiazepines, most commonly diazepam. Almost half the subjects (48%; 95% CI, 41-55) had injected benzodiazepines, 17% (95% CI, 12-22) within the preceding six months. Diazepam and temazepam were the most widely injected benzodiazepines., Conclusions: Flunitrazepam, diazepam and temazepam should be prescribed to heroin users with caution. A less popular and rarely injected benzodiazepine, nitrazepam, may be a better option for this group.