Duncan Stewart

Bio: Duncan Stewart is an academic researcher from University of York. The author has contributed to research in topics: Poison control & Heroin. The author has an hindex of 46, co-authored 139 publications receiving 7363 citations. Previous affiliations of Duncan Stewart include Home Office & City University London.

The Maudsley Addiction Profile (MAP):A brief instrument for assessing treatment outcome.

Abstract: Aim. To develop a brief, multi-dimensional instrument for assessing treatment outcome for people with drug and/or alcohol problems. The Maudsley Addiction Profile (MAP) is the first instrument to be developed in the United Kingdom for this purpose. Design. Field testing with quota-recruitment of problem drug users and problem alcohol users in treatment with researcher and clinician-administered test-retest interviews. Setting. Two community and two inpatient services at the Bethlem Royal and Maudsley Hospital, London. Participants. Subjects (160 drug users and 80 alcohol users) interviewed by eight interviewers (four researchers and four clinicians), each of whom interviewed 30 subjects on two occasions. Measures. Sixty items across substance use, health risk physical/psychological health and personal/social functioning domains. Findings. Average completion time of the MAP was 12 minutes. The questionnaire was acceptable to a majority of subjects and performed well with both researcher and clinician interviewers. Internal reliability and feasible concurrent validity assessments of the scales and items were highly satisfactory. Test-retest reliability was good, average intraclass correlation coefficients across eight substances were 0.94 and 0.81 across health risk, health problems, relationship conflict, employment and crime measures. Conclusions. The MAP can serve as a core research instrument with additional outcome measures added as required. The collection of a set of reliable quantitative measures of problems among drug and alcohol users by research or treatment personnel for outcome evaluation purposes need not be time-consuming.

The National Treatment Outcome Research Study (NTORS): 4-5 year follow-up results.

Abstract: Aims The National Treatment Outcome Research Study (NTORS) is the first prospective national study of treatment outcome among drug misusers in the United Kingdom. NTORS investigates outcomes for drug misusers treated in existing services in residential and community settings. Design, setting and participants The study used a longitudinal, prospective cohort design. Data were collected by structured interviews at intake to treatment, 1 year, 2 years and at 4–5 years. The sample comprised 418 patients from 54 agencies and four treatment modalities. Measurements Measures were taken of illicit drug use, injecting and sharing injecting equipment, alcohol use, psychological health and crime. Findings Rates of abstinence from illicit drugs increased after treatment among patients from both residential and community (methadone) programmes. Reductions were found for frequency of use of heroin, non-prescribed methadone, benzodiazepines, injecting and sharing of injecting equipment. For most variables, reductions were evident at 1 year with outcomes remaining at about the 1 year level or with further reductions. Crack cocaine and alcohol outcomes at 4–5 years were not significantly different from intake. Conclusions Substantial reductions across a range of problem behaviours were found 4–5 years after patients were admitted to national treatment programmes delivered under day-to-day conditions. The less satisfactory outcomes for heavy drinking and use of crack cocaine suggest the need for services to be modified to tackle these problems more effectively. Despite differences between the United Kingdom and the United States in patient populations and in treatment programmes, there are many similarities between the two countries in outcomes from large-scale, multi-site studies.

A prospective study of mortality among drug misusers during a 4-year period after seeking treatment

Abstract: Aims The opportunity to study deaths as they occur within the framework of a prospective cohort study is relatively uncommon. This study investigates deaths among drug misusers over a 4-year period, with specific attention to the circumstances and causes of death, and risk factors for mortality. The study also critically examines the recording of drug-related deaths. Design, Setting, Participants Prospective cohort study of 1075 drug misusers recruited to 54 treatment programmes during 1995. Measurements Data derived from interviews conducted with clients at intake, death certificates and post-mortem examinations. Findings The annual mortality rate was 1.2%, about six times higher than that for a general, age-matched population. Fourteen per cent of the deaths were due to self-inflicted injuries, accidents or violence and 18% were due to medical causes. The majority of deaths (68%) were associated with drug overdoses. Opiates were the drugs most commonly detected during post-mortem examinations. In the majority of cases, more than one drug was detected. Polydrug use and, specifically, heavy drinking, and use of benzodiazepines and amphetamines, were identified as risk factors for mortality. Anxiety and homelessness were also predictive of increased mortality. Conclusions We suggest that drug misusers and those working with drug misusers need to be more alert to the risks of polydrug use, including the combined use of alcohol with illicit drugs. The study revealed inconsistencies in the recording of drug-related deaths on death certificates. The routine recording of all substances detected during toxicological examination would improve the accuracy of death certification.

Factors associated with abstinence, lapse or relapse to heroin use after residential treatment: Protective effect of coping responses.

Abstract: Aims This study investigates factors associated with abstinence, lapse or relapse to heroin use after residential treatment and, specifically, the extent to which changes in cognitive, avoidance and distraction coping responses were related to heroin use and other drug use outcomes. Design, setting, participants The sample comprised 242 clients from 23 residential programmes in the NTORS project, who used heroin before treatment and who were followed-up after treatment during the first 12 months of the study. Measurements Data on client characteristics and problems, coping responses, drug use and other outcomes, were collected by structured face-to-face interviews. Findings Many clients (60%) used heroin after treatment, with the first occasion of heroin use usually occurring very soon after leaving treatment: 40% remained abstinent from heroin. Analyses were conducted for three groups based upon heroin outcome status (abstinent, lapsed, relapsed). Clients who avoided a full relapse to heroin use (abstinent and lapse groups) consistently made more use of cognitive, avoidance and distraction coping strategies at follow-up than at intake. Treatment completion was related to better outcome. The lapse and relapse groups reported higher rates of use of illicit drugs other than heroin after treatment than the abstinent group. Conclusions Despite generally satisfactory drug use outcomes, the lapses and relapses to heroin use give rise to concern. Treatment services should develop further and strengthen relapse prevention and relapse coping skills among drug misusers.

The Pharmacology and Clinical Pharmacology of 3,4-Methylenedioxymethamphetamine (MDMA, “Ecstasy”)

Abstract: The amphetamine derivative (±)-3,4-methylenedioxymethamphetamine (MDMA, ecstasy) is a popular recreational drug among young people, particularly those involved in the dance culture. MDMA produces an acute, rapid enhancement in the release of both serotonin (5-HT) and dopamine from nerve endings in the brains of experimental animals. It produces increased locomotor activity and the serotonin behavioral syndrome in rats. Crucially, it produces dose-dependent hyperthermia that is potentially fatal in rodents, primates, and humans. Some recovery of 5-HT stores can be seen within 24 h of MDMA administration. However, cerebral 5-HT concentrations then decline due to specific neurotoxic damage to 5-HT nerve endings in the forebrain. This neurodegeneration, which has been demonstrated both biochemically and histologically, lasts for months in rats and years in primates. In general, other neurotransmitters appear unaffected. In contrast, MDMA produces a selective long-term loss of dopamine nerve endings in mice. Studies on the mechanisms involved in the neurotoxicity in both rats and mice implicate the formation of tissue-damaging free radicals. Increased free radical formation may result from the further breakdown of MDMA metabolic products. Evidence for the occurrence of MDMA-induced neurotoxic damage in human users remains equivocal, although some biochemical and functional data suggest that damage may occur in the brains of heavy users. There is also some evidence for long-term physiological and psychological changes occurring in human recreational users. However, such evidence is complicated by the lack of knowledge of doses ingested and the fact that many subjects studied are or have been poly-drug users.

Mortality risk during and after opioid substitution treatment: systematic review and meta-analysis of cohort studies

Abstract: Objective To compare the risk for all cause and overdose mortality in people with opioid dependence during and after substitution treatment with methadone or buprenorphine and to characterise trends in risk of mortality after initiation and cessation of treatment. Design Systematic review and meta-analysis. Data sources Medline, Embase, PsycINFO, and LILACS to September 2016. Study selection Prospective or retrospective cohort studies in people with opioid dependence that reported deaths from all causes or overdose during follow-up periods in and out of opioid substitution treatment with methadone or buprenorphine. Data extraction and synthesis Two independent reviewers performed data extraction and assessed study quality. Mortality rates in and out of treatment were jointly combined across methadone or buprenorphine cohorts by using multivariate random effects meta-analysis. Results There were 19 eligible cohorts, following 122 885 people treated with methadone over 1.3-13.9 years and 15 831 people treated with buprenorphine over 1.1-4.5 years. Pooled all cause mortality rates were 11.3 and 36.1 per 1000 person years in and out of methadone treatment (unadjusted out-to-in rate ratio 3.20, 95% confidence interval 2.65 to 3.86) and reduced to 4.3 and 9.5 in and out of buprenorphine treatment (2.20, 1.34 to 3.61). In pooled trend analysis, all cause mortality dropped sharply over the first four weeks of methadone treatment and decreased gradually two weeks after leaving treatment. All cause mortality remained stable during induction and remaining time on buprenorphine treatment. Overdose mortality evolved similarly, with pooled overdose mortality rates of 2.6 and 12.7 per 1000 person years in and out of methadone treatment (unadjusted out-to-in rate ratio 4.80, 2.90 to 7.96) and 1.4 and 4.6 in and out of buprenorphine treatment. Conclusions Retention in methadone and buprenorphine treatment is associated with substantial reductions in the risk for all cause and overdose mortality in people dependent on opioids. The induction phase onto methadone treatment and the time immediately after leaving treatment with both drugs are periods of particularly increased mortality risk, which should be dealt with by both public health and clinical strategies to mitigate such risk. These findings are potentially important, but further research must be conducted to properly account for potential confounding and selection bias in comparisons of mortality risk between opioid substitution treatments, as well as throughout periods in and out of each treatment.