Rebecca McKetin

Major physical and psychological harms of methamphetamine use

ISSUES The major physical and psychological health effects of methamphetamine use, and the factors associated with such harms. APPROACH Comprehensive review. KEY FINDINGS Physical harms reviewed included toxicity and mortality, cardiovascular/cerebrovascular pathology, dependence and blood-borne virus transmission. Psychological harms include methamphetamine psychosis, depression, suicide, anxiety and violent behaviours. IMPLICATIONS While high-profile health consequences, such as psychosis, are given prominence in the public debate, the negative sequelae extend far beyond this. This is a drug class that causes serious heart disease, has serious dependence liability and high rates of suicidal behaviours. CONCLUSION The current public image of methamphetamine does not portray adequately the extensive, and in many cases insidious, harms caused.

The rise of methamphetamine in Southeast and East Asia

INTRODUCTION AND AIMS Southeast and East Asia has become a global hub for methamphetamine production and trafficking over the past decade. This paper describes the rise of methamphetamine supply and to what extent use of the drug is occurring in the region. METHOD AND DESIGN The current review uses data collected through the Drug Abuse Information Network for Asia and the Pacific (DAINAP) and other available sources to analyse retrospectively methamphetamine trends within Southeast and East Asia. RESULTS Southeast and East Asia has experienced a methamphetamine epidemic in the past decade which began around 1997 and peaked in 2000-2001. While the situation has since stabilised in many countries, methamphetamine trafficking and use are still increasing in parts of the Mekong region and there is evidence of large-scale manufacture in Cambodia, Indonesia, Malaysia and the Philippines. Methamphetamine is typically smoked or ingested, but injection of the drug is apparent. CONCLUSION While the peak of the methamphetamine epidemic has passed in parts of Southeast and East Asia, attention is needed to minimise the potential consequences of spreading methamphetamine production, trafficking and use in the Mekong region and in the peninsular and archipelago of Southeast Asia.

A double-blind, placebo-controlled trial of modafinil (200 mg/day) for methamphetamine dependence

AIM To examine the safety and efficacy of modafinil (200 mg/day) compared to placebo in the treatment of methamphetamine dependence and to examine predictors of post-treatment outcome. PARTICIPANTS AND DESIGN Eighty methamphetamine-dependent subjects in Sydney, Australia were allocated randomly to modafinil (200 mg/day) (n = 38) or placebo (n = 42) under double-blind conditions for 10 weeks with a further 12 weeks post-treatment follow-up. MEASURES Comprehensive drug use data (urine specimens and self-report) and other health and psychosocial data were collected weekly during treatment and research interviews at baseline, week 10 and week 22. RESULTS Treatment retention and medication adherence were equivalent between groups. There were no differences in methamphetamine abstinence, craving or severity of dependence. Medication-compliant subjects tended to provide more methamphetamine-negative urine samples over the 10-week treatment period (P = 0.07). Outcomes were better for methamphetamine-dependent subjects with no other substance dependence and those who accessed counselling. There were statistically significant reductions in systolic blood pressure (P = 0.03) and weight gain (P = 0.05) in modafinil-compliant subjects compared to placebo. There were no medication-related serious adverse events. Adverse events were generally mild and consistent with known pharmacological effects. CONCLUSIONS Modafinil demonstrated promise in reducing methamphetamine use in selected methamphetamine-dependent patients. The study findings support definitive trials of modafinil in larger multi-site trials.

Attention and memory in illicit amphetamine users: comparison with non-drug-using controls

The purpose of this study was to clarify the extent of neuropsychological impairment previously found among amphetamine users (McKetin and Mattick, 1997) by comparing them with a non-drug-using control group. Amphetamine users who were classified as low dependence (n = 15) or high dependence (n = 11) according to the severity of dependence scale (SDS) were compared to non-drug-using control subjects (n = 9) on indices of the Wechsler Memory Scale-Revised (WMS-R). Dependent amphetamine users (high dependence group) performed approximately one half of a standard deviation worse than controls on the verbal memory, attention/concentration and delayed recall indices of the WMS-R but amphetamine users who were less dependent (low dependence group) showed no impairment.

Attention and memory in illicit amphetamine users

The purpose of this study was to assess cognitive functioning in a group of illicit amphetamine users. A neuropsychological test battery (Wechsler Memory Scale-Revised (WMS-R) and the digit symbol, block design and vocabulary subtests of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and the National Adult Reading Test (NART)) was administered to 78 amphetamine users (mean age = 22.5 years; 46 males, 33 females). Severity of amphetamine dependence was found to be associated with poorer performance on both memory and attention/concentration indices of the WMS-R. The relative contribution of amphetamine dependence, concurrent drug use and other drug related factors to neuropsychological functioning are discussed.

Dose-Related Psychotic Symptoms in Chronic Methamphetamine Users: Evidence From a Prospective Longitudinal Study

CONTEXT Methamphetamine is associated with psychotic phenomena, but it is not clear to what extent this relationship is due to premorbid psychosis among people who use the drug. OBJECTIVE To determine the change in the probability of psychotic symptoms occurring during periods of methamphetamine use. DESIGN Longitudinal prospective cohort study. A fixed-effects analysis of longitudinal panel data, consisting of 4 noncontiguous 1-month observation periods, was used to examine the relationship between changes in methamphetamine use and the risk of experiencing psychotic symptoms within individuals over time. SETTING Sydney and Brisbane, Australia. PARTICIPANTS A total of 278 participants 16 years of age or older who met DSM-IV criteria for methamphetamine dependence on entry to the study but who did not meet DSM-IV criteria for lifetime schizophrenia or mania. MAIN OUTCOME MEASURES Clinically significant psychotic symptoms in the past month, defined as a score of 4 or more on any of the Brief Psychiatric Rating Scale items of suspiciousness, hallucinations, or unusual thought content. The number of days of methamphetamine use in the past month was assessed using the Opiate Treatment Index. RESULTS There was a 5-fold increase in the likelihood of psychotic symptoms during periods of methamphetamine use relative to periods of no use (odds ratio [OR], 5.3 [95% CI, 3.4-8.3]; P < .001), this increase being strongly dose-dependent (1-15 days of methamphetamine use vs abstinence in the past month: OR, 4.0 [95% CI, 2.5-6.5]; ≥16 days of methamphetamine use vs abstinence in the past month: OR, 11.2 [95% CI, 5.9-21.1]). Frequent cannabis and/or alcohol use (≥16 days of use in the past month) further increased the odds of psychotic symptoms (cannabis: OR, 2.0 [95% CI, 1.1-3.5]; alcohol: OR, 2.1 [95% CI, 1.1-4.2]). CONCLUSIONS There was a large dose-dependent increase in the occurrence of psychotic symptoms during periods of methamphetamine use among users of the drug.

Methamphetamine use, aggressive behavior and other mental health issues among high-school students in Cape Town, South Africa

OBJECTIVE Methamphetamine use has become a growing problem in a number of countries over the past two decades, but has only recently emerged in South Africa. This study investigated the prevalence of methamphetamine use among high-school students in Cape Town and whether students reporting methamphetamine use were more likely to be at risk for mental health and aggressive behavior problems. METHODS A cross-sectional survey of 15 randomly selected high schools in Cape Town, of 1561 males and females grade 8-10 students (mean age 14.9), was conducted using the Problem Oriented Screening Instrument for Teenagers (POSIT) and the Beck Depression Inventory (BDI). RESULTS Findings indicated that 9% of the students had tried methamphetamine at least once. Ordinal logistic regression analyses showed that methamphetamine use in the past year was significantly associated with higher aggressive behavior scores (OR=1.81, 95% CI: 1.04-3.15, p<0.05), mental health risk scores (OR=2.04, 95% CI: 1.26-3.31, p<0.01) and depression scores (OR=2.65, 95% CI: 1.64-4.28, p<0.001). CONCLUSIONS Methamphetamine use has become a serious problem in Cape Town, particularly among adolescents. Screening adolescents in school settings for methamphetamine use and behavior problems may be useful in identifying youth at risk for substance misuse, providing an opportunity for early intervention. These findings have implications for other parts of the world where methamphetamine use may be occurring at younger ages and highlight the importance of looking at co-morbid issues related to methamphetamine use.

Evaluating the impact of community-based treatment options on methamphetamine use: findings from the Methamphetamine Treatment Evaluation Study (MATES)

AIMS To evaluate the impact of community-based drug treatment on methamphetamine use using inverse probability of treatment-weighted (IPTW) estimators to derive treatment effects. DESIGN A longitudinal prospective cohort study with follow-ups at 3 months, 1 year and 3 years. Treatment effects were derived by comparing groups at follow-up. IPTW estimators were used to adjust for pre-treatment differences between groups. SETTING Sydney and Brisbane, Australia. PARTICIPANTS Participants were methamphetamine users entering community-based detoxification (n = 112) or residential rehabilitation (n = 248) services and a quasi-control group of methamphetamine users (n = 101) recruited from the community. MEASUREMENTS Frequency of methamphetamine use between interviews (no use, less than weekly, 1-2 days per week, 3+ days per week), continuous abstinence from methamphetamine use, past month methamphetamine use and methamphetamine dependence. FINDINGS Detoxification did not reduce methamphetamine use at any follow-up relative to the quasi-control group. Relative to quasi-control and detoxification groups combined, residential rehabilitation produced large reductions in the frequency of methamphetamine use at 3 months [odds ratio (OR) = 0.23, 95% confidence interval (CI) 0.15-0.36, P < 0.001), with a marked attenuation of this effect at 1 year (OR 0.62, 95% CI 0.40-0.97, P = 0.038) and 3 years (OR = 0.71, 95% CI 0.42-1.19, P = 0.189). The greatest impact was for abstinence: for every 100 residential rehabilitation clients there was a gain of 33 being continuously abstinent at 3 months, with this falling to 14 at 1 year and 6 at 3 years. CONCLUSIONS Community-based residential rehabilitation may produce a time-limited decrease in methamphetamine use, while detoxification alone does not appear to do so.

Methamphetamine-related fatalities in Australia: Demographics, circumstances, toxicology and major organ pathology

AIM To examine the demographic characteristics, circumstances of death, toxicological results and major organ pathology of methamphetamine-related deaths in Australia. DESIGN Retrospective review of coronial files. SETTING Australia. METHODS Cases in which methamphetamine was listed as a cause of death were identified from the National Coronial Information System (NCIS). FINDINGS A total of 371 cases were identified. The mean age of decedents was 32.7 years; 77% were male and 35% were employed. Route of administration was predominantly by injection (89%). Drugs other than methamphetamine were detected in 89% of cases, most commonly benzodiazepines (41%) and morphine (36%). The median blood methamphetamine concentration was 0.2 mg/l (range 0.02-15.0 mg/l). Deaths were overwhelmingly accidental, with 14% determined to be suicides, and occurred in a private home (71%). Cardiovascular pathology, typically coronary artery atherosclerosis, was detected in 54% of decedents. Cerebrovascular pathology, most commonly cerebral haemorrhage and hypoxia, was present in 20% of cases. CONCLUSIONS Methamphetamine has contributed to a substantial number of deaths in Australia. Users need to be informed of the potential harms of methamphetamine use, particularly those associated with the cardiotoxicity of methamphetamine and the use of methamphetamine in conjunction with other drugs.

The risk of psychotic symptoms associated with recreational methamphetamine use

INTRODUCTION AND AIMS To determine whether recreational methamphetamine use is associated with an increased risk of psychotic symptoms. DESIGN AND METHOD A cross-sectional survey of 157 people attending dance events in Sydney, Australia. Participants were assessed for psychotic symptoms in the past year using items from the Psychosis Screen. Participants with and without psychotic symptoms were compared on methamphetamine use, polydrug use and other demographic factors. An ordinal logistic regression was used to determine the probability of psychotic symptoms by methamphetamine use and level of polydrug use. RESULTS Psychotic symptoms in the past year were predicted by methamphetamine use and heavier polydrug use in the past year, and a history of a psychotic disorder (schizophrenia, schizoaffective or bipolar affective disorder). After removing participants with a history of a psychotic disorder (n = 16) and adjusting for polydrug use, methamphetamine use increased the probability of two or more psychotic symptoms (indicative of psychosis risk) from 9% to 21%. There was a non-significant increase in the risk of psychotic symptoms with higher levels of polydrug use. Methamphetamine use was typically monthly or less often (83%), and most users described their use as recreational (85%). DISCUSSION AND CONCLUSIONS Within the context of polydrug use, recreational methamphetamine use is associated with a twofold to threefold increase in the probability of psychotic symptoms.