The emergence of potent forms of methamphetamine in Sydney, Australia: a case study of the IDRS as a strategic early warning system

Trends in methamphetamine use, markets and harms in Australia, 2003-2019

INTRODUCTION

To describe trends in methamphetamine use, markets and harms in Australia from 2003 to 2019.

METHODS

Data comprised patterns of use and price from sentinel samples of people who inject drugs and who use MDMA/other illicit stimulants and population-level amphetamine-related police seizures, arrests, hospitalisations, treatment episodes and deaths from approximately 2003 to 2019. Bayesian autoregressive time-series models were analysed for: no change; constant rate of change; and change over time differing in rate after one to three changepoints. Related indicators were analysed post hoc with identical changepoints.

RESULTS

The percentage of people who inject drugs reporting weekly use increased from 2010 to 2013 onwards, while use among samples of people who regularly use ecstasy and other illicit stimulants decreased. Seizures and arrests rose steeply from around 2009/10 to 2014/15 and subsequently plateaued. Price increased ($15.9 [95% credible interval, CrI $9.9, $28.9] per point of crystal per year) from around 2009 to 2011, plateauing and then declining from around 2017. Hospitalisation rates increased steeply from around 2009/10 until 2015/16, with a small subsequent decline. Treatment also increased (19.8 episodes [95% CrI 13.2, 27.6] with amphetamines as the principal drug of concern per 100 000 persons per year) from 2010/11 onwards. Deaths involving amphetamines increased (0.285 per 100 000 persons per year) from 2012 until 2016.

DISCUSSION AND CONCLUSIONS

These findings suggest that problematic methamphetamine use and harms escalated from 2010 to 2012 in Australia, with continued demand and a sustained market for methamphetamine.

The effect of adolescent social isolation on vulnerability for methamphetamine addiction behaviours in female rats

RATIONALE

Stress exposure during adolescence contributes to developing a methamphetamine (METH) use disorder. However, most of the studies investigating addiction-related behaviours include only male rodents, despite METH addiction rates being higher in females. Furthermore, animal studies investigating the effects of stress on methamphetamine addiction have used only basic self-administration models which may not be sensitive to the effects of stress.

OBJECTIVES

This project explored whether adolescent isolation stress exposure increases the incidence of four key addiction-related behaviours in female rats.

METHODS

Thirty-two female rat pups were caged in groups of four or individually during adolescence from postnatal (PND) day 22, with the latter being re-socialised in groups of four on PND 43. In adulthood, rats were tested for addiction-like behaviours in a METH self-administration paradigm modelling motivation to take METH, persistence in drug-seeking behaviour when METH was not available, resistance to extinction, and propensity to reinstate after a period of withdrawal.

RESULTS

Adolescent social isolation resulted in lower METH intake during acquisition; however, the paradigm modelling drug-seeking when the drug was unavailable engendered intermittent METH bingeing in all rats, abolishing the group differences in intake during this phase. Adolescent social isolation also accelerated extinction of non-reinforced lever pressing, and increased stress-primed reinstatement, compared to the group-housed rats.

CONCLUSIONS

Adolescent social isolation stress alters various methamphetamine addiction-like behaviours in female rats.

Changing Pattern of Chemsex Drug Use Among Newly Diagnosed HIV-Positive Taiwanese from 2015 to 2020 in the Era of Treat-All Policy

Chemsex drug use (CDU) is a frequent, yet neglected issue in the era of treat-all policy. We evaluated the temporal pattern of CDU, factors associated with CDU, and drug-drug interactions (DDIs) between chemsex drugs and initial antiretroviral therapy (ART) by surveying 621 Taiwanese individuals (mean age: 29.7 years; 99.2% men; 92.9% men who have sex with men) diagnosed with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) from 2015 to 2020 [2015 to 2016 (period 1), 2017 to 2018 (period 2), and 2019 to 2020 (period 3)]. CDU was defined as chemsex in the past 1 year before HIV diagnosis. CDU remained prevalent across three periods (34.3-30.5%). Among CDU, methamphetamine (43.4%) was most frequently used, followed by amphetamine (40.0%) and poppers (various alkyl nitrites) (39.5%). We identified significantly increasing amphetamine use (37.0-61.5%) and decreasing ecstasy (methylenedioxy-methamphetamine) use (32.1-17.9%) in CDU across three periods. Besides, polydrug chemsex also significantly increased in CDU across three periods (23.5-43.6%), with amphetamine plus gamma-hydroxybutyrate being the most commonly used combination. CDU was associated with multiple sexual partners and a history of sexually transmitted diseases (STDs). DDIs between chemsex drugs and initial ART remained stable across three periods (10.6-7.8%), with cobicistat/elvitegravir and methamphetamine most common combination. In summary, the magnitude of CDU remained high across 2015-2020 in Taiwan, causing DDIs with initial ART agents. Strategies to reduce the frequency of high-risk sexual practices, STD transmission, and DDIs for newly diagnosed HIV-positive patients engaging in chemsex should be implemented.

A prospective cohort of people who use methamphetamine in Melbourne and non-metropolitan Victoria, Australia: Baseline characteristics and correlates of methamphetamine dependence

INTRODUCTION AND AIMS

Limited research has investigated methamphetamine use and related harms in rural and regional Australia. We investigated whether people who used methamphetamine in non-metropolitan Victoria differed in their sociodemographics and were more likely to be methamphetamine-dependent than those recruited in Melbourne.

DESIGN AND METHODS

We used baseline data from an ongoing prospective cohort study, 'VMAX'. Participants were recruited from Melbourne and three non-metropolitan Victorian regions. Sequential multivariable logistic regression of nested models assessed unadjusted and adjusted associations between residential locations and methamphetamine dependence.

RESULTS

The sample mostly (77%) comprised people who used methamphetamine via non-injecting means (N = 744). Thirty-nine percent were female. Melbourne-based participants were less likely than non-metropolitan participants to identify as Aboriginal and Torres Strait Islander, be heterosexual, have children and be unemployed. More frequent methamphetamine use (adjusted odds ratio 1.22, 95% confidence interval 1.12-1.34) and using crystal methamphetamine versus 'speed' powder (adjusted odds ratio 2.38, 95% confidence interval 1.26-3.64) were independently (P < 0.05) associated with being classified as methamphetamine-dependent. A significantly higher percentage of participants in every non-metropolitan region were classified as methamphetamine-dependent vs. those in Melbourne, but this relationship was attenuated when adjusting for methamphetamine use frequency and primary form used. Despite 65% of participants being classified as methamphetamine-dependent, less than half had recently (past year) accessed any professional support for methamphetamine, with minimal variation by recruitment location.

DISCUSSIONS AND CONCLUSIONS

VMAX participants in non-metropolitan Victoria were more likely to be methamphetamine-dependent than those living in Melbourne. Unmet need for professional support appears to exist among people using methamphetamine across the state, regardless of geographical location.

Clinical and demographic characteristics of people who smoke versus inject crystalline methamphetamine in Australia: Findings from a pharmacotherapy trial

INTRODUCTION AND AIMS

There has been a rapid increase in smoking crystalline methamphetamine in Australia. We compare the clinical and demographic characteristics of those who smoke versus inject the drug in a cohort of people who use methamphetamine.

DESIGN AND METHODS

Participants (N = 151) were dependent on methamphetamine, aged 18-60 years, enrolled in a pharmacotherapy trial for methamphetamine dependence, and reported either injecting (n = 54) or smoking (n = 97) methamphetamine. Measures included the Timeline Followback, Severity of Dependence Scale, Amphetamine Withdrawal Questionnaire, Craving Experience Questionnaire and the Brief Psychiatric Rating Scale (symptoms of depression, hostility, psychosis and suicidality). Simultaneous regression was used to identify independent demographic correlates of smoking methamphetamine and to compare the clinical characteristics of participants who smoked versus injected.

RESULTS

Compared to participants who injected methamphetamine, those who smoked methamphetamine were younger and less likely to be unemployed, have a prison history or live alone. Participants who smoked methamphetamine used methamphetamine on more days in the past 4 weeks than participants who injected methamphetamine (26 vs. 19 days, P = 0.001); they did not differ significantly in their severity of methamphetamine dependence, withdrawal, craving or psychiatric symptoms (P > 0.05). After adjustment for demographic differences, participants who smoked had lower craving [b (SE) = -1.1 (0.5), P = 0.021] and were less likely to report psychotic symptoms [b (SE) = -1.8 (0.7), P = 0.013] or antidepressant use [b (SE) = -1.1 (0.5), P = 0.022].

DISCUSSION AND CONCLUSIONS

Smoking crystalline methamphetamine is associated with a younger less marginalised demographic profile than injecting methamphetamine, but a similarly severe clinical profile.

Parent and child co-resident status among an Australian community-based sample of methamphetamine smokers

INTRODUCTION

Children in families where there is substance misuse are at high risk of being removed from their parents' care. This study describes the characteristics of a community sample of parents who primarily smoke methamphetamine and their child or children's residential status.

DESIGN AND METHODS

Baseline data from a prospective study of methamphetamine smokers ('VMAX'). Participants were recruited via convenience, respondent-driven and snowball sampling. Univariable and multivariable logistic regression analyses were used to estimate associations between parental status; fathers' or mothers' socio-demographic, psychosocial, mental health, alcohol, methamphetamine use dependence, alcohol use and child or children's co-residential status.

RESULTS

Of the 744 participants, 394 (53%) reported being parents; 76% (88% of fathers, 57% of mothers) reported no co-resident children. Compared to parents without co-resident children, parents with co-resident children were more likely to have a higher income. Fathers with co-resident children were more likely to be partnered and not to have experienced violence in the previous 6 months. Mothers with co-resident children were less likely to have been homeless recently or to have accessed treatment for methamphetamine use.

DISCUSSION AND CONCLUSIONS

The prevalence of non-co-resident children was much higher than previously reported in studies of parents who use methamphetamine; irrespective of whether in or out of treatment. There is a need for accessible support and services for parents who use methamphetamine; irrespective of their child or children's co-residency status. Research is needed to determine the longitudinal impact of methamphetamine use on parents' and children's wellbeing and to identify how parents with co-resident children (particularly mothers) can be supported.

Mental health outcomes associated with of the use of amphetamines: A systematic review and meta-analysis

BACKGROUND

The use of amphetamines is a global public health concern. We summarise global data on use of amphetamines and mental health outcomes.

METHODS

A systematic review and meta-analysis (CRD 42017081893). We searched Medline, EMBASE, PsycInfo for methamphetamine or amphetamine combined with psychosis, violence, suicidality, depression or anxiety. Included studies were human empirical cross-sectional surveys, case-control studies, cohort studies and randomised controlled trials that assessed the association between methamphetamine and one of the mental health outcomes. Random effects meta-analysis was used to pool results for any use of amphetamines and amphetamine use disorders.

FINDINGS

149 studies were eligible and 59 were included in meta-analyses. There was significant heterogeneity in effects. Evidence came mostly from cross-sectional studies. Any use of amphetamines was associated with higher odds of psychosis (odds ratio [OR] = 2.0, 95%CI 1.3-3.3), violence (OR = 2.2, 95%CI 1.2-4.1; adjusted OR [AOR] = 1.4, 95%CI 0.8-2.4), suicidality OR = 4.4, 95%CI 2.4-8.2; AOR = 1.7, 95%CI 1.0-2.9) and depression (OR = 1.6, 95%CI 1.1-2.2; AOR = 1.3, 95%CI 1.2-1.4). Having an amphetamine use disorder was associated with higher odds of psychosis (OR = 3.0, 95%CI 1.9-4.8; AOR = 2.4, 95%CI 1.6-3.5), violence (OR = 6.2, 95%CI 3.1-12.3), and suicidality (OR = 2.3, 95%CI 1.8-2.9; AOR = 1.5, 95%CI 1.3-1.8).

INTERPRETATION

Methamphetamine use is an important risk factor for poor mental health. High quality population-level studies are needed to more accurately quantify this risk. Clinical responses to methamphetamine use need to address mental health harms.

Exploring How People Affected by Methamphetamine Exchange Social Support Through Online Interactions on Facebook: Content Analysis

BACKGROUND

Methamphetamine is an illicit and addictive psychostimulant that remains to be a significant cause of economic burden in Australia. Social media is increasingly being used by nongovernment organizations and health services to encourage the growth of social support networks among people with health-related issues. Several studies have investigated the utility of social media in providing social support to groups of people with health-related issues. However, limited research exists that explores how people who have been directly or indirectly affected by methamphetamine use social media for social support.

OBJECTIVE

This study aimed to determine the types of social support being sought and provided by people affected by methamphetamine when interacting with others on a Facebook page.

METHODS

A total of 14,777 posts were collected from a Facebook page and transferred into an Excel document for content analysis. The posts were manually coded into categories of social support using an adapted version of Cutrona and Suhr's Social Support Behavior Code. Posts could be coded into more than one category. Saturation was reached at 2000 posts, which were used to draw inferences.

RESULTS

Emotional support was the most offered support type, with 42.05% (841/2000) of posts providing this form of support. This is followed by esteem support, which was provided in 40.40% (808/2000) of posts. Overall, 24.20% (484/2000) of posts offered informational support. Network support and tangible support were the least offered support types, with 2.25% (45/2000) and 1.70% (34/2000) of posts offering these types of support, respectively.

CONCLUSIONS

This study suggests that online social support groups can be effective in challenging stigma by encouraging people affected by methamphetamine to connect with each other and talk about their struggles. This in turn represents an important step toward successful rehabilitation.

Multi-drug cocktails: Impurities in commonly used illicit drugs seized by police in Queensland, Australia

BACKGROUND

Impurities in commonly used illicit drugs raise concerns for unwitting consumers when pharmacologically active adulterants, especially new psychoactive substances (NPS), are used. This study examines impurities detected in illicit drugs seized in one Australian jurisdiction.

METHODS

Queensland Health Forensic and Scientific Services provided analytical data. Data described the chemical composition of 9346 samples of 11 illicit drugs seized by police during 2015-2016. Impurities present in primary drugs were summarized and tabulated. A systematic search for published evidence reporting similar analyses was conducted.

RESULTS

Methamphetamine was the primary drug in 6608 samples, followed by MDMA (1232 samples) and cocaine (516 samples). Purity of primary drugs ranged from ∼30% for cocaine, 2-CB and GHB to >90% for THC, methamphetamine, heroin and MDMA. Methamphetamine and MDMA contained the largest variety of impurities: 22 and 18 variants, respectively. Drug adulteration patterns were broadly similar to those found elsewhere, including NPS, but in some primary drugs impurities were found which had not been reported elsewhere. Psychostimulants were adulterated with each other. Levamisole was a common impurity in cocaine. Psychedelics were adulterated with methamphetamine and NPS. Opioids were quite pure, but some samples contained methamphetamine and synthetic opioids.

CONCLUSIONS

Impurities detected were mostly pharmacologically active adulterants probably added to enhance desired effects or for active bulking. Given the designer nature of these drug cocktails, the effects of the adulterated drugs on users from possible complex multi-drug interactions is unpredictable. Awareness-raising among users, research into complex multi-drug effects and ongoing monitoring is required.

Longitudinal patterns of amphetamine use from adolescence to adulthood: A latent class analysis of a 20-year prospective study of Australians

BACKGROUND

To examine the longitudinal patterns of amphetamine use over twenty years from adolescence to the mid-thirties; and identify adolescent antecedents of future problematic patterns of use.

DESIGN

Ten-wave longitudinal study following participants from age 15 to age 35 in Victoria, Australia. Participants (N = 1755; 47% males) first enrolled in the Victoria Adolescent Health Cohort Study in 1992.

MEASUREMENTS

Outcome: Self-reported frequency of amphetamine use.

PREDICTORS

Gender, depression and anxiety, peer alcohol and tobacco use; self-reported alcohol, tobacco and cannabis use, self-reported adolescent antisocial behavior.

FINDINGS

Three different longitudinal patterns were identified: Non-user (83.7%); Occasional user (14.5%); Regular user (1.8%). Among the two user patterns, amphetamine use was commonly initiated in late teenage years or early 20s, peaked at mid-20s, and declined substantially by mid-30s. Participants who used cannabis and had smoking peers during adolescence were at significantly more likely to become an occasional or regular user (p <  .05).

CONCLUSION

Regular cannabis use and peer tobacco use during adolescence were the two strongest predictors of a longitudinal pattern of regular amphetamine use in the mid-30s. This suggests that prevention programs could be implemented around or before mid-adolescence and interventions to reduce amphetamine harms focus on high-risk individuals in their 20s when amphetamine use was at its peak.

Crystal Methamphetamine use among Gay Men in Sydney

Crystal methamphetamine is used by gay men in Sydney in a variety of social and sexual contexts and by various means including injection. This paper presents detailed ethnographic data that explore some of the social and cultural characteristics of Sydney gay men's crystal use and other associated practices. The meaning of these practices is explored through a discussion of cultural boundaries and social exchange that traverses them. These boundaries help to limit drug-related harms in some ways but also generate certain risks. A nuanced understanding of the cultural meaning of various drug use practices may assist in producing culturally relevant harm-reduction education.

A Web-Based Toolkit to Provide Evidence-Based Resources About Crystal Methamphetamine for the Australian Community: Collaborative Development of Cracks in the Ice

BACKGROUND

The use of crystal methamphetamine (ice) and the associated harms for individuals, families, and communities across Australia has been the subject of growing concern in recent years. The provision of easily accessible, evidence-based, and up-to-date information and resources about crystal methamphetamine for the community is a critical component of an effective public health response.

OBJECTIVE

This paper aims to describe the codevelopment process of the Web-based Cracks in the Ice Community Toolkit, which was developed to improve access to evidence-based information and resources about crystal methamphetamine for the Australian community.

METHODS

Development of the Cracks in the Ice Community Toolkit was conducted in collaboration with community members across Australia and with experts working in the addiction field. The iterative process involved the following: (1) consultation with end users, including community members, crystal methamphetamine users, families and friends of someone using crystal methamphetamine, health professionals, and teachers (n=451) via a cross-sectional Web-based survey to understand information needs; (2) content and Web development; and (3) user testing of a beta version of the Web-based toolkit among end users (n=41) and experts (n=10) to evaluate the toolkit's acceptability, relevance, and appeal.

RESULTS

Initial end user consultation indicated that the most commonly endorsed reasons for visiting a website about crystal methamphetamine were "to get information for myself" (185/451, 41.0%) and "to find out how to help a friend or a family member" (136/451, 30.2%). Community consultation also revealed the need for simple information about crystal methamphetamine, including what it is, its effects, and when and where to seek help or support. Feedback on a beta version of the toolkit was positive in terms of content, readability, layout, look, and feel. Commonly identified areas for improvement related to increasing the level of engagement and personal connection, improving the ease of navigation, and balancing a "low prevalence of use, yet high impact" message. A total of 9138 users visited the website in the 3 months immediately post launch, and over 25,000 hard-copy Cracks in the Ice booklets and flyers were distributed across Australia. Of these resources, 60.93% (15,525/25,480) were distributed to relevant organizations and mailing list subscribers, and 39.07% (9955/25,480) were ordered directly by individuals, services, and community groups via the Cracks in the Ice website.

CONCLUSIONS

The codevelopment process resulted in an engaging Web-based resource for the Australian community to access up-to-date and evidence-based resources about crystal methamphetamine. The Cracks in the Ice Community Toolkit provides much-needed information and support for individuals, families, and communities.

A Comparison of Methamphetamine-Induced Psychosis and Schizophrenia: A Review of Positive, Negative, and Cognitive Symptomatology

Methamphetamine is a potent psychostimulant that can induce psychosis among recreational and chronic users, with some users developing a persistent psychotic syndrome that shows similarities to schizophrenia. This review provides a comprehensive critique of research that has directly compared schizophrenia with acute and chronic METH psychosis, with particular focus on psychiatric and neurocognitive symptomatology. We conclude that while there is considerable overlap in the behavioral and cognitive symptoms between METH psychosis and schizophrenia, there appears to be some evidence that suggests there are divergent aspects to each condition, particularly with acute METH psychosis. Schizophrenia appears to be associated with pronounced thought disorder, negative symptoms more generally and cognitive deficits mediated by the parietal cortex, such as difficulties with selective visual attention, while visual and tactile hallucinations appear to be more prevalent in acute METH-induced psychosis. As such, acute METH psychosis may represent a distinct psychotic disorder to schizophrenia and could be clinically distinguished from a primary psychotic disorder based on the aforementioned behavioral and cognitive sequelae. Preliminary evidence, on the other hand, suggests that chronic METH psychosis may be clinically similar to that of primary psychotic disorders, particularly with respect to positive and cognitive symptomatology, although negative symptoms appear to be more pronounced in schizophrenia. Limitations of the literature and avenues for future research are also discussed.

Rates, characteristics and circumstances of methamphetamine-related death in Australia: a national 7-year study

AIMS

To (1) assess trends in the number and mortality rates of methamphetamine-related death in Australia, 2009-15; (2) assess the characteristics and the cause, manner and circumstances of death; and (3) assess the blood methamphetamine concentrations and the presence of other drugs in methamphetamine-related death.

DESIGN

Analysis of cases of methamphetamine-related death retrieved from the National Coronial Information System (NCIS).

SETTING

Australia.

CASES

All cases in which methamphetamine was coded in the NCIS database as a mechanism contributing to death (n = 1649).

MEASUREMENTS

Information was collected on cause and manner of death, demographics, location, circumstances of death and toxicology.

FINDINGS

The mean age of cases was 36.9 years, and 78.4% were male. The crude mortality rate was 1.03 per 100 000. The rate increased significantly over time (P < 0.001), and at 2015 the mortality rate was 1.8 [confidence interval (CI) = 1.2-2.4] times that of 2009. Deaths were due to accidental drug toxicity (43.2%), natural disease (22.3%), suicide (18.2%), other accident (14.9%) and homicide (1.5%). In 40.8% of cases, death occurred outside the major capital cities. The median blood methamphetamine concentration was 0.17 mg/l, and cases in which only methamphetamine was detected had higher concentrations than other cases (0.30 versus 0.15 mg/l, P < 0.001). The median blood methamphetamine concentration varied within a narrow range (0.15-0.20 mg/l) across manner of death. In the majority (82.8%) of cases, substances other than methamphetamine were detected, most frequently opioids (43.1%) and hypnosedatives (38.0%).

CONCLUSIONS

Methamphetamine death rates doubled in Australia from 2009 to 2015. While toxicity was the most frequent cause, natural disease, suicide and accident comprised more than half of deaths.

The 'Worst of the Worst': Detectives' Beliefs about Dangerous Violent Offenders and How to Deal with Them

Police detectives come into contact with a community's most dangerous violent offenders, but there is little empirical research concerning detectives' beliefs about their characteristics. Twenty experienced detectives compared the characteristics and attributes of two offenders they believed to be the most dangerous repeat violent offenders in their community with two violent offenders who they believed to be less dangerous. Eighty offenders were identified in total. Thirteen bipolar dangerous-less dangerous constructs that differentiate the most dangerous violent offenders from other violent offenders were identified. The most frequently identified themes, mentioned by three quarters or more of the detectives, are being a heavy drug user (particularly amphetamines), being impulsive, and not thinking of the consequences of one's actions. The next three themes, mentioned by half of the detectives are extensive and regular offending, breadth of offending, and wishing to portray oneself as a 'tough guy'. One theme detectives did not mention frequently is mental illness as being associated with the most violent offenders, suggesting that detectives may miss mental illness in their interactions with offenders. Detectives suggested responding to the most dangerous violent offenders with longer sentences, extensive monitoring and better intelligence.

Barriers to accessing methamphetamine treatment: A systematic review and meta-analysis

BACKGROUND

Methamphetamine use is associated with a range of poor health, social and justice outcomes. In many parts of the world increased methamphetamine use has been identified as a major public health concern. Methamphetamine treatment programmes have been effective in reducing and ceasing use, however a range of barriers have prevented these programmes being widely adopted by methamphetamine users. This review examines the barriers to accessing meth/amphetamine treatment identified in the literature.

METHODS

Databases were systematically searched using relevant terms for peer-reviewed articles describing original research exploring the barriers to accessing treatment for meth/amphetamine use. Reviews and grey literature were excluded. Eleven studies conducted in 5 countries were included in data synthesis; this involved a systematic review of all 11 studies, and meta-analysis of the prevalence of barriers reported in 6 studies that published sufficient quantitative data.

RESULTS

Psychosocial/internal barriers to accessing methamphetamine treatment were most prevalent across studies (10/11 studies). Meta-analysis confirmed the four most commonly endorsed barriers to treatment access across studies all psychosocial barriers were embarrassment or stigma (60%, 95% CI: 54-67%); belief that treatment was unnecessary (59%, 95% CI:54-65%); preferring to withdraw alone without assistance (55%, 95% CI:45-65); and privacy concerns (51%, 95% CI:44-59%).

CONCLUSIONS

The primary barriers to accessing methamphetamine treatment are psychosocial/internal. Services and treatment models that address these barriers are urgently required. There is a growing need for methamphetamine-appropriate treatment services. Further research evaluating treatment engagement and effectiveness for methamphetamine and polysubstance use, including the development of effective pharmacotherapies is warranted.

Crystalline methamphetamine use and methamphetamine-related harms in Australia

INTRODUCTION AND AIMS

Concerns about crystal methamphetamine use and harm have increased in multiple countries. This paper describes how changes in the availability and use of crystal methamphetamine have impacted on methamphetamine-related harms in Australia.

DESIGN AND METHODS

Data on methamphetamine use were obtained from population-level surveys, health service data and surveys of drug use among sentinel groups of ecstasy users and people who inject drugs. Data were obtained on seizures, arrests, clandestine laboratory detections, hospital separations, mental health unit admissions, drug telephone helpline calls and drug treatment episodes. Segmented linear regression models were fitted to identify changes in these series using log-transformed data where appropriate.

RESULTS

The availability of crystal methamphetamine has increased as evidenced by increased laboratory detections, domestic seizures and purity of the seized drug. Population surveys do not report an increase in the number of people who used at least once in the past year. However, more users report using crystal methamphetamine rather than lower-purity powder methamphetamine and more regular use. Indicators of methamphetamine-related harms have increased in parallel with this change. Amphetamine-related helpline calls, drug treatment, arrests and hospital admissions for amphetamine disorders and psychosis all peaked in the mid-2000s, declined for several years and have increased steeply since 2010.

DISCUSSION AND CONCLUSIONS

The increased availability and use of crystal methamphetamine have been associated with increased regular use and harms. Treatment is required for those experiencing problems and the capacity of health services to provide care needs to be enhanced.[Degenhardt L, Sara G, Connor JP, McKetin R, Roxburgh A, Dobbins T, Farrell M, Burns L, Hall WD. Crystalline methamphetamine use and methamphetamine-related harms in Australia. Drug Alcohol Rev 2017;36:160-170].

The stigmatisation of 'ice' and under-reporting of meth/amphetamine use in general population surveys: A case study from Australia

BACKGROUND AND AIMS

Stigmatisation of illicit drug use is known to discourage people from reporting their use of illicit drugs. In the context of Australia's two recent "ice-epidemics" this study examines whether rapid increases in community concern about meth/amphetamine concurrent with increased stigmatising media reporting about meth/amphetamine "epidemics" are associated with increased under-reporting of its use in population surveys.

METHODS

We examined the relationship between general population trends in self-reported lifetime use of and attitudes towards meth/amphetamine between 2001 and 2013, contextualised against related stimulants and heroin, using five waves of Australia's National Drug Strategy Household Survey (NDSHS), alongside trends in print media reporting on meth/amphetamine from 2001 to 2014.

RESULTS

Analysis of NDSHS data showed significant increases in community concern about meth/amphetamine between 2004 and 2007, and 2010 and 2013 in all birth cohorts and age groups. In both periods self-reported lifetime use of meth/amphetamine fell in many birth cohorts. The falls were only statistically significant in the first period, for birth cohorts from 1961-1963 to 1973-1975. Falls in lifetime use within a cohort from one period to the next are incongruous and we did not observe them in the other drugs considered. Equally, increases in concern were specific to meth/amphetamine. We counted substantial and rapid increase in the number of newspaper reports about meth/amphetamine in both periods, particularly reports including the term 'epidemic'.

CONCLUSIONS

Rapid increases in the quantum of media reporting stigmatising a drug (through its construction as an 'epidemic') accompanying increased general public concerns about the drug may increase the tendency to under-report lifetime use. This may make it difficult to rely upon household surveys to observe trends in patterns of use and suggests that policy makers, media and others in the AOD sector should avoid stigmatisation of drugs, particularly during periods of heightened concern.

Global patterns of methamphetamine use

PURPOSE OF REVIEW

As the most popular psychostimulant in the world, methamphetamine use has reached epidemic proportions. Its enormous popularity has created subcultures of methamphetamine users all over the globe. The purpose of this review is to describe the geographic availability of different types of methamphetamine, the characteristics of each user population, and the psychosocial impact the two have on society.

RECENT FINDINGS

Methamphetamine has diversified immensely from the early days of its use. Different forms of methamphetamine - ICE, powder, and pills - have different pharmacokinetic characteristics that make them popular among certain types of users. New studies have shown that addiction to methamphetamine results in a very characteristic loss of inhibition that augments various risk-taking behaviors in its users. Also, recent seizure data suggest that its production and trafficking is spreading into new areas of the globe.

SUMMARY

From recreational use to addiction, methamphetamine use represents a serious risk to health and wellbeing of the community. Recognizing the pattern of abuse in specific populations is the key to assessing the risk, implementing prevention, and harm reduction measures, as well as making public policies.

Steroid users and the unique challenge they pose to needle and syringe program workers

INTRODUCTION AND AIMS

Needle and syringe programs (NSP), which provide sterile injecting equipment, are a cornerstone of Australia's drug harm reduction strategy and assist in reducing the spread of blood-borne virus infections, such as HIV and hepatitis C, among people who inject drugs. Some reports suggest that steroid users are an increasing proportion of clientele at NSPs. In this research, we investigate the experience of NSP workers who come into contact with people who use steroids and other performance- and image-enhancing drugs (PIED).

DESIGN AND METHOD

Thirteen NSP workers were recruited using purposive sampling strategies. Participants were interviewed using a semi-structured interview guide. Interviews were recorded, transcribed and coded for themes.

RESULTS

There are three key findings of this study. Firstly, NSP workers do not feel well informed about the substances that PIED users are injecting. Secondly, they were unsure what equipment PIED users required. Thirdly, PIED users were perceived to differ from other client groups, and these differences impacted upon the level of rapport staff could build with this group.

DISCUSSION AND CONCLUSION

PIED users pose unique challenges for NSP workers compared with other NSP client groups. The PIEDs used and the way in which they are used are substantially different compared with other NSP clients, and there appears to be a lack of knowledge within the workforce about these substances. This study highlights the need to engage in workforce training, but also the need to more effectively engage with PIED users in relation to effective harm reduction strategies.

Attitudes of regular injecting drug users towards the legal status of the major illicit drugs

INTRODUCTION AND AIMS

The study aimed to determine injecting drug users' (IDU) attitudes, and correlates of attitudes, towards continued prohibition, decriminalisation or legalisation of the major illicit drugs.

DESIGN AND METHODS

This study used structured interview with 300 IDUs who had injected on at least a weekly basis over the preceding 12 months.

RESULTS

Methamphetamine was rated the most harmful of the five illicit substances and cannabis the lowest. By far the highest level of support for legislative change was for cannabis, with only 8.7% supporting continued prohibition. While there was majority support for change to the legal status of heroin, the modal position was for decriminalisation. Support for changing the status of the three illicit psychostimulants was low, with the majority believing that methamphetamine (63.3%), cocaine (53.3%) and 3,4-methylenedioxy-N-methylamphetamine (53.3%) should remain illegal. Demographic characteristics were largely unrelated to attitudes. Lower levels of perceived harm were associated with increased likelihood of support for legalisation of all substances. Recent use was positively related to support for both decriminalisation and legality of heroin, but was not associated with views on other substances. Higher lifetime polydrug use was associated with support for the legalisation of heroin, methamphetamine, cocaine and 3,4-methylenedioxy-N-methylamphetamine.

DISCUSSION AND CONCLUSIONS

IDUs expressed nuanced views on different substances. In policy debates, care should be taken not to speak for IDUs by imputing their beliefs. It is clear that the fact that a group uses illegal drugs does not necessarily imply that they support changes to their legal status.

Enacting multiple methamphetamines: the ontological politics of public discourse and consumer accounts of a drug and its effects

Over the last decade in Australia, methamphetamine has come to be seen as a significant issue for drug research, policy and practice. Concerns have been expressed over its potency, the increasing prevalence of its use and its potential for producing greater levels, and more severe forms, of harm compared to amphetamine or other drugs. In this article, we critically examine some of the ways in which methamphetamine and its effects are produced and reproduced within and through Australian public discourse, focusing in particular on the associations made between methamphetamine and psychosis. We show how public discourse enacts methamphetamine as an anterior, stable, singular and definite object routinely linked to the severe psychological 'harm' of psychosis. We contrast the enactment of methamphetamine within public discourse with how methamphetamine is enacted by consumers of the drug. In their accounts, consumers perform different methamphetamine objects and offer different interpretations of the relationships of these objects to psychological problems and of the ontological nature (i.e. relating to what is real, what is, what exists) of these problems. In examining public discourse and consumer accounts, we challenge conventional ontological understandings of methamphetamine as anterior, singular, stable and definite, and of its psychological effects as indicative of pathology. In line with recent critical social research on drugs, we draw on social studies of science and technology that focus on the performativity of scientific knowledge and material practices. We suggest that recognising the ontological contingency, and therefore the multiplicity, of methamphetamine offers a critical counterpoint to conventional research, policy and practice accounts of methamphetamine and its psychological effects.

A Preference for Mephedrone: Drug Markets, Drugs of Choice, and the Emerging “Legal High” Scene

This study focuses on individuals’ preferences for mephedrone, a new psychoactive substance that has emerged in several countries. We examine the reasons for mephedrone preferences, and describe the positive and negative effects of the drug experience, route of administration and consumers’ views about the legality of mephedrone. Data were collected through semi-structured interviews with 45 adults who had used mephedrone since January 2010. Respondents resided in one of two jurisdictions that were characterized by different legislative controls over mephedrone. The findings suggest the importance of macro-level drug market factors that shaped people's preferences for mephedrone. Additionally, respondents’ preferences were guided by pharmacological properties that helped them conceal the effects of mephedrone in public and semi-public spaces. Respondents were not deterred by the (impending) change from legal to illicit drug. The findings have implications for the study of localized drug markets, and in particular, legislative controls over emerging legal highs.

Drug use, community action, and public health: gay men and crystal meth in NYC

In 2004, GLBT and HIV/AIDS service providers in NYC mobilized against use of crystal methamphetamine among gay men. Both drug use and mobilization were shaped by the history of HIV, particularly the institutions, action repertoires, and social networks forged in earlier AIDS work. This paper is based on qualitative research conducted from 2007 to 2009 with advocates, service providers, and men who have sex with men recruited from diverse venues in NYC gay communities. The crystal use epidemic among gay men in NYC indicates the importance of social and historical context in shaping drug use and antidrug mobilization, including the potential for public health responses to drug use.

Methamphetamine use, dependence and treatment access in rural and regional North Coast of New South Wales, Australia

INTRODUCTION AND AIMS

To identify the sociodemographic, health, drug use patterns, treatment coverage and barriers to treatment among regular methamphetamine users in rural and regional North Coast of New South Wales.

DESIGN AND METHODS

A structured questionnaire was used to measure sociodemographic factors, health and well-being, drug use patterns, methamphetamine dependence, engagement in methamphetamine treatment and barriers to treatment. Participants were 140 regular methamphetamine users. Dependent and non-dependent participants were compared to identify factors associated with dependence.

RESULTS

Participants were predominantly in their thirties, male and had low levels of education, high levels of unemployment and polydrug use. Participants who were dependent on methamphetamine (59%) were more likely to report impaired mental health and to have been diagnosed with depression, anxiety and drug-induced psychosis. One quarter of dependent methamphetamine users had received treatment in the last year and half had ever received treatment. The main barriers to receiving treatment were a lack of perceived need or motivation to seek treatment and concerns about confidentiality.

DISCUSSION AND CONCLUSIONS

Methamphetamine users living on the North Coast of New South Wales require treatment options tailored to address a complex array of physical and psychological problems. The findings highlight the need for psychiatric support and improved coordination between mental health and drug and alcohol services in rural and regional areas.

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.

Meth/amphetamine use and associated HIV: Implications for global policy and public health

Amphetamine type stimulants (ATS) have become the focus of increasing attention worldwide. There are understandable concerns over potential harms including the transmission of HIV. However, there have been no previous global reviews of the extent to which these drugs are injected or levels of HIV among users. A comprehensive search of the international peer-reviewed and grey literature was undertaken. Multiple electronic databases were searched and documents and datasets were provided by UN agencies and key experts from around the world in response to requests for information on the epidemiology of use. Amphetamine or methamphetamine (meth/amphetamine, M/A) use was documented in 110 countries, and injection in 60 of those. Use may be more prevalent in East and South East Asia, North America, South Africa, New Zealand, Australia and a number of European countries. In countries where the crystalline form is available, evidence suggests users are more likely to smoke or inject the drug; in such countries, higher levels of dependence may be occurring. Equivocal evidence exists as to whether people who inject M/A are at differing risk of HIV infection than other drug injectors; few countries document HIV prevalence/incidence among M/A injectors. High risk sexual behaviour among M/A users may contribute to increased risk of HIV infection, but available evidence is not sufficient to determine if the association is causal. A range of possible responses to M/A use and harm are discussed, ranging from supply and precursor control, to demand and harm reduction. Evidence suggests that complex issues surround M/A, requiring novel and sophisticated approaches, which have not yet been met with sufficient investment of time or resources to address them. Significant levels of M/A in many countries require a response to reduce harms that in many cases remain poorly understood. More active models of engagement with M/A users and provision of services that meet their specific needs are required.

A review of the clinical pharmacology of methamphetamine

AIMS

To examine the literature regarding clinical pharmacokinetics, direct effects and adverse clinical outcomes associated with methamphetamine use.

METHODS

Relevant literature was identified through a PubMed search. Additional literature was obtained from relevant books and monographs.

FINDINGS AND CONCLUSIONS

The mean elimination half-life for methamphetamine is approximately 10 hours, with considerable inter-individual variability in pharmacokinetics. Direct effects at low-to-moderate methamphetamine doses (5-30 mg) include arousal, positive mood, cardiac stimulation and acute improvement in cognitive domains such as attention and psychomotor coordination. At higher doses used typically by illicit users (> or =50 mg), methamphetamine can produce psychosis. Its hypertensive effect can produce a number of acute and chronic cardiovascular complications. Repeated use may induce neurotoxicity, associated with prolonged psychiatric symptoms, cognitive impairment and an increased risk of developing Parkinson's disease. Abrupt cessation of repeated methamphetamine use leads to a withdrawal syndrome consisting of depressed mood, anxiety and sleep disturbance. Acute withdrawal lasts typically for 7-10 days, and residual symptoms associated with neurotoxicity may persist for several months.

Changes in the initiation of heroin use after a reduction in heroin supply

Increasing heroin use in Australia over the past 30 years has been associated with a decline in the age of initiation to heroin use. The 2001 Australian heroin shortage was used to assess the effects of a reduction in heroin supply on age of initiation into heroin injecting. Data collected from regular injecting drug users (IDU) over the period 1996 - 2004 as part of the Australian Illicit Drug Reporting System were examined for changes in self-reported age of first heroin use after the onset of the heroin shortage. Estimates were also made of the number of young people who may not have commenced injecting heroin during the heroin shortage. The proportion of IDU interviewed in the IDRS who were aged <or=24 years decreased from 46% in 1996 to 12% in 2004, with the most marked drop in 2001, the year in which there was an abrupt and marked reduction in heroin availability. Of those who reported first injecting between 1993 and 2000, similar proportions reported heroin and amphetamine as the first drug injected. After 2000, methamphetamine was the drug most often reported as being the first injected. Estimates suggested that between 2745 and 10,560 young people may not have begun to inject heroin in 2001 as a result of reduced heroin supply. If around one in four of these young users had progressed to regular or dependent heroin use, then there may have been a reduction of between 700 and 2500 dependent heroin users. There was an increase in amphetamine injecting but it is unclear to what extent any reduction in heroin injecting has been offset by increased amphetamine injecting. Reduced heroin availability probably resulted in a reduction in the number of new heroin injectors in Australia. Efforts need to be made to reduce the chances that young people who have initiated methamphetamine injecting do not move to heroin injecting when the heroin supply returns.

Reflections on the development and implementation of an early warning system for ecstasy and related drug markets in Australia

Regular and systematic monitoring of drug markets provides the basis for evidence-based policy. In Australia, trends in ecstasy and related drug (ERD) markets have been monitored in selected jurisdictions since 2000 and nationally since 2003, by the Party Drugs Initiative (PDI). The PDI maximises the validity of conclusions by triangulating information from (a) interviews with regular ecstasy users (REU), (b) interviews with key experts and (c) indicator data. There is currently no other system in Australia for monitoring these markets systematically; however, the value of the PDI has been constrained by the quality of available data. Difficulties in recruiting and interviewing appropriate consumers (REU) and key experts have been experienced, but largely overcome. Limitations of available indicator data from both health and law enforcement continue to present challenges and there remains considerable scope for enhancing existing routine data collection systems, to facilitate monitoring of ERD markets. With an expanding market for ecstasy and related drugs in Australia, and in the context of indicator data that continue to be limited in scope and detail, there is a strong argument for the continued collection of annual, comparable data from a sentinel group of REU, such as those recruited for the PDI.

A review of psychosocial interventions for amphetamine use

There are clear signs that amphetamine use is increasing in Australia and internationally, yet there are few services that offer amphetamine-specific interventions. This review examines the evidence for the use of psychosocial interventions for amphetamine users. The literature is very limited in the number of well-conducted, controlled studies, but the evidence available suggests that cognitive-behavioural therapy appears to be current best practice. Motivational interviewing has been recommended as a strategy to assist those ambivalent for treatment. There is also some evidence that contingency management is effective while clients are in treatment. The effectiveness of other types of intervention is not well supported. The literature is particularly hindered by a paucity of well-conducted studies among primary amphetamine users. Recommendations about appropriate interventions for use in clinical settings are offered and directions for future research are considered.

Careers in ecstasy use: do ecstasy users cease of their own accord? Implications for intervention development

Background

Ecstasy (MDMA, 3, 4-methylenodioxymethamphetamine) use is widespread in the Netherlands, with a lifetime prevalence of 4.3%, and two-thirds of dance party visitors being ecstasy users. However, research into Dutch ecstasy use patterns is lacking. In addition, recent studies suggest that ecstasy users cease their use automatically, which implies that interventions would do better to better focus on the promotion of harm reduction strategies than on inducing cessation. The current study addresses this process of ecstasy cessation.

Methods

32 participants from the Dutch dance scene were interviewed, and the results were systematically analysed using NVivo.

Results

Most ecstasy users had started to use out of curiosity. During use, users applied a host of harm reduction strategies, albeit inconsistently and sometimes incorrectly. Most users appeared to cease ecstasy use automatically because of loss of interest or changing life circumstances (e.g. a new job or relationship).

Conclusion

It appears that cessation of ecstasy use is largely determined by environmental variables and not by health concerns. This supports the idea that health promotion resources are better spent in trying to promote consistent and correct application of harm reduction practices than in trying to induce cessation.

Characteristics and harms associated with injecting versus smoking methamphetamine among methamphetamine treatment entrants

INTRODUCTION AND AIMS

To compare the characteristics and harms associated with injecting and smoking methamphetamine among methamphetamine treatment entrants.

METHOD AND DESIGN

A structured face-to-face interview was used to assess demographics, drug use patterns and harms [physical and mental health, psychological distress, psychotic symptoms, crime and human immunodeficiency virus (HIV) risk behaviour] among 400 methamphetamine treatment entrants in Sydney and Brisbane, Australia. Participants who had injected but not smoked methamphetamine in the month before treatment (n = 195, injectors) were compared to participants who had either: (a) injected and smoked (n = 90, injectors who smoke), or (b) smoked but not injected (n = 73, smokers), during this time.

RESULTS

In comparison with injectors, smokers were primarily non-injecting drug users, who were younger, more likely to be female and use ecstasy rather than heroin. After adjusting for these differences smokers were less dependent on methamphetamine than injectors, but they took the drug as often and had similarly high levels of psychological distress, poor physical and mental health, psychotic symptoms, sexual risk behaviour and criminal involvement. Injectors who smoked had a similar demographic and clinical profile to injectors, including comparable levels of needle sharing, but they used methamphetamine more often and had greater criminal involvement.

CONCLUSION

Within this treatment sample, smoking methamphetamine occurred among both long-standing injecting drug users and a comparatively younger group of non-injecting drug users. It was associated with less severe methamphetamine dependence than injecting, but more intense use patterns and similar levels of other harms.

The epidemiology of methamphetamine use and harm in Australia

INTRODUCTION AND AIMS

There has been considerable media attention recently upon possible increases in methamphetamine use in Australia. Much of this debate has focused upon extreme cases of problematic crystal methamphetamine use, without reference to the broader population context. This paper provides data on methamphetamine use in Australia, and documents trends in methamphetamine-related harms.

DESIGN AND METHODS

Data used were from: (1) Australian Customs Service drug detections; (2) Australian Crime Commission drug seizure, arrest and clandestine laboratory detections data; (3) National Drug Strategy Household Survey (NDSHS) and Australian Secondary Student Alcohol and Drug Survey (ASSADS); (4) data from the Illicit Drug Reporting System (IDRS) and Ecstasy and related Drug Reporting System (EDRS); and (5) data from NSW Emergency Department Information System, National Hospital Morbidity Database and Australian Bureau of Statistics causes of death databases.

RESULTS

There appears to have been an increase in both importation and local manufacture of meth/amphetamine. Population data show that meth/amphetamine use remains low and stable. However, clear increases in crystal methamphetamine use have occurred among sentinel groups of regular drug users. Frequent crystal use among regular injecting drug users is associated with earlier initiation to injecting, greater injection risk behaviours and more extensive criminal activity. In recent years, indicators of meth/amphetamine-related harm have stabilised, following steady increases in earlier years.

DISCUSSION AND CONCLUSIONS

Some methamphetamine users experience significant problems related to their use; harms are particularly prevalent among regular IDU. Methamphetamine users, however, are a diverse group, and strategies need to be appropriately targeted towards different kinds of users.

Surge in treatment admissions related to methamphetamine use in Cape Town, South Africa: implications for public health

INTRODUCTION AND AIMS

In the past decade, methamphetamine has become increasingly a drug of concern globally. The purpose of this study is to describe the changing trends in treatment admissions for methamphetamine abuse in Cape Town, South Africa and to highlight the implications of these changes for policy, practice and research.

DESIGN AND METHODS

Data were collected on admissions for drug abuse treatment through a regular monitoring system involving drug treatment centres and programmes in Cape Town every 6 months as part of the South African Community Epidemiology Network on Drug Use (SACENDU). A one-page form was completed by treatment centre personnel to obtain demographic data, the patients' primary and secondary substances of abuse, the mode, frequency and age of first use of substance and information on prior treatment.

RESULTS

The results indicate that between 2004 and 2006 a dramatic increase in treatment admissions for methamphetamine abuse occurred, a large proportion of the methamphetamine patients are adolescents and that the drug is almost exclusively smoked.

DISCUSSION AND CONCLUSIONS

The rapid increase in admissions for methamphetamine abuse is of great concern, particularly as the drug has a number of serious, often chronic, side effects and that a large proportion of the patients are adolescents. The implications for public health are discussed.

High ambient temperature increases intravenous methamphetamine self-administration on fixed and progressive ratio schedules in rats

Methamphetamine is a drug that is often consumed at dance parties or nightclubs where the ambient temperature is high. The present study determined whether such high ambient temperatures alter intravenous methamphetamine self-administration in the rat. Male Hooded Wistar rats were trained to self-administer intravenous methamphetamine (0.1 mg/kg/infusion) under a fixed ratio 1 (FR1) or progressive ratio (PR) schedule of reinforcement at an ambient temperature of 23 +/- 1 degrees C. They were then given their daily self-administration session at a raised ambient temperature of 30 +/- 1 degrees C. Methamphetamine self-administration was increased at 30 degrees C under both FR1 and PR reinforcement schedules, with the latter effect indicating that heat enhances the motivation to obtain methamphetamine. High temperatures did not alter self-administration of the D1 receptor agonist SKF 82958 in methamphetamine-experienced rats suggesting some specificity in the methamphetamine effect. When rats were given access to drink isotonic saline solution during methamphetamine self-administration sessions they drank much more solution at 30 degrees C than 23 degrees C. However, availability of isotonic saline to drink did not alter the heat-induced facilitation of methamphetamine self-administration (PR schedule) indicating that the heat effect does not simply reflect increased motivation for intravenous fluids. Hyperthermia was evident in rats self-administering methamphetamine at high ambient temperatures and fluid consumption did not prevent this effect. Heat did not affect blood levels of methamphetamine, or its principal metabolite amphetamine indicating that the facilitatory effect of heat did not reflect altered methamphetamine pharmacokinetics. Overall, these results show that high ambient temperatures increase the reinforcing efficacy of methamphetamine and encourage higher levels of drug intake.