Methamphetamine Use, Methamphetamine Use Disorder, and Associated Overdose Deaths Among US Adults.

Importance: Mortality associated with methamphetamine use has increased markedly in the US. Understanding patterns of methamphetamine use may help inform related prevention and treatment. Objective: To assess the national trends in and correlates of past-year methamphetamine use, methamphetamine use disorder (MUD), injection, frequent use, and associated overdose mortality from 2015 to 2019. Design, Setting, and Participants: This cross-sectional study analyzed methamphetamine use, MUD, injection, and frequent use data from participants in the 2015 to 2019 National Surveys on Drug Use and Health (NSDUH). Mortality data were obtained from the 2015 to 2019 National Vital Statistics System Multiple Cause of Death files. Exposures: Methamphetamine use. Main Outcomes and Measures: Methamphetamine use, MUD, injection, frequent use, and overdose deaths. Results: Of 195 711 NSDUH respondents aged 18 to 64 years, 104 408 were women (weighted percentage, 50.9%), 35 686 were Hispanic individuals (weighted percentage, 18.0%), 25 389 were non-Hispanic Black (hereafter, Black) individuals (weighted percentage, 12.6%), and 114 248 were non-Hispanic White (hereafter, White) individuals (weighted percentage, 60.6%). From 2015 to 2019, overdose deaths involving psychostimulants other than cocaine (largely methamphetamine) increased 180% (from 5526 to 15 489; P for trend <.001); methamphetamine use increased 43% (from 1.4 million [95% CI, 1.2-1.6 million] to 2.0 million [95% CI, 1.7-2.3 million]; P for trend = .002); frequent methamphetamine use increased 66% (from 615 000 [95% CI, 512 000-717 000] to 1 021 000 [95% CI, 860 000-1 183 000]; P for trend = .002); methamphetamine and cocaine use increased 60% (from 402 000 [95% CI, 306 000-499 000] to 645 000 [95% CI, 477 000-813 000]; P for trend = .001); and MUD without injection increased 105% (from 397 000 [95% CI, 299 000-496 000] to 815 000 [95% CI, 598 000-1 033 000]; P for trend = .006). The prevalence of MUD or injection surpassed the prevalence of methamphetamine use without MUD or injection in each year from 2017 to 2019 (60% to 67% vs 37% to 40%; P for trend ≤.001). Adults with MUD or using injection were more likely to use methamphetamine frequently (52.68%-53.84% vs 32.59%; adjusted risk ratio, 1.62-1.65; 95% CI, 1.35-1.94). From 2015 to 2019, the adjusted prevalence of MUD without injection more than tripled among heterosexual women (from 0.24% to 0.74%; P < .001) and lesbian or bisexual women (from 0.21% to 0.71%; P < .001) and more than doubled among heterosexual men (from 0.29% to 0.79%; P < .001) and homosexual or bisexual men (from 0.29% to 0.80%; P = .007). It increased over 10-fold among Black individuals (from 0.06% to 0.64%; P < .001), nearly tripled among White individuals (from 0.28% to 0.78%; P < .001), and more than doubled among Hispanic individuals (from 0.39% to 0.82%; P < .001). Risk factors for methamphetamine use, MUD, injection, and frequent use included lower educational attainment, lower annual household income, lack of insurance, housing instability, criminal justice involvement, comorbidities (eg, HIV/AIDS, hepatitis B or C virus, depression), suicidal ideation, and polysubstance use. Conclusions and Relevance: This cross-sectional study found consistent upward trends in overdose mortality, greater risk patterns of methamphetamine use, and populations at higher risk for MUD diversifying rapidly, particularly those with socioeconomic risk factors and comorbidities. Evidence-based prevention and treatment interventions are needed to address surges in methamphetamine use and MUD.

Reinforcing effects of synthetic cathinones in rhesus monkeys: Dose-response and behavioral economic analyses.

The abuse of synthetic cathinones ("bath salts") with psychomotor stimulant and/or entactogenic properties emerged as a public health concern when they were introduced as "legal" alternatives to drugs of abuse such as cocaine or MDMA. In this study, experiments were conducted in nonhuman primates to examine how differences in transporter selectivity might impact the reinforcing effects of synthetic cathinones. Rhesus monkeys (N = 5) were trained to respond for intravenous injections under a fixed-ratio (FR) 30, timeout 60-s schedule of reinforcement. The reinforcing effects of selected cathinones (e.g., MDPV, αPVP, MCAT, and methylone) with a range of pharmacological effects at dopamine and serotonin transporters were compared to cocaine and MDMA using dose-response analysis under a simple FR schedule and behavioral economic procedures that generated demand curves for two doses of each drug. Results show that one or more doses of all drugs were readily self-administered in each subject and, excepting MDMA (21 injections/session), peak levels of self-administration were similar across drugs (between 30 and 40 injections/session). Demand elasticity for the peak and the peak + 1/2-log dose of each drug did not significantly differ, and when data for the two doses were averaged for each drug, the following rank-order of reinforcing strength emerged: cocaine > MCAT = MDPV = methylone > αPVP = MDMA. These results indicate that the reinforcing strength of synthetic cathinones are not related to their selectivity in binding dopamine or serotonin transporter sites.

Behavioral economic analysis of the reinforcing effects of "bath salts" mixtures: studies with MDPV, methylone, and caffeine in male Sprague-Dawley rats.

RATIONALE: "Bath salts" preparations often contain combinations of synthetic cathinones (e.g., 3,4-methylenedioxymethcathinone [methylone], 3,4-methylenedioxypyrovalerone [MDPV]), and caffeine, and evidence suggests that mixtures of synthetic cathinones and caffeine (e.g., MDPV + caffeine or methylone + caffeine) can be more potent and/or effective reinforcers than predicted for an additive interaction. OBJECTIVE: To use demand curve analyses to compare the reinforcing effectiveness of MDPV and methylone to mixtures of MDPV + caffeine and methylone + caffeine. METHODS: Male Sprague-Dawley rats acquired methylone self-administration (0.32 mg/kg/inf) under a fixed ratio (FR) 1 schedule of reinforcement and generated full dose-response curves for methylone (0.01-1 mg/kg/inf) under an FR5 schedule of reinforcement. Demand curves were then obtained for methylone, MDPV, caffeine, and methylone + caffeine and MDPV + caffeine mixtures by increasing the FR across sessions according to the following series: 3, 10, 18, 32, 56, 100, 178, etc. RESULTS: Self-administration of methylone was rapidly acquired by 87.5% of rats and was maintained across a range of doses, producing an inverted U-shaped dose-response curve. Rank order demand for the individual constituents was MDPV > methylone > caffeine. Demand for the 3:1 (but not 10:1) methylone + caffeine mixture was greater than that for methylone alone, and demand for MDPV alone was similar to both MDPV + caffeine mixtures evaluated. CONCLUSIONS: These studies provide additional evidence that although methylone is an effective reinforcer, combining methylone with caffeine results in an enhanced reinforcing effectiveness compared to methylone alone. Thus, abused "bath salts" preparations containing synthetic cathinones and caffeine may have higher abuse liability than preparations containing only synthetic cathinones.

Quantifying the societal cost of methamphetamine use to Australia.

Globally, there are increasing concerns about the harms associated with methamphetamine use. This paper i) reports on the results of a cost-of-illness (CoI) study that quantified the social costs associated with methamphetamine use in Australia and, ii) drawing on examples from this study, critically examines the general applicability of CoI studies for the alcohol and other drug field. A prevalence approach was used to estimate costs in 2013/2014, the most recent year for which reasonably comprehensive data were available. The value selected for a statistical life-year in our central estimate was AUD 281,798. Other costs were estimated from diverse sources. Total cost was estimated at AUD 5023.8 million in 2013/14 (range, AUD 2502.3 to AUD 7016.8 million). The greatest cost areas were crime including costs related to policing, courts, corrections and victims of crime (AUD 3244.5 million); followed by premature death (AUD 781.8 million); and, workplace costs (AUD 289.4 million). The social costs of methamphetamine use in Australia in 2013/14 are high, and the identification of crime and premature mortality as the largest cost areas is similar to USA findings and represents important areas for prevention and cost remediation. However, caution is required in interpreting the findings of any CoI study, as there is uncertainty associated with estimates owing to data limitations. Moreover, CoI estimates on their own do not identify which, if any, of the costs are avoidable (with drug substitution being a particular problem) nor do they shed light on the effectiveness of any potential interventions. We also recognise that data limitations prevent some costs from being estimated at all.

Chemsex among men - a questionnaire study. / Chemsex blant menn ­ en spørreundersøkelse.

BAKGRUNN: Formålet med undersøkelsen var å kartlegge forekomsten av rusmiddelbruk under sex (chemsex) blant et utvalg av mannlige pasienter ved Olafiaklinikken i Oslo, en poliklinikk for seksuelt overførbare infeksjoner. Vi ønsket også å se hvilke variabler innen psykisk helse, seksuelt overførbare infeksjoner og seksualatferd som var assosiert med chemsex for menn som har sex med menn og menn som har sex med kvinner. MATERIALE OG METODE: Studien var anonym og spørreskjemabasert blant mannlige pasienter ved poliklinikken i perioden 1.7.2016-20.10.2016. RESULTATER: Svarprosenten var 96 (1 050 fikk utdelt skjema, 1 013 ble inkludert). Av disse rapporterte 144 (14 %) bruk av chemsex i løpet av det siste året - 87 (17 %) menn som har sex med menn og 57 (12 %) menn som har sex med kvinner. Av de som hadde hatt chemsex, oppga flere menn som har sex med menn hivinfeksjon, at de hadde hatt syfilis, over ti sexpartnere og hadde deltatt på sexfest det siste året. Flere menn som har sex med kvinner oppga psykiske plager. FORTOLKNING: Det bør utredes nærmere hvordan helsevesenet best kan møte chemsexbrukernes behov. Spesielt er det viktig med informasjon om skadereduksjonstiltak og støtte til de som ønsker å slutte eller redusere bruken av chemsex.

Accumulation of Jail Incarceration and Hardship, Health Status, and Unmet Health Care Need Among Women Who Use Drugs.

BACKGROUND: Jail is frequently described as a "revolving door," which can be profoundly destabilizing to people moving in and out of the system. However, there is a dearth of research attempting to understand the impacts of the accumulation of incarceration events on women who use drugs. We examined the association of the frequency of jail incarceration with hardship, perceived health status, and unmet health care need among women who use drugs. METHODS: Our community-based sample included women who use heroin, methamphetamine, crack cocaine, and/or powder cocaine (N = 624) in Oakland, California, from 2012 to 2014. Poisson regression models with robust variances were built to estimate adjusted prevalence ratios between the frequency of jail incarcerations and measures of hardship, perceived health, and unmet health care need, adjusting for a set of a priori specified covariates. RESULTS: We observed associations between high levels of jail frequency and higher levels of homelessness (p = .024), feeling unsafe in their living situation (p = .011), stress (p = .047), fair to poor mental health (p = .034), unmet mental health care need (p = .037), and unmet physical health care need (p = .041). We did not observe an association between jail frequency and unmet subsistence needs score or fair to poor physical health. CONCLUSIONS: We observed associations between higher levels of jail frequency and a higher prevalence of hardship, poor mental health, and unmet health care need. Our findings suggest areas for additional research to untangle the impacts of frequent incarceration on women's health and well-being.

Persistent effect of withdrawal from intravenous methamphetamine self-administration on brain activation and behavioral economic indices involving an effort cost.

Exposure to drugs of abuse produces maladaptive changes in cost-benefit decision-making, including the evaluation of time and risk. Studies probing the effects of drug exposure on such evaluations have primarily used experimenter-administered drug regimens. Similarly, while much is known about the neural bases of effort, there have been relatively fewer investigations of the effects of drug experience on effort-based choices. We recently reported that experimenter-administered methamphetamine (meth) resulted in steeper discounting of effort for food rewards in rats, when assessed in protracted withdrawal. Here, we studied rats that underwent withdrawal from weeks of meth intravenous self-administration that later could freely select between a high effort, preferred option (progressive ratio lever pressing for sucrose pellets) versus a low effort, less preferred option (freely-available lab chow). We found decreased effort for the preferred reward and changes in a behavioral economic index demonstrating an increased sensitivity to effort in meth-experienced rats. Critically, the decreased effort for the preferred option was only present in the context of a competing option, not when it was the only option. We also confirmed rats preferred sucrose pellets over chow when both were freely available. These long-lasting changes were accompanied by decreased c-Fos activation in ventral striatum and basolateral amygdala, regions known to be important in effort-based choices. Taken together with our previous observations, these results suggest a robust and enduring effect of meth on value-based decision-making, and point to the underlying neural mechanisms that support the evaluation of an effort cost.

Assessment of tolerance to the effects of methamphetamine on daytime and nighttime activity evaluated with actigraphy in rhesus monkeys.

RATIONALE: Methamphetamine is one of the most largely consumed illicit drugs, and its use is associated with abuse liability and several adverse health effects, such as sleep impairment. Importantly, sleep quality can influence addiction treatment outcomes. Evidence suggests that tolerance can develop to the sleep-disrupting effects of stimulant drugs. OBJECTIVE: The aim of the present study was to investigate the development of tolerance to the actigraphy-based sleep-disrupting and stimulant effects of methamphetamine self-administration in rhesus monkeys. METHODS: Methamphetamine (0.03 mg/kg/inf, i.v.) self-administration was carried out following three different protocols: 14 consecutive days of self-administration, 5 days/week for 3 weeks, with a 2-day interval between 5-day blocks of self-administration, and 3 days/week for 3 weeks, with a 4-day interval between 3-day blocks of self-administration. Daytime activity and activity-based sleep measures were evaluated with Actiwatch monitors a week before (baseline parameters) and throughout each protocol. RESULTS: Methamphetamine self-administration markedly disrupted sleep-like measures and increased daytime activity. Tolerance developed to those effects with repeated methamphetamine intake exceeding five consecutive days. Inclusion of washout periods (2 or 4 days) between blocks of methamphetamine self-administration attenuated the development of tolerance, with longer breaks from methamphetamine intake being more effective in maintaining the sleep-disrupting and stimulant effects of methamphetamine. CONCLUSIONS: Tolerance can develop to the stimulant and sleep-disrupting effects of methamphetamine self-administration. Interruption of drug intake extends the effects of methamphetamine on sleep-like measures and daytime activity.

Self-administration and behavioral economics of second-generation synthetic cathinones in male rats.

RATIONALE: Synthetic cathinones have become increasingly available as drugs of abuse. Distribution of these drugs is made possible by altering the chemical structures of prohibited cathinones and marketing them under misleading labels. Very little is known about the relative reinforcing effectiveness of new synthetic cathinones relative to known drugs of abuse. OBJECTIVE: We examined self-administration of three second-generation synthetic cathinones: alpha-pyrrolidinopentiophenone (alpha-PVP), 4-methyl-N-ethylcathinone (4-MEC), and 4-methyl-alpha-pyrrolidinopropiophenone (4-MePPP) relative to methamphetamine. METHOD: Male, Sprague-Dawley rats, implanted with intravenous catheters, were trained to self-administer methamphetamine (0.05 mg/kg/injection) under a fixed-ratio schedule. Following training, various doses of methamphetamine (0.006-0.1 mg/kg/injection), alpha-PVP (0.0015-0.1 mg/kg/injection), 4-MEC (0.1-3.2 mg/kg/injection), or 4-MePPP (0.1-0.8 mg/kg/injection) were available for self-administration in separate groups, followed by a behavioral-economics evaluation of the reinforcing effectiveness of each drug. RESULTS: For all drugs, at least one dose functioned as a reinforcer. Alpha-PVP and 4-MePPP maintained the highest numbers of infusions per session and both were more effective reinforcers relative to methamphetamine. 4-MEC and methamphetamine were not significantly different in terms of infusions per session or reinforcing effectiveness. CONCLUSION: Emerging synthetic cathinones whose primary pharmacological mechanism is to block dopamine uptake but with little effects on monoamine release or serotonin uptake may have a greater degree of abuse potential compared with known abused stimulants.

Brain dopamine neurone 'damage': methamphetamine users vs. Parkinson's disease - a critical assessment of the evidence.

The objective of this review is to evaluate the evidence that recreational methamphetamine exposure might damage dopamine neurones in human brain, as predicted by experimental animal findings. Brain dopamine marker data in methamphetamine users can now be compared with those in Parkinson's disease, for which the Oleh Hornykiewicz discovery in Vienna of a brain dopamine deficiency is established. Whereas all examined striatal (caudate and putamen) dopamine neuronal markers are decreased in Parkinson's disease, levels of only some (dopamine, dopamine transporter) but not others (dopamine metabolites, synthetic enzymes, vesicular monoamine transporter 2) are below normal in methamphetamine users. This suggests that loss of dopamine neurones might not be characteristic of methamphetamine exposure in at least some human drug users. In methamphetamine users, dopamine loss was more marked in caudate than in putamen, whereas in Parkinson's disease, the putamen is distinctly more affected. Substantia nigra loss of dopamine-containing cell bodies is characteristic of Parkinson's disease, but similar neuropathological studies have yet to be conducted in methamphetamine users. Similarly, it is uncertain whether brain gliosis, a common feature of brain damage, occurs after methamphetamine exposure in humans. Preliminary epidemiological findings suggest that methamphetamine use might increase risk of subsequent development of Parkinson's disease. We conclude that the available literature is insufficient to indicate that recreational methamphetamine exposure likely causes loss of dopamine neurones in humans but does suggest presence of a striatal dopamine deficiency that, in principle, could be corrected by dopamine substitution medication if safety and subject selection considerations can be resolved.

Intimate partner violence among men and women who use methamphetamine: A mixed-methods study in South Africa.

INTRODUCTION: The prevalence of methamphetamine use has risen dramatically in parts of South Africa. Globally, methamphetamine has been linked to intimate partner violence (IPV) and other forms of aggression. The aim of this mixed-methods study was to examine the experiences of physical IPV and its contextual factors among methamphetamine users in an urban community in Cape Town, South Africa. METHODS: Active methamphetamine users were recruited using respondent driven sampling. All participants (n = 360) completed structured surveys, and a subset (n = 30) completed in-depth interviews with discussions of personal IPV experiences. Quantitative data were examined separately by gender, and regression models were used to identify factors that were associated with physical IPV victimisation and perpetration. Qualitative data were analysed to provide contextual understanding. RESULTS: In the past 3 months, 47% of women and 31% of men reported being a victim of IPV, and 30% of women and 28% men reported being a perpetrator of IPV. Victimisation and perpetration were highly correlated, and both were significantly associated with histories of other traumas. Although the survey data suggests gender equivalence in IPV, the qualitative data provides a more nuanced context, with female victimisation by male partners being particularly frequent and intense. In narratives, IPV was a product of male aggression while using methamphetamine, norms around sex trading and gender-based attitudes endorsing violence against women. CONCLUSION: Addiction to methamphetamine creates heightened risks of IPV, especially among those with previous traumas. The findings emphasise the importance of identifying and addressing IPV among methamphetamine users in South Africa. [Watt MH, Guidera KE, Hobkirk AL, Skinner D, Meade CS. Intimate partner violence among men and women who use methamphetamine: A mixed-methods study in South Africa. Drug Alcohol Rev 2017;36:97-106].

Regular clinic attendance in two large San Francisco HIV primary care settings.

Although poor clinic attendance is associated with increased morbidity and mortality among HIV-infected individuals, less is known about predictors of retention and the acceptability of targeted interventions to increase regular clinic attendance. To better understand which patients are at risk for irregular clinic attendance and to explore interventions to aid in retention to care, we surveyed patients attending two outpatient HIV clinics affiliated with the University of California, San Francisco. A total of 606 participants were surveyed, and the analysis was restricted to the 523 male respondents. Of this group, 45% (N = 299) reported missing at least one visit a year. Missing a clinic visit was associated with being African American (aOR = 1.99; 95%CI 1.12-3.52), being a man who has sex with both men and women (aOR=2.72; 95%CI 1.16-6.37), and reporting at least weekly methamphetamine use (aOR=5.79; 95%CI 2.47-13.57). Participants who reported a monthly income greater than $2000 were less likely to miss an appointment (aOR = 0.56; 95%CI 0.34-0.93). Regarding possible retention interventions, most patients preferred phone calls over other forms of support. These findings support the need for ongoing engagement support with particular attention to at-risk sub-groups.

An Internet Study of User's Experiences of the Synthetic Cathinone 4-Methylethcathinone (4-MEC).

Abstract A synthetic cathinone called 4-methylethcathinone (4-MEC) emerged online in 2010, and was cyber-marketed to be a replacement for mephedrone. The study aimed to present user experiences of 4-MEC as reported on the Internet, with a focus on user profiles, sourcing and product characteristics, routes of administration, dosage, positive and undesirable effects, and comparisons to mephedrone. Twenty-three individual, anonymous trip reports of the sole use of 4-MEC, and 112 screenshots of general 4-MEC user discussion boards, were taken from a purposeful sample of public drug-related sites. A content textual analysis was conducted on extracted qualitative information and produced 41 categories compiled into five general themes: "Type of 4-MEC user"; "Sourcing, informed decision making, product characteristics, and quality assurance"; "Routes of administration, gauging of dosage, and consumption of other drugs"; "Time course effects and outcomes"; and "Comparisons with mephedrone." 4-MEC is sold as white beads, crystalline shards, or green balls. User motives centered on curiosity, pricing, and ease of web sourcing. Oral, nasal, injecting, eyeball, and rectal routes of administration were described. Testing for purity, "allergy testing," and gauging of dosage were common. Users described euphoric but short-lived effects, with little comedown. Continued research is vital to inform harm reduction.

Assessment of HIV testing among young methamphetamine users in Muse, Northern Shan State, Myanmar.

BACKGROUND: Methamphetamine (MA) use has a strong correlation with risky sexual behaviors, and thus may be triggering the growing HIV epidemic in Myanmar. Although methamphetamine use is a serious public health concern, only a few studies have examined HIV testing among young drug users. This study aimed to examine how predisposing, enabling and need factors affect HIV testing among young MA users. METHODS: A cross-sectional study was conducted from January to March 2013 in Muse city in the Northern Shan State of Myanmar. Using a respondent-driven sampling method, 776 MA users aged 18-24 years were recruited. The main outcome of interest was whether participants had ever been tested for HIV. Descriptive statistics and multivariate logistic regression were applied in this study. RESULTS: Approximately 14.7% of young MA users had ever been tested for HIV. Significant positive predictors of HIV testing included predisposing factors such as being a female MA user, having had higher education, and currently living with one's spouse/sexual partner. Significant enabling factors included being employed and having ever visited NGO clinics or met NGO workers. Significant need factors were having ever been diagnosed with an STI and having ever wanted to receive help to stop drug use. CONCLUSIONS: Predisposing, enabling and need factors were significant contributors affecting uptake of HIV testing among young MA users. Integrating HIV testing into STI treatment programs, alongside general expansion of HIV testing services may be effective in increasing HIV testing uptake among young MA users.

Contextualizing gender differences and methamphetamine use with HIV prevalence within a South African community.

BACKGROUND: This study was conducted in a large Black African township outside of Cape Town, South Africa, where HIV infection has been endemic at extremely high levels for years. Problems associated with high HIV prevalence are compounded by gender inequality and high rates of gender-based violence exacerbated by heavy alcohol use and increasing methamphetamine use. METHODS: Informal drinking establishments (known as shebeens) were geocoded and mapped. Based on visual examination, we identified 36 neighbourhoods, each of which contained between three to seven drinking venues clustered together. Neighbourhoods were separated from each other by at least 200m. We randomly selected 30 of the 36 neighbourhoods. Outreach workers screened males in shebeens and screened their female partners. This analysis includes 580 study participants recruited from 30 neighbourhoods between 2010 and 2012. All participants completed a baseline questionnaire that included individual-level, couple-level, and neighbourhood-level measures of alcohol and other drug use, HIV infection, and HIV risk behaviours. Multilevel fixed effects regression analyses stratified by gender were conducted to examine correlates of HIV infection. RESULTS: Women were twice as likely as men to be HIV infected, yet they reported fewer sex partners. Neighbourhood prevalence of HIV was correlated with greater likelihood of HIV infection among women, but not men. Neighbourhood methamphetamine use was marginally associated with HIV among women but not among men. At the individual level, heavy alcohol use was marginally associated with HIV infection among men but not among women. Having an HIV positive partner was the strongest correlate of being HIV positive among both men and women. CONCLUSION: Findings from this study underscore the need for policy makers to direct scarce resources to the communities, places within communities, and populations, especially vulnerable women, where the impact on HIV prevention and onward transmission will be greatest.

A new survey of methamphetamine users in treatment: who they are, why they like "meth," and why they need additional services.

The quality and quantity of illicit methamphetamine has recently increased due to introduction of a new precursor, 1-phenyl-2-propanone (P2P). This paper updates the problems associated with methamphetamine use. Methamphetamine-using clients (N = 222) entering a Texas program participated in computer-assisted interviews in 2010 and 2011 about routes of administration, other drugs used, severity of dependence, mental and physical health, perceived risks and benefits of use, family history, and abuse and neglect experienced as children and adults. Special needs of this population include therapies for trauma, gender-focused counseling, safe housing, and prevention messages to discourage use of the drug.

The whole is just the sum of its parts: limited polydrug use among the "big three" expensive drugs in the United States.

Data from surveys of arrestees and the household population in the U.S. suggest there is only modest overlap among demand for the big three expensive illegal drugs (cocaine/crack, heroin, and methamphetamine). In particular, the number of chronic users of these substances (defined as consuming on four or more days in the previous month) is only about 10% below a naïve estimate obtained by simply summing the numbers of chronic users for each of the three substances, while ignoring polydrug use entirely. This finding does not gainsay that polydrug use is common or important. One would estimate greater overlap if one adopted a more expansive definition of polydrug use (e.g., has the individual ever used another substance at any time in their life) or a more expansive list of substances (e.g., allowing marijuana or alcohol to count as one of the substances makes polydrug use seem much more common). However, it does suggest that when focusing on the illegal drug markets that generate the most crime, violence, and overdose death in the U.S., one can usefully think of three more or less separate markets populated at any given time by largely distinct populations of drug users.

Meth mouth severity in response to drug-use patterns and dental access in methamphetamine users.

Meth mouth is the rapid development of tooth decay in methamphetamine users. Our study questioned whether drug-use patterns and dental care access are risk factors affecting the severity of meth mouth. Participants received dental examinations, and the number of decayed, missing and filled teeth (DMFT) were counted and used to measure meth mouth severity.

Alternative reinforcer response cost impacts methamphetamine choice in humans.

Methamphetamine use disorders are a persistent public health concern. Behavioral treatments have demonstrated that providing access to non-drug alternative reinforcers reduces methamphetamine use. The purpose of this human laboratory experiment was to determine how changes in response cost for non-drug alternative reinforcers influenced methamphetamine choice. Seven subjects with past year histories of recreational stimulant use completed a placebo-controlled, crossover, double-blind protocol in which they first sampled doses of oral methamphetamine (0, 8 or 16 mg) and completed a battery of subject-rated and physiological measures. During subsequent sessions, subjects then made eight discrete choices between 1/8th of the sampled dose and an alternative reinforcer ($0.25). The response cost to earn a methamphetamine dose was always 500 responses (FR500). The response cost for the alternative reinforcer varied across sessions (FR500, FR1000, FR2000, FR3000). Methamphetamine functioned as a positive reinforcer and produced prototypical stimulant-like effects (e.g., elevated blood pressure, increased ratings of Stimulated). Choice for doses over money was sensitive to changes in response cost for alternative reinforcers in that more doses were taken at higher FR values than at lower FR values. Placebo choices changed as a function of alternative reinforcer response cost to a greater degree than active methamphetamine choices. These findings suggest that manipulating the effort necessary to earn alternative reinforcers could impact methamphetamine use.