Mechanisms and treatments of methamphetamine and HIV-1 co-induced neurotoxicity: a systematic review.

Combination antiretroviral therapy (cART) has dramatically reduced mortality in people with human immunodeficiency virus (HIV), but it does not completely eradicate the virus from the brain. Patients with long-term HIV-1 infection often show neurocognitive impairment, which severely affects the quality of life of those infected. Methamphetamine (METH) users are at a significantly higher risk of contracting HIV-1 through behaviors such as engaging in high-risk sex or sharing needles, which can lead to transmission of the virus. In addition, HIV-1-infected individuals who abuse METH exhibit higher viral loads and more severe cognitive dysfunction, suggesting that METH exacerbates the neurotoxicity associated with HIV-1. Therefore, this review focuses on various mechanisms underlying METH and HIV-1 infection co-induced neurotoxicity and existing interventions targeting the sigma 1 receptor, dopamine transporter protein, and other relevant targets are explored. The findings of this review are envisaged to systematically establish a theoretical framework for METH abuse and HIV-1 infection co-induced neurotoxicity, and to suggest novel clinical treatment targets.

The development and validation of a knowledge, attitude, and practice questionnaire of methamphetamine use.

Methamphetamine is a synthetic psychostimulant that is showing a rising trend of usage among adolescents and youths. Its harmful side effects and high risk of developing addiction is a public health problem. Recognizing the knowledge, attitudes, and practices (KAP) on methamphetamine is critical in the planning of an intervention strategy. Currently there is a lack of KAP questionnaires on methamphetamine. The study aims to develop and validate a KAP questionnaire on methamphetamine-use for use among Malaysian adolescents. Following an extensive literature review, face and content validity were carried out among healthcare workers, the public, students, and local subject matter experts. A pilot study was conducted amongst 50 students to assess the test-retest reliability. The questionnaire was then distributed to two groups of 269 and 331 individuals for the Exploratory (EFA) and Confirmatory Factor Analysis (CFA), respectively. The internal reliability was also assessed among these groups. The content validation consisting of Item Content Validity Index (I-CVI, ranging from 0.875 to 1.00), and Scale Content Validity Index (S-CVI/Ave = 0.941) both showed good validation scores. Test-retest reliability showcased an Intraclass Correlation Coefficient (ICC) of > 0.7, indicating its reliability. The model was constructed via the EFA resulting in four constructs, and the model's goodness of fit was confirmed with CFA. An internal reliability was calculated with Cronbach's Alpha and showed acceptable reliability (α-values > 0.6) for all constructs. The KAP questionnaire of methamphetamine use is a valid and reliable tool that can be used among Malaysian adolescents. The model arising from this study, can also be used as a guide for future intervention models for adolescent methamphetamine-use disorder.

Reasons for using methamphetamine: Systematic review.

BACKGROUND AND OBJECTIVES: Use of methamphetamine has increased in the last decade. The reasons for using methamphetamine vary according to the characteristics of the users. The literature includes review studies on methamphetamine use; however, no systematic review on the reasons for using methamphetamine was found. This study aims to determine the reasons for methamphetamine use through a systematic review of the literature. METHOD: The data from a systematic review of the literature review were reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Science Direct, Ovid-Medline, and Google Scholar databases were scanned using the keywords "methamphetamine", "crystal", "meth", "addiction", "reason for use", and "motivation to use". The articles (n = 25,004) were reviewed based on the inclusion and exclusion criteria, and 21 articles were finally selected for this study. RESULTS: The reasons for using methamphetamine included improving performance, staying awake, increasing sexual performance and impulses, reducing the effects of withdrawal from other substances, coping with problems, socializing, having fun, and coping with pain and discomfort. DISCUSSION AND CONCLUSIONS: Methamphetamine users typically take this drug to provide performance enhancement and cope with problems in different areas. It is recommended to inform the users correctly about methamphetamine, to teach effective methods of coping with withdrawal, and to carry out supply prevention studies. SCIENTIFIC SIGNIFICANCE: This is the first systematic literature review to reveal the reasons why people take methamphetamine. Revealing these causes is very important in terms of intervention (basic, primary, secondary, and tertiary protection) strategies.

Prevalence of Methamphetamine (Mkpurummiri) use in south east Nigeria: a community-based cross-sectional study.

BACKGROUND: Methamphetamine (MA) (Mkpurummiri) is seen as the most common, accessible and new drug of use/abuse in south east Nigeria. Despite the overwhelming evidence of the dire consequences of this drug to the users, there is lack of empirical research to determine its prevalence in this area where use is assumed to be common. This study aimed to determine the prevalence of MA use, characteristics of the users and the control measures. METHODS: A descriptive cross-sectional survey research design was conducted from May through November 2023 among adolescents/adults at the age bracket of 15-64 years in the five states of south east, Nigeria. Three hundred and seventy-one (371) respondents were recruited using purposive/convenience sampling methods. A semi structured questionnaire was the instrument used. Data were analyzed using percentage, bivariate and multivariate logistics regression statistics. The Prevalence of MA was determined using percentages whereas the factors that are associated with MA use were expressed using multivariate logistics regression statistics AORs and 95%CIs. The level of significance was set at P < 0.05. RESULTS: The prevalence of Methamphetamine (Mkpurummiri) was (21.8%). The most common reason for MA use was depression (86.5%), the most common route of administration was inhalation (64.9%). The most common characteristic of MA (Mkpurummiri) user was aggressive/violent behaviour (94.1%).The control measures were self-control (92.2%), parental monitoring (85.7%), drug education (83.1%) and legal control (80.8%). The multivariate logistics regression statistics AOR shows that off-campus were 3 times (AOR = 0.298; CI = 0.12-0.73 P = 0.008), family house 4 times (AOR = 0.241; CI = 0.09-0.65; P = 0.005 ≤ 0.05 ) less likely than on-campus to predict MA use. Recently married were 3.25 times (aOR = 3.25; CI = 1.47-7.18), divorced 3.45 times (aOR = 3.45; CI = 1.23-9.58), polygamy 2.3 times (aOR = 2.3; CI = 1.08-4.90; P = 0.031 ≤ 0.05 ), tradition 4.44 times (aOR = 4.44; CI = 1.77-11.15; P = 0.001 ≤ 0.05 ) , more likely than others to use MA. CONCLUSIONS: MA use prevalence was relatively high, and marital status, living arrangements, family type and religion were the predictors. These findings underscore the need for concerted effort among the relevant government agencies, community stakeholders, families, religious bodies and school authorities to designing MA use policy/laws with special focus on adopting the punitive measure used in checking cocaine users. This may help to arrest and prosecute the manufacturers, distributors and users of MA.

Brain mGlu5 Is Linked to Cognition and Cigarette Smoking but Does Not Differ From Control in Early Abstinence From Chronic Methamphetamine Use.

BACKGROUND: The group-I metabotropic glutamate receptor subtype 5 (mGlu5) has been implicated in methamphetamine exposure in animals and in human cognition. Because people with methamphetamine use disorder (MUD) exhibit cognitive deficits, we evaluated mGlu5 in people with MUD and controls and tested its association with cognitive performance. METHODS: Positron emission tomography was performed to measure the total VT of [18F]FPEB, a radiotracer for mGlu5, in brains of participants with MUD (abstinent from methamphetamine for at least 2 weeks, N = 14) and a control group (N = 14). Drug use history questionnaires and tests of verbal learning, spatial working memory, and executive function were administered. Associations of VT with methamphetamine use, tobacco use, and cognitive performance were tested. RESULTS: MUD participants did not differ from controls in global or regional VT, and measures of methamphetamine use were not correlated with VT. VT was significantly higher globally in nonsmoking vs smoking participants (main effect, P = .0041). MUD participants showed nonsignificant weakness on the Rey Auditory Verbal Learning Task and the Stroop test vs controls (P = .08 and P = .13, respectively) with moderate to large effect sizes, and significantly underperformed controls on the Spatial Capacity Delayed Response Test (P = .015). Across groups, Rey Auditory Verbal Learning Task performance correlated with VT in the dorsolateral prefrontal cortex and superior frontal gyrus. CONCLUSION: Abstinent MUD patients show no evidence of mGlu5 downregulation in brain, but association of VT in dorsolateral prefrontal cortex with verbal learning suggests that medications that target mGlu5 may improve cognitive performance.

U.S. trends in methamphetamine-involved psychiatric hospitalizations in the United States, 2015-2019.

BACKGROUND: In the U.S., overdose deaths and substance treatment admissions related to methamphetamine are rising. This study aims to measure and compare U.S. temporal trends in methamphetamine-involved psychiatric hospitalizations. METHODS: We conducted a population-based, trend analysis of U.S. psychiatric hospitalizations and calculated quarterly (Q) rates per 100,000 population of substance-involved psychiatric hospitalizations. We assessed U.S. regional quarterly percentage hospitalization rate changes using Joinpoint regression. RESULTS: From Q4 2015-Q4 2019, there were 963,202 psychiatric hospitalizations, 50,223 (5.2 %) involved methamphetamine and 102,877 (10.7 %) involved opioids and/or cocaine without methamphetamine. Methamphetamine-involved psychiatric hospitalization rates increased by 68.0 %, psychiatric hospitalizations rates involving opioid and/or cocaine without methamphetamine decreased by 22 %, while nonsubstance-involved psychiatric hospitalizations rates remained unchanged. The largest significant increases in methamphetamine-involved psychiatric hospitalization rates were among people >61 years old, males, and Midwesterners. Methamphetamine-involved psychiatric hospitalization rates doubled among Black patients. The largest average percent increase among methamphetamine-involved psychiatric hospitalizations was 10.2 % from Q4 2015-Q2 2017 in the Midwest. CONCLUSION AND RELEVANCE: Most psychiatric hospitalizations did not involve substances. Methamphetamine-involved psychiatric hospitalizations greatly increased while opioid-involved psychiatric hospitalizations decreased, but involved more total encounters. Greater access to harm reduction services, contingency management programs, and mental health services is urgently needed.

Ten-year cardiovascular disease risk and related factors in lifetime marijuana use with comorbid methamphetamine-associated psychotic disorder: a QRISK®3 study.

BACKGROUND: Methamphetamine use and related direct and indirect problems are increasing all over the world. The coexistence of lifetime marijuana use (LMU) and methamphetamine use disorder (MUD) may also be accompanied by psychotic symptoms (MAP). Methamphetamine and marijuana use are known to pose risks for cardiovascular diseases (CVDs). However, ten-year CVD risk and inflammation markers of LMU-MUD (non-psychosis group) and LMU-MAP (psychosis group) subjects and the relationship of various sociodemographic and clinical variables with these markers have not yet been examined. METHODS: Thirty-two male subjects were included in non-psychosis group and 72 male subjects in psychosis group. Sociodemographic and clinical characteristics were recorded. Psychotic symptom severity of psychosis group subjects was measured. The ten-year CVD risk was calculated using QRISK®3 model. RESULTS: Age, cigarettes/pack-years, alcohol use onset age, drug use onset age, methamphetamine use onset age, duration of methamphetamine use, education and marital status of the groups were similar (p > 0.05). There was a statistical difference between the non-psychosis and psychosis groups in terms of self-mutilation history (p < 0.001), suicidal attempt history (p = 0.007), homicidal attempt history (p = 0.002), psychiatric hospitalization history (p = 0.010). Ten-year QRISK®3 score was 4.90 ± 9.30 in the psychosis group, while it was 1.60 ± 1.43 in the non-psychosis group (p = 0.004). The mean heart age of the psychosis group was 14 years higher than their chronological age, while the mean heart age of the non-psychosis group was 8 years higher. Neutrophil to lymphocyte ratio (NLR) (p = 0.003) was higher in the psychosis group. A significant correlation was detected between ten-year QRISK®3 and positive psychotic symptoms in the psychosis group (r = 0.274, p = 0.020). Regression analysis showed that self-mutilation history, NLR and relative risk obtained from QRISK®3 can be used to distinguish non-psychosis group and psychosis group subjects (sensitivity = 91.7; Nagelkerke R2 0.438; p = 0.001). CONCLUSIONS: This study is important as it demonstrates for the first time that among the subjects using marijuana and methamphetamine, those with psychotic symptoms have a higher NLR and ten-year CVD risk.

"Jail isn't the answer for these inmates": how to respond to methamphetamine use in prisons.

PURPOSE: The correctional system continues to face challenges with responding to and managing methamphetamine use among incarcerated individuals. This study aims to uncover what resources and policies could better help correctional workers deal with these challenges. The authors also examined methamphetamine's impact on correctional work and staff well-being. DESIGN/METHODOLOGY/APPROACH: An online survey was distributed to correctional workers (n = 269) in Manitoba, Canada, featuring questions about their experiences related to methamphetamine use in populations under their care, what supports are needed to adequately address the concern, and the potential effects on self and their occupational responsibilities. Using NVivo software, survey responses were analysed using an emergent theme approach. FINDINGS: Correctional workers believed policies and protocols for managing methamphetamine use and withdrawal are currently inadequate. Correctional workers reported having monthly contact with incarcerated individuals experiencing methamphetamine withdrawal, posing safety concerns to them and other incarcerated individuals. Respondents proposed more education and training on managing incarcerated people withdrawing from methamphetamines, related to the symptoms of use and withdrawal and how to support persons detoxing. Increased human and material resources were reported as being needed (e.g. more nurses onsite and better screening devices). Respondents also desired more medical intervention, safe living spaces for methamphetamine users and programming to support addiction. ORIGINALITY/VALUE: The current study unpacks correctional workers' perspectives, support desires and their experiences managing methamphetamine use amongst incarcerated people. The authors discuss the required knowledge to respond to gaps in prison living, re-entry and related policy needs.

Missed Opportunity or Cause for Concern? Methamphetamine Use Is Associated With Greater Interest in Event-Driven PrEP Among Sexual Minority Men.

Our study assessed the association between methamphetamine (i.e., crystal meth, CM) use and awareness and interest in event-driven (ED) PrEP among HIV-negative and those with unknown serostatus cisgender males and transgender people. We performed log-binomial regression analysis to predict awareness (i.e., having heard of ED PrEP) and being interested in ED PrEP. We found that participants who recently used CM were less likely to know of ED PrEP (aPR = 0.83, 95% CI [0.69, 0.99]) but more interested in ED PrEP (aPR = 1.12, 95% CI [1.01, 1.30]), after accounting for demographic and HIV-related behaviors. Opportunities to expand PrEP uptake and improve adherence among individuals who report CM use are essential to impact the HIV epidemic significantly. Continued research on the needs and best practices to work with this community is needed to ensure a successful rollout and implementation of ED PrEP.

20-year trends in Australian methamphetamine-related deaths, 2001-2020.

BACKGROUND: Over the past two decades methamphetamine-related harms have increased in Australia. Previous analysis of methamphetamine-related deaths has covered limited timeframes, and largely focused on drug-toxicity deaths. This paper examines long-term trends in methamphetamine-related deaths over 20 years, including deaths due to a range of specific causes. METHODS: Descriptive analyses were conducted on Australian methamphetamine-related deaths (2001-2023) by cause, extracted from the National Coronial Information System, an online database containing deaths reported to coroners in Australia and New Zealand. Joinpoint trend analyses were used to assess changes over time between 2001 and 2020 (with data from 2021 to 2023 likely incomplete and thus excluded). RESULTS: Unintentional drug toxicity was the cause of 49.8 % of methamphetamine-related deaths, intentional self-harm (including toxicity) 23.3 %, unintentional injury 15.1 %, natural causes 9.6 %, and assaults 2.3 %. Between 2001 and 2020, joinpoint analysis showed three trend change points among all-cause methamphetamine-related mortality rates, resulting in four distinct periods: two periods where they increased (2001-2006 - annual percentage change (APC) = 15.4 %; 2009-2016 - APC 25.5 %), and two where they decreased (2006-2009 - APC = -11.8 %; 2017-2020 - APC = -2.9 %). Similar patterns were evident among rates of intentional self-harm and unintentional injury. Deaths caused by unintentional drug toxicity saw two trend change points (2011, 2016), and rates increased across all three periods. Natural cause deaths had three trend change points (2007, 2010, 2015), and rates continued to rise after 2015, largely driven by increases in circulatory diseases. CONCLUSION: Cause-specific models highlighted diverse trends. Recent trends show unintentional drug toxicity deaths have slightly increased, intentional self-harm stabilised, and unintentional injury and assault deaths have declined. Deaths from natural causes involving methamphetamine continued to increase, highlighting a public health concern and a potential need for early circulatory disease screening among people who use methamphetamine.

Combined Diagnostic Value of Hsa-miR-592 and Hsa-miR-9-3p in Plasma for Methamphetamine Addicts.

A number of studies have reported that drug addiction is associated with microRNAs (miRNAs). However, the roles of plasma miRNAs in methamphetamine (METH) addicts have not been clearly explained. This study aimed to profile a panel of miRNAs as non-invasive predictive biomarkers and therapeutic targets for METH addiction. Differentially expressed miRNAs were derived from next-generation sequencing technology (NGS) and were validated by quantitative real-time PCR (RT-qPCR). The diagnostic value of specific altered miRNAs was evaluated by receiver operating characteristic (ROC) analysis and area under the curve (AUC). NGS results revealed that 63 miRNAs were significantly altered in the METH-exposed paradigm. The levels of hsa-miR-592, hsa-miR-9-3p, hsa-miR-206 and hsa-let-7b-3p were significantly elevated in the plasma of METH addicts. Hsa-miR-9-3p was a useful biomarker discriminating METH addicts from normal (AUC was 0.756). Importantly, combining detection of hsa-miR-592 and hsa-miR-9-3p achieved the highest AUC of 0.87, with a sensitivity and specificity of 82.7% and 78.9%, respectively. Target gene BDNF decreased significantly in METH addicts. Although METH addicts showed significant depressive symptoms, there was no correlation between the expression level of miR-592 and miR-9-3p and the degree of depression. Our findings suggested that hsa-miR-592, hsa-miR-9-3p, hsa-miR-206, and hsa-let-7b-3p may play a potential role in the pathology of METH addiction, and a combination of hsa-miR-592 and hsa-miR-9-3p could serve as potential peripheral biomarker and therapeutic target for METH addiction.

Systematic review protocol to determine the most effective pharmacological and non-pharmacological interventions for the management of acute methamphetamine toxicity.

INTRODUCTION: This study describes the protocol for a systematic review. The systematic review will address experiences of managing methamphetamine intoxication, specifically violence and agitation related to intoxication, in the emergency department (ED). METHODS AND ANALYSIS: This study uses the Grading of Recommendations Assessment, Development and Evaluation system to guide the methods in this section. The primary objective of the review is to identify experimental studies assessing the effectiveness of both pharmacological and non-pharmacological strategies to manage acute methamphetamine intoxication in patients presenting violently in the ED. Our secondary objectives will be to assess the impact of specific strategies on the time it takes to achieve de-escalation and/or sedation, the length of stay in the ED, frequency of admission, mortality and provider satisfaction with the intervention. ETHICS AND DISSEMINATION: Ethics approval has been obtained from the Conjoint Health Research Ethics Board REB21-1387. Results will be published in a peer-reviewed journal and presented at healthcare conferences in Canada. TRIAL REGISTRATION NUMBER: The protocol is registered through the International Prospective Register of Systematic Reviews (identification number: CRD42020157938) and will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extensions for systematic review protocols.

Impact of methamphetamine use on HIV and other health outcomes at an urban HIV medicine clinic.

BACKGROUND: The methamphetamine epidemic threatens progress towards ending the HIV epidemic in the United States. Further characterizing the prevalence and impact of methamphetamine use among people with HIV (PWH) is necessary to inform integrated HIV and methamphetamine treatment strategies. METHODS: We conducted a retrospective chart review to characterize methamphetamine use among 3092 PWH at an urban HIV Medicine clinic between July 1, 2022 and June 30, 2023. The chi-squared test was utilized to assess for statistically significant differences in demographics and HIV and other health outcomes among PWH who use and do not use methamphetamine. RESULTS: The prevalence of methamphetamine use among PWH in this cohort was 17%. PWH who used methamphetamine were more likely to be <40 years of age, identify as White race, live in neighborhoods with low Healthy Places Index scores, identify as lesbian, gay, or bisexual, report male sex with men (MSM), MSM and injection drug use (IDU), or IDU as HIV transmission risk factor, miss scheduled HIV primary care visits, and screen positive for hepatitis C virus antibody, gonorrhea, chlamydia, and major depressive disorder. PWH who use methamphetamine were also less likely to be virally suppressed and have a CD4 + cell count ≥200 cells/mm 3 . CONCLUSION: Methamphetamine use is prevalent among PWH at this urban HIV Medicine Clinic and is associated with worse HIV and other health outcomes which likely increase the risk of HIV transmission. The integration of methamphetamine use disorder treatment into HIV primary care is necessary to work toward ending the syndemics of methamphetamine and HIV.

Identification of Methamphetamine Abusers Can Be Supported by EEG-Based Wavelet Transform and BiLSTM Networks.

Methamphetamine (MA) is a neurological drug, which is harmful to the overall brain cognitive function when abused. Based on this property of MA, people can be divided into those with MA abuse and healthy people. However, few studies to date have investigated automatic detection of MA abusers based on the neural activity. For this reason, the purpose of this research was to investigate the difference in the neural activity between MA abusers and healthy persons and accordingly discriminate MA abusers. First, we performed event-related potential (ERP) analysis to determine the time range of P300. Then, the wavelet coefficients of the P300 component were extracted as the main features, along with the time and frequency domain features within the selected P300 range to classify. To optimize the feature set, F_score was used to remove features below the average score. Finally, a Bidirectional Long Short-term Memory (BiLSTM) network was performed for classification. The experimental result showed that the detection accuracy of BiLSTM could reach 83.85%. In conclusion, the P300 component of EEG signals of MA abusers is different from that in normal persons. Based on this difference, this study proposes a novel way for the prevention and diagnosis of MA abuse.

Modulation of dlPFC function and decision-making capacity by repetitive transcranial magnetic stimulation in methamphetamine use disorder.

This study explores the impact of repetitive transcranial magnetic stimulation (rTMS) on decision-making capabilities in individuals with methamphetamine use disorder (MUD), alongside potential underlying psychological mechanisms. Employing the Iowa Gambling Task (IGT) and computational modeling techniques, we assessed the decision-making processes of 50 male MUD participants (24 underwent rTMS treatment, 26 received no treatment) and 39 healthy controls (HC). We compared pre- and post-rTMS treatment alterations in the left dorsolateral prefrontal cortex (dlPFC). Results revealed inferior performance in the IGT among the MUD group, characterized by aberrant model parameters in the Value-Plus-Perseverance (VPP) model, including heightened learning rate, outcome sensitivity, and reinforcement learning weight, alongside diminished response consistency and loss aversion. RTMS treatment demonstrated efficacy in reducing craving scores, enhancing decision-making abilities, and partially restoring normalcy to certain model parameters in the MUD cohort. Nonetheless, no linear relationship between changes in model parameters and craving was observed. These findings lend support to the somatic marker hypothesis, implicating the dlPFC in the decision-making deficits observed in MUD, with rTMS potentially ameliorating these deficits by modulating the function of these brain regions. This study not only offers novel insights and methodologies for MUD rehabilitation but also underscores the necessity for further research to corroborate and refine these findings. Trial Registration www.chictr.org.cn Identifier: No. ChiCTR17013610.

Psychometric validation of the Chinese Version of the stimulant relapse risk scale (SRRS) in patients with methamphetamine use disorder.

BACKGROUND: Evaluating the risk of relapse is a pivotal step in the treatment of patients with methamphetamine use disorder (MUD). The 30-item Stimulant Relapse Risk Scale (SRRS) was originally developed in Japan to meet the demand. This study examined the reliability, validity, and factor structure of the Chinese version of the SRRS for patients with MUD. METHODS: 247 patients with MUD self-rated the Chinese version of the SRRS. Cronbach's alpha coefficients and inter-item correlation analysis were used to assess the internal consistency reliability. Construct validity was determined through confirmatory factor analysis (CFA), and concurrent validity was examined using the visual analogue scale (VAS) for drug craving and the severity of dependence scale (SDS). We followed the participants for 1 year and assessed the predictive validity based on the correlation of the scores of the Chinese version of the SRRS with the relapse rate within 3, 6, and 12 months of follow-up. RESULTS: CFA revealed satisfactory model fit estimates for the 22-item Chinese version of the SRRS that consisted of four subscales. The four-factored 22-item Chinese version of the SRRS had adequate internal consistency with Cronbach's alphas ranging from 0.76 to 0.92. The 22-item Chinese version of the SRRS scores were significantly correlated with the VAS and SDS scores as well as the relapse rate within 3, 6, and 12 months, indicating good concurrent and predictive validity of this scale. The receiver operating characteristic curve revealed a cutoff score of 40 could discriminate between participants with (SDS score ≥ 4) and without (SDS score < 4) methamphetamine dependence (area under the curve = 0.71, p < 0.01). CONCLUSIONS: The 22-item Chinese version of the SRRS that consists of four subscales is a valid and reliable instrument to assess the relapse risk in patients with MUD.

Clustering of methamphetamine users based on personality characteristics and self-efficacy in the west of Iran.

With the substantial increase in the use of stimulants, especially methamphetamine, in recent years, the present study aimed to cluster methamphetamine users based on personality traits and self-efficacy, and compare their mental health, sleep quality, and the risk of relapse in the identified clusters. This cross-sectional study was conducted through convenience sampling on 501 methamphetamine users in addiction treatment centers in Kermanshah, western Iran. The data were collected using the Schwarzer General Self-Efficacy Scale, Zuckerman-Kuhlman Personality Questionnaire, Goldberg and Hiller General Health Questionnaire (GHQ), Zuckerman-Kuhlman Personality Questionnaire, and Stimulant Relapse Risk Scale (SRRS). A total of 501 methamphetamine users were distinguished into three clusters with frequencies of 111 (22.2%), 298 (59.5%), and 92 (18.4%) members through hierarchical cluster analysis. The participants in the first cluster were characterized by low self-efficacy, high neuroticism, sensation seeking, and aggressiveness, along with low extroversion and activity, low positive health, high negative health, low sleep quality, and high risk of drug relapse. The participants in the second cluster reported moderate levels of self-efficacy, neuroticism, sensation seeking, activity, and aggressiveness, high extroversion, and moderate levels of mental health, sleep quality, and the risk of relapse. Moreover, the participants in the third cluster reported the highest level of self-efficacy, the lowest level of neuroticism, sensation seeking, and aggressiveness, moderate extroversion and high activity, low relapse risk, high sleep quality, as well as high positive and low negative health symptoms. The third cluster was significantly different from the other two clusters in terms of the mentioned factors. The findings of this study suggest that low self-efficacy and the presence of neuroticism, sensation seeking, and high aggressiveness contribute to reduced mental health and sleep quality, as well as an increased risk of relapse in methamphetamine users.

Neural correlates of impulsivity in amphetamine use disorder.

Impulsivity is a trait associated with several psychiatric conditions, not least addictive disorders. While the neural mechanisms behind certain aspects of impulsivity have been studied extensively, there are few imaging studies examining this neurocircuitry in populations with substance use disorders. Therefore, we aimed to examine the functional connectivity of relevant neural networks, and their possible association with trait impulsivity, in a sample with severe amphetamine use disorder and a control group of healthy subjects. We used data collected in a randomized clinical trial studying the acute effects of oral naltrexone in amphetamine use disorder. Our final sample included 32 amphetamine users and 27 healthy controls. Trait impulsivity was rated with the Barratt Impulsiveness Scale-11, and functional connectivity was measured during resting-state fMRI, looking specifically at networks involving prefrontal regions previously implicated in studies of impulsivity. Amphetamine users had higher subjective ratings of impulsivity as compared to healthy controls, and these scores correlated positively with a wide-spread prefrontal hyperconnectivity that was found among the amphetamine users. These findings highlight the importance of aberrant prefrontal function in severe addiction.