Major physical and psychological harms of methamphetamine use

Geographic and Racial/Ethnic Differences in Access to Methamphetamine Detoxification Services, United States, 2021

INTRODUCTION

Methamphetamine detoxification before entering formal and longer term treatment may have a positive impact on treatment retention and success. Understanding geographic distribution of methamphetamine specialty detox services and differential access by race/ethnicity is critical for establishing policies that ensure equitable access across populations.

METHODS

We used the Mental health and Addiction Treatment Tracking Repository to identify treatment facilities that offered any substance use detoxification in 2021 (N=2346) as well as the census block group in which they were located. We sourced data from the US Census Bureau to identify the percentage of a census block group that was White, Black, and Hispanic. We used logistic regression to model the availability of methamphetamine-specific detox, predicted by the percentage of a block group that was Black and Hispanic. We adjusted for relevant covariates and defined state as a random effect. We calculated model-based predicted probabilities.

RESULTS

Over half (60%) of detox facilities offered additional detox services specifically for methamphetamine. Sixteen states had <10 methamphetamine-specific detox facilities. The predicted probability of methamphetamine-specific detox availability was 60% in census block groups with 0%-9% Black residents versus only 46% in census block groups with 90%-100% Black residents, and was 61% in census block groups with 0%-9% Hispanic residents versus 30% in census block groups with 90%-100% Hispanic residents.

CONCLUSIONS

During an unprecedented national methamphetamine crisis, access to a critical health care service was disproportionately lower in communities that were predominately Black and Hispanic. We orient our findings around a discussion of health disparities, residential segregation, and the upstream causes of the systematic exclusion of minoritized communities from health care.

A narrative systematic review of associations and temporality between use of methamphetamine, ecstasy/MDMA, or cocaine with anxiety or depressive symptoms

OBJECTIVE

Anxiety and depression are prevalent mental health problems in people who use illicit stimulants. Improved understanding of the temporal relationship between methamphetamine, ecstasy/MDMA, or cocaine use with anxiety or depression informs public health interventions and treatment options for those experiencing this co-occurrence. This narrative systematic review sought to examine associations and temporality between the use of methamphetamine, ecstasy/MDMA, or cocaine, with anxiety or depressive symptoms. Method Systematic searches of 4 electronic databases were conducted up to August 2023. Study eligibility included the measurement of anxiety and/or depressive symptoms, and frequency of illicit stimulant use (methamphetamine, cocaine, or ecstasy/MDMA) at two separate time points, with data analysis of the association between these variables. The Joanna Briggs Critical Appraisal Checklist was utilised to assess quality. Data was extracted, and a narrative synthesis incorporating an eight-criteria framework to assess associations was conducted. Results 4432 studies were screened for eligibility; 11 studies (3 RCTs and 8 prospective cohort studies) were included. Evidence for an association between depressive symptoms and methamphetamine use was demonstrated in six studies, with temporal evidence in three studies supporting methamphetamine use preceding depressive symptoms. Three studies reported an association between cocaine use and depressive symptoms. Evidence for associations with any of the illicit stimulants and anxiety symptoms was lacking.

CONCLUSIONS

There was some evidence to support a case for temporality, particularly for methamphetamine use and depressive symptoms. Investing in longitudinal studies is pivotal to understanding the dynamic and reciprocal relationship between illicit stimulant use and anxiety or depressive symptoms. A limitation of the study was the variation in the measurement and analysis of outcomes.

Mortality, morbidity, and predictors of death among amphetamine-type stimulant users - a longitudinal, nationwide register study

Introduction

Use of amphetamine-type stimulants (ATS) contributes substantially to the global burden of disease. Large-scale follow-up studies of morbidity and mortality in ATS users are few. This study analysed morbidity, mortality, and potential predictors of all-cause mortality in a nationwide cohort of patients with ATS use disorder.

Methods

Data was acquired from national Swedish registers. All Swedish residents 18 years or older, with a registered ATS use diagnosis in 2013-2014 were included (N = 5,018) and followed until December 31, 2017. Comorbid diagnoses and causes of death were assessed and potential predictors of all-cause mortality were examined through Cox regression.

Results

Median age at inclusion was 36.6 years (interquartile range 27.4---48.1) and 70.5 % were men. The crude mortality rate was 24.6 per 1,000 person-years. The adjusted all-cause standardized mortality ratio was 12.4 (95 % CI [11.34-13.55]). The most common cause of death was overdose (28.9 %). Multiple drug use (hazard ratio 1.39, 95 % CI [1.14-1.70], p = 0.004), anxiety (hazard ratio 1.39, 95 % CI [1.11-1.72], p = 0.014), viral hepatitis (hazard ratio 1.85, 95 % CI [1.50-2.29], p = 0.004), and liver disease (hazard ratio 2.41, 95 % CI [1.55-3.74], p = 0.004) were predictors of all-cause mortality.

Conclusions

Multiple drug use, anxiety disorders, viral hepatitis and liver diseases were identified as risk factors for death. Our findings call for better screening, prevention, and treatment of somatic and psychiatric comorbidity among ATS users to reduce mortality.

Estimating changes in overdose death rates from increasing methamphetamine supply in Ohio: Evidence from crime lab data

Background

We investigate the relationship between the supply of methamphetamine and overdose death risk in Ohio. Ohio and the overall US have experienced a marked increase in overdose deaths from methamphetamine combined with fentanyl over the last decade. The increasing use of methamphetamine may be increasing the risk of overdose death. However, if people are using it to substitute away from more dangerous synthetic opioids, it may reduce the overall risk of overdose death.

Methods

Ohio's Bureau of Criminal Investigation's crime lab data include a detailed list of the content of drug samples from law enforcement seizures, which are used as a proxy for drug supply. We use linear regressions to estimate the relationship between the proportion of methamphetamine in lab samples and unintentional drug overdose death rates from January 2015 through September 2021.

Results

Relatively more methamphetamine in crime lab data in a county-month has either no statistically significant relationship with overdose death rates (in small and medium population counties) or a negative and statistically significant relationship with overdose death rates (in large population counties). Past overdose death rates do not predict future increases in methamphetamine in crime lab data.

Conclusions

The results are consistent with a relatively higher supply of methamphetamine reducing the general risk of overdose death, possibly due to substitution away from more dangerous synthetic opioids. However, the supply of methamphetamine appears unrelated to the past illicit drug risk environment. The non-lethal and yet serious health effects of MA use were not explored and, thus, even if the presence of MA reduces the population-level overdose mortality rate, the rise of other adverse health effects may counteract any public health benefits of fewer deaths.

The Association Between Rumination and Craving in Chinese Methamphetamine-Dependent Patients: The Masking Effect of Depression

BACKGROUND

Craving is a core feature of addiction. Rumination and depression play a crucial role in the process of methamphetamine addiction. The aim of this study was to examine the relationship between rumination, depression and craving in methamphetamine patients, which has not been explored yet.

METHODS

A total of 778 patients with methamphetamine user disorder (MUD) at the Xinhua Drug Rehabilitation Center, located in Mianyang City, Sichuan Province, China. We used a set of self-administered questionnaires that included socio-demographic, detailed drug use history, rumination, depression and craving information. The Rumination Response Scale (RRS) was used to measure rumination, the Beck Depression Inventory (BDI) to measure depression and the Visual Analogue Scale (VAS) to measure craving.

RESULTS

There was a significant positive correlation between rumination and craving, or depression, and between depression and craving. Furthermore, depression mediated between rumination and craving, with a mediation effect of 160%.

CONCLUSIONS

Our findings suggest that there is a close interrelationship between rumination, craving and depression in MUD patients, and that depression may play a mediating role between rumination and craving.

Descriptive study on substance uses and risk of sexually transmitted infections in the practice of Chemsex in Spain

Background

In recent years, there has been an increasing use of sex-related substances (known as "Chemsex") to facilitate, intensify, and prolong the sexual experience of men who have sex with men. This phenomenon poses a public health problem, increasing the risk of sexually transmitted infections (STIs) and mental disorders.

Objective

The primary aim of this study was to delve into the correlation between substance use and sexual health, specifically examining the association between different substances used and the risk of sexually transmitted infections (STIs) in the context of Chemsex in Spain.

Methods

An observational, descriptive, cross-sectional study was conducted among 563 Spanish participants between January and April 2023. Non-probabilistic purposive sampling was used by the investigators. The researchers administered a questionnaire to men who have sex with men who use substances, especially in the sexual sphere, in all the autonomous communities of Spain.

Results

14.7% reported having practiced slamsex in the last year, and 17.94% were diagnosed with a Sexually Transmitted Infection in the previous 6 months. Of these, 21% were on PREP treatment, with the main STIs being gonorrhea (p < 0.001), chlamydia (p < 0.001), genital herpes (p = 0.020), and syphilis (p < 0.001). The 63.7% used methamphetamines as the main drug in the practice of chemsex.

Discussion

Chemsex in Spain is linked to a high prevalence of STIs, especially gonorrhea and chlamydia, even among those on PrEP treatment. The use of various drugs during chemsex, such as amyl nitrite, GHB, ecstasy, and others, correlates with higher rates of STIs, highlighting the need for interventions to reduce risk and harm. The drugs most associated with slamsex include ketamine, mephedrone, and methamphetamine, underscoring the importance of addressing the risk behaviors associated with this activity.

Conclusion

This study shows that chemsex appears to be associated with a high prevalence among men who have sex with men. Who use multiple substances in a sexual context, and are particularly exposed to sexually transmitted infections (STIs), indicating a particular need for STI prevention and care in this group.

Pilot study with randomised control of dual site theta burst transcranial magnetic stimulation (TMS) for methamphetamine use disorder: a protocol for the TARTAN study

BACKGROUND

Transcranial magnetic stimulation (TMS) (including the theta burst stimulation (TBS) form of TMS used in this study) is a non-invasive means to stimulate nerve cells in superficial areas of the brain. In recent years, there has been a growth in the application of TMS to investigate the modulation of neural networks involved in substance use disorders. This study examines the feasibility of novel TMS protocols for the treatment of methamphetamine (MA) use disorder in an ambulatory drug and alcohol treatment setting.

METHODS

Thirty participants meeting the criteria for moderate to severe MA use disorder will be recruited in community drug and alcohol treatment settings and randomised to receive active TMS or sham (control) intervention. The treatment is intermittent TBS (iTBS) applied to the left dorsolateral prefrontal cortex (DLPFC), then continuous TBS (cTBS) to the left orbitofrontal cortex (OFC). Twelve sessions are administered over 4 weeks with opt-in weekly standardized cognitive behaviour therapy (CBT) counselling and a neuroimaging sub-study offered to participants. Primary outcomes are feasibility measures including recruitment, retention and acceptability of the intervention. Secondary outcomes include monitoring of safety and preliminary efficacy data including changes in substance use, cravings (cue reactivity) and cognition (response inhibition).

DISCUSSION

This study examines shorter TBS protocols of TMS for MA use disorder in real-world drug and alcohol outpatient settings where withdrawal and abstinence from MA, or other substances, are not eligibility requirements. TMS is a relatively affordable treatment and staff of ambulatory health settings can be trained to administer TMS. It is a potentially scalable and translatable treatment for existing drug and alcohol clinical settings. TMS has the potential to provide a much-needed adjuvant treatment to existing psychosocial interventions for MA use disorder. A limitation of this protocol is that the feasibility of follow-up is only examined at the end of treatment (4 weeks).

TRIAL REGISTRATION

Australia New Zealand Clinical Trial Registry ACTRN12622000762752. Registered on May 27, 2022, and retrospectively registered (first participant enrolled) on May 23, 2022, with protocol version 7 on February 24, 2023.

Crystal methamphetamine and its effects on mental and oral health: A narrative review

The purpose of this comprehensive literature review is to present the available evidence on the effects of methamphetamine on mental and oral health, as well as provide an overview of the most widely used medical and dental care strategies in the management of meth mouth. For this purpose, PubMed and Google Scholar electronic databases were searched for relevant articles, yielding 115 search results, which were further scrutinized for their relevance, leaving 55 for a detailed review. The analysis of the gathered data indicates that a comprehensive patient-centered approach that takes into consideration the physical, mental, and social aspects is crucial for mitigating the detrimental effects of increasing methamphetamine use.

Transient receptor potential ankyrin 1 channel modulates the abuse-related mechanisms of methamphetamine through interaction with dopamine transporter

BACKGROUND AND PURPOSE

Methamphetamine (METH) use disorder has risen dramatically over the past decade, and there are currently no FDA-approved medications due, in part, to gaps in our understanding of the pharmacological mechanisms related to METH action in the brain.

EXPERIMENTAL APPROACH

Here, we investigated whether transient receptor potential ankyrin 1 (TRPA1) mediates each of several METH abuse-related behaviours in rodents: self-administration, drug-primed reinstatement, acquisition of conditioned place preference, and hyperlocomotion. Additionally, METH-induced molecular (i.e., neurotransmitter and protein) changes in the brain were compared between wild-type and TRPA1 knock-out mice. Finally, the relationship between TRPA1 and the dopamine transporter was investigated through immunoprecipitation and dopamine reuptake assays.

KEY RESULTS

TRPA1 antagonism blunted METH self-administration and drug-primed reinstatement of METH-seeking behaviour. Further, development of METH-induced conditioned place preference and hyperlocomotion were inhibited by TRPA1 antagonist treatment, effects that were not observed in TRPA1 knock-out mice. Similarly, molecular studies revealed METH-induced increases in dopamine levels and expression of dopamine system-related proteins in wild-type, but not in TRPA1 knock-out mice. Furthermore, pharmacological blockade of TRPA1 receptors reduced the interaction between TRPA1 and the dopamine transporter, thereby increasing dopamine reuptake activity by the transporter.

CONCLUSION AND IMPLICATIONS

This study demonstrates that TRPA1 is involved in the abuse-related behavioural effects of METH, potentially through its modulatory role in METH-induced activation of dopaminergic neurotransmission. Taken together, these data suggest that TRPA1 may be a novel therapeutic target for treating METH use disorder.

"Everything is kind of the same except my mind is with me": exploring cannabis substitution in a sample of adults in early recovery from an opioid or stimulant addiction

BACKGROUND

Recovery from addiction is frequently equated with abstinence. However, some individuals who resolve an addiction continue to use substances, including via substitution (i.e., increased use of one substance after eliminating/ reducing another). Substitution may play a distinct role during early recovery (≤ 1 year), as this period is marked by dramatic change and adjustment. Cannabis is one of the most used substances and is legal for medical and recreational use in an increasing number of states. Consequently, cannabis an increasingly accessible substitute for substances, like fentanyl, heroin, cocaine and methamphetamine, with higher risk profiles (e.g., associated with risk for withdrawal, overdose, and incarceration).

METHODS

Fourteen participants reported that they had resolved a primary opioid or stimulant addiction and subsequently increased their cannabis use within the previous 12 months. Using grounded theory, the interviewer explored their experiences of cannabis use during early recovery. Data were analyzed in three stages: line by line coding for all text related to cannabis use and recovery, focused coding, and axial coding to generate a theory about recovery with cannabis substitution. The motivational model of substance use provided sensitizing concepts.

RESULTS & DISCUSSION

The final sample included eight men and six women ranging in age from 20 to 50 years old. Three participants resolved an addiction to methamphetamine and the remaining 11, an addiction to opioids. Participants explained that cannabis was appealing because of its less harmful profile (e.g., no overdose risk, safe supply, few side effects). Participants' primary motives for cannabis use included mitigation of psychiatric symptoms, withdrawal/ cravings, and boredom. While cannabis was effective toward these ends, participants also reported some negative side effects (e.g., decreased productivity, social anxiety). All participants described typical benefits of recovery (e.g., improved self-concept, better relationships) while continuing to use cannabis. Their experiences with and beliefs about substitution suggest it can be an effective strategy for some individuals during early recovery.

CONCLUSIONS

Cannabis use may benefit some adults who are reducing their opioid or stimulant use, especially during early recovery. The addiction field's focus on abstinence has limited our knowledge about non-abstinent recovery. Longitudinal studies are needed to understand the nature of substitution and its impact on recovery over time.

Cardiomyopathy in Patients With Acute Ischemic Stroke and Methamphetamine Use: Relevance for Cardioembolic Stroke and Outcome

BACKGROUND

Methamphetamine use has emerged as a major risk factor for cardiovascular and cerebrovascular disease in young adults. The aim of this study was to investigate a possible association of methamphetamine use with cardioembolic stroke.

METHODS AND RESULTS

We performed a retrospective study of patients with acute ischemic stroke admitted at our medical center between 2019 and 2022. All patients were screened for methamphetamine use and cardiomyopathy, defined as left ventricular ejection fraction ≤45%. Among 938 consecutive patients, 46 (4.9%) were identified as using methamphetamine. Compared with the nonmethamphetamine group (n=892), the methamphetamine group was significantly younger (52.8±9.6 versus 69.7±15.2 years; P<0.001), included more men (78.3% versus 52.8%; P<0.001), and had a significantly higher rate of cardiomyopathy (30.4% versus 14.0%; P<0.01). They were also less likely to have a history of atrial fibrillation (8.7% versus 33.4%; P<0.01) or hyperlipidemia (28.3% versus 51.7%; P<0.01). Compared with patients with cardiomyopathy without methamphetamine use, the patients with cardiomyopathy with methamphetamine use had significantly lower left ventricular ejection fraction (26.0±9.59% versus 32.47±9.52%; P<0.01) but better functional outcome at 3 months, likely attributable to significantly younger age and fewer comorbidities. In the logistic regression model of clinical variables, methamphetamine-associated cardiomyopathy was found to be significantly associated with cardioembolic stroke (odds ratio, 1.79 [95% CI, 1.04-3.06]; P<0.05).

CONCLUSIONS

We demonstrate that methamphetamine use is significantly associated with cardiomyopathy and cardioembolic stroke in young adults.

Methamphetamine use shortens telomere length in male adults and rats

BACKGROUND

Methamphetamine (MA) use increases the risk of age-related diseases. However, it remains uncertain whether MA use exhibits accelerated biological aging, as indicated by telomere length (TL), a proposed marker of aging. Here we conducted studies in both humans and rats to investigate the association between MA use and TL.

METHODS

We recruited 125 male MA users and 66 healthy controls, aged 30-40 years. MA users were diagnosed using DSM-5 criteria and categorized into two groups: non-severe (n = 78) and severe (n = 47) MA use disorder (MUD). MA-treated conditioned place preference (CPP) rats were utilized to validate our clinical investigations. TL was assessed using real-time polymerase chain reaction.

RESULTS

At clinical levels, MA users exhibited significantly shorter leukocyte TL compared to healthy controls. Among MA users, individuals with severe MUD had significantly shorter leukocyte TL than those with non-severe MUD. Importantly, both univariate and multivariate linear regression analyses demonstrated a negative association between the severity of MA use and leukocyte TL. In a rat model of MA-induced CPP, leukocyte TL was also significantly shortened after MA administration, especially in rats with higher CPP expression or reinstatement scores.

CONCLUSION

MA use shortened TL, and the severity of MA use was negatively correlated with TL. These findings provide new insights into the pathophysiology of accelerated aging caused by MA use and may have implications for identifying biomarkers and developing novel treatment strategies for MUD.

Determination of Methamphetamine by High-Performance Liquid Chromatography in Odor-Adsorbent Material Used for Training Drug-Detection Animals

The objective of the present report was to develop and validate a simple, sensitive, and selective analytical method for the determination of methamphetamine in an odor-adsorbent material (gauze) which was used to improve and standardize the training method used for drug-detection animals. High-performance liquid chromatography (HPLC) was performed using a Spherisorb ODS2 C18 column (200 mm × 4.6 mm, 5 μm), with a mobile phase consisting of a 0.25% methanol/triethylamine aqueous solution (V:V = 20:80), the pH of which was adjusted to 3.1 using glacial acetic acid, at a flow rate of 1.0 mL/min. The column temperature was 25 °C, and the detection of the analytes was performed at a wavelength of 260 nm. Methamphetamine showed good linearity (R2 = 0.9999) in the range of 4.2~83.2 mg/mL. The stability of the test material was good over 24 h. The precision of the method was good, with an average spiked recovery of 86.2% and an RSD of 2.9%. The methamphetamine content in the gauze sample was determined to be 7.8 ± 2.2 μg/sample. A high-performance liquid chromatography (HPLC) method was optimized and validated for the determination of methamphetamine in adsorbent materials (gauze). Validation data in terms of specificity, linearity, the limit of detection and the limit of quantification, reproducibility, precision, stability, and recovery indicated that the method is suitable for the routine analysis of methamphetamine in adsorbent materials (gauze) and provided a basis for training drug-detection animals.

Causes and circumstances of death in stimulant and opioid use-A comparative study

AIMS

To investigate the individual characteristics, causes and circumstances around deaths in stimulant use, and to examine how individuals who died with stimulants in their body differ from individuals who died with opioids in their body.

METHODS

This study includes individuals who died during the years 2000-2018 and underwent a forensic autopsy at Forensic Medicine in Lund, Skåne County, Sweden. All individuals over 18 years of age with stimulants (n = 310), opioids (n = 2,039) or both stimulants and opioids (n = 385) in the body at the time of death, were included. The three groups were assessed regarding gender, age, place of death, BMI, other substances detected in forensic toxicological analysis, organ weights and underlying and contributing causes of death. The data were analysed by frequency and proportion calculations, cross-tabulations and comparisons of medians.

RESULTS

The median age at death of the study population (n = 2,734) was 45.5 years (interquartile range ☯IQR] 32-60 years) and 73.2% were men. The most common cause of death in the stimulant group was suicide (26.8%), higher proportion compared to the opioid group (20.8%) (p = 0.017) and in the polysubstance group accidental poisoning (38.2%), higher proportion compared to the opioid group (18.0%) (p<0.001). Death by transport accidents was significantly associated with the stimulant group (p<0.001) as well as death by other accidents (p = 0.016).

CONCLUSIONS

Individuals who died with stimulants in their body died at a higher rate from suicide, transport accidents and other accidents, compared to individuals who died with opioids in their body. This study indicates the need to identify and prevent psychiatric conditions, elevated suicide risk, and risk-taking behaviors among people who use stimulants.

Analysing the behaviour change of brain regions of methamphetamine abusers using electroencephalogram signals: Hope to design a decision support system

Long-term use of methamphetamine (meth) causes cognitive and neuropsychological impairments. Analysing the impact of this substance on the human brain can aid prevention and treatment efforts. In this study, the electroencephalogram (EEG) signals of meth abusers in the abstinence period and healthy subjects were recorded during eyes-closed and eyes-opened states to distinguish the brain regions that meth can significantly influence. In addition, a decision support system (DSS) was introduced as a complementary method to recognize substance users accompanied by biochemical tests. According to these goals, the recorded EEG signals were pre-processed and decomposed into frequency bands using the discrete wavelet transform (DWT) method. For each frequency band, energy, KS entropy, Higuchi and Katz fractal dimensions of signals were calculated. Then, statistical analysis was applied to select features whose channels contain a p-value less than 0.05. These features between two groups were compared, and the location of channels containing more features was specified as discriminative brain areas. Due to evaluating the performance of features and distinguishing the two groups in each frequency band, features were fed into a k-nearest neighbour (KNN), support vector machine (SVM), multilayer perceptron neural networks (MLP) and linear discriminant analysis (LDA) classifiers. The results indicated that prolonged consumption of meth has a considerable impact on the brain areas responsible for working memory, motor function, attention, visual interpretation, and speech processing. Furthermore, the best classification accuracy, almost 95.8%, was attained in the gamma band during the eyes-closed state.

Impact of miR-29c-3p in the Nucleus Accumbens on Methamphetamine-Induced Behavioral Sensitization and Neuroplasticity-Related Proteins

Methamphetamine (METH) abuse inflicts both physical and psychological harm. While our previous research has established the regulatory role of miR-29c-3p in behavior sensitization, the underlying mechanisms and target genes remain incompletely understood. In this study, we employed the isobaric tags for relative and absolute quantitation (iTRAQ) technique in conjunction with Ingenuity pathway analysis (IPA) to probe the putative molecular mechanisms of METH sensitization through miR-29c-3p inhibition. Through a microinjection of AAV-anti-miR-29c-3p into the nucleus accumbens (NAc) of mice, we observed the attenuation of METH-induced locomotor effects. Subsequent iTRAQ analysis identified 70 differentially expressed proteins (DEPs), with 22 up-regulated potential target proteins identified through miR-29c-3p target gene prediction and IPA analysis. Our focus extended to the number of neuronal branches, the excitatory synapse count, and locomotion-related pathways. Notably, GPR37, NPC1, and IREB2 emerged as potential target molecules for miR-29c-3p regulation, suggesting their involvement in the modulation of METH sensitization. Quantitative PCR confirmed the METH-induced aberrant expression of Gpr37, Npc1, and Ireb2 in the NAc of mice. Specifically, the over-expression of miR-29c-3p led to a significant reduction in the mRNA level of Gpr37, while the inhibition of miR-29c-3p resulted in a significant increase in the mRNA level of Gpr37, consistent with the regulatory principle of miRNAs modulating target gene expression. This suggests that miR-29c-3p potentially influences METH sensitization through its regulation of neuroplasticity. Our research indicates that miR-29c-3p plays a crucial role in regulating METH-induced sensitization, and it identified the potential molecular of miR-29c-3p in regulating METH-induced sensitization.

The effect of CNQX on self-administration: present in nicotine, absent in methamphetamine model

Objective

Addiction is a chronic disease with limited pharmacological options for intervention. Focusing on reducing glutamate levels in the brain seems to be a promising strategy in addiction treatment research. Our research aimed to evaluate the effects of CNQX, an antagonist that targets AMPA and kainate glutamatergic receptors while also exhibiting affinity for the NMDA receptor, especially by modulating its glycine site. We conducted this assessment on the self-administration of nicotine and methamphetamine via intravenous (IV) administration in rats.

Methods

An operant IV self-administration model was used in male Wistar rats. When animals maintained a stable intake of nicotine or methamphetamine, we administered a single injection of CNQX (in the dose of 3 or 6 mg/kg IV) to evaluate its effect on drug intake. Subsequently, the rats were forced to abstain by staying in their home cages for 2 weeks. The period of abstinence was followed by a context-induced relapse-like session before which animals were pretreated with the injection of CNQX (3 or 6 mg/kg IV) to evaluate its effect on drug seeking.

Results

CNQX significantly reduced nicotine intake during the maintenance phase, but no effect was revealed on nicotine seeking after forced abstinence. CNQX did not affect methamphetamine taking or seeking.

Conclusion

The effect of reducing nicotine taking but not seeking could be explained by different involvement of glutamatergic receptors in various stages of nicotine dependence.

Predictive role of impulsivity, anxiety, and depression in the efficacy of intermittent theta burst transcranial magnetic stimulation modalities for treating methamphetamine use disorder: A randomized clinical trial

INTRODUCTION

Methamphetamine use disorder (MUD) can cause impulsive behavior, anxiety, and depression. Stimulation of the left dorsolateral prefrontal cortex in MUD patients by intermittent theta burst repetitive transcranial magnetic stimulation (iTBS-rTMS) is effective in reducing cravings, impulsive behavior, anxiety, and depression. The purpose of this study was to explore whether these psychological factors helped to predict MUD patients' responses to iTBS-rTMS treatment.

METHODS

Fifty MUD patients and sixty healthy subjects matched for general conditions were used as study subjects. The study randomly divided MUD patients into iTBS-rTMS and sham stimulation groups and received 20 sessions of real or sham iTBS-rTMS treatment, and the study collected cue-related evoked craving data before and after treatment. All subjects completed the Barratt Impulsiveness Scale (BIS-11), Self-rating Anxiety Scale (SAS), and Self-rating Depression Scale (SDS).

RESULTS

The MUD patients showed significantly higher levels of impulsivity, anxiety, and depression than the healthy subjects. The MUD patients who received the real treatment had significantly lower impulsivity, anxiety, and depression scores, and better treatment effects on cravings than the sham stimulation group. The Spearman rank correlation and stepwise multiple regression analyses showed that the baseline BIS-11 and the reduction rate (RR) of BIS-11 and RR of SDS were positively correlated with the decrease in cravings in the iTBS-rTMS group. ROC curve analysis showed that RR of SDS (AUC = 91.6 %; 95 % CI = 0.804-1.000) had predictive power to iTBS- rTMS therapeutic efficacy, the cutoff value is 15.102 %.

CONCLUSIONS

iTBS-rTMS had a good therapeutic effect in MUD patients and the baseline impulsivity, the improved depression and impulsivity were associated with therapeutic effect of iTBS-rTMS. The improved depression had the potential to predict the efficacy of the iTBS-rTMS modality for MUD treatment.

Mucocutaneous alterations and complications in amphetamine abusers: a narrative review

Amphetamines are the second most commonly used illicit drug worldwide. Amphetamine use can result in significant cutaneous morbidity. This review highlights the dermatological manifestations of amphetamine abuse.

Single-nucleus transcriptome profiling of prefrontal cortex induced by chronic methamphetamine treatment

Background

Methamphetamine (METH) addiction causes a huge burden on society. The prefrontal cortex (PFC), associated with emotion and cognitive behaviours, is also involved in addiction neurocircuitry. Although bulk RNA sequencing has shown METH-induced gene alterations in the mouse PFC, the impact on different cell types remains unknown.

Aims

To clarify the effects of METH treatment on different cell types of the PFC and the potential pathways involved in METH-related disorders.

Methods

We performed single-nucleus RNA sequencing (snRNA-seq) to examine the transcriptomes of 20 465 nuclei isolated from the PFC of chronic METH-treated and control mice. Main cell types and differentially expressed genes (DEGs) were identified and confirmed by RNA fluorescence in situ hybridization(FISH).

Results

Six main cell types were identified depending on the single-cell nucleus sequencing; of particular interest were the mature oligodendrocytes in the PFC. The DEGs of mature oligodendrocytes were enriched in the myelin sheath, adenosine triphosphate (ATP) metabolic process, mitochondrial function and components, and so on. The messenger RNA levels of Aldoc and Atp5l (FISH) and the protein level of the mitochondrial membrane pore subunit TOM40 (immunofluorescence) decreased in the mature oligodendrocytes. Fast blue staining and transmission electron microscopy image indicated myelin damage, and the myelin thickness decreased in METH brains.

Conclusions

snRNA-seq reveals altered transcriptomes of different cell types in mouse PFC induced by chronic METH treatment, underscoring potential relationships with psychiatric disorders.

Active learning impairments in substance use disorders when resolving the explore-exploit dilemma: A replication and extension of previous computational modeling results

BACKGROUND

Substance use disorders (SUDs) represent a major public health risk. Yet, our understanding of the mechanisms that maintain these disorders remains incomplete. In a recent computational modeling study, we found initial evidence that SUDs are associated with slower learning rates from negative outcomes and less value-sensitive choice (low "action precision"), which could help explain continued substance use despite harmful consequences.

METHODS

Here we aimed to replicate and extend these results in a pre-registered study with a new sample of 168 individuals with SUDs and 99 healthy comparisons (HCs). We performed the same computational modeling and group comparisons as in our prior report (doi: 10.1016/j.drugalcdep.2020.108208) to confirm previously observed effects. After completing all pre-registered replication analyses, we then combined the previous and current datasets (N = 468) to assess whether differences were transdiagnostic or driven by specific disorders.

RESULTS

Replicating prior results, SUDs showed slower learning rates for negative outcomes in both Bayesian and frequentist analyses (partial η2=.02). Previously observed differences in action precision were not confirmed. Learning rates for positive outcomes were also similar between groups. Logistic regressions including all computational parameters as predictors in the combined datasets could differentiate several specific disorders from HCs, but could not differentiate most disorders from each other.

CONCLUSIONS

These results provide robust evidence that individuals with SUDs adjust behavior more slowly in the face of negative outcomes than HCs. They also suggest this effect is common across several different SUDs. Future research should examine its neural basis and whether learning rates could represent a new treatment target or moderator of treatment outcome.

Psychosocial stress and methamphetamine use: A mixed-methods study of intersectional stigma and Aboriginal and Torres Strait Islander methamphetamine use

BACKGROUND

Regular methamphetamine use can cause a range of physical, psychological and social harms. Stigma is one factor that impacts engagement and successful completion of treatment. In Australia, Aboriginal and Torres Strait Islander people who regularly use methamphetamine experience multiple stigmas, which further compounds access to treatment and quality of life. This paper explores the cumulative and compounding effects of participating in a stigmatised activity such as illicit drug use in relation to the stigma experienced by Aboriginal and Torres Strait Islander people as a population marginalised through colonisation.

METHODS

Ten sites nationally participated in a cross-sectional survey measuring a range of factors including psychosocial stress in methamphetamine users. The survey sample size was 734, with 59% identifying as Aboriginal and Torres Strait Islander (n = 433). In addition, a total of 147 mainly Aboriginal and Torres Strait Islander people who use methamphetamine, community and family members, and service providers took part in a total of 19 focus groups and 7 interviews.

RESULTS

Aboriginal and Torres Strait Islander participants experienced multiple psychosocial stressors at significantly higher rates than non-Indigenous participants. These stressors include diminished access to health care (33%), experiences of racism (34%), grief and sorrow (39%), worry for family (46%), and child welfare experiences (46%). The qualitative findings highlight the cumulative impact of historical, political and social stressors on an already stigmatised population.

CONCLUSIONS

The findings of this unique analysis demonstrate the disruptive impact of methamphetamine use on the lives of those who use methamphetamines and their family members. They also illustrate challenges, such as stigma, that may confront those seeking assistance for drug-related issues. Aboriginal and Torres Strait Islander community involvement is necessary to provide support and education for the individual, the family, and the community as a whole. Stigma reduction is therefore a worthy target for intervention.

The New Zealand drug harms ranking study: A multi-criteria decision analysis

AIMS

The harms arising from psychoactive drug use are complex, and harm reduction strategies should be informed by a detailed understanding of the extent and nature of that harm. Drug harm is also context specific, and so any comprehensive assessment of drug harm should be relevant to the characteristics of the population in question. This study aimed to evaluate and rank drug harms within Aotearoa New Zealand using a multi-criteria decision analysis (MCDA) framework, and to separately consider harm within the total population, and among youth.

METHODS

Two facilitated workshops involved the separate ranking of harm for the total population, and then for youth aged 12-17, by two expert panels. In the total population workshop, 23 drugs were scored against 17 harm criteria, and those criteria were then evaluated using a swing weighting process. Scoring and weighting were subsequently updated during the youth-specific workshop. All results were recorded and analysed using specialised MCDA software.

RESULTS

When considering overall harm, the MCDA modelling results indicated that alcohol, methamphetamine and synthetic cannabinoids were the most harmful to both the overall population and the youth, followed by tobacco in the total population. Alcohol remained the most harmful drug for the total population when separately considering harm to those who use it, and harm to others.

CONCLUSIONS

The results provide detailed and context-specific insight into the harm associated with psychoactive drugs use within Aotearoa New Zealand. The findings also demonstrate the value of separately considering harm for different countries, and for different population subgroups.

Gegen-Qinlian decoction-A traditional Chinese medicine formula-Alleviates methamphetamine withdrawal induced anxiety by targeting GABAergic interneuron-pyramidal neuron pathway in mPFC

Methamphetamine (Meth) withdrawal elicits anxiety, which is a public health concern with limited therapeutic options. Previous studies implied a strong correlation between mPFC and Meth withdrawal. Here, we examined the role of Gegen-Qinlian decoction (GQD) in Meth withdrawal anxiety and explored potential therapeutic targets in mPFC. We found that intra-gastric administration of GQD during the withdrawal period efficiently alleviated anxiety-like behaviours in Meth-withdrawn mice. Further, GQD could restore Meth withdrawal-triggered pathway of GABAergic interneurons (GABA IN)-pyramidal neurons (PN) in the mPFC of Meth-withdrawn mice, especially the prelimbic cortex (PrL) sub-region and PV-positive GABA IN. While, GQD had no obvious effects on the glial cells in the mPFC of Meth-withdrawn mice. By transcriptomic analysis and validation of several gene candidates, we found that genes in the MAPK signalling pathway, especially those related to heat shock proteins, including Hspa1a, Hspa1b and Hspb1, might be GQD-targeting genes in mPFC to treat Meth withdrawal anxiety, as indicated that these genes were up-regulated by Meth withdrawal but rescued by GQD in mPFC. Collectively, our findings identified for the first time that GQD could efficiently alleviate Meth withdrawal anxiety, partially through regulating the local GABA IN-PN pathway and transcriptomic profile of mPFC. The present study confirms that TCM, such as GQD, will be a desirable therapeutic approach in the treatment of drug addiction and related emotional deficits.

A qualitative study of interest in and preferences for potential medications to treat methamphetamine use disorder

INTRODUCTION

We examined acceptability of and preferences for potential medications for treating methamphetamine use disorder (MUD) among people who use methamphetamine and examined how benefits and drawbacks of methamphetamine use affect perceived acceptability and preferences.

METHODS

We conducted qualitative interviews as part of a larger study in 2019-2020. The interview assessed patterns of substance use (including methamphetamine), benefits and drawbacks of methamphetamine use, and interest in a medication to treat MUD. Analysis used an inductive thematic approach, guided by three primary questions: (1) would participants be interested in taking a potential medication for MUD?; (2) what effects would they would like from such a medication?; and (3) what would their ideal treatment route and schedule be (e.g. daily pill, monthly injection)?.

RESULTS

We interviewed 20 people reporting methamphetamine use in the past 3 months (10 from Reno, Nevada, USA and 10 from Rio Arriba County, New Mexico, USA). Seven used exclusively methamphetamine, while thirteen used other substances in addition to methamphetamine. Most were enthusiastic about a potential medication to treat MUD. Of those who were not interested (n = 5), all indicated no current concerns about their methamphetamine use. Perceived functional benefits of methamphetamine use (i.e., energy, counteracting opioid sedation, and improved social and emotional wellbeing) informed preferences for a replacement-type medication that would confer the same benefits while mitigating drawbacks (e.g., psychosis, hallucinations, withdrawal). Opinions on preferred dosing varied, with some preferring longer acting medications for convenience, while others preferred daily dosing that would align with existing routines.

CONCLUSION

Participants were excited about a potential for a medication to treat MUD. Their preferences were informed by the functional role of methamphetamine in their lives and a desire to maintain the stimulant effects while mitigating harms of illicit methamphetamine. Treatment outcomes that emphasize functioning and wellbeing, rather than abstinence, should be explored.

Chatbot-assisted therapy for patients with methamphetamine use disorder: a preliminary randomized controlled trial

Background

Methamphetamine (MA) use disorder is associated with a large public health burden. Despite the therapeutic effects of psychosocial interventions based on current evidence, finding an approach to retain patients in treatment remains a real-world challenge. The rapid development of mobile health (mHealth) systems suggests the potential to provide real-time personalized care at any time and from any location, minimize barriers to treatment, maximize use, and promote the dissemination of accessible therapeutic tools in at-risk populations. Our study aimed to investigate the feasibility and effectiveness of chatbots for the treatment of MA use disorder.

Method

The inclusion criteria were (a) a diagnosis of MA use disorder as defined by the DSM-5, (b) age between 18 and 65 years, (c) no acute exacerbation of severe mental illness during the initial assessment, such as schizophrenia or bipolar I disorder, (d) willingness to participate in standard outpatient treatment for ≥ 6 months, and (e) an Android phone. Participants were randomly allocated to either a chatbot-assisted therapy via smartphone (CAT) group or a control group following simple randomization procedures (computerized random numbers) without blinding. All participants were followed up for 6 months. Treatment retention and monthly urine test results were analyzed as outcome measures. Participants' satisfaction with CAT was also assessed.

Results

In total, 50 and 49 participants were allocated to the CAT and control groups, respectively. There were no significant differences in retention time between the two treatment groups (df = 1, p = 0.099). The CAT group had fewer MA-positive urine samples than the control group (19.5% vs. 29.6%, F = 9.116, p = 0.003). The proportion of MA-positive urine samples was positively correlated with the frequency of MA use (r = 0.323, p = 0.001), severity of MA use disorder (r = 0.364, p < 0.001), and polysubstance use (r = 0.212, p = 0.035), and negatively correlated with readiness to change (r = -0.330, p = 0.001). Totally 55 participants completed the study at the 6-month follow-up and 60% reported relative satisfaction.

Conclusion

Participants in this study had favorable acceptance and generally positive outcomes, which indicates that chatbot is feasible for treating people who use MA.

The Neurobiology of Methamphetamine Addiction and the Potential to Reduce Misuse Through Conjugate Vaccines Targeting Toll-Like Receptor 4

The methamphetamine epidemic continues to worsen each year and has contributed to more overdose deaths than opioids. Methamphetamine was listed in the top ten lethal drugs in 2021 in the United States. The drug has been shown to cause health problems such as addiction and neurological and behavioral changes. One possible solution to address this crisis is through vaccinations. Vaccinations consist of injecting a controlled substance with the goal of creating compound-specific antibodies. Although still early in development, vaccinations have been found to improve withdrawal symptoms and decrease drug-seeking behavior with minimal health side effects in rodent studies. This paper provides an overview of the clinical presentation and neurobiology of methamphetamine addiction and drug-seeking behaviors. The responses and adverse effects of conjugate vaccines IXTv-100 with adjuvant glucopyranosyl lipid A administered in oil-water stable emulsion and tetanus-toxoid conjugated to succinyl-methamphetamine adsorbed on aluminum hydroxide combined with adjuvant E6020 are examined.

Methamphetamine use increases the risk of cerebral small vessel disease in young patients with acute ischemic stroke

Methamphetamine use causes spikes in blood pressure. Chronic hypertension is a major risk factor for cerebral small vessel disease (cSVD). The aim of this study is to investigate whether methamphetamine use increases the risk of cSVD. Consecutive patients with acute ischemic stroke at our medical center were screened for methamphetamine use and evidence of cSVD on MRI of the brain. Methamphetamine use was identified by self-reported history and/or positive urine drug screen. Propensity score matching was used to select non-methamphetamine controls. Sensitivity analysis was performed to assess the effect of methamphetamine use on cSVD. Among 1369 eligible patients, 61 (4.5%) were identified to have a history of methamphetamine use and/or positive urine drug screen. Compared with the non-methamphetamine group (n = 1306), the patients with methamphetamine abuse were significantly younger (54.5 ± 9.7 vs. 70.5 ± 12.4, p < 0.001), male (78.7% vs. 54.0%, p < 0.001) and White (78.7% vs. 50.4%, p < 0.001). Sensitivity analysis showed that methamphetamine use was associated with increased white matter hyperintensities, lacunes, and total burden of cSVD. The association was independent of age, sex, concomitant cocaine use, hyperlipidemia, acute hypertension, and stroke severity. Our findings suggest that methamphetamine use increases the risk of cSVD in young patients with acute ischemic stroke.

Aberrant topology of white matter networks in patients with methamphetamine dependence and its application in support vector machine-based classification

Brain white matter (WM) networks have been widely studied in neuropsychiatric disorders. However, few studies have evaluated alterations in WM network topological organization in patients with methamphetamine (MA) dependence. Therefore, using machine learning classification methods to analyze WM network topological attributes may give new insights into patients with MA dependence. In the study, diffusion tensor imaging-based probabilistic tractography was used to map the weighted WM networks in 46 MA-dependent patients and 46 control subjects. Using graph-theoretical analyses, the global and regional topological attributes of WM networks for both groups were calculated and compared to determine inter-group differences using a permutation-based general linear model. In addition, the study used a support vector machine (SVM) learning approach to construct a classifier for discriminating subjects with MA dependence from control subjects. Relative to the control group, the MA-dependent group exhibited abnormal topological organization, as evidenced by decreased small-worldness and modularity, and increased nodal efficiency in the right medial superior temporal gyrus, right pallidum, and right ventromedial putamen; the MA-dependent group had the higher hubness scores in 25 regions, which were mainly located in the default mode network. An SVM trained with topological attributes achieved classification accuracy, sensitivity, specificity, and kappa values of 98.09% ± 2.59%, 98.24% ± 4.00%, 97.94% ± 4.26%, and 96.18% ± 5.19% for patients with MA dependence. Our results may suggest altered global WM structural networks in MA-dependent patients. Furthermore, the abnormal WM network topological attributes may provide promising features for the construction of high-efficacy classification models.

Active learning impairments in substance use disorders when resolving the explore-exploit dilemma: A replication and extension of previous computational modeling results

Background

Substance use disorders (SUDs) represent a major public health risk. Yet, our understanding of the mechanisms that maintain these disorders remains incomplete. In a recent computational modeling study, we found initial evidence that SUDs are associated with slower learning rates from negative outcomes and less value-sensitive choice (low "action precision"), which could help explain continued substance use despite harmful consequences.

Methods

Here we aimed to replicate and extend these results in a pre-registered study with a new sample of 168 individuals with SUDs and 99 healthy comparisons (HCs). We performed the same computational modeling and group comparisons as in our prior report (doi: 10.1016/j.drugalcdep.2020.108208) to confirm previously observed effects. After completing all pre-registered replication analyses, we then combined the previous and current datasets (N = 468) to assess whether differences were transdiagnostic or driven by specific disorders.

Results

Replicating prior results, SUDs showed slower learning rates for negative outcomes in both Bayesian and frequentist analyses (η 2 =.02). Previously observed differences in action precision were not confirmed. Logistic regressions including all computational parameters as predictors in the combined datasets could differentiate several specific disorders from HCs, but could not differentiate most disorders from each other.

Conclusions

These results provide robust evidence that individuals with SUDs have more difficulty adjusting behavior in the face of negative outcomes than HCs. They also suggest this effect is common across several different SUDs. Future research should examine its neural basis and whether learning rates could represent a new treatment target or moderator of treatment outcome.

Clinical management of psychostimulant withdrawal: review of the evidence

It is estimated that a majority of people who use psychostimulants, particularly methamphetamine (MA) and cocaine, experience withdrawal upon abstinence from sustained use. This review of clinical research reports the evidence regarding biomedical and behavioral treatments for psychostimulant withdrawal symptoms. It provides a framework for clinicians and scientists to increase impact on attenuating MA and cocaine withdrawal during initial and sustained abstinence. Articles reviewed included reports of controlled clinical trials (randomized or non-randomized) reporting at least one withdrawal symptom among the outcomes or specifically studying patients in withdrawal. Potential efficacy for MA withdrawal is noted for a few medications (mirtazapine, naltrexone, bupropion) and repetitive transcranial magnetic stimulation during acute (first week), early protracted (weeks 2-4) and late protracted (> 4 weeks) withdrawal phases. Topiramate shows mixed evidence of efficacy for cocaine withdrawal. In general, there is inconsistent signal for biomedical and behavioral treatments on MA and cocaine withdrawal.

Identifying barriers and facilitators for implementing harm reduction strategies for methamphetamine use into hospital settings

INTRODUCTION

Harm reduction strategies for substance use disorder are not currently offered in Canadian hospitals. Previous research has suggested that substance use may continue to occur which can lead to further complications such as new infections. Harm reduction strategies may be a solution to this issue. This secondary analysis aims to explore the current barriers and potential facilitators for implementing harm reduction into the hospital from the perspective of health care and service providers.

METHOD

Primary data was collected from 31 health care and service providers who participated in a series of virtual focus groups and one-to-one interviews regarding their perspectives on harm reduction. All staff were recruited from hospitals in Southwestern Ontario, Canada from February 2021 to December 2021. Health care and service professionals completed a one-time individual interview or a virtual focus group using an open-ended qualitative interview survey. Qualitative data was transcribed verbatim and analyzed using an ethnographic thematic approach. Themes and subthemes were identified and coded based on responses.

FINDINGS

Attitude and Knowledge, Pragmatics, and Safety/Reduction of Harm were identified as the core themes. Attitudinal barriers such as stigma and lack of acceptance were reported but education, openness and community support were regarded as potential facilitators. Cost, space, time and availability of substances on site were regarded as Pragmatic barriers but potential facilitators such as organizational support, flexible harm reduction services and a specialized team were identified. Policy and liability were perceived as both a barrier and a potential facilitator. Safety and impact of substances on treatment were considered as both a barrier and a potential facilitator but sharps boxes and continuity of care were regarded as potential facilitators.

DISCUSSION

Although barriers in implementing harm reduction in hospital settings exist, there are opportunities to facilitate change. As identified in this study, feasible and achievable solutions are available. Education on harm reduction for staff was considered to be a key clinical implication in facilitating harm reduction implementation.

Tryptophan and Substance Abuse: Mechanisms and Impact

Addiction, the continuous misuse of addictive material, causes long-term dysfunction in the neurological system. It substantially affects the control strength of reward, memory, and motivation. Addictive substances (alcohol, marijuana, caffeine, heroin, methamphetamine (METH), and nicotine) are highly active central nervous stimulants. Addiction leads to severe health issues, including cardiovascular diseases, serious infections, and pulmonary/dental diseases. Drug dependence may result in unfavorable cognitive impairments that can continue during abstinence and negatively influence recovery performance. Although addiction is a critical global health challenge with numerous consequences and complications, currently, there are no efficient options for treating drug addiction, particularly METH. Currently, novel treatment approaches such as psychological contingency management, cognitive behavioral therapy, and motivational enhancement strategies are of great interest. Herein, we evaluate the devastating impacts of different addictive substances/drugs on users' mental health and the role of tryptophan in alleviating unfavorable side effects. The tryptophan metabolites in the mammalian brain and their potential to treat compulsive abuse of addictive substances are investigated by assessing the functional effects of addictive substances on tryptophan. Future perspectives on developing promising modalities to treat addiction and the role of tryptophan and its metabolites to alleviate drug dependency are discussed.

Methamphetamine-related forensic autopsy cases in a Japanese prefecture over a 7-year period: Characteristics of deaths and blood concentrations

Understanding the actual conditions of methamphetamine (MA)-related death is important from the perspectives of criminal justice and public health. In this report, we review 104 cases of MA-related death handled by our departments between January 2014 and December 2020. Based on information from police and autopsy examinations, we classified the cases into the following categories: "accidental intoxication" ("MA only" and "multiple drugs or alcohol"), "fatal disease" ("definitively MA-related," "possibly MA-related," and "unlikely MA-related"), "accident," "suicide," "homicide," and "undetermined." The total number and annual trends for each category and their respective femoral blood concentrations were investigated. "Fatal disease" was the most common category (48 cases), followed by "suicide" (25 cases), "accidental intoxication" (14 cases), and "accident" (11 cases). "Definitively MA-related" in which MA may have played a role in their onset or exacerbation accounted for the majority of "fatal disease": 12 cases of heart disease, 4 cases of aortic dissection, 12 cases of cerebral hemorrhage, and 4 cases of subarachnoid hemorrhage. Cases classified as "definitively MA-related" died with lower femoral blood concentrations of MA compared with "MA only." Cases with "fatal disease" might have been misdiagnosed as "death by natural causes" if a proper autopsy and toxicology examinations were not performed. In death investigations, it is necessary to keep in mind that there are some MA-related deaths, and efforts should be made to increase awareness about the risk of death in using this drug.

Does illicit amphetamine seizures quantity associated with amphetamine use disorder related admissions in Saudi Arabia?

BACKGROUND

Illicit amphetamine-type stimulants (ATS) trafficking activities have increased substantially in Saudi Arabia over the last 10 years. In the period 2013-2017 Saudi Arabia seized the largest quantities of amphetamine at the global level. The current study examines whether the increased quantity of ATS seizures has an impact on amphetamine use disorder admissions.

METHOD

This is an ecological study combining two datasets, the first dataset was obtained from United Nations Office on Drugs and Crime (UNODC), and the Al-Amal Hospital Electronic Health Record System in the city of Dammam, Eastern region of Saudi Arabia from 2005 to 2018. The annual incidence of patients diagnosed with amphetamine use was the dependent variable. The independent variable was the annual reported count of seized quantities of ATS in Saudi Arabia. We used a random intercept Negative Binomial model to predict the yearly count of amphetamine use disorder admission rates.

RESULTS

A total of 910 amphetamine disorder admission patients in Al-Amal rehabilitation and addiction center, and the quantity equivalent to 200 tons of ATS was seized from 2005 to 2018. The amphetamine disorder admission rate has increased from 1.33% in 2005 to 18.27% in 2018. For each one-unit increase in the amphetamine confiscated quantities, the amphetamine use disorder admission rate increased by 49 to 88%.

CONCLUSION

The current study found that reported amphetamine seized quantities were significantly and positively associated with the increase of amphetamine use disorder-related admission rates. In 2018, both ATS seized quantities and admission rates significantly increased, nearly doubling from the previous year. Rigorous, and multidisciplinary interventional studies to evaluate factors associated with increasing abuse of ATS should be a priority for policymakers and researchers in Saudi.

Methamphetamine-associated cardiomyopathy: an addiction medicine perspective

Methamphetamine-associated cardiomyopathy (MaCM) is an increasingly recognised serious complication from methamphetamine (MA) use. It is characterised as the development of otherwise unexplained heart failure in the context of MA use. MaCM predominantly affects a young and vulnerable population with high morbidity and mortality. It is the second leading cause of mortality in patients with MA use disorder (MUD). Our understanding of MaCM pathogenesis is based on observational cohorts and autopsy studies. Currently, the treatment of MaCM is predicated on abstinence. Medical therapies offer some benefit to a minority of patients; however, without abstinence, medical therapies are often ineffective. Abstinence is difficult for most patients to achieve; all clinicians require an understanding of MaCM and how to educate patients on the risks of ongoing use. Where available, referral to addiction medicine specialists to assist with treatment of MUD is recommended. This review aims to: (i) explain the proposed pathologic mechanisms of MaCM; (ii) summarise recent recommendations of the screening and treatment of MaCM; and (iii) highlight the role of addiction medicine in the management of patient with MaCM.

The predictive role of impulsivity and perceived social support in psychiatric symptoms of women with methamphetamine use disorder

Background

Currently, few studies have examined the mental states of Women methamphetamine patients, and the influence of impulsivity and perceived social support on substance misuse-induced mental disorders is unclear. We want to examine the mental state of women with methamphetamine use disorder and compare it to the Chinese norm value of healthy women. Investigate the connection between impulsivity, perceived social support and mental state of women with methamphetamine use disorder.

Method

Two hundred thirty women subjects with a history of methamphetamine usage were recruited. The Chinese version of the SCL-90-R, (SCL-90) was used to evaluate psychological health problems, while the Multidimensional Scale of Perceived Social Support (MSPSS) and Barratt Impulsiveness Seale-11 (BIS-11) were utilized to evaluate perceived social support and impulsivity, respectively. The t-test, Pearson correlation analysis, multivariable linear regression, stepwise regression models, moderating effect analysis were used to analyze the statistics.

Results

There was a noticeable difference between the Chinese norm and all participants' SCL-90 ratings, especially for Somatization (t = 24.34, p < 0.001), Anxiety (t = 22.23, p < 0.001), Phobic anxiety (t = 26.47, p < 0.001), and Psychoticism (t = 24.27, p < 0.001). In addition, perceived social support levels and impulsivity levels are independently predictive of SCL-90 scores. Lastly, the impact of Impulsivity on SCL-90 can be modulated by perceived social support.

Conclusion

According to this study, women with methamphetamine use disorder have worse mental health conditions compared to healthy subjects. Furthermore, certain psychological symptoms associated with methamphetamine use in women can be aggravated by impulsivity, while perceived social support acts as a protective factor for methamphetamine-related psychiatric symptoms. Specifically, perceived social support weakens the impact of impulsivity on psychiatric symptoms in women with methamphetamine use disorder.

Analiza przypadków samobójstw w materiale sekcyjnym Katedry Medycyny Sądowej Collegium Medicum w Bydgoszczy Uniwersytetu Mikołaja Kopernika w Toruniu w latach 2011-2020

Cel pracy: Analiza samobójstw na podstawie sądowo-lekarskich sekcji zwłok przeprowadzonych w Katedrze Medycyny Sądowej w Bydgoszczy w porównaniu z danymi z lat wcześniejszych i innych ośrodków. Materiał i metody: Ocenie poddano 6564 opinii sądowo-lekarskich z przeprowadzonych badań pośmiertnych z lat 2011-2020, wśród których wyodrębniono 1073 przypadki samobójstw, uwzględniając płeć i wiek pokrzywdzonych, miejsce w którym dokonano czynu samobójczego, wpływ alkoholu lub innych środków odurzających, sposoby popełniania samobójstw oraz data (miesiąc i rok). Wyniki: Samobójstwa stanowiły 16,34% wszystkich badań pośmiertnych. Najczęstszą metodą samobójstwa było powieszenie – 73%. Drugim co do częstości sposobem odebrania sobie życia był upadek z wysokości –8%. Najliczniejszą grupą wiekową wśród popełniających samobójstwo stanowią osoby pomiędzy 51, a 60 rokiem życia. W większości przypadków samobójcy byli trzeźwi. Widoczna jest istotna różnica pomiędzy stanem trzeźwości, a płcią ofiary. Zdecydowanie częściej pod wpływem alkoholu w trakcie dokonania samobójstwa były ofiary płci męskiej. 14% ogółu samobójstw popełniły kobiety, zaś 86% mężczyźni. Nieco częściej zgon w wyniku samobójstwa miał miejsce w granicach dużych aglomeracji miejskich, niż na terenie miasteczek i wsi. Wnioski: Badania wykazały wzrost odsetka samobójstw w stosunku do lat poprzednich. Powieszenie nadal jest najczęstszym sposobem samobójstwa. Odnotowano wzrost liczby samobójstw osób w wieku podeszłym oraz zwiększenie liczby tzw. samobójstw kombinowanych. Słowa kluczowe: samobójstwa, sekcja zwłok Analysis of suicide cases in the autopsy material of the Department of Forensic Medicine Collegium Medicum in Bydgoszcz, University of Nicolaus Copernicus in Toruń in 2011-2020 Aim of the study: Analysis of suicides on the basis of forensic post mortem examinations conducted at the Department of Forensic Medicine in Bydgoszcz in comparison with data from previous years and other centers. Material and methods: The assessment included 6,564 forensic medical opinions from the post mortem examinations carried out in 2011–2020, including 1,073 cases of suicide, taking into account the sex and age of the victims, the place where the suicide was committed, the influence of alcohol or other intoxicants, methods of committing suicides and date (month and year). Results: Suicides accounted for 16.34% of all post mortem examinations. The most common method of suicide was hanging – 73%. The second most common way to take your own life was fall from height – 8%. The most numerous age group among those committing suicide are people between 51 and 60 years of age. In most cases, the suicide victims were sober. There is a significant difference between the state of sobriety and the gender of the victim. Male victims were much more often under the influence of alcohol during the suicide. 14% of all suicides were committed by women, and 86% by men. Death as a result of suicide took place somewhat more often within the boundaries of large urban agglomerations than in towns and villages. Conclusions: The research showed an increase in the suicide rate compared to the previous years. Hanging is still the most common form of suicide. There has been an increase in the number of suicides in the elderly and an increase in the number of so-called combined suicides.

A Review of Methods Used to Detect Methamphetamine from Indoor Air and Textiles in Confined Spaces

Methamphetamine manufacture, use, and the resulting contamination is a significant issue that affects public health, the environment, and the economy. Third-hand exposure to methamphetamine can result in adverse health risks for individuals and first responders. Such exposures can result from the inhalation of airborne residues or from contact with contaminated objects. This review was conducted to determine the current methods used for methamphetamine extraction from indoor air and porous fabric materials. Dynamic solid phase microextraction (SPME) and sorbent sampling tubes have been applied to extract airborne methamphetamine residues from contaminated properties. SPME and solvent extraction have been applied to sample clothing and textiles for methamphetamine detection. This review demonstrates that there is limited literature on the detection of methamphetamine from indoor air and clothing. Supplementary and consistent methods to detect methamphetamine from air and porous surfaces should be developed and published to allow better assessment of the environmental risk to public health caused by third-hand exposure to methamphetamine.

Epigenetic clock analysis in methamphetamine dependence

Methamphetamine (MA) is used worldwide and causes serious public health and social problems. MA affects the central nervous, cardiac, and immune systems, which causes neuropsychiatric and cardiovascular diseases and infection. Epigenetic changes, including DNA methylation (DNAm), are associated with various clinical phenotypes of MA abuse. DNAm is related to biological aging and health risks; hence, we aimed to assess the changes in biological aging in MA dependence using the DNAm age and DNA methylation-based telomere length (DNAmTL). We used five measures of DNAm age (HorvathAge, HannumAge, SkinBloodAge, PhenoAge, and GrimAge), DNAmTL, and DNAm-based age-predictive factors (plasma proteins and blood cell composition). We compared patients with MA dependence and healthy controls (n = 24 each) using the DNAm profiles obtained from whole-blood samples. Patients with MA dependence showed significant acceleration in PhenoAge and GrimAge, as well as a trend for significant acceleration in DNAmTL. Following adjustment for confounding factors, MA dependence was significantly associated with accelerations in PhenoAge, GrimAge, and DNAmTL, as well as alterations in DNAm-based age-predictive factors (beta-2-microglobulin, granulocytes, and naive cluster of differentiation 4+ T cells). Our results suggested an acceleration of biological aging and specific changes in the DNAm of age- predictive factors in MA dependence.

Characterising methamphetamine use to inform health and social policies in Manitoba, Canada: a protocol for a retrospective cohort study using linked administrative data

INTRODUCTION

Rising use of methamphetamine is causing significant public health concern in Canada. The biological and behavioural effects of methamphetamine range from wakefulness, vigour and euphoria to adverse physical health outcomes like myocardial infarction, haemorrhagic stroke, arrhythmia and seizure. It can also cause severe psychological complications such as psychosis. National survey data point to increasing rates of methamphetamine use, as well as increasing ease of access and serious methamphetamine-related harms. There is an urgent need for evidence to address knowledge gaps, provide direction to harm reduction and treatment efforts and inform health and social policies for people using methamphetamine. This protocol describes a study that aims to address this need for evidence.

METHODS

The study will use linked, whole population, de-identified administrative data from the Manitoba Population Research Data Repository. The cohort will include individuals in the city of Winnipeg, Manitoba, who came into contact with the health system for reasons related to methamphetamine use from 2013 to 2021 and a comparison group matched on age, sex and geography. We will describe the cohort's sociodemographic characteristics, calculate incidence and prevalence of mental disorders associated with methamphetamine use and examine rates of health and social service use. We will evaluate the use of olanzapine pharmacotherapy in reducing adverse emergency department outcomes. In partnership with Indigenous co-investigators, outcomes will be stratified by First Nations and Métis identity.

ETHICS AND DISSEMINATION

The study was approved by the University of Manitoba Health Research Ethics Board, and access datasets have been granted by all data providers. We also received approval from the First Nations Health and Social Secretariat of Manitoba's Health Information Research Governance Committee and the Manitoba Métis Federation. Dissemination will be guided by an 'Evidence 2 Action' group of public rightsholders, service providers and knowledge users who will ensure that the analyses address the critical issues.

“I Had No Problems and Just Felt So Fabulous”: The “Storylines” of Methamphetamine Initiation in Aotearoa/New Zealand

This qualitative life course-based study analyses the key circumstances preceding methamphetamine initiation. This paper utilizes Agnew’s “storylines” concept to analyse the background and situational factors that led 42 Aotearoa/New Zealanders to initiate methamphetamine. Multiple exposure to adversity across multiple life domains placed participants at heightened risk of early-onset drug use. Preceding methamphetamine initiation, the impact of social bonds and social roles were identified within the domains of family, romantic relationships, friendship and work. Whilst drug use onset broadly follows the stage theory sequence of drug use, participants did not initiate methamphetamine until age 27 on average. Initial use typically took place in a private setting among friends, family and co-workers. The initial effect was typically very positive, which greatly contributed to escalating use. Analysis revealed four main storylines, which highlight the importance of psychological state, social bonds, romantic attachments and social functioning in methamphetamine initiation.

Protocol for a cluster randomised crossover pilot trial of Goal Management Training+ (GMT+) for methamphetamine use disorder

Background

Methamphetamine use disorder (MUD) is associated with executive dysfunctions, which are linked with poorer treatment outcomes. However, current treatments for MUD do not directly address cognition. We recently modified Goal Management Training (now Goal Management Training⁺; GMT⁺), a group-based intervention originally designed to improve executive functions after brain injury, to enhance suitability for MUD. Here, we describe the rationale and design of a trial which aims to determine the acceptability and feasibility of GMT⁺ during residential rehabilitation for MUD, and its impact on executive functions and clinical outcomes.

Methods

We used a cluster randomised crossover design: participants are randomised at the cluster level to receive either GMT⁺ or psychoeducation-control (Brain Health Workshop; BHW). GMT⁺ is delivered in four 90-min weekly sessions and includes a between-session journal with 10-min daily activities. The program targets attention, impulse control, goal-setting, and decision-making. BHW is a health-oriented intervention that delivers information about the brain and promotes healthy exercise, diet, and sleep. It is matched to GMT⁺ on program format, length, and time with therapists. We will recruit forty-eight participants with MUD from residential treatment services. Our primary outcomes are acceptability, feasibility, and self-reported executive functioning. Secondary outcomes include craving, quality of life and cognitive performance. Outcome assessments are performed at baseline, post-interventions, 4-week follow-up, and 12-week follow-up.

Conclusions

This study will provide GMT⁺ feasibility and acceptability data and will indicate initial efficacy on executive functions and clinical outcomes in residential treatment for MUD. Information from this pilot trial will inform a powered RCT.

Dynamic immune and exosome transcriptomic responses in patients undergoing psychostimulant methamphetamine withdrawal

Methamphetamine (METH) addiction and withdrawal cause serious harm to both the immune system and nervous system. However, the pathogenesis remains largely unknown. Herein, we investigated the peripheral cytokines and exosomal transcriptome regulatory networks in the patients with METH use disorders (MUDs) undergoing withdrawal. Twenty-seven cytokines were simultaneously assessed in 51 subjects, including 22 at the acute withdrawal (AW) stage and 29 at the protracted withdrawal (PW) stage, and 31 age and gender-matched healthy controls (HCs). Compared to the HCs, significantly decreased levels of interleukin (IL)-1β, IL-9, IL-15, Basic FGF, and MIP1a, increased levels of IL-1rα, IL-6, Eotaxin IP-10, VEGF, and RANTES were identified in AW. These disturbances were mostly or partly restored to the baseline in PW. However, the cytokines IL-6, IL-7, and IL-12p70 were consistently increased even after one year of withdrawal. Besides, a significant decrease in CD3+T and CD4+T cell numbers was observed in AW, and the diminishment was restored to baseline in PW. Comparatively, there were no statistically significant changes in CD8+T, NK, and B cells. Furthermore, the exosomal mRNAs and long non-coding RNAs (lncRNA) were profiled, and the lncRNA-miRNA-mRNA networks were constructed and associated with METH AW and PW stages. Notably, the chemokine signaling was remarkably upregulated during AW. By contrast, the differentially expressed mRNAs/lincRNAs were significantly enriched in neurodegeneration-related diseases. Taken together, a group of METH withdrawal-related cytokines and exosomal mRNA/lncRNA regulatory networks were obtained, which provides a useful experimental and theoretical basis for further understanding of the pathogenesis of the withdrawal symptoms in MUDs.

Methamphetamine Use: A Narrative Review of Adverse Effects and Related Toxicities

Methamphetamine has been labeled "America's most dangerous drug" and has received significant public health attention. Stimulant addiction and tolerance are heavily documented in the literature; increasingly larger doses maintain euphoria in short time periods to withstand stimulant tolerance. Stimulant deaths are high in the United States and abroad. Between 2013 and 2019, deaths related to methamphetamine use quadrupled from 3,616 to 16,127. Methamphetamine use increased four-fold from 2015 to 2016. Due to this increase in methamphetamine use and its associated medical complications, the mortality rate associated with methamphetamine use has doubled over the past ten years. Cardiopulmonary symptoms include chest pain, palpitations, and shortness of breath. Methamphetamine-related myocardial infarction can also occur. Central nervous system symptoms include agitation, anxiety, delusions, hallucinations, and seizures. Methamphetamine-induced psychosis may unmask underlying psychiatric disorders. It can also cause cerebral vasculitis, which elicits cortical blindness and ischemic strokes. Methamphetamine-induced neurotoxicity in serotonergic systems is more diffuse, involving the striatum, hippocampus, septum, amygdala, and hypothalamus leading to mood changes, psychosis, and memory impairment. This narrative review will aim to highlight the adverse effects as well as the toxicity that can occur with methamphetamine use.

Correlates of anxiety and depression in a community cohort of people who smoke methamphetamine

OBJECTIVE

Anxiety and depression are the most common mental health disorders experienced by Australians. These disorders are commonly found in people who use methamphetamine; however, much of this research has involved participants recruited from treatment settings who inject methamphetamine. We therefore explored (1) the prevalence of moderate to severe anxiety and depression in a community-recruited cohort who smoked methamphetamine and (2) examined potential factors associated with moderate to severe anxiety or depression in this cohort.

METHOD

Data were derived from baseline surveys of 725 participants of the prospective 'VMAX' study, recruited from metropolitan and non-metropolitan areas of Victoria, Australia, via snowball and respondent-driven sampling. Anxiety and depression were measured using the Generalized Anxiety Disorder-7 and the Patient Health Questionnaire-9 instruments. Independent associations between moderate to severe scores on these measures and demographic, socio-economic, substance use and other health and social characteristics were examined using multivariable logistic regression.

RESULTS

More than half (60%) of the participants were classified as experiencing moderate to severe anxiety and/or depression. In the multivariable models, having poor/very poor self-rated health, methamphetamine dependence and being unemployed were associated with higher odds of experiencing both moderate to severe depression and moderate to severe anxiety. Living in a large rural town, identifying as Aboriginal and Torres Strait Islander and smoking methamphetamine were associated with lower odds of experiencing moderate to severe depression. Being female was associated with higher odds of experiencing moderate to severe anxiety.

CONCLUSION

The high rates of anxiety and/or depression found in the VMAX cohort were associated with demographic, socio-economic, substance use and other health and social factors. The prevalence of moderate to severe anxiety is a novel finding that warrants further study. Further work is needed to determine how anxiety and depression change over time among people who smoke methamphetamine, to help identify key intervention points.

Demographic and geographic shifts in the preferred route of methamphetamine administration among treatment cases in the US, 2010-2019

BACKGROUND

Methamphetamine use disorder has increased rapidly in the past decade. Injecting is also increasing and has multifaceted implications for disease severity, overall health, and treatment outcomes, but less is known about where or among whom injecting has shifted the most. This national study assessed temporal changes in the preferred route of methamphetamine administration by race/ethnicity and within urban/rural geographies.

METHODS

We used the Treatment Episode Dataset-Discharges (2010-2019) to identify outpatient treatment cases who reported methamphetamine as their primary drug of choice at admission (N = 531,799; 2010 n = 33,744; 2019 n = 81,885). We created a combined variable indicating race/ethnicity and the rural/urban location of treatment, and used logistic regression to model the predicted probability of cases reporting injection, smoking, or snorting as their preferred route of administration. We included an interaction term to determine differences over time (race/ethnicity/rurality*year).

RESULTS

Across all years, smoking methamphetamine was the most common route of administration (66%), followed by injection (24%) and snorting (10%). Over time and among most sub-groups, the rates of injection increased while the rates of smoking decreased. Compared to 2010, the odds of injecting methamphetamine in 2019 were highest among Black cases in urban areas (aOR = 2.30, 95% CI = 1.76-3.00, p < 0.0001).

CONCLUSION

Increasing methamphetamine injection was most pronounced among Black treatment cases in more urban areas, which is in contrast to the longstanding narrative that methamphetamine is a White and rural drug. Methamphetamine prevention, treatment, and harm reduction should target populations with high injection prevalence and growing incidence.

Illicit Substance Use and the COVID-19 Pandemic in the United States: A Scoping Review and Characterization of Research Evidence in Unprecedented Times

We carried out a scoping review to characterize the primary quantitative evidence addressing changes in key individual/structural determinants of substance use risks and health outcomes over the first two waves of the COVID-19 pandemic in the United States (US). We systematically queried the LitCovid database for US-only studies without date restrictions (up to 6 August 2021). We extracted quantitative data from articles addressing changes in: (a) illicit substance use frequency/contexts/behaviors, (b) illicit drug market dynamics, (c) access to treatment and harm reduction services, and (d) illicit substance use-related health outcomes/harms. The majority of 37 selected articles were conducted within metropolitan locations and leveraged historical timeseries medical records data. Limited available evidence supported changes in frequency/behaviors/contexts of substance use. Few studies point to increases in fentanyl and reductions in heroin availability. Policy-driven interventions to lower drug use treatment thresholds conferred increased access within localized settings but did not seem to significantly prevent broader disruptions nationwide. Substance use-related emergency medical services’ presentations and fatal overdose data showed a worsening situation. Improved study designs/data sources, backed by enhanced routine monitoring of illicit substance use trends, are needed to characterize substance use-related risks and inform effective responses during public health emergencies.

Local efficiency analysis of restingstate functional brain network in methamphetamine users

This study set out to assess restingstate functional connectivity (rs-FN) and graph theorybased local efficiency within the left and right hemispheres of methamphetamine (MA) abusers. Functional brain networks of 19 MA abusers and 21 control participants were analyzed using restingstate fMRI. Graph edges in functional networks of the brain were defined and recurrence plot was used. We found that MA abuse may be accompanied by alterations of rs-FN within the defaultmode network (DMN), executive control network (ECN), and the salience network (SN) in both hemispheres of the brain. We also observed that such effects of MA may be correlated with duration of MA abuse and abstinence in many components of the DMN and SN. The results would seem to suggest that MAinduced alterations of local efficiency may, in part, account for maladaptive decision making, deficits in executive function and control over drug seeking/taking, and relapse.

Impairments in the Default Mode and Executive Networks in Methamphetamine Users During Short-Term Abstinence

Purpose

Methamphetamine use may cause severe neurotoxicity and cognitive impairment, leading to addiction, overdose, and high rates of relapse. However, few studies have systematically focused on functional impairments detected by neuroimaging in methamphetamine abstainers (MAs) during short-term abstinence. This study aimed to investigate effective connectivity, resting-state networks, and internetwork functional connectivity in MA brains to improve clinical treatment.

Methods

Twenty MAs and 27 age- and education-matched healthy controls underwent resting-state functional magnetic resonance imaging. The amplitude of low-frequency fluctuations and Granger causality were analyzed to investigate disrupted brain regions and effective connectivity, respectively. Independent component analysis and functional network connectivity were used to identify resting-state networks and internetwork functional connectivity, respectively.

Results

Compared with healthy controls, MAs demonstrated abnormal amplitudes of low-frequency fluctuations in the bilateral precuneus, left posterior cingulate cortex (PCC), left middle frontal gyrus (MFG), left superior parietal lobule, left supplementary motor area (SMA), and left inferior parietal lobule (IPL). Moreover, MAs showed decreased effective connectivity from the left PCC to the left precuneus, increased effective connectivity from the left precuneus to the left MFG and from the right precuneus to the left SMA, and altered functional connectivity within the default mode network (DMN), frontoparietal network, sensorimotor network, ventral attention network, cerebellar network, and visual network. Importantly, hyperconnectivity between the DMN and ventral attention network and hypoconnectivity between the DMN and cerebellar network as well as the DMN and frontoparietal network were demonstrated in MAs.

Conclusion

Our study implies that in short-term methamphetamine abstinence, disruptions to the DMN and executive network may a play key role, providing new insights for early rehabilitation.