Reduced drug use as an alternative valid outcome in individuals with stimulant use disorders: Findings from 13 multisite randomized clinical trials

BACKGROUND AND AIMS

Total abstinence has historically been the goal of treatment for substance use disorders; however, there is a growing recognition of the health benefits associated with reduced use as a harm reduction measure in stimulant use disorders treatment. We aimed to assess the validity of reduced stimulant use as an outcome measure in randomized controlled trials (RCTs) of pharmacological interventions for stimulant use disorder.

DESIGN

We conducted a secondary analysis of a pooled dataset of 13 RCTs.

SETTING AND PARTICIPANTS

Participants were individuals seeking treatment for cocaine or methamphetamine use disorders (N = 2062) in a wide range of treatment facilities in the United States.

MEASUREMENTS

We validated reduced stimulant use against a set of clinical indicators drawn from harmonized measurements, including severity of problems caused by drug use, comorbid depression, global severity of substance use and improvement, severity of drug-seeking behavior, craving and high-risk behaviors, all assessed at the end of the trial, as well as follow-up urine toxicology. A series of mixed effect regression models was conducted to validate reduction in frequency of use against no reduction in use and abstinence.

FINDINGS

More participants reduced frequency of primary drug use than achieved abstinence (18.0% vs. 14.2%, respectively). Reduced use was significantly associated with decreases in craving for the primary drug [60.1%, 95% confidence interval (CI) = 54.3%-64.7%], drug seeking behaviors (41.0%, 95% CI = 36.6%-45.7%), depression severity (39.9%, 95% CI = 30.9%-48.3%), as well as multiple measures of global improvement in psychosocial functioning and severity of drug-related problems, albeit less strongly so than abstinence. Moreover, reduced use was associated with sustained clinical benefit at follow-up, as confirmed by negative urine tests (adjusted odds ratio compared with those with no reduction in use: 0.50, 95% CI = 0.35-0.71).

CONCLUSION

Reduced frequency of stimulant use appears to be associated with meaningful improvement in various clinical indicators of recovery. Assessment of reduced use, in addition to abstinence, could broaden the scope of outcomes measured in randomized controlled trials of stimulant use disorders and facilitate the development of more diverse treatment approaches.

A preliminary study on the association of single nucleotide polymorphisms and methylation of dopamine system-related genes with psychotic symptoms in patients with methamphetamine use disorder

Methamphetamine use disorder (MAUD) can substantially jeopardize public security due to its high-risk social psychology and behaviour. Given that the dopamine reward system is intimately correlated with MAUD, we investigated the association of single nucleotide polymorphisms (SNPs), as well as methylation status of dopamine receptor type 4 (DRD4), catechol-O-methyltransferase (COMT) genes, and paranoid and motor-impulsive symptoms in MAUD patients. A total of 189 MAUD patients participated in our study. Peripheral blood samples were used to detect 3 SNPs and 35 CpG units of methylation in the DRD4 gene promoter region and 5 SNPs and 39 CpG units in the COMT gene. MAUD patients with the DRD4 rs1800955 C allele have a lower percentage of paranoid symptoms than those with the rs1800955 TT allele. Individuals with paranoid symptoms exhibited a reduced methylation degree at a particular DRD4 CpG2.3 unit. The interaction of the DRD4 rs1800955 C allele and the reduced DRD4CpG2.3 methylation degree were associated with a lower occurrence of paranoid symptoms. Meanwhile, those with the COMT rs4818 CC allele had lower motor-impulsivity scores in MAUD patients but greater COMT methylation levels in the promoter region and methylation degree at the COMT CpG 51.52 unit. Therefore, based only on the COMT rs4818 CC polymorphism, there was a negative correlation between COMT methylation and motor-impulsive scores. Our preliminary results provide a clue that the combination of SNP genotype and methylation status of the DRD4 and COMT genes serve as biological indicators for the prevalence of relatively high-risk psychotic symptoms in MAUD patients.

The Effectiveness of Mindfulness in the Treatment of Methamphetamine Addiction Symptoms: Does Neuroplasticity Play a Role?

INTRODUCTION

Methamphetamine is a highly stimulating psychoactive drug that causes life-threatening addictions and affects millions of people around the world. Its effects on the brain are complex and include disturbances in the neurotransmitter systems and neurotoxicity. There are several known treatment methods, but their effectiveness is moderate. It must be emphasised that no drugs have been approved for treatment. For this reason, there is an urgent need to develop new, effective, and safe treatments for methamphetamine. One of the potential treatments is mindfulness meditation. In recent years, this technique has been researched extensively in the context of many neurological and psychiatric disorders.

METHODS

This review explores the use of mindfulness in the treatment of methamphetamine addiction. Searches were conducted in the PubMed/Medline, Research Gate, and Cochrane databases.

RESULTS

Ten studies were identified that used mindfulness-based interventions in the treatment of methamphetamine addiction. The results show that mindfulness is an effective form of reducing hunger, risk of relapses, stress indicators, depression, and aggression, alone or in combination with transcranial direct current stimulation (tDCS). Mindfulness also improved the cognitive function in addicts. The included studies used only behavioural measures. The potential mechanisms of mindfulness in addiction were explained, and it was proposed that it can induce neuroplasticity, alleviating the symptoms of addiction.

CONCLUSIONS

Evidence from the studies suggest that mindfulness may be an effective treatment option for methamphetamine addiction, used alone or in combination with tDCS. However, further high-quality research is required to establish the role of this treatment option in this field. The use of neuroimaging and neurophysiological measures is fundamental to understand the mechanisms of mindfulness.

Alterations in the brain functional network of abstinent male individuals with methamphetamine use disorder

Methamphetamine is a highly addictive psychostimulant drug that is abused globally and is a serious threat to health worldwide. Unfortunately, the specific mechanism underlying addiction remains unclear. Thus, this study aimed to investigate the characteristics of functional connectivity in the brain network and the factors influencing methamphetamine use disorder in patients using magnetic resonance imaging. We included 96 abstinent male participants with methamphetamine use disorder and 46 age- and sex-matched healthy controls for magnetic resonance imaging. Compared with healthy controls, participants with methamphetamine use disorder had greater impulsivity, fewer small-world attributes of the resting-state network, more nodal topological attributes in the cerebellum, greater functional connectivity strength within the cerebellum and between the cerebellum and brain, and decreased frontoparietal functional connectivity strength. In addition, after controlling for covariates, the partial correlation analysis showed that small-world properties were significantly associated with methamphetamine use frequency, psychological craving, and impulsivity. Furthermore, we revealed that the small-word attribute significantly mediated the effect of methamphetamine use frequency on motor impulsivity in the methamphetamine use disorder group. These findings may further improve our understanding of the neural mechanism of impulse control dysfunction underlying methamphetamine addiction and assist in exploring the neuropathological mechanism underlying methamphetamine use disorder-related dysfunction and rehabilitation.

Virtual agents among participants with methamphetamine use disorders: Acceptability and usability study

INTRODUCTION

While the potential future role of virtual agents (VAs) in treating addiction is promising, participants' attitudes toward the use of VAs in psychotherapy remain insufficiently investigated. This lack of investigation could pose barriers to the adoption of VA-led psychotherapy for people with substance use disorders (SUD). This research aims to explore the acceptability and usability of VAs for people with methamphetamine use disorder.

METHODS

Following a single session of psychotherapy led by VAs through the Echo-app, a group of 49 individuals actively seeking treatment for current DSM-V substance dependence (with a mean age of 39.06 ± 8.02) completed self-administered questionnaires and participated in focus group interviews. These questionnaires aimed to investigate participants' preference regarding the type of psychotherapy and their willingness to engage in VA-led psychotherapy, taking into account their diverse psychological needs.

RESULTS

Quantitative data were subjected to analysis through both descriptive and inferential statistical methods. Interestingly, participants exhibited a significantly higher acceptability for traditional face-to-face psychotherapy compared to email-based psychotherapy (p = 0.042), but there was no statistically significant difference between their acceptance of traditional psychotherapy and VA-led psychotherapy (p = 0.059). The questionnaire outcomes indicated participants' willingness to engage in VA-led psychotherapy for purposes such as relapse prevention intervention, addressing emotional issues, managing somatic experiences, and facilitating social and family functional recovery. Furthermore, the participants' attitudes toward VA-led psychotherapy were predicted by factors including the need for anxiety-focused psychotherapy (p = 0.027; OR [95%CI] = 0.14[0.03,0.80]), the presence of chronic somatic diseases (p = 0.017; OR [95%CI] = 13.58[1.59,116.03]), and marital status (p = 0.031; OR [95%CI] = 5.02[1.16,21.79]).

DISCUSSION

Through the interviews, the study uncovered the factors that either supported or hindered participants' experiences with VA-led psychotherapy, while also gathering suggestions for future improvements. This research highlights the willingness and practicality of individuals with SUD in embracing VA-led psychotherapy. The findings are anticipated to contribute to the refinement of VA-led tools to better align with the preferences and needs of the users.

An electroencephalographic signature predicts craving for methamphetamine

Craving is central to methamphetamine use disorder (MUD) and both characterizes the disease and predicts relapse. However, there is currently a lack of robust and reliable biomarkers for monitoring craving and diagnosing MUD. Here, we seek to identify a neurobiological signature of craving based on individual-level functional connectivity pattern differences between healthy control and MUD subjects. We train high-density electroencephalography (EEG)-based models using data recorded during the resting state and then calculate imaginary coherence features between the band-limited time series across different brain regions of interest. Our prediction model demonstrates that eyes-open beta functional connectivity networks have significant predictive value for craving at the individual level and can also identify individuals with MUD. These findings advance the neurobiological understanding of craving through an EEG-tailored computational model of the brain connectome. Dissecting neurophysiological features provides a clinical avenue for personalized treatment of MUD.

Uncovering transcriptomic biomarkers for enhanced diagnosis of methamphetamine use disorder: a comprehensive review

Introduction

Methamphetamine use disorder (MUD) is a chronic relapsing disorder characterized by compulsive Methamphetamine (MA) use despite its detrimental effects on physical, psychological, and social well-being. The development of MUD is a complex process that involves the interplay of genetic, epigenetic, and environmental factors. The treatment of MUD remains a significant challenge, with no FDA-approved pharmacotherapies currently available. Current diagnostic criteria for MUD rely primarily on self-reporting and behavioral assessments, which have inherent limitations owing to their subjective nature. This lack of objective biomarkers and unidimensional approaches may not fully capture the unique features and consequences of MA addiction.

Methods

We performed a literature search for this review using the Boolean search in the PubMed database.

Results

This review explores existing technologies for identifying transcriptomic biomarkers for MUD diagnosis. We examined non-invasive tissues and scrutinized transcriptomic biomarkers relevant to MUD. Additionally, we investigated transcriptomic biomarkers identified for diagnosing, predicting, and monitoring MUD in non-invasive tissues.

Discussion

Developing and validating non-invasive MUD biomarkers could address these limitations, foster more precise and reliable diagnostic approaches, and ultimately enhance the quality of care for individuals with MA addiction.

Prescription psychostimulants as a harm reduction and treatment intervention for methamphetamine use disorder and the implications for nursing clinical practice: A scoping review of the literature

The global rise in methamphetamine use and its negative effects warrants the need for research exploring harm reduction and treatment interventions for individuals with methamphetamine use disorder. Agonist medications have been utilized for years for the treatment of heroin and opioid addiction, but have yet to be incorporated into mainstream Canadian practice for methamphetamine dependence. This review aims to provide an overview of the current trends of prescription psychostimulant usage for individuals with methamphetamine use disorder from a Canadian perspective, identifies the barriers to accessing prescription psychostimulants for methamphetamine use disorder and highlights the nursing clinical practice implications in caring for individuals with the disorder. Discourse on the sustained abstinence and harm reduction debate is presented from the perspective of methamphetamine abuse is provided along with the neuropsychiatric complications of chronic methamphetamine use. The impacts of specific prescription psychostimulants on cognition are discussed as is the use of neuroimaging techniques to assess neuronal damage in methamphetamine users. Sign of toxicity, overdose and the contraindications for use of these prescription psychostimulants is also presented. The implications to nursing clinical practice in caring for this population is provided, touching on the clinical presentation of methamphetamine use, completing thorough assessment and screening and patient education. The findings of this review indicate the need for further research in this area exploring the benefits of prescription psychostimulants as a harm reduction and treatment intervention for the global problem of methamphetamine dependence.

The gut microbiota as a potential biomarker for methamphetamine use disorder: evidence from two independent datasets

Background

Methamphetamine use disorder (MUD) poses a considerable public health threat, and its identification remains challenging due to the subjective nature of the current diagnostic system that relies on self-reported symptoms. Recent studies have suggested that MUD patients may have gut dysbiosis and that gut microbes may be involved in the pathological process of MUD. We aimed to examine gut dysbiosis among MUD patients and generate a machine-learning model utilizing gut microbiota features to facilitate the identification of MUD patients.

Method

Fecal samples from 78 MUD patients and 50 sex- and age-matched healthy controls (HCs) were analyzed by 16S rDNA sequencing to identify gut microbial characteristics that could help differentiate MUD patients from HCs. Based on these microbial features, we developed a machine learning model to help identify MUD patients. We also used public data to verify the model; these data were downloaded from a published study conducted in Wuhan, China (with 16 MUD patients and 14 HCs). Furthermore, we explored the gut microbial features of MUD patients within the first three months of withdrawal to identify the withdrawal period of MUD patients based on microbial features.

Results

MUD patients exhibited significant gut dysbiosis, including decreased richness and evenness and changes in the abundance of certain microbes, such as Proteobacteria and Firmicutes. Based on the gut microbiota features of MUD patients, we developed a machine learning model that demonstrated exceptional performance with an AUROC of 0.906 for identifying MUD patients. Additionally, when tested using an external and cross-regional dataset, the model achieved an AUROC of 0.830. Moreover, MUD patients within the first three months of withdrawal exhibited specific gut microbiota features, such as the significant enrichment of Actinobacteria. The machine learning model had an AUROC of 0.930 for identifying the withdrawal period of MUD patients.

Conclusion

In conclusion, the gut microbiota is a promising biomarker for identifying MUD and thus represents a potential approach to improving the identification of MUD patients. Future longitudinal studies are needed to validate these findings.

Methamphetamine exposure and depression-A systematic review and meta-analysis

ISSUES

Methamphetamine use is a public health concern that has been associated with comorbid mental health problems. We aim to better understand the relationship between methamphetamine use and depression by: (i) systematically reviewing and meta-analysing the risks of depression by methamphetamine use; and (ii) investigating the risk of unmeasured confounding.

APPROACH

A systematic review and meta-analysis were conducted following PRISMA guidelines. EMBASE, PsycINFO and PubMed were searched to identify human studies reporting on the association between methamphetamine or amphetamine use and depressive outcomes. The data were summarised narratively and meta-analysed, stratified by cross-sectional and longitudinal estimates. Unmeasured confounding was assessed by E-values analyses.

KEY FINDINGS

From the 6606 studies that came up from the search, 14 eligible studies were included in the narrative review and had data for meta-analysis. A significant association was found between any use of methamphetamine and any depression outcomes in cross-sectional (odds ratio [OR] = 1.66 [95% confidence interval [CI] 1.34, 2.05]) and longitudinal estimates (OR = 1.18 [95% CI 1.08, 1.28]). People with a methamphetamine use disorder had significantly higher odds of depression than those without (OR = 2.80 [95% CI 1.40, 5.90]). The E-values ranged from 1.28 to 6.30 for cross-sectional studies and from 2.37 to 3.21 for longitudinal studies.

CONCLUSION

Based on limited data, people who used methamphetamine have higher odds of depression than people who do not. There were mostly a low to moderate risk of unmeasured confounding in the longitudinal study results. Future longitudinal studies conducted using causal framework methods are warranted.

EGCG attenuates METH self-administration and reinstatement of METH seeking in mice

Methamphetamine (METH) use disorder is a chronic, relapsing disorder and involves frequent failures of self-control of drug seeking and taking. Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenolic compounds of green tea, which has shown great therapeutic effectiveness in neurological disorders. However, it is still unknown whether and how EGCG affects METH seeking behaviour. Here, we show nanostructured EGCG/ascorbic acid nanoparticles (EGCG/AA NPs) dose-dependently reduced METH self-administration (SA) under fixed-ratio 1 (FR1) and progressive ratio (PR) reinforcement schedules in mice and shifted METH dose-response curves downward. Furthermore, EGCG/AA NPs decreased drug- and cue-induced METH seeking. In addition, we found that METH SA led to a decrease in inhibitory postsynaptic currents (IPSCs) and increase in the AMPAR/NMDAR ratio and excitation/inhibition (E/I) ratio in ex vivo midbrain slices from ventral tegmental area (VTA) dopamine neurons. EGCG/AA NPs enhanced Gamma-aminobutyric acid (GABA)ergic inhibition and normalized the E/I ratio. EGCG restored the balance between excitation and inhibition in VTA dopamine neurons, which may contribute to the attenuation of METH SA. These findings indicate that EGCG is a promising pharmacotherapy for METH use disorder.

Feasibility, Engagement, and Usability of a Remote, Smartphone-Based Contingency Management Program as a Treatment Add-On for Patients Who Use Methamphetamine: Single-Arm Pilot Study

BACKGROUND

In the United States, methamphetamine-related overdoses have tripled from 2015 to 2020 and continue to rise. However, efficacious treatments such as contingency management (CM) are often unavailable in health systems.

OBJECTIVE

We conducted a single-arm pilot study to evaluate the feasibility, engagement, and usability of a fully remotely delivered mobile health CM program offered to adult outpatients who used methamphetamine and were receiving health care within a large university health system.

METHODS

Participants were referred by primary care or behavioral health clinicians between September 2021 and July 2022. Eligibility criteria screening was conducted by telephone and included self-reported methamphetamine use on ≥5 out of the past 30 days and a goal of reducing or abstaining from methamphetamine use. Eligible participants who agreed to take part then completed an initial welcome phase that included 2 videoconference calls to register for and learn about the CM program and 2 "practice" saliva-based substance tests prompted by a smartphone app. Participants who completed these welcome phase activities could then receive the remotely delivered CM intervention for 12 consecutive weeks. The intervention included approximately 24 randomly scheduled smartphone alerts requesting a video recording of themselves taking a saliva-based substance test to verify recent methamphetamine abstinence, 12 weekly calls with a CM guide, 35 self-paced cognitive behavioral therapy modules, and multiple surveys. Financial incentives were disbursed via reloadable debit cards. An intervention usability questionnaire was completed at the midpoint.

RESULTS

Overall, 37 patients completed telephone screenings, with 28 (76%) meeting the eligibility criteria and consenting to participate. Most participants who completed a baseline questionnaire (21/24, 88%) self-reported symptoms consistent with severe methamphetamine use disorder, and most had other co-occurring non-methamphetamine substance use disorders (22/28, 79%) and co-occurring mental health disorders (25/28, 89%) according to existing electronic health records. Overall, 54% (15/28) of participants successfully completed the welcome phase and were able to receive the CM intervention. Among these participants, engagement with substance testing, calls with CM guides, and cognitive behavioral therapy modules varied. Rates of verified methamphetamine abstinence in substance testing were generally low but varied considerably across participants. Participants reported positive opinions about the intervention's ease of use and satisfaction with the intervention.

CONCLUSIONS

Fully remote CM can be feasibly delivered within health care settings lacking existing CM programs. Although remote delivery may help reduce barriers to treatment access, many patients who use methamphetamine may struggle to engage with initial onboarding. High rates of co-occurring psychiatric conditions in the patient population may also contribute to uptake and engagement challenges. Future efforts could leverage greater human-to-human connection, more streamlined onboarding procedures, larger incentives, longer durations, and the incentivization of non-abstinence-based recovery goals to increase uptake and engagement with fully remote mobile health-based CM.

Identification of PROK2 gene polymorphisms as predictors of methamphetamine use disorder risk and indicators of craving scale in the Chinese Han population

Background: Methamphetamine use disorder (MUD) has become a global problem due to the highly addictive nature of methamphetamine. Earlier research have demonstrated that PROK2 functions as a compensatory and protective response against neurotoxic stress by stimulating astrocyte reactivity. The aim of our study was to evaluate the correlation between the PROK2 gene and both MUD risk susceptibility and craving scale in the Chinese Han population. Methods: A total of 5,282 participants (1,796 MUD patients and 3,486 controls) were recruited. Seven tag SNPs of the PROK2 gene were chosen and genotyped in the samples. Genetic association analyses were performed to capture the significant SNPs. To investigate the relationship between PROK2 levels and craving scores with the associated-SNP genotypes, we conducted a linear model. Results: SNP rs75433452 was significantly linked with MUD risk (p-value = 1.54 × 10^-8), with the A allele being positively correlated with an increased risk of MUD. Moreover, the average serum level of PROK2 decreased when more copies of the A allele were presented in both MUD patients (p-value = 4.57 × 10^-6) and controls (p-value = 1.13 × 10^-5). Furthermore, the genotypes of SNP rs75433452 were strongly correlated with the craving scores in MUD patients (p-value = 4.05 × 10^-4). Conclusion: Our study identified a significant association signal of the PROK2 gene with MUD risk susceptibility and methamphetamine craving scores in the Chinese Han population, providing potential valuable insights into the underlying mechanisms of METH dependence.

A Systematic Review of the Effect of Short Term Transcranial Direct Current Stimulation Therapy in Methamphetamine Use Disorder

Background: Methamphetamine use disorder (MUD) has become more and more common. Some studies have shown that Transcranial Direct Current stimulation (tDCS) may reduce craving when stimulating the dorsal lateral prefrontal cortex. Objectives: The aim of this systematic review was to evaluate the effect of transcranial direct current stimulation (tDCS) on MUD. Databases were searched through May 2022. Randomized Controlled Trials (RCT) and pre-post studies investigating the efficacy of tDCS in MUD were included. The Cochrane Manual of Systematic Evaluation 6.3 bias risk assessment tool was used to assess the risk of bias. For each article, where possible, we extracted the population(s), standardized mean differences (SMD), standard deviations, and other study metrics (design, year, randomization, and details) on efficacy and tolerability outcomes. We assessed each article's quality via the GRADE assessment protocol. Results: Six studies involving 220 patients were included. All six studies included reported continuous data on craving. Results from craving favored active tDCS over sham tDCS at the end of treatment (SMD -0.58, 95% CI -0.85 to -0.30; studies = 6, participants = 220; I2 = 60%). Tolerability data showed that tDCS does not cause more tingling or itching sensation compared to sham tDCS. Conclusions: Further trials with larger sample sizes and longer durations are needed to determine whether tDCS is a valuable tool in treating MUD.

Identification of Potential Biomarkers for Diagnosis of Patients with Methamphetamine Use Disorder

The current method for diagnosing methamphetamine use disorder (MUD) relies on self-reports and interviews with psychiatrists, which lack scientific rigor. This highlights the need for novel biomarkers to accurately diagnose MUD. In this study, we identified transcriptome biomarkers using hair follicles and proposed a diagnostic model for monitoring the MUD treatment process. We performed RNA sequencing analysis on hair follicle cells from healthy controls and former and current MUD patients who had been detained in the past for illegal use of methamphetamine (MA). We selected candidate genes for monitoring MUD patients by performing multivariate analysis methods, such as PCA and PLS-DA, and PPI network analysis. We developed a two-stage diagnostic model using multivariate ROC analysis based on the PLS-DA method. We constructed a two-step prediction model for MUD diagnosis using multivariate ROC analysis, including 10 biomarkers. The first step model, which distinguishes non-recovered patients from others, showed very high accuracy (prediction accuracy, 98.7%). The second step model, which distinguishes almost-recovered patients from healthy controls, showed high accuracy (prediction accuracy, 81.3%). This study is the first report to use hair follicles of MUD patients and to develop a MUD prediction model based on transcriptomic biomarkers, which offers a potential solution to improve the accuracy of MUD diagnosis and may lead to the development of better pharmacological treatments for the disorder in the future.

Intermittent theta burst stimulation to the left dorsolateral prefrontal cortex improves working memory of subjects with methamphetamine use disorder

BACKGROUND

Repetitive transcranial magnetic stimulation has been employed to treat drug dependence, reduce drug use and improve cognition. The aim of the study was to analyze the effectiveness of intermittent theta-burst stimulation (iTBS) on cognition in individuals with methamphetamine use disorder (MUD).

METHODS

This was a secondary analysis of 40 MUD subjects receiving left dorsolateral prefrontal cortex (L-DLPFC) iTBS or sham iTBS for 20 times over 10 days (twice-daily). Changes in working memory (WM) accuracy, reaction time, and sensitivity index were analyzed before and after active and sham rTMS treatment. Resting-state EEG was also acquired to identify potential biological changes that may relate to any cognitive improvement.

RESULTS

The results showed that iTBS increased WM accuracy and discrimination ability, and improved reaction time relative to sham iTBS. iTBS also reduced resting-state delta power over the left prefrontal region. This reduction in resting-state delta power correlated with the changes in WM.

CONCLUSIONS

Prefrontal iTBS may enhance WM performance in MUD subjects. iTBS induced resting EEG changes raising the possibility that such findings may represent a biological target of iTBS treatment response.

Differences in clinical features and gut microbiota between individuals with methamphetamine casual use and methamphetamine use disorder

Background

The transition from methamphetamine (MA) casual use (MCU) to compulsive use is enigmatic as some MA users can remain in casual use, but some cannot. There is a knowledge gap if gut microbiota (GM) play a role in differing MCU from MA use disorder (MUD). We aimed to investigate the clinical features and GM differences between individuals with MCU and MUD.

Method

We recruited two groups of MA users -MCU and MUD - and matched them according to age and body mass index (n=21 in each group). Participants were accessed using the Semi-Structured Assessment for Drug Dependence and Alcoholism, and their fecal samples were undergone 16S ribosomal DNA sequencing. We compared the hosts' clinical features and GM diversity, composition, and structure (represented by enterotypes) between the two groups. We have identified differential microbes between the two groups and performed network analyses connecting GM and the clinical traits.

Result

Compared with the casual users, individuals with MUD had higher incidences of MA-induced neuropsychiatric symptoms (e.g., paranoia, depression) and withdrawal symptoms (e.g., fatigue, drowsiness, and increased appetite), as well as stronger cravings for and intentions to use MA, and increased MA tolerance. The GM diversity showed no significant differences between the two groups, but four genera (Halomonas, Clostridium, Devosia, and Dorea) were enriched in the individuals with MUD (p<0.05). Three distinct enterotypes were identified in all MA users, and Ruminococcus-driven enterotype 2 was dominant in individuals with MUD compared to the MCU (61.90% vs. 28.60%, p=0.03). Network analysis shows that Devosia is the hub genus (hub index = 0.75), which is not only related to the counts of the MUD diagnostic criteria (ρ=0.40; p=0.01) but also to the clinical features of MA users such as reduced social activities (ρ=0.54; p<0.01). Devosia is also associated with the increased intention to use MA (ρ=0.48; p<0.01), increased MA tolerance (ρ=0.38; p=0.01), craving for MA (ρ=0.37; p=0.01), and MA-induced withdrawal symptoms (p<0.05).

Conclusion

Our findings suggest that Ruminococcus-driven enterotype 2 and the genera Devosia might be two influential factors that differentiate MA casual use from MUD, but further studies are warranted.

OCT Findings in Patients with Methamphetamine Use Disorder

PURPOSE

In the present study, the purpose was to examine the results of optical coherence tomography (OCT) measurements in patients diagnosed with methamphetamine use disorder (MUD) by comparing them with healthy controls.

MATERIALS AND METHODS

A total of 114 eyes were evaluated in this study (27 patients and 30 control group participants). After detailed biomicroscopic examinations of all participants by the same ophthalmologist, both eyes were evaluated by OCT. The retinal nerve fiber layer thickness (RNFL) and macular thickness were calculated from OCT.

RESULTS

No statistically significant differences were detected between the demographic data of the patient and control groups (p > 0.05). When OCT findings were evaluated, macular thickness and volume were not different between the groups (p > 0.05). With respect to RNFL, the left eye superior, inferior, temporal, and nasal quadrants, as well as the left eye's total measurements were found to be thicker than those of controls (p < 0.05). In both eyes, the left eye nasal quadrant and APIS total score were negatively correlated, the total RNLF measurement of the right eye and APIS motivation subscale score were negatively correlated, central macular thickness and the APIS motivation subscale score were positively correlated, and the APIS substance use characteristics subscale score and left eye temporal quadrant RNLF measurement were positively correlated.

CONCLUSION

Our study is the first to evaluate addiction severity and OCT findings in MUD. However, this study needs to be supported by further studies so that OCT findings, which can be used as an effective method for demonstrating possible neurodegeneration in methamphetamine use disorder, gain importance.

Virtual Digital Psychotherapist App-Based Treatment in Patients With Methamphetamine Use Disorder (Echo-APP): Single-Arm Pilot Feasibility and Efficacy Study

BACKGROUND

Substance use disorder is one of the severe public health problems worldwide. Inequitable resources, discrimination, and physical distances limit patients' access to medical help. Automated conversational agents have the potential to provide in-home and remote therapy. However, automatic dialogue agents mostly use text and other methods to interact, which affects the interaction experience, treatment immersion, and clinical efficacy.

OBJECTIVE

The aim of this paper is to describe the design and development of Echo-APP, a tablet-based app with the function of a virtual digital psychotherapist, and to conduct a pilot study to explore the feasibility and preliminary efficacy results of Echo-APP for patients with methamphetamine use disorder.

METHODS

Echo-APP is an assessment and rehabilitation program developed for substance use disorder (SUD) by a team of clinicians, psychotherapists, and computer experts. The program is available for Android tablets. In terms of assessment, the focus is on the core characteristics of SUD, such as mood, impulsivity, treatment motivation, and craving level. In terms of treatment, Echo-APP provides 10 treatment units, involving awareness of addiction, motivation enhancement, emotion regulation, meditation, etc. A total of 47 patients with methamphetamine dependence were eventually enrolled in the pilot study to receive a single session of the Echo-APP-based motivational enhancement treatment. The outcomes were assessed before and after the patients' treatment, including treatment motivation, craving levels, self-perception on the importance of drug abstinence, and their confidence in stopping the drug use.

RESULTS

In the pilot study, scores on the Stages of Change Readiness and Treatment Eagerness Scale and the questionnaire on motivation for abstaining from drugs significantly increased after the Echo-APP-based treatment (P<.001, Cohen d=-0.60), while craving was reduced (P=.01, Cohen d=0.38). Patients' baseline Generalized Anxiety Disorder-7 assessment score (β=3.57; P<.001; 95% CI 0.80, 2.89) and Barratt Impulsiveness Scale (BIS)-motor impulsiveness score (β=-2.10; P=.04; 95% CI -0.94, -0.02) were predictive of changes in the patients' treatment motivation during treatment. Moreover, patients' baseline Generalized Anxiety Disorder-7 assessment score (β=-1.607; P=.03; 95% CI -3.08, -0.14), BIS-attentional impulsivity score (β=-2.43; P=.004; 95% CI -4.03, -0.83), and BIS-nonplanning impulsivity score (β=2.54; P=.002; 95% CI 0.98, 4.10) were predictive of changes in craving scores during treatment.

CONCLUSIONS

Echo-APP is a practical, accepted, and promising virtual digital psychotherapist program for patients with methamphetamine dependence. The preliminary findings lay a good foundation for further optimization of the program and the promotion of large-scale randomized controlled clinical studies for SUD.

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.

The association of FKBP5 polymorphisms with the severity of depressive disorder in patients with methamphetamine use disorders

Background

Co-occurring depressive disorder (DD) in patients of methamphetamine use disorder (MAUD) impacts the diagnosis, treatment, and prognosis of the disease. Although FKBP5 has been associated with a variety of psychiatric disorders, whether FKBP5 influences depression susceptibility in MAUD is unknown so far.

Methods

Here, we sequenced six FKBP5 single-nucleotide polymorphism (SNP) sites (rs4713916, rs6926133, rs9470080, rs737054, rs4713902, and rs9470079) in 282 methamphetamine users. MAUD and DD were evaluated by clinical questionnaires. SPSS was used to analyze the relationship between FKBP5 SNPs and DD in individuals with MAUD.

Results

Of the 282 methamphetamine users, 161 individuals met the MAUD criteria, and among them, 50 patients (31.1%) had DD co-occurring. Importantly, the incidence of DD in individuals with MAUD was 3.314 times greater than that of the methamphetamine users who did not meet the MAUD criteria (p < 0.001). Although none of the six SNPs of FKBP5 were correlated with the co-occurrence of DD in the population with MAUD, two FKBP5 alleles (rs4713916A and rs6926133A) were substantially associated with the higher DD scores in patients with MAUD (p < 0.05). Moreover, those with the two risk alleles do not have much higher scores than those with a single risk allele, and the strong linkage disequilibrium of the two SNPs may be the underlying cause of this result. Despite having weak linkage disequilibrium with either rs4713916 or rs6926133, FKBP5 rs9470079 became risky when paired with either.

Conclusion

The results of this study revealed that the FKBP5 risk alleles (rs4713916A and rs6926133A) were associated with a greater probability of severe DD in patients with MAUD. These findings here would help with the development of biological early warning markers and the creation of personalized treatment strategies for MAUD.

Multiple comparison of different noninvasive brain stimulation and pharmacologic interventions in patients with methamphetamine use disorders: A network meta-analysis of randomized controlled trials

AIM

In recent decades, the prevalence of amphetamine and methamphetamine use disorders has at least doubled in some regions/countries, with accompanying high risks of drug overdose-associated mortality. Noninvasive brain stimulation (NIBS) methods may be effective treatments. However, the comparative efficacy of the NIBS protocol for amphetamine/methamphetamine use disorder (AUD/MUD) remains unknown to date. The aim of this network meta-analysis (NMA) was to compare the efficacy and acceptability of various NIBS methods/protocols for AUD/MUD management.

METHODS

A frequentist model-based NMA was conducted. We included randomized controlled trials (RCTs) that investigated the efficacy of NIBS and guideline-recommended pharmacologic treatments to reduce craving severity in patients with either AUD or MUD.

RESULTS

Twenty-two RCTs including 1888 participants met the eligibility criteria. Compared with the sham/placebo group (study = 19, subjects = 891), a combination of intermittent theta burst stimulation over the left dorsolateral prefrontal cortex (DLPFC) and continuous TBS over the left ventromedial prefrontal cortex (study = 1, subjects = 19) was associated with the largest decreases in craving severity [standardized mean difference (SMD) = -1.50; 95% confidence intervals (95%CIs) = -2.70 to -0.31]. High-frequency repetitive transcranial magnetic stimulation over the left DLPFC was associated with the largest improvements in depression and quality of sleep (study = 3, subjects = 86) (SMD = -2.48; 95%CIs = -3.25 to -1.71 and SMD = -2.43; 95%CIs = -3.38 to -1.48, respectively). The drop-out rate of most investigated treatments did not significantly differ between groups.

CONCLUSION

The combined TBS protocol over the prefrontal cortex was associated with the greatest improvement in craving severity. Since few studies were available for inclusion, additional large-scale randomized controlled trials are warranted.

Active and Passive Immunization with an Anti-Methamphetamine Vaccine Attenuates the Behavioral and Cardiovascular Effects of Methamphetamine

BACKGROUND

Methamphetamine use disorder (MUD) is a growing health concern with no FDA-approved treatment. The present series of studies build upon our previous work developing an anti-methamphetamine (MA) vaccine for MUD. We determined the effects of a formulation that included tetanus-toxoid (TT) conjugated to succinyl-methamphetamine (TT-SMA) adsorbed onto aluminum hydroxide (alum) in combination with the novel Toll-Like Receptor-5 agonist, entolimod.

METHODS

Mice were vaccinated (0, 3, 6 weeks) with TT-SMA+alum and various doses of entolimod to determine an optimal dose for enhancing immunogenicity against MA. Functional effects were then assessed using MA-induced locomotor activation in mice. Experiments using passive immunization of antibodies generated by the vaccine tested its ability to attenuate MA-induced cardiovascular effects and alter the reinforcing effects of MA in an MA-induced reinstatement of a drug seeking model of relapse in male and female rats.

RESULTS

Antibody levels peaked at 10 weeks following vaccination with TT-SMA+alum combined with entolimod (1, 3 and 10 μg). MA-induced locomotor activation was significantly attenuated in vaccinated vs. unvaccinated mice and antibody levels significantly correlated with ambulation levels. Passive immunization decreased mean arterial pressure following MA dosing in rats of both sexes but did not alter heart rate. Passive immunization also attenuated the ability of MA to reinstate extinguished drug-seeking behavior in male and female rats. Results support further development of this vaccine for relapse prevention for individuals with MUD.

Biochemical Neuroadaptations in the Rat Striatal Dopaminergic System after Prolonged Exposure to Methamphetamine Self-Administration

Perturbations in striatal dopamine (DA) homeostasis might underlie the behavioral and pathobiological consequences of METH use disorder in humans. To identify potential consequences of long-term METH exposure, we modeled the adverse consequence DSM criterion of substance use disorders by giving footshocks to rats that had escalated their intake of METH during a drug self-administration procedure. Next, DA D1 receptor antagonist, SCH23390 was injected. Thereafter, rats were euthanized to measure several indices of the striatal dopaminergic system. Footshocks split the METH rats into two phenotypes: (i) shock-sensitive that decreased their METH-intake and (ii) shock-resistant that continued their METH intake. SCH23390 caused substantial dose-dependent reduction of METH taking in both groups. Stopping SCH23390 caused re-emergence of compulsive METH taking in shock-resistant rats. Compulsive METH takers also exhibited greater incubation of METH seeking than non-compulsive rats during withdrawal from METH SA. Analyses of DA metabolism revealed non-significant decreases (about 35%) in DA levels in resistant and sensitive rats. However, striatal contents of the deaminated metabolites, DOPAL and DOPAC, were significantly increased in sensitive rats. VMAT2 and DAT protein levels were decreased in both phenotypes. Moreover, protein expression levels of the D1-like DA receptor, D5R, and D2-like DA receptors, D3R and D4R, were significantly decreased in the compulsive METH takers. Our results parallel findings in post-mortem striatal tissues of human METH users who develop Parkinsonism after long-term METH intake and support the use of this model to investigate potential therapeutic interventions for METH use disorder.

Association between white matter microstructure and cognitive function in patients with methamphetamine use disorder

Methamphetamine use disorder (MUD) has been associated with broad neurocognitive impairments. While the cognitive impairments of MUD have been demonstrated, the neuropathological underpinnings remain inadequately understood. To date, the published human diffusion tensor imaging (DTI) studies involving the correlation between diffusion parameters and neurocognitive function in MUD are limited. Hence, the present study aimed to examine the association between cognitive performance and white matter microstructure in patients with MUD. Forty-five patients with MUD and 43 healthy controls (HCs) completed their demographic information collection, cognitive assessments, and DTI imaging. DTI images were preprocessed to extract fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of various fiber tracts. Univariate tests were used to examine group differences in cognitive assessments and DTI metrics. Linear regression was used to examine the relationship between these two metrics. The results revealed that patients with MUD had lower subset scores of the MATRICS Consensus Cognitive Battery (MCCB), which reflects five cognitive domains: processing speed, attention, verbal learning, visual learning, problem-solving. Patients with MUD also had significantly higher AD, MD, and RD values of the left superior longitudinal fasciculus than HCs. Furthermore, the RD value of the left superior longitudinal fasciculus was a significant predictor of processing speed and problem-solving ability, as shown by the digit-symbol coding test and NAB-Mazes scores, respectively. Findings extended our understanding of white matter microstructure that is related to neurocognitive deficits in MUD and provided potential targets for the prevention and treatment of this chronic disorder.

The effects of acute oral naltrexone pretreatment on the abuse potential of intranasal methamphetamine, and the relationship between reward/punishment sensitivity and methamphetamine's effects

One potential medication for treating methamphetamine use disorder is the opioid antagonist naltrexone (NLTX). Despite encouraging preclinical findings, the results of clinical studies have been mixed. The primary aim of the current trial was to examine the effects of acute NLTX pretreatment on the subjective and reinforcing effects of intranasal methamphetamine. Nonmedical psychostimulant users completed outpatient testing sessions in which they received oral placebo (0 mg) or NLTX (50 mg) before intranasal methamphetamine (30 mg/70 kg). Primary outcome measures were peak positive subjective effects (e.g. drug 'Liking') assessed on a visual analog scale (0-100), and methamphetamine self-administration using an operant self-administration task. Participants also completed a probabilistic categorization task to assess reward and punishment learning sensitivity. Complete data were available from 13 male and 1 transgender (male-to-female) participant (age: 33.4 ± 7.6 years). Intranasal methamphetamine significantly increased subjective ratings of drug 'Liking', 'Good Effect' and 'High' from baseline (P's < 0.01), but did not significantly vary as a function of placebo or NLTX pretreatment. Similarly, methamphetamine self-administration did not vary between the placebo and NLTX pretreatment conditions. This sample did not demonstrate a significant 'bias' in learning from positive and negative outcomes (i.e. reward and punishment sensitivity), and reward/punishment sensitivity was not correlated with the effects of methamphetamine or the effects of NLTX on methamphetamine. The current study argues against the use of NLTX as a stand-alone medication for treating methamphetamine use disorder.

Brain morphometric abnormalities and their associations with affective symptoms in males with methamphetamine use disorder during abstinence

BACKGROUND

Methamphetamine (METH) use induces neurotoxic effects in brain structures and affective symptoms that persist during abstinence. However, the brain morphometry of individuals with METH use disorder (MUD) remains unclear, as well as their associations with affective symptoms during abstinence.

METHODS

Forty-eight abstinent males with MUD and 66 age-, sex-, and education-matched healthy controls (HCs) underwent high-resolution T1-weighted magnetic resonance imaging. Cortical thickness, surface area, volume, local gyrification index (LGI), and subcortical volume were obtained with FreeSurfer software. Brain morphometry differences between groups and their associations with affective symptoms and drug abuse history within the males with MUD were examined, with intracranial volume, age, and years of education as covariates.

RESULTS

Compared with the HCs, the individuals with MUD showed a significantly higher LGI in the right cuneus gyrus, left lingual gyrus, bilateral supramarginal gyrus, right inferior parietal gyrus (IPG), and right dorsal anterior cingulate cortex (clusterwise p < 0.05, Monte Carlo-corrected), as well as a smaller volume of the left nucleus accumbens (NAcc) (p < 0.05, FDR-corrected). However, there were no significant group differences in cortical thickness, area or volume. In addition, the LGI in the right IPG was positively associatedwith the severity of depression and anxiety symptoms in MUDs (p < 0.05, FDR-corrected).

CONCLUSION

Brain morphometric abnormalities in abstinent males with MUD were characterized by hypergyrification across multiple mid-posterior brain regions anda smaller volume of the left NAcc.Gyrification of the right IPG may be a potential neural substrate underlying the affective symptoms experienced by MUDs during abstinence.

Correlates of Aggression in Men With Methamphetamine Use Disorder: Childhood Trauma and Methamphetamine-Use Characteristics

BACKGROUND

Aggression is common among individuals with methamphetamine use disorder (MAUD) and constitutes a serious public health issue. The current study aimed to examine associations of methamphetamine-use characteristics and childhood trauma with aggression in men with MAUD.

METHODS

This cross-sectional study was conducted from December 2017 to August 2018. MAUD patients recruited from a compulsory drug rehabilitation center (n = 360) and healthy comparison subjects (n = 604) completed a survey that measured aggression and childhood trauma, using the Chinese version of Buss-Perry Aggressive Questionnaire (AQ-CV), and the short form of Childhood Trauma Questionnaire (CTQ-SF), respectively. MAUD patients also provided information on methamphetamine-use characteristics such as the age of MAUD onset, MAUD severity, and co-occurring alcohol use disorder (AUD) and tobacco use disorder (TUD) using standard or self-designed questionnaires. Chi-square tests and t-tests were used to compare childhood trauma and aggression between the MAUD and comparison groups. Multiple linear regressions were conducted to determine correlates of overall aggression and its five sub-scales among the MAUD group.

RESULTS

The MAUD group had higher childhood trauma and aggression scores than the comparison group. Within the MAUD group, age of MAUD onset, having severe MAUD, co-occurring AUD, co-occurring TUD, and childhood trauma were associated with overall aggression, with slightly different correlates found for its five sub-scales.

CONCLUSIONS

Our study shows a high level of childhood trauma and aggression in the MAUD group. Both methamphetamine-use characteristics (age of MAUD onset, severe MAUD, co-occurring AUD/TUD) and childhood trauma were associated with aggression in MAUD. Our findings provide useful information on potential risk factors for aggression and inform future longitudinal research to establish causal relationships between these factors and aggression to guide further prevention and treatment programs.

Intermittent Theta Burst Stimulation vs. High-Frequency Repetitive Transcranial Magnetic Stimulation in the Treatment of Methamphetamine Patients

BACKGROUND AND AIMS

In this brief report, we compare the effectiveness and safety of intermittent theta burst stimulation (iTBS) and conventional 10 Hz repetitive transcranial magnetic stimulation (rTMS) in patients with methamphetamine use disorder (MAUD). Our study suggests that iTBS would also reduce drug craving in patients with MAUD just as the 10 Hz; thus, there may be no difference in treatment effects between these two methods.

METHODS

In total twenty male methamphetamine (MA) addicts were randomly assigned to iTBS (n = 10) or 10 Hz (n = 10) groups for 12 treatments. Cue-evoked cravings, anxiety, depression, and withdrawal symptoms were measured at baseline before the first treatment, and post-tests after days 10, 15, and 20.

RESULTS

The results showed that iTBS and 10 Hz treatment had similar effectiveness in reducing cue-induced craving in male addicts for MA. Both 10 Hz and iTBS improved withdrawal symptoms of patients with MAUD.

CONCLUSIONS

Intermittent theta burst stimulation may be similar in effectiveness as 10 Hz in treating patients with MAUD. The clinical usefulness of rTMS could be improved substantially because of the increase in its capacity, cost, and accessibility. Importantly, the effectiveness of rTMS in the treatment of patients with MAUD is not yet proven, and should be tested in the large double-blind sham-controlled studies.

Associations of executive function and age of first use of methamphetamine with methamphetamine relapse

BACKGROUND AND AIMS

Methamphetamine (MA) is a psychostimulant associated with a high relapse rate among patients with MA use disorder (MUD). Long-term use of MA is associated with mental disorders, executive dysfunction, aggressive behaviors, and impulsivity among patients with MUD. However, identifying which factors may be more closely associated with relapse has not been investigated. Thus, we aimed to investigate the psychological factors and the history of MA use that may influence MA relapse.

METHODS

This cross-sectional study included 168 male MUD patients (MUD group) and 65 healthy male residents (control group). Each patient was evaluated with self-report measures of executive dysfunction, psychopathological symptoms, impulsiveness, aggressiveness, and history of MA use. Data were analyzed with t-tests, analyses of variance, and correlation and regression analyses.

RESULTS

The MUD group reported greater executive dysfunction, psychopathological symptoms, impulsivity, and aggression than the control group. Lower age of first MA use was associated both with having relapsed one or more times and with having relapsed two or more times; greater executive dysfunction was associated only with having relapsed two or more times.

CONCLUSION

Patients with MUD reported worse executive function and mental health. Current results also suggest that lower age of first MA use may influence relapse rate in general, while executive dysfunction may influence repeated relapse in particular. The present results add to the literature concerning factors that may increase the risk of relapse in individuals with MUD.

Housing Correlates in Pregnant and Parenting Women Using Methamphetamine and Accessing Psychiatric Care

BACKGROUND

Integrated care is a promising model for pregnant and parenting women with problems related to methamphetamine use. Yet more research is imperative to guide services for this vulnerable population as methamphetamine use contributes to housing instability, which is associated with heavier use and overdose death.

METHOD

This prospective observational study analyzed how housing at discharge from psychiatric care was related to patient characteristics, program participation, and aftercare in 102 pregnant and/or parenting women.

RESULTS

Twelve of 23 women who were unstably housed at admission (three of six homeless) achieved stable housing by discharge from integrated care. Women were more likely unstably housed at discharge when unstably housed at admission, single, living apart from at least one minor, or when the other parent had a substance use disorder (p < 0.05). Unstably housed women at discharge were also more likely to have used social and inpatient services, and to transition to inpatient rehabilitation (p < 0.05). Among baseline characteristics, logistic regression identified unstable housing at admission (OR = 6.07) and being single (OR = 4.01) as the strongest unique contributors to unstable housing at discharge (p < 0.05).

CONCLUSION

Unstably housed women and single women seem particularly at risk of remaining in precarious living conditions despite accessing integrated care for problems associated with methamphetamine use. Future work should investigate whether stronger partnerships with government and community agencies could be a way forward to help these women attain and maintain stable housing.

Altered Fecal Microbiota Correlated With Systemic Inflammation in Male Subjects With Methamphetamine Use Disorder

Methamphetamine use disorder (MUD) is a major public health problem worldwide with limited effective treatment options. Previous studies have reported methamphetamine-associated alterations in gut microbiota. A potential role of gut microbiota in regulating methamphetamine-induced brain dysfunction through interactions with the host immune system has been proposed, but evidence for this hypothesis is limited. The present study aimed to investigate the alterations in the fecal microbiota and explore its relationship with systemic inflammation in MUD. Fecal samples were obtained from 26 male subjects with MUD and 17 sex- and age- matched healthy controls. Fecal microbial profiles were analyzed by 16S rRNA sequencing. Plasma inflammatory markers were measured using enzyme-linked immunosorbent assay. Associations between fecal microbiota, systemic inflammatory markers and clinical characteristics were examined by Spearman partial correlation analysis while controlling for possible confounders. Compared with healthy controls, individuals with MUD showed no difference in fecal microbial diversity, but exhibited differences in the relative abundance of several microbial taxa. At the genus level, a higher abundance of Collinsella, Odoribacter and Megasphaera and lower levels of Faecalibacterium, Blautia, Dorea and Streptococcus were detected in subjects with MUD. More importantly, altered fecal microbiota was found to be correlated with plasma levels of CRP, IL-2, IL-6 and IL-10. The order Lactobacillales, exhibiting lower abundance in participants with MUD, was positively related to the duration of methamphetamine abstinence and the plasma level of anti-inflammatory cytokine IL-10. This study is the first to provide evidence for a link between altered fecal microbiota and systemic inflammation in MUD. Further elucidation of interactions between gut microbiota and the host immune system may be beneficial for the development of novel therapeutic approaches for MUD.

Examination of optical coherence tomography findings in patients with methamphetamine use disorder

OBJECTIVE

In our study, we aimed to examine Optical Coherence Tomography (OCT) findings in patients diagnosed with methamphetamine use disorder (MUD) by comparing them with healthy controls.

METHODS

Sixty-five people were included in our study and 130 eyes were evaluated; 33 cases were included in the patient group with MUD according to DSM-5 diagnostic criteria and 32 as the healthy control group. Detailed biomicroscopic examinations and then both eyes were evaluated through OCT by the same ophthalmologist.

RESULTS

There was no statistically significant difference between the patient and control groups in terms of gender and age (p > 0.05). When the OCT findings were evaluated, the measurements of the patients in any quadrant for retinal nerve fiber layer (RNFL) were not statistically different from the control group (p > 0.05). Macula and choroidal layer thickness did not differ between the groups (p > 0.05). Only right intraocular pressure was found to be decreased in the patient group (p = 0.026).

CONCLUSIONS

There are a limited number of studies examining OCT findings in patients with MUD. Visual symptoms and intraocular pressure should be considered when evaluating patients with MUD and planning their treatment. In addition; in order for OCT findings to gain importance, which can be used as an effective method to show the possible neurodegeneration that may occur in substance use disorder, it should be supported with further research.

Are methamphetamine users compulsive? Faulty reinforcement learning, not inflexibility, underlies decision making in people with methamphetamine use disorder

Methamphetamine use disorder involves continued use of the drug despite negative consequences. Such 'compulsivity' can be measured by reversal learning tasks, which involve participants learning action-outcome task contingencies (acquisition-contingency) and then updating their behaviour when the contingencies change (reversal). Using these paradigms, animal models suggest that people with methamphetamine use disorder (PwMUD) may struggle to avoid repeating actions that were previously rewarded but are now punished (inflexibility). However, difficulties in learning task contingencies (reinforcement learning) may offer an alternative explanation, with meaningful treatment implications. We aimed to disentangle inflexibility and reinforcement learning deficits in 35 PwMUD and 32 controls with similar sociodemographic characteristics, using novel trial-by-trial analyses on a probabilistic reversal learning task. Inflexibility was defined as (a) weaker reversal phase performance, compared with the acquisition-contingency phases, and (b) persistence with the same choice despite repeated punishments. Conversely, reinforcement learning deficits were defined as (a) poor performance across both acquisition-contingency and reversal phases and (b) inconsistent postfeedback behaviour (i.e., switching after reward). Compared with controls, PwMUD exhibited weaker learning (odds ratio [OR] = 0.69, 95% confidence interval [CI] [0.63-0.77], p < .001), though no greater accuracy reduction during reversal. Furthermore, PwMUD were more likely to switch responses after one reward/punishment (OR = 0.83, 95% CI [0.77-0.89], p < .001; OR = 0.82, 95% CI [0.72-0.93], p = .002) but just as likely to switch after repeated punishments (OR = 1.03, 95% CI [0.73-1.45], p = .853). These results indicate that PwMUD's reversal learning deficits are driven by weaker reinforcement learning, not inflexibility.

Microglia imaging in methamphetamine use disorder: a positron emission tomography study with the 18 kDa translocator protein radioligand [F-18]FEPPA

Activation of brain microglial cells, microgliosis, has been linked to methamphetamine (MA)-seeking behavior, suggesting that microglia could be a new therapeutic target for MA use disorder. Animal data show marked brain microglial activation following acute high-dose MA, but microglial status in human MA users is uncertain, with one positron emission tomography (PET) investigation reporting massively and globally increased translocator protein 18 kDa (TSPO; [C-11](R)-PK11195) binding, a biomarker for microgliosis, in MA users. Our aim was to measure binding of a second-generation TSPO radioligand, [F-18]FEPPA, in brain of human chronic MA users. Regional total volume of distribution (V_T ) of [F-18]FEPPA was estimated with a two-tissue compartment model with arterial plasma input function for 10 regions of interest in 11 actively using MA users and 26 controls. A RM-ANOVA corrected for TSPO rs6971 polymorphism was employed to test significance. There was no main effect of group on [F-18]FEPPA V_T (P = .81). No significant correlations between [F-18]FEPPA V_T and MA use duration, weekly dosage, blood MA concentrations, regional brain volumes, and self-reported craving were observed. Our preliminary findings, consistent with our earlier postmortem data, do not suggest substantial brain microgliosis in MA use disorder but do not rule out microglia as a therapeutic target in MA addiction. Absence of increased [F-18]FEPPA TSPO binding might be related to insufficient MA dose or blunting of microglial response following repeated MA exposure, as suggested by some animal data.

Integrated Care for Pregnant Women and Parents With Methamphetamine-Related Mental Disorders

Background: Methamphetamine use is a rapidly increasing cause of morbidity and mortality. Pregnant women and new parents who consume methamphetamine are at high risk since they seldom seek health services despite having multiple needs. We addressed this care gap by implementing an easily accessible program that pools resources from psychiatric, obstetric, and pediatric departments as well as community and government agencies. Method: This real-life observational study evaluated an integrated care program in 27 expecting parents and 57 parents of minors. The outcome criteria were treatment retention, psychosocial functioning, and abstinence. We compared participant demographics according to outcome and applied ordinal logistic regression to predict treatment success. Results: Patients received integrated care for almost 7 months on average. Nearly half achieved stable abstinence and functional recovery. Only one pregnant woman dropped out before a care plan could be implemented, and all women who gave birth during treatment completed it successfully. Three-fourths of patients had psychiatric comorbidities. Patients with depressive disorders were almost 5 times less likely to succeed with treatment. Attention-deficit hyperactivity disorder (ADHD) was diagnosed in nearly 30% of patients who dropped out of a care plan, which was about 4 times more often than in the successful outcome group. Conclusion: Our program engaged pregnant women and parents in treatment and helped them recover from methamphetamine-related mental disorders. Management of comorbid ADHD and depression should be an integral part of care initiatives to counter the methamphetamine crisis that affects parents and children across the globe.

Features of Psychotic Symptoms in Methamphetamine Use Disorder Patients and Ketamine Use Disorder Patients: A Cross-Sectional Study

BACKGROUND

Methamphetamine and ketamine are commonly used club drugs. Both of them have been reported to mimic psychotic symptoms of schizophrenia. However, the prevalence and detailed features of psychotic symptoms among methamphetamine use disorder (MUD) and ketamine use disorder (KUD) patients are largely unknown. This study aimed to measure psychotic symptoms among patients with MUD and KUD.

METHODS

A total sample of 842 patients from voluntary drug rehabilitation centers, including 462 MUD patients and 380 KUD patients, were invited to this study. The Positive and Negative Syndrome Scale (PANSS) was applied to assess psychotic symptoms in these two groups of patients.

RESULTS

The prevalence of psychotic symptoms was significantly higher among MUD patients than KUD patients (75.1 vs. 50.5%, 95% CI: 3.532 - 11.858, p < 0.001). Compared with KUD patients, MUD patients were more likely to experience positive symptoms (PANSS positive scores: 11.5 ± 6.07 vs. 15.1 ± 8.22, P < 0.001) and negative symptoms (PANSS negative scores: 12.4 ± 6.60 vs. 14.5 ± 8.63, P < 0.001), but not general symptoms (PANSS general scores: 31.2 ± 13.90 vs. 32.2 ± 15.13, P < 0.001).

CONCLUSIONS

The current study found that more than half of MUD and KUD patients experienced psychotic symptoms, and that patients with MUD are more likely to experience positive and negative symptoms than patients with KUD. The findings provide a new perspective for exploring the neuropathological mechanism of psychotic symptoms of schizophrenia.

A Scoping Review on Cue Reactivity in Methamphetamine Use Disorder

The experience of craving via exposure to drug-related cues often leads to relapse in drug users. This study consolidated existing empirical evidences of cue reactivity to methamphetamine to provide an overview of current literature and to inform the directions for future research. The best practice methodological framework for conducting scoping review by Arkey and O'Malley was adopted. Studies that have used a cue paradigm or reported on cue reactivity in persons with a history of methamphetamine use were included. Databases such as Medline, EMBASE, PsycINFO and CINAHL were searched using key terms, in addition to citation check and hand search. The search resulted in a total of 32 original research articles published between 2006 to 2020. Three main themes with regard to cue reactivity were identified and synthesized: (1) effects of cue exposure, (2) individual factors associated with cue reactivity, and (3) strategies that modulate craving or reactivity to cues. Exposure to methamphetamine-associated cues elicits significant craving and other autonomic reactivity. Evidence suggests that drug cue reactivity is strongly associated with indices of drug use and other individual-specific factors. Future studies should focus on high quality studies to support evidence-based interventions for reducing cue reactivity and to examine cue reactivity as an outcome measure.

rTMS-Induced Changes in Glutamatergic and Dopaminergic Systems: Relevance to Cocaine and Methamphetamine Use Disorders

Cocaine use disorder and methamphetamine use disorder are chronic, relapsing disorders with no US Food and Drug Administration-approved interventions. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation tool that has been increasingly investigated as a possible therapeutic intervention for substance use disorders. rTMS may have the ability to induce beneficial neuroplasticity in abnormal circuits and networks in individuals with addiction. The aim of this review is to highlight the rationale and potential for rTMS to treat cocaine and methamphetamine dependence: we synthesize the outcomes of studies in healthy humans and animal models to identify and understand the neurobiological mechanisms of rTMS that seem most involved in addiction, focusing on the dopaminergic and glutamatergic systems. rTMS-induced changes to neurotransmitter systems include alterations to striatal dopamine release and metabolite levels, as well as to glutamate transporter and receptor expression, which may be relevant for ameliorating the aberrant plasticity observed in individuals with substance use disorders. We also discuss the clinical studies that have used rTMS in humans with cocaine and methamphetamine use disorders. Many such studies suggest changes in network connectivity following acute rTMS, which may underpin reduced craving following chronic rTMS. We suggest several possible future directions for research relating to the therapeutic potential of rTMS in addiction that would help fill current gaps in the literature. Such research would apply rTMS to animal models of addiction, developing a translational pipeline that would guide evidence-based rTMS treatment of cocaine and methamphetamine use disorder.

Social Incentives Anticipation and Consummation: Investigating Neural Activity in Women Using Methamphetamine

Individuals with methamphetamine use disorder are considered to have enhanced reactivity to rewards or drug cues. However, whether this holds true in the social incentives processing is still unclear. The current study investigated the electroencephalographical (EEG) evidence of social incentives processing in women with methamphetamine use disorder (MA group, n = 19) and in a healthy control group (HC group, n = 20) using social incentive delay (SID) tasks. In the SID, participants received a "Like" (e.g., thumbs up) or "Unlike" (e.g., thumbs down) from WeChat emojis as social incentives, or neutral feedback. During the anticipation stage, the Cue-P3 and stimulus-preceding negativity (SPN) were larger for the social incentives condition than for the neutral condition. During the consummation stage, the feedback-related negativity (FRN) was marginally significantly larger in the HC group than the MA group for the social incentive condition, whereas there was no significant difference between the groups for neutral condition. Interestingly, the FB-P3 was larger for social positive feedback than for social negative feedback in the MA group, but not in HC group. Furthermore, only the HC group showed significant positive correlation between the anticipatory event-related brain potential (ERP, such as Cue-P3) and the consummatory ERP (FB-P3) in the social incentive condition. The findings suggest that women with MA use disorder have a blunted neural response to the processing of social incentives and a blunted neural response to negative social feedback, which helps to elucidate the neural mechanisms of social incentives processing in individuals with MA use disorder.

Decision-Making by Patients With Methamphetamine Use Disorder Receiving Contingency Management Treatment: Magnitude and Frequency Effects

BACKGROUND

Individuals with substance use disorders exhibit maladaptive decision-making on the Iowa Gambling Task (IGT), which involves selecting from card decks differing in the magnitudes of rewards, and the frequency and magnitude of losses. We investigated whether baseline IGT performance could predict responses to contingency management (CM) by treatment-seeking individuals with methamphetamine use disorder (MA Use Disorder) in Cape Town, South Africa.

METHODS

Twenty-nine individuals with MA Use Disorder underwent an 8-week, escalating reinforcement, voucher-based CM treatment in a study on the suitability of CM therapy for the South African context. Along with 20 healthy control participants, they performed a computerized version of the IGT before starting CM treatment. Seventeen participants maintained abstinence from methamphetamine throughout the trial (full responders), and 12 had an incomplete response (partial responders). Performance on the IGT was scored for magnitude effect (selection of large immediate rewards with high long-term loss) and for frequency effect (preference for frequent rewards and avoidance of frequent losses). Group differences were investigated using linear mixed-effect modeling.

RESULTS

Partial responders made more selections from decks providing large, immediate rewards and long-term losses than healthy controls [p = 0.038, g = -0.77 (-1.09: -0.44)]. Full responders showed a greater, nonsignificant preference for frequent rewards and aversion to frequent losses than partial responders [p = 0.054, g = -0.63 (-0.95: -0.29)].

CONCLUSIONS

A predilection for choices based on the size and immediacy of reward may reflect a cognitive strategy that works against CM. Pretesting with a decision-making task, such as the IGT, may help in matching cognitive therapies to clients with MA Use Disorder.

Contingency management treatment for methamphetamine use disorder in South Africa

INTRODUCTION AND AIMS

As South Africa, especially the Western Cape Province, faces an epidemic of methamphetamine use disorder, therapeutic approaches suited to the South African context are needed. This secondary analysis assessed retention and methamphetamine abstinence outcomes in response to an 8-week pilot contingency management (CM) intervention trial of neural correlates of methamphetamine abstinence, exploring sociodemographic and clinical differences between responders and non-responders.

DESIGN AND METHODS

Research participants provided thrice-weekly monitored urine samples, which were analysed by qualitative radioimmunoassay. The primary outcome for this analysis was therapeutic response, defined as abstinence from methamphetamine (≥23 of 24 possible methamphetamine-negative urine samples).

RESULTS

Data from 30 adults living in Cape Town, South Africa (34 ± 6.1 years of age, mean age ± SD, 21 men) were included. Sixty-three percent (12 men) were responders. In bivariate comparisons, baseline measurements showed fewer responders reported monthly household income ≥25 000+ South African Rand (ZAR; ~USD $1880; vs. ZAR < 25 000) than non-responders (15.8% vs. 63.6%; P = 0.007). Furthermore, responders had higher median years of education (12 vs. 10; Kruskal-Wallis χ² = 4.25, DF = 1, P = 0.039) and lower median body mass index than non-responders (19 vs. 24; Kruskal-Wallis χ² = 6.84, P = 0.008).

DISCUSSION AND CONCLUSIONS

Therapeutic response in this study were comparable to those obtained with CM for methamphetamine use disorder in North America and Europe. Our findings suggest that CM may be a useful component of treatment strategies to boost retention and continuous abstinence from methamphetamine in Cape Town, South Africa. Larger efficacy studies are needed in this setting.

Cognition and Related Neural Findings on Methamphetamine Use Disorder: Insights and Treatment Implications From Schizophrenia Research

Despite the prevalence of methamphetamine (meth) use disorder, research on meth is disproportionately scarce compared to research on other illicit drugs. Existing evidence highlights cognitive deficits as an impediment against daily function and treatment of chronic meth use. Similar deficits are also observed in schizophrenia, and this review therefore draws on schizophrenia research by examining similarities and differences between the two disorders on cognition and related neural findings. While meth use disorder and schizophrenia are two distinct disorders, they are highly co-morbid and share impairments in similar cognitive domains and altered brain structure/function. This narrative review specifically identifies overlapping features such as deficits in learning and memory, social cognition, working memory and inhibitory/impulse control. We report that while working memory deficits are a core feature of schizophrenia, such deficits are inconsistently observed following chronic meth use. Similar structural and functional abnormalities are also observed in cortical and limbic regions between the two disorders, except for cingulate activity where differences are observed. There is growing evidence that targeting cognitive symptoms may improve functional outcome in schizophrenia, with evidence of normalized abnormal brain activity in regions associated with cognition. Considering the overlap between meth use disorder and schizophrenia, targeting cognitive symptoms in people with meth use disorder may also improve treatment outcome and daily function.

Effectiveness of music therapy on improving treatment motivation and emotion in female patients with methamphetamine use disorder: A randomized controlled trial

OBJECTIVES

The purpose of the study was to investigate whether Group Music Therapy (GMT) could enhance the treatment motivation and change the negative emotion among female patients with methamphetamine use disorder in a randomized clinical trial. Methods: Participants (N = 60) were randomized to the group of GMT combined with treatment as usual (TAU) or the group with TAU only. Questionnaire of Motivation for Abstaining from Drugs was used to measure the motivation for abstaining from drugs of the female patients. And Self-Rating Depression Scale and Self-Rating Anxiety Scale were used to measure negative emotion of participants. The measurements were conducted at T0 (baseline), T1 (post 13 sessions of intervention) and T2 (3-month follow-up after T1) by the independent trained researcher. Results: The postintervention and 3-month follow-up results according to the intention-to-treat principle indicated that GMT + TAU intervention showed significantly positive group-by-time effect on the scores of the subscale-tending to rehabilitation-internal motivation (p = 0.01) and avoiding abuse-external motivation (p = 0.04). In 3-month follow-up, total scores of the questionnaire of motivation for abstaining from drugs (p = 0.02), scores of avoiding abuse-internal motivation subscale (p = 0.05), and scores of confidence of abstaining from drugs subscale (p = 0.01) in GMT + TAU were also presented with significantly positive group x time effect. The changes of total score of Questionnaire of Motivation for Abstaining from Drugs (from baseline to 3-month follow-up) was significantly positive association with the changes of scores of SAS in GMT + TAU group (r = -0.55, p = 0.00). Conclusions: The present study suggests that GMT could be used as an effective treatment strategy to enhance treatment motivation of female patients with methamphetamine use disorder.

Working memory predicts methamphetamine hair concentration over the course of treatment: moderating effect of impulsivity and implications for dual-systems model

High impulsivity and poor executive function are characteristic of methamphetamine use disorder. High arousal in the impulsive system has been proposed to compromise the executive system's regulating ability (i.e. the dual-systems model). While interaction between these variables may partly explain poor treatment outcomes associated with methamphetamine use disorder, previous research has tended to examine each factor separately. We investigated whether high impulsivity (measured with an impulsive choice task) and poor executive function (measured with a working memory task) predict methamphetamine use (determined by hair sample) in the 6 weeks following treatment commencement. We also investigated whether impulsive choice moderates the relationship between working memory and methamphetamine use. One hundred and eight individuals with methamphetamine use disorder (75 percent male) were tested within 3 weeks of commencing treatment; 80 (74 percent) were followed up 6 weeks following baseline testing. Cognitive measures significantly predicted drug use after controlling for nuisance variables. Working memory was a significant predictor, while impulsive choice was not. The interaction model included working memory as a predictor and impulsive choice as a moderator. This model was significant, as was the interaction term. Working memory significantly predicted levels of methamphetamine use in early treatment, and impulsive choice moderated this relationship. Those with working memory deficits are particularly vulnerable to using greater amounts of methamphetamine. As working memory increased methamphetamine use decreased among individuals with low/medium delay discounting. Pre-treatment cognitive testing may identify patients at high risk, while remediation of working memory function may be a treatment target for reducing methamphetamine use.

A Newly Designed Mobile-Based Computerized Cognitive Addiction Therapy App for the Improvement of Cognition Impairments and Risk Decision Making in Methamphetamine Use Disorder: Randomized Controlled Trial

Background

Cognitive rehabilitation therapy has been found to improve cognitive deficits and impulse control problems in methamphetamine use disorder (MUD). However, there is limited research regarding this therapy’s feasibility when using mobile-based health technologies in supporting recovery from MUD in China.

Objective

The main aim of this study was to test whether 4 weeks of a newly designed computerized cognitive addiction therapy (CCAT) app can improve cognitive impairments, eliminate drug-related attention bias, and attenuate risk decision-making behaviors in participants with MUD.

Methods

Forty MUD participants were assigned randomly to either the CCAT group (n=20), who received 4 weeks of CCAT plus regular detoxification treatment as usual, or the control group (n=20), who only received the regular detoxification treatment as usual, in drug rehabilitation centers in Shanghai. The CCAT was designed by combine methamphetamine use-related picture stimuli with cognitive training with the aim of improving cognitive function and eliminating drug-related attention bias. The CogState Battery, Delay Discounting Task (DDT), Iowa Gambling Task (IGT), and Balloon Analog Risk Task (BART) were administered face-to-face to all participants before and after CCAT interventions.

Results

Forty male patients were recruited. The mean age was 32.70 (SD 5.27) years in the CCAT group and mean 35.05 (SD 8.02) years in the control group. Compared to the control group, CCAT improved working memory in the CCAT group (P=.01). Group×time interactions were observed among DDT, IGT, and BART tasks, with rates of discounting delayed rewards, IGT, and BART scores (P<.001) being reduced among those who received CCAT, whereas no changes were found in the control group.

Conclusions

The newly designed CCAT can help to improve cognitive impairment and impulsive control in MUD. Further study is needed to understand the underlying brain mechanisms of the cognitive therapy.

Trial Registration

ClinicalTrials.gov NCT03318081; https://clinicaltrials.gov/ct2/show/NCT03318081 (Archived by WebCite at https://clinicaltrials.gov/ct2/show/NCT03318081)

Decision-making processes as predictors of relapse and subsequent use in stimulant-dependent patients

BACKGROUND

Decision-making processes have been posited to affect treatment outcome in addicted patients.

OBJECTIVE

The present multi-site study assessed whether two measures of decision-making predicted relapse and subsequent use in stimulant-dependent patients.

METHODS

A total of 160 methamphetamine- or cocaine-dependent patients participating in a multi-site clinical trial evaluating a modified 12-step facilitation intervention for stimulant-dependent patients (STAGE-12) were assessed. Decision-making processes of risk and delay (Iowa Gambling Task [IGT]) and response reversal (Wisconsin Card Sorting Task [WCST]) were obtained shortly after treatment admission followed by assessment of stimulant use over the next six months. The relationships of the IGT and WCST (Perseverative Errors) with relapse (yes/no) and days of stimulant use during the 6-month period following post-randomization were evaluated.

RESULTS

Performance on the IGT and WCST did not significantly predict relapse status or time to relapse. Unexpectedly, worse performance on the IGT was associated with a fewer number of stimulant use days (p = 0.001). In contrast, worse performance on the WCST (more perseverative errors) was associated with a greater number of stimulant use days (p = 0.0003). The predictive effects of perseverative errors on subsequent use were confined to methamphetamine-dependent and Minority participants.

CONCLUSIONS

Decision-making processes, as measured in the current study, do not uniformly predict relapse or subsequent use. A decrease in the salience attribution of non-drug reinforcers may explain the positive relationship between IGT performance and post-relapse use. More comprehensive and global measures of impulsiveness may better assess relapse risk and use.

A review of treatment options for co-occurring methamphetamine use disorders and depression

Co-occurring methamphetamine use and depression interferes with treatment outcomes. Female methamphetamine users are known to have higher rates of depression than male methamphetamine users, although this is also true for the general population. There are limited treatment options for the management of depression among methamphetamine users. In this integrative review, we summarize data on treatment strategies for co-occurring depression and methamphetamine use disorders. English-language articles were identified from PsychINFO, CINAHL, PubMed, and Medline as well as from reference lists of key articles. Search terms included "methamphetamine," "depression," and "treatment." Research articles describing psychological (n = 3), pharmacological (n = 6), nutritional supplement (n = 1), and psychological combined with pharmacological (n = 3) approaches for the treatment of methamphetamine use or withdrawal and/or depression are included in this review. Psychological and combination of psychological with pharmacological approaches have not been shown to be effective in treating these co-occurring conditions. Antidepressants have been determined to be ineffective and/or to introduce side effects. Gender differences with response to treatment were examined in only one of the published studies. There is a large gap in knowledge regarding treatment of co-occurring methamphetamine use disorders and depression. Considering that female methamphetamine users experience higher rates of depression than men, a focus on gender-specific treatment approaches is warranted.