The experience of methamphetamine use disorder and the negative consequences of relapse - a qualitative study

BACKGROUND

The rate of relapse for people in recovery for substance use disorder is as high as 85% within the first 12 months of recovery, however, research on the lived experience of relapse is limited.

OBJECTIVE

The present qualitative study investigated the experience of relapse with people who have Methamphetamine use disorder and the reasons why they returned to recovery.

METHODS

The exploratory study recruited five (n = 5) adults who identified as having Methamphetamine use disorder. All participants had sought treatment for more than 12 months, they were attending an addiction support service, and had experienced a relapse within the past 15 months. Interviews were conducted in which participants were asked an open-ended question about their most recent relapse and the negative consequences associated with their drug use. Data were analyzed using thematic analysis.

RESULTS

A return to daily drug use led to negative consequences such as relationship breakdowns, poor mental health and acting in ways that went against the participant's morals and values. This study provides an insight into the types of experiences people who relapse after seeking treatment for Methamphetamine use disorder may have and how these experiences can influence their decision to return to recovery.

CONCLUSIONS

People who regularly attend a recovery program are still susceptible to relapse. Those who have maintained abstinence for a period of time prior to relapse may be able to assess the negative consequences of their drug use more easily. This prior experience of recovery might influence their decision to stop using again.

Dysfunctional feedback processing in male methamphetamine abusers: Evidence from neurophysiological and computational approaches

Methamphetamine use disorder (MUD) as a major public health risk is associated with dysfunctional neural feedback processing. Although dysfunctional feedback processing in people who are substance dependent has been explored in several behavioral, computational, and electrocortical studies, this mechanism in MUDs requires to be well understood. Furthermore, the current understanding of latent components of their behavior such as learning speed and exploration-exploitation dilemma is still limited. In addition, the association between the latent cognitive components and the related neural mechanisms also needs to be explored. Therefore, in this study, the underlying neurocognitive mechanisms of feedback processing of such impairment, and age/gender-matched healthy controls are evaluated within a probabilistic learning task with rewards and punishments. Mathematical modeling results based on the Q-learning paradigm suggested that MUDs show less sensitivity in distinguishing optimal options. Additionally, it may be worth noting that MUDs exhibited a slight decrease in their ability to learn from negative feedback compared to healthy controls. Also through the lens of underlying neural mechanisms, MUDs showed lower theta power at the medial-frontal areas while responding to negative feedback. However, other EEG measures of reinforcement learning including feedback-related negativity, parietal-P300, and activity flow from the medial frontal to lateral prefrontal regions, remained intact in MUDs. On the other hand, the elimination of the linkage between value sensitivity and medial-frontal theta activity in MUDs was observed. The observed dysfunction could be due to the adverse effects of methamphetamine on the cortico-striatal dopamine circuit, which is reflected in the anterior cingulate cortex activity as the most likely region responsible for efficient behavior adjustment. These findings could help us to pave the way toward tailored therapeutic approaches.

Professional stigma towards clients with methamphetamine use disorder - a qualitative study

Background

Methamphetamine use disorder (MUD) is associated with poor health outcomes. Pharmacists play a role in delivery of substance use treatment, with several studies having examined their attitudes to people with opioid use disorder, but little is known about their attitude towards people with MUD. This study aimed to explore pharmacists' perspectives on the provision of services to clients with MUD.

Methods

A convenience sampling strategy was used to recruit community pharmacists across Sydney, Australia. Semi structured interviews examined views and ideas of pharmacists surrounding the treatment and management of MUD, followed by coding of transcribed interview data by all members of the research team.

Results

Nineteen pharmacists completed the interviews. The main theme identified was stigma held by healthcare professionals. The almost unanimous perception amongst pharmacists was fear and apprehension towards people with MUD, including underlying assumptions of criminality, misinformation regarding people with MUD, and lack of education and knowledge surrounding MUD.

Conclusion

A substantial amount of stigma towards people with MUD was found in this study. Negative attitudes by healthcare professionals can perpetuate healthcare disparities and impede the accessibility of future treatment programs for people with MUD. Appropriate educational interventions on MUD for pharmacists are needed.

Methamphetamine use shortens telomere length in male adults and rats

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Applications of TMS in individuals with methamphetamine use disorder: A review

Methamphetamine abuse results in a host of social and medical issues. Methamphetamine use disorder (MUD) can hinder the brain and impair cognitive functions and mental health. Transcranial magnetic stimulation (TMS) is a non-invasive approach in the treatment of MUD. Recent studies have demonstrated encouraging and positive effects of TMS on the craving, affective symptoms, sleep quality, and cognitive functions in individuals with MUD. The regulation of specific brain activities through TMS has also been found to be a contributing factor to these positive outcomes. It is essential to employ more techniques, participants, and stimulation parameters and targets in the future.

GxE interaction effects of HCRTR2 single nucleotide polymorphism and adverse childhood experiences on methamphetamine use disorder

Background: Methamphetamine use disorder (MUD) is a worldwide health concern. The hypothalamic orexin system regulates stress response and addictive behaviors. The genetic variation in the hypocretin receptor 2 (HCRTR2), rs2653349, is associated with substance use disorder.Objectives: We explored the gene-environment (GxE) interaction of rs2653349 and adverse childhood experiences (ACEs) associated with MUD susceptibility.Methods: Four hundred and one individuals (336 males, 65 females) with MUD and 348 healthy controls (288 males, 60 females) completed a self-report questionnaire evaluating ACEs, encompassing childhood abuse and household dysfunction categories, and were genotyped for SNP rs2653349. Methamphetamine use variables were collected using the Diagnostic Interview for Genetic Studies. We used regression analyses to assess the GxE effect on MUD risk.Results: The MUD group had a comparable genotypic distribution for rs2653349 to the control group, albeit with a higher prevalence and number of types of ACEs, correlating with an increased MUD risk (p < .05). No significant genetic impact of rs2653349 on MUD risk was found. However, we observed a GxE interaction effect between the minor allele of rs2653349 and the number of childhood abuse or household dysfunction types, correlating with a reduced MUD risk (OR = -0.71, p = .04, Benjamini-Hochberg adjusted p = .08 and OR = -0.59, p = .045, Benjamini-Hochberg adjusted p = .09, respectively).Conclusion: HCRTR2 SNP rs2653349 has no significant impact on MUD risk, but ACEs may increase this risk. GxE results suggest that rs2653349 could offer protection against developing MUD in individuals experiencing multiple types of ACEs.

Effects of Positive versus Negative Framing on Stigma toward Individuals Recovering from Methamphetamine Use Disorder during Randomized Brief Video Exposure

Eighty-two Australians (mean age = 30.07; 61% female) were blindly randomized to view either a video edited to depict a positive or negative presentation of individuals in recovery from methamphetamine use disorder. Participants completed the Social Distance Scale for Substance Users, Dangerousness Scale for Substance Users and Affect Scale for Substance Users before and after video exposure. Following video exposure, those exposed to the positive video portrayal reported lower desire for social distance (p < .001), lower perceptions of dangerousness (p = .011), and more favorable affective reactions (p < .001). Participants' previous level of contact with the target group did not predict baseline stigma or moderate the experimental effect. Participants' qualitative responses to the experiment were assessed via content analysis and indicated mainly positive or ambivalent attitudes, unchanged by the video; however, 18% of those receiving the positive video reported attitudes becoming more sympathetic/favorable. Findings suggest that media depictions which include people with methamphetamine use disorder displaying friendliness and recovery narratives may improve community perceptions of people recovering from methamphetamine use disorder, and conversely, unsmiling portrayals focusing on harm done to others increases desire for social distance and perceived dangerousness.

Relationships Between Impulsivity, Methamphetamine use Disorder and Gambling Disorder

Methamphetamine use disorder (MAUD) and gambling disorder (GD) frequently co-occur. Individuals with both conditions are typically more difficult to treat than those with either disorder alone. This study aimed to investigate the co-occurrence and clinical characteristics of people with MAUD and GD. Between March 2018 and August 2020, 350 men with methamphetamine use entering a compulsory drug rehabilitation center in Changsha, Hunan Province received semi-structured interviews. Participants completed the Barratt Impulsiveness Scale-11 and provided information on childhood upbringings and drug use characteristics. Independent sample t-tests compared differences between individuals with MAUD and with and without co-occurring GD. Dichotomous logistic regression was used to statistically predict co-occurring GD. The prevalence of GD was 45.1%. Most individuals (39.1% overall) had post-onset methamphetamine use (PoMAU-GD). The number of MAUD symptoms, history of gambling by family members, age of first sexual activity, and non-planning impulsivity statistically predicted PoMAU-GD, jointly explaining 24.0% of the total variance. The regression model fit well (HLχ2 = 5.503, p = 0.70), in which the specificity was 0.80, the sensitivity was 0.64, and the area under the curve was 0.79 (95%CI: 0.75-0.84). This study clarifies the prevalence of and potential risk factors for GD among individuals engaging in compulsory MAUD treatment in China. The high prevalence and associated clinical features of GD in the MAUD group highlight the importance of screening for GD in this population and intervening accordingly.

Elevated C-reactive protein/albumin ratio in patients with methamphetamine use disorder

BACKGROUND

Methamphetamine use disorder causes significant crises, which have individual, familial, and social consequences. Identifying inflammatory biomarkers for methamphetamine use disorder may be useful for following the inflammatory status of patients in clinical assessment. In this study, we aimed to investigate whether neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), C-reactive protein/albumin ratio (CAR) and neutrophil/albumin ratio (NAR) levels can be used as inflammatory biomarkers in methamphetamine use disorder.

METHODS

The sample comprised 139 treatment-seeking participants who met the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for methamphetamine use disorder and 139 sociodemographically matched controls. Only hospitalised patients were included. An independent sample t-test, Pearson's correlation test, and binominal logistic regression analysis were performed.

RESULTS

CAR (p = 0.016) and NAR (p = 0.048) levels were significantly higher in individuals with methamphetamine use disorder when compared with healthy controls. The CAR level was found to be a significant predictor of group membership in regression analysis for methamphetamine use disorder.

CONCLUSION

CAR may be a potential inflammatory biomarker for patients with methamphetamine use disorder. CAR as a relatively easier-to-measure biomarker could be beneficial to follow the inflammatory status and treatment response of patients.

Association between rumination and drug craving in Chinese male methamphetamine use disorder patients with childhood trauma

BACKGROUND

In China, males make up the majority of methamphetamine (MA) dependent individuals and the majority of treatment seekers. Childhood trauma (CT) and rumination are associated with an increased risk of MA use. However, the association between CT, rumination, and drug craving remains largely unknown.

OBJECTIVE

The present study aims to explore the association between rumination and drug craving in methamphetamine use disorder (MAUD) patients with CT.

PARTICIPANTS AND SETTING

This study recruited 404 male participants with MAUD from a male drug rehabilitation center in Southwest China.

METHODS

Patients with CT were identified by the short form of Childhood Trauma Questionnaire (CTQ-SF). Rumination and drug craving were assessed by the Ruminative Responses Scale (RRS) and the Obsessive Compulsive Drug Use Scale (OCDUS), respectively.

RESULTS

188 patients (46.5 %) experienced CT. Patients who had experienced CT showed significantly higher RRS symptom rumination score and OCDUS total score than those who had not. In patients with CT, RRS total and all subscale scores were positively associated with OCDUS interference of drug. Furthermore, the RRS brooding (β = 0.34, p < 0.001) and total scores (β = 0.38, p < 0.001) were determined to be separate contributors to the OCDUS total score in patients with CT.

CONCLUSIONS

Our study suggests that CT is common in male MAUD patients, and those who have suffered CT may exhibit higher levels of rumination and drug craving. Moreover, CT may play an influential role in the association between rumination and drug craving in patients with MAUD.

Psychometric properties of the Treatment Effectiveness Assessment in methamphetamine use disorder

INTRODUCTION

The ability for people living with stimulant use disorder to live meaningful lives requires not only abstinence from addictive substances, but also healthy engagement with their community, lifestyle practices, and overall health. The Treatment Effectiveness Assessment (TEA) assesses components of recovery consisting of four functional domains: substance use, health, lifestyle, and community. This secondary data analysis of 403 participants with severe methamphetamine use disorder tested the reliability and validity of the TEA.

METHODS

Participants were enrolled in the Accelerated Development of Additive Pharmacotherapy Treatment (ADAPT-2) for methamphetamine use disorder. The study used total TEA and domain scores at baseline to assess factor structure and internal consistency, as well as construct validity related to substance cravings (visual analog scale [VAS]), quality of life (quality-of-life assessment [QoL]), mental health (Patient Health Questionnaire-9 [PHQ-9], Concise Health Risk Tracking Scale Self-Report [CHRT-SR16]), and social support (CHRT-SR16).

RESULTS

Individual TEA items showed moderate to large correlations with each other (r = 0.27-0.51; p < .001), and strong correlations to the total score (r = 0.69-0.78; p < .001). Internal consistency was strong (coefficient α = 0.73 [0.68-0.77]; coefficient ω = 0.73 [0.69-0.78]). Construct validity was acceptable, with the strongest correlation between the TEA Health item and the general health status item on the QoL (r = 0.53, p < .001).

CONCLUSIONS

TEA has acceptable levels of reliability and validity supporting prior similar findings in a sample of participants with moderate to severe methamphetamine use disorder. Results from this study provide support for its use in assessing clinically meaningful changes beyond simply reduced substance use.

Decomposing risky decision-making in methamphetamine use disorder: Behavioral updating and D2 dopamine receptors

BACKGROUND

Escalating misuse of amphetamine-type stimulants, mainly methamphetamine, has led to a staggering rise in associated overdose deaths and a pressing need to understand the basis of methamphetamine use disorder (MUD). MUD is characterized by disadvantageous decision-making, and people with MUD perform below controls on the Balloon Analogue Risk Task (BART), a laboratory test of decision-making under uncertainty. The BART presents a series of choices with progressively higher stakes-greater risk of loss and greater potential monetary reward. This research aimed to clarify whether impaired behavioral updating contributes to maladaptive performance on the BART.

METHODS

Two groups (28 drug-abstinent participants with MUD and 16 healthy control participants) were compared on BART performance. Using a computational model, we deconstructed behavior into risk-taking and behavioral updating. A subset of participants (22 MUD, 15 healthy control) underwent [18F]fallypride positron emission tomography scans to measure dopamine D2-type receptor availability (BPND) in the striatum (caudate and accumbens nuclei and putamen) and the globus pallidus.

RESULTS

Participants with MUD exhibited slower behavioral updating than the healthy controls (p = 0.0004, d=1.77). BPND in all four bilateral volumes of interest were higher in the healthy control group (ps < 0.005, ds < 2.16), and updating rate correlated positively with BPND in the caudate nucleus (p = 0.002), putamen (p = 0.002), and globus pallidus (p = 0.03).

CONCLUSIONS

The findings indicate that behavioral updating contributes to maladaptive decision-making in MUD and suggest that dysregulation of D2-type receptor signaling in the striatum and globus pallidus contributes to this behavioral deficit.

Associations and relative risks of pulmonary hypertension and lung diseases in individuals with methamphetamine use disorder

OBJECTIVE

Methamphetamine causes considerable short- and long-term adverse health effects. Our aim was to assess the effects of methamphetamine use on pulmonary hypertension and lung diseases at the population level.

METHODS

This population-based retrospective study used data from the Taiwan National Health Insurance Research Database between 2000 and 2018 that included 18,118 individuals with methamphetamine use disorder (MUD) and 90,590 matched participants of the same age and sex without substance use disorder as the non-exposed group. A conditional logistic regression model was used to estimate associations of methamphetamine use with pulmonary hypertension and lung diseases such as lung abscess, empyema, pneumonia, emphysema, pleurisy, pneumothorax, or pulmonary hemorrhage. Incidence rate ratios (IRRs) of pulmonary hypertension and hospitalization due to lung diseases were determined between the methamphetamine group and non-methamphetamine group using negative binomial regression models.

RESULTS

During an 8-year observation period, 32 (0.2%) individuals with MUD and 66 (0.1%) non-methamphetamine participants suffered from pulmonary hypertension, and 2652 (14.6%) individuals with MUD and 6157 (6.8%) non-methamphetamine participants suffered from lung diseases. After adjusting for demographic characteristics and comorbidities, individuals with MUD were 1.78 times (95% confidence interval (CI) = 1.07-2.95) more likely to have pulmonary hypertension and 1.98 times (95% CI = 1.88-2.08) more likely to have a lung disease, especially emphysema, lung abscess, and pneumonia in descending order. Furthermore, compared to the non-methamphetamine group, the methamphetamine group was associated with higher risks of hospitalization caused by pulmonary hypertension and lung diseases. The respective IRRs were 2.79 and 1.67. Individuals with polysubstance use disorder were associated with higher risks of empyema, lung abscess, and pneumonia compared to individuals with MUD alone, with respective adjusted odds ratios of 2.96, 2.21, and 1.67. However, pulmonary hypertension and emphysema did not differ significantly between MUD individuals with or without polysubstance use disorder.

CONCLUSIONS

Individuals with MUD were associated with higher risks of pulmonary hypertension and lung diseases. Clinicians need to ensure that a methamphetamine exposure history is obtained as part of the workup for these pulmonary diseases and provide timely management for this contributing factor.

"There's a big tag on my head": exploring barriers to treatment seeking with women who use methamphetamine in Sydney, Australia

BACKGROUND

Australia has a high prevalence of regular use of methamphetamine. While half of people who use methamphetamine regularly are women, they make up only one third of people seeking treatment for methamphetamine use disorder. There is a lack of qualitative research into the facilitators and barriers to treatment for women who use methamphetamine regularly. The study seeks a better understanding of the experiences and treatment preferences of women who use methamphetamine, to inform person-centred changes in practice and policy that break down barriers to treatment.

METHODS

We conducted semi-structured interviews with 11 women who frequently use methamphetamine (at least once a week), and who are not engaged in treatment. Women were recruited from health services surrounding a stimulant treatment centre at an inner-city hospital. Participants were asked about their methapmhetamine use and health service needs and preferences. Thematic analysis was completed using Nvivo® software.

RESULTS

Three themes were developed from participants' responses around experiences of regular methamphetamine use and treatment needs: 1. Resistance of stigmatised identity including dependence; 2. Interpersonal violence; 3. Institutionalised stigma. A fourth set of themes on service delivery preferences were also elicited, including continuity of care, integrated health care, and provision of non-judgmental services.

CONCLUSION

Gender-inclusive health care services for people who use methamphetamine should actively work to address stigma, support a relational approach to assessment and treatment, and seek to provide structurally competent health care that is trauma and violence informed, and integrated with other services. Findings may also have application for substance use disorders other than methamphetamine.

Evaluation of Adenosine A2A receptor gene polymorphisms as risk factors of methamphetamine use disorder susceptibility and predictors of craving degree

The adenosine A2A receptor (ADORA2A) is highly expressed in the central nervous system and plays vital roles in drug addiction. In this study, we aimed to explore the susceptibility of ADORA2A to methamphetamine use disorder (MUD) and the craving degree based on a two-stage association analysis. A total of 3,542 (1,216 patients with MUD and 2,326 controls) and 1,740 participants (580 patients with MUD and 1,160 controls) were recruited in discovery and replication stage, respectively. Significant SNPs identified in the discovery stage were genotyped in the replication samples. Serum levels of ADORA2A were measured using enzyme-linked immunosorbent assay kits. The genetic association signal of each SNP was examined using Plink. A linear model was fitted to investigate the relationship between craving scores and genotypes of significant SNPs. SNP rs5751876 was significantly associated with MUD in the discovery samples and this association signal was then further replicated in the replication samples. Significant associations were also identified between serum levels of ADORA2A and the genotypes of rs5751876 (P = 0.0002). The craving scores in patients with MUD were strongly correlated with rs5751876 genotypes. Our results suggest that polymorphisms of the ADORA2A gene could affect the susceptibility to MUD and its craving degree.

Applying the Addictions Neuroclinical Assessment to derive neurofunctional domains in individuals who use methamphetamine

The Addictions Neuroclinical Assessment (ANA) was proposed as a neuroscience-informed clinical framework to understand heterogeneity in addiction encompassing dysfunction in three domains: incentive salience, negative emotionality, and executive functions. The ANA has been validated in the alcohol field but has not been extended to other substances. Thus, the objective of the current study was to replicate and extend the ANA framework to methamphetamine use disorder. Non-treatment seeking individuals (N = 185) who reported regular methamphetamine use completed a deep phenotyping battery comprising self-report and behavioral measures that assessed methamphetamine craving and emotional withdrawal symptoms, mood and anxiety symptomatology, risk-taking behaviors, working memory, attention, and impulsivity. Factor analytic techniques were used in an iterative manner to derive latent factors that explained biobehavioral variation in the sample. The relationship between factor scores and demographic and clinical indicators of methamphetamine use were examined to assess the construct validity of the latent factors. Deep phenotyping combined with factor analytic techniques implicated three intercorrelated neurofunctional domains that map on to the proposed ANA domains: incentive salience, negative emotionality, and executive function. Each of the domains were associated with demographic and clinical indicators of methamphetamine use providing initial support for their construct validity. The ANA framework holds promise for explaining heterogeneity in addiction by identifying neuroscience-informed phenotypes. Knowledge from the ANA framework may be applied to advance precision medicine and inform medications development for a host of substance use disorders, particularly those with no approved pharmacotherapy such as methamphetamine.

Mirtazapine for the treatment of amphetamine and methamphetamine use disorder: A systematic review and meta-analysis

BACKGROUND

Amphetamine-type stimulants continue to dominate the global drug markets. Despite this, no pharmacotherapy has been approved for treatment of amphetamine and methamphetamine use disorder (AMD). We evaluate the efficacy of mirtazapine in the treatment of AMD, given emerging evidence that it may alleviate methamphetamine and amphetamine (MA/A) cravings and withdrawals.

METHODS

We searched five databases from inception until January 28, 2021 for studies with a comparator group evaluating mirtazapine for treatment of AMD. We collected data on reduction in MA/A use, treatment retention, sexual behaviors, depression symptoms, cravings and adverse events. We assessed certainty of evidence using GRADE. Where appropriate, we conducted fixed-effect meta-analyses weighted by inverse variance and calculated the absolute risk reduction.

RESULTS

Among the 206 studies screened, we included two parallel-arm placebo-controlled RCTs conducted among cis-gender men and transgender women (n = 180). We found that mirtazapine use likely results in a small reduction of methamphetamine use compared to placebo after 12-weeks (relative risk [RR]=0.81, 95% confidence interval [CI]: 0.63, 1.03; n = 133; moderate certainty evidence due to imprecision). We also found that the use of mirtazapine probably does not improve retention in treatment (RR=1.01, 95% CI: 0.91, 1.12; n = 180; moderate certainty evidence) or depression symptom severity (mean difference [MD]=0.45, 95% CI: -2.88, 3.78; n = 53; moderate certainty evidence). There were no serious adverse events.

CONCLUSIONS AND RELEVANCE

Mirtazapine probably results in a small reduction in continued methamphetamine use among cisgender men and transgender women with AMD, but probably does not improve patients' retention in treatment or depression symptom severity.

STUDY REGISTRATION

PROSPERO ID: CRD42021236806.

Difference in topological organization of white matter structural connectome between methamphetamine and heroin use disorder

The psychological symptoms caused by heroin and methamphetamine are significantly different in people with substance use disorders. The topological organization of structural connections that may underlie these differences remains unknown. The study sample consisted of 23 males with methamphetamine use disorder (MAUD), 20 males with heroin use disorder (HUD), and 21 male healthy controls (HCs) who were demographically matched. Diffusion tensor imaging and probabilistic tractography were used for white matter network construction. Psychological symptoms were evaluated by the Symptom Checklist-90. Using graph theoretical analysis, we examined the difference in graph-level and nodal-level properties among the groups. The network Hubs distribution and the relationship between the network alterations and psychological symptoms were identified. The MAUD group demonstrated significantly higher scores on anxiety, hostility, and symptoms of schizophrenia than the HUD and HCs groups. The HUD group showed significantly higher global efficiency and network strength than the HCs group, and higher network strength than the MAUD group. Compared with the HUD group, the MAUD group showed significantly lower Nodal Strength and efficiency, distributed mainly in the temporal, parietal, and occipital regions. We also found the network Hubs were decreased in the MAUD group, but increased in the HUD group. The Nodal Strength in the right superior temporal gyrus was significantly correlated with psychological symptoms in the MAUD group. These findings reflect the significant differences in topological structural connection between HUD and MAUD. This evidence helps shed some light on the neurobiological mechanisms of the psychological differences between HUD and MAUD, and extend our understanding of the structural disruption underlying MAUD-related psychological symptoms.

Footshock-Induced Abstinence from Compulsive Methamphetamine Self-administration in Rat Model Is Accompanied by Increased Hippocampal Expression of Cannabinoid Receptors (CB1 and CB2)

Methamphetamine (METH) use disorder (MUD) is characterized by compulsive and repeated drug taking despite negative life consequences. Large intake of METH in humans and animals is accompanied by dysfunctions in learning and memory processes. The endocannabinoid system (ECS) is known to modulate synaptic plasticity and cognitive functions. In addition, the ECS has been implicated in some of the manifestations of substance use disorders (SUDs). We therefore sought to identify potential changes in the expression of various enzymes and of the receptors (CB1 and CB2) that are members of that system. Herein, we used a model of METH self-administration (SA) that includes a punishment phase (footshocks) that helps to separate rats into a compulsive METH phenotype (compulsive) that continues to take METH and a non-compulsive METH (abstinent) group that suppressed or stopped taking METH. Animals were euthanized 2 h after the last METH SA session and their hippocampi were used to measure mRNA levels of cannabinoid receptors (CB/Cnr), as well as those of synthesizing (DAGL-A, DAGL-B, NAPEPLD) and metabolizing (MGLL, FAAH, PTGS2) enzymes of the endocannabinoid cascade. Non-compulsive rats exhibited significant increased hippocampal expression of CB1/Cnr1 and CB2/Cnr2 mRNAs. mRNA levels of the synthesizing enzyme, DAGL-A, and of the metabolic enzymes, MGLL and FAAH, were also increased. Non-compulsive rats also exhibited a significant decrease in hippocampal Ptgs2 mRNA levels. Taken together, these observations implicate the hippocampal endocannabinoid system in the suppression of METH intake in the presence of adverse consequences.

Effect of aerobic exercise on executive function in individuals with methamphetamine use disorder: Modulation by the autonomic nervous system

This study assessed the effects of aerobic exercise on cardiac autonomic nervous system function (based on heart rate variability [HRV]) and executive function among individuals with methamphetamine use disorder (MUD). We further examine the role of autonomic nervous system control in aerobic exercise (assessed via cardiopulmonary fitness) and executive function. A total of 330 individuals with MUD were randomly divided into exercise (n = 165) and control (n = 165) groups, who underwent eight-week aerobic exercise/health education program consisting of five 60 min sessions a week. The outcome measures included cardiopulmonary fitness, HRV time-domain and frequency-domain parameters, and executive function. Our statistical analyses comprised repeated-measures analyses of variance, correlation analyses, and mediation and moderation effect tests. The results indicated that aerobic exercise could simultaneously improve autonomic nervous system function and executive function among individuals with MUD. Moreover, the changes in cardiopulmonary fitness, high frequency HRV, and executive function were positively correlated. HRV did not significantly mediate the relationship between aerobic exercise and executive function; however, it did have a moderating effect, which was eliminated after adjusting for demographic and drug-use covariates. Among the covariates, age was the greatest confounder and was inversely proportional to cardiopulmonary function, HRV, and executive function. Cardiac autonomic nervous system function exerted a moderating, rather than a mediating, effect on the relationship between aerobic exercise and executive function. However, this potential effect was largely influenced by covariates, particularly age.

Assessing methamphetamine-related cue reactivity in people with methamphetamine use disorder relative to controls

Methamphetamine use disorder involves methamphetamine-related cues invoking intense craving leading to relapse. Such cue reactivity is thought to arise from Pavlovian conditioning that occurs during the drug-taking experience. Cue reactivity then should be selective to methamphetamine cues (and not other cues), and not observed in people who have never experienced methamphetamine. However, these premises have never been tested and reported using objective measures such as skin conductance response (SCR). The primary aim of this study was to test these premises using a cue reactivity paradigm we developed using control cues. The secondary aim was to explore the relationship between cue reactivity, drug use characteristics, and cognition. Thirty people with a current diagnosis of methamphetamine use disorder and 30 matched controls with no history of substance use disorder were recruited. We observed higher overall subjective reactivity (F = 62.810; p < 0.001) and cue-selective physiological reactivity (F = 5.160; p = 0.026) in people with methamphetamine use disorder but not in controls. Co-morbid sedative use was associated with higher subjective craving (r = 0.521; p = 0.003). People who use methamphetamine intravenously had higher cue-selective SCR than smokers (t = 3.750; p < 0.001). Low inhibitory control measured by the Stroop task was associated with increased craving across the cue paradigm (r = -0.494; p = 0.006). Overall, these results support that cue reactivity in people with methamphetamine use disorder is due to Pavlovian conditioning. Its association with drug use and cognition highlights cue reactivity paradigm's utility in understanding methamphetamine use disorder to develop new treatments targeting cue-induced craving.

Current and Emerging Treatments for Methamphetamine-use Disorder

Almost two decades have passed since the last methamphetamine (METH) abuse epidemic. In recent years, METH abuse in the United States has been rapidly increasing and is currently one of the leading causes of death in our country. Available statistical data indicates re-emergence of METH popularity and suggest an impending third epidemic of METH abuse. Alarmingly, there is no FDA-approved medication for METH use disorder (MUD). This disorder is currently treated with behavioral therapies; however, these therapies have limitations and would benefit from the addition of a MUD pharmacotherapy. Unfortunately, clinical trials have not yet found consistently effective pharmacotherapy for MUD. This review outlines the history of METH use, provides information on current prevalence of METH abuse and MUD, describes medications that have been in clinical trials for MUD, and addresses current as well as potential new treatments for MUD.

Lack of longitudinal changes in cognition in individuals with methamphetamine use disorder during the first 6 weeks after commencing treatment

Background: Methamphetamine use disorder (MUD) associates with cognitive impulsivity deficits. However, few studies have examined longitudinal changes in cognition, and it remains unclear if deficits resolve during early recovery.Objectives: To compare: (1) cognitive function of individuals with MUD at treatment onset and six-weeks later with controls tested over the same period; (2) cognitive changes in MUD-individuals who remained abstinent versus relapsed.Method: We recruited 108 participants meeting DSM-IV-TR criteria for methamphetamine dependence (81 males) and 50 demographically matched controls (38 males); 77 methamphetamine- dependent participants (59 males) and 48 controls (36 males) were retained at follow-up. We administered response inhibition, delay discounting and uncertainty-based decision-making tests at both endpoints. Relapse was defined as methamphetamine concentrations >0.4 ng/mg at follow-up in hair toxicology.Results: We found a significant time-by-group interaction on uncertainty-based decision-making (effect size: η² = .05), although post-hoc tests to disentangle this interaction yielded inconclusive results (p-range = .14-.40; BF₁₀-range = 0.43-1.67). There were no significant time-by-group interactions on response inhibition or delay discounting, with the former likely a null effect (η²-interaction = .003 and .02; BF_incl = 0.23 and 0.71). There were no significant differences in cognitive recovery between individuals who maintained abstinence (n = 12) versus relapsed (n = 65) (η²-range = .003-.04), although evidence was inconclusive toward whether findings reflected true null effects (BF_incl-range = 0.33-0.75).Conclusion: We did not find evidence that MUD-related cognitive impulsivity deficits improve beyond practice effects over 6 weeks. Findings do not support previous, albeit conflicting, evidence of early recovery of cognitive deficits in MUD.

The transcranial direct current stimulation over prefrontal cortex combined with the cognitive training reduced the cue-induced craving in female individuals with methamphetamine use disorder: A randomized controlled trial

BACKGROUND

Craving and cognitive deficits are potential treatment targets for methamphetamine use disorder (MUD). Previous studies implied that transcranial direct current stimulation (tDCS) and cognitive training respectively improve these symptoms, but the combined effect is unknown. In this study, we investigated the combined effects of tDCS over dorsolateral prefrontal cortex (DLPFC) and computerized cognitive addiction therapy (CCAT) on cue-induced craving and cognitive functions among female individuals with MUD.

METHODS

Seventy-five patients with MUD were randomly assigned to three groups: CCAT + tDCS group, CCAT + sham tDCS group and the control group. The former two groups received 20 sessions of cognitive training combined 1.5 mA active/sham tDCS over DLPFC (20min/session, 5times/week), while the control group received usual care which includes routine medical care, health education, physical exercises and psychological support related to relapse prevention. The cue-induced craving and cognitive functions were tested at the baseline, the end of 2nd week and 4th week.

RESULTS

The CCAT + tDCS group showed a significant reduction in cue-induced craving after 4-week intervention. Moreover, the craving score of the real CCAT + tDCS group was significantly lower than that of the CCAT + sham tDCS group and that of the control group at the end of 4th week. A significant improvement in accuracy of TWOB task was only observed in the CCAT + tDCS group at the end of 4th week when compared to baseline. Unexpectedly, participants who received CCAT plus active or sham tDCS did not change their discounting, whereas those in the control group performed more impulsively over time.

CONCLUSIONS

The study found that the intervention of tDCS over DLPFC combined with CCAT may have potential benefit in improving treatment outcome in patients with MUD. More research is needed to explore the underlying mechanism.

Protocol for the methamphetamine approach-avoidance training (MAAT) trial, a randomised controlled trial of personalised approach bias modification for methamphetamine use disorder

Background

Globally, methamphetamine use has increased in prevalence in recent years. In Australia, there has been a dramatic increase in numbers of people seeking treatment, including residential rehabilitation, for methamphetamine use disorder (MUD). While residential rehabilitation is more effective for MUD than withdrawal treatment (i.e. “detoxification”) alone, relapse rates remain high, with approximately half of rehabilitation clients using methamphetamine within 3 months of rehabilitation. “Approach bias modification” (ABM) is a computerised cognitive training approach that aims to dampen automatically triggered impulses to approach drugs and drug-related stimuli. ABM has been demonstrated to reduce alcohol relapse rates, but no randomised controlled trials of ABM for MUD have yet been conducted. We aim to test whether a novel “personalised” form of ABM, delivered during rehabilitation, reduces post-treatment methamphetamine use, relative to a sham-training control condition. Secondary outcomes will include dependence symptoms, cravings, and approach bias.

Methods

We aim to recruit 100 participants attending residential rehabilitation for MUD at 3 sites in the Melbourne metropolitan area. Participants will complete baseline measures of methamphetamine use, craving, dependence severity, and approach bias before being randomised to receiving 6 sessions of ABM or “sham” training. In the active condition, ABM will be personalised for each participant, using those methamphetamine images that they rate as most relevant to their recent methods of methamphetamine use as “avoidance” images and using positive images representing their goals or healthy sources of pleasure as “approach” images. Approach bias and craving will be re-assessed following completion of training, and methamphetamine use, dependence, and craving will be assessed 4 weeks and 3 months following discharge from residential treatment.

Discussion

This study is the first randomised controlled trial of ABM for MUD and also the first ABM study to test using a personalised set of both approach and avoid images for ABM training. If effective, the low cost and easy implementation of ABM means it could be widely implemented as a standard part of MUD treatment.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12620000072910. Registered on 30 January 2020 (prospectively registered): https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378804&isReview=true

Executive Function and Contingency Management in Methamphetamine Use Disorder

OBJECTIVES

Contingency management is a promising intervention for Methamphetamine Use Disorder (MUD).Impaired executive function may decrease adherence to such treatment, but there are few data on whether impairment in executive function predicts treatment outcomes. We therefore evaluated whether baseline performance on tests of executive function predicted treatment response in a trial of contingency management for MUD.

METHODS

Thirty participants with MUD and 23 healthy controls performed the Connors Continuous Performance Task (CPT) and the Trail Making Task. MUD participants then entered an 8-week contingency management trial. Participants were categorized as responders (n=17; no methamphetamine-positive urine tests) or non-responders (n=13; >1 positive test). The Kruskal-Wallis test was used to compare scores in participants with MUD and healthy controls, and in responders versus non-responders.

RESULTS

Participants withMUD performed worse than controls on the CPT (d-prime) (p=0.012); non-responders performed worse than responders (p = 0.034). Performance of MUD participants did not differ significantly from controls on the Trail Making Task B (time to completion), but variation was high with non-responders performing worse than responders (p=0.013).

CONCLUSION

These findings suggest that tests of executive function at baseline may be useful in predicting treatment response in MUD. Future work in larger samples may ultimately allow a more personalized treatment approach to methamphetamine use disorder.

Methamphetamine exposure and its cessation alter gut microbiota and induce depressive-like behavioral effects on rats

RATIONALE

Methamphetamine is a highly abused psychostimulant drug and its use remains a major public health concern worldwide with limited effective treatment options. Accumulative evidence reveals the influence of gut microbiota on the brain, behavior, and health as a part of the gut-brain axis but its involvement in modulating this substance use disorder remains poorly understood.

OBJECTIVE

We sought to determine whether methamphetamine exposure and cessation or withdrawal alter the intestinal gut microbiota as well as characterize cessation-induced behavioral changes.

METHODS

Male, Sprague-Dawley rats were administered methamphetamine (2 mg/kg; s.c.) or vehicle (n = 8 per group) twice per day for 14 consecutive days. On various days before, during, and after administration, fecal samples were collected and tests of anxiety- and depressive-like behaviors were conducted.

RESULTS

Methamphetamine administration and cessation did not alter the relative abundance of bacteria but significantly changed the composition of gut bacteria through 16S rRNA sequencing. These changes were normalized after 7 days of methamphetamine cessation. Moreover, acute methamphetamine cessation induced depressive-like behavior, with an increase in immobility in the forced swim test but did not alter anxiety-like behaviors in tests of open field test or elevated plus maze.

CONCLUSIONS

These findings provide direct evidence that methamphetamine and its cessation cause gut dysbiosis and that the latter associates with depressive-like behavior in rodents. Our observation will contribute to a better understanding of the function of gut microbiota in the process of substance use disorders and guide the choice of target therapeutics.

Psychosocial and pharmacologic interventions for methamphetamine addiction: protocol for a scoping review of the literature

BACKGROUND

Methamphetamine use and harms are rising rapidly. Management of patients with methamphetamine use disorder (MUD) and problematic methamphetamine use (PMU) is challenging, with no clearly established best approach; both psychosocial and pharmacologic interventions have been described. Furthermore, given the diversity of individuals that use methamphetamines, there is a need to assess evidence for treatments for subgroups including youths; gay, bisexual, and other men who have sex with men; individuals with mental health comorbidities; and individuals in correction services. Establishing awareness of the messages regarding treatment from recent clinical practice guidelines (CPG) in the field is also of value. The first study objective will be to establish a greater understanding of the methods, populations, and findings of controlled studies for psychosocial and pharmacologic treatments for MUD and PMU. Investigation of this information can help establish the potential for advanced syntheses of the evidence (such as network meta-analysis) to compare therapies for this condition and to identify gaps related to key populations where more primary research is needed. Summarizing the recommendations regarding treatment of MUD/PMU from recent CPGs and systematic reviews will be an important secondary objective.

METHODS

A scoping review will be performed. Using the OVID platform, MEDLINE, Embase, PsycINFO, and relevant Cochrane databases from EBM Reviews will be searched (from databases' inception onwards). Eligibility criteria will include individuals described as having MUD or PMU, with designs of interest including randomized trials, non-randomized trials, and controlled cohort studies with three or more months of follow-up; systematic reviews and CPGs will also be sought. Two reviewers (with support from automation tools) will independently screen all citations, full-text articles, and chart data. Different approaches to handling and summarizing the data will be implemented for each type of study design. Tables and graphics will be used to map evidence sources and identify evidence gaps.

DISCUSSION

This research will enhance awareness of evidence addressing the effects of psychosocial and pharmacologic interventions for MUD/PMU overall and in sub-populations, both in terms of recent CPGs/reviews and primary studies; inspection of the latter will also help establish the feasibility of future syntheses to compare treatments, such as network meta-analysis. SYSTEMATIC REVIEW PROTOCOL REGISTRATION: Open Science Framework ( https://osf.io/9wy8p ).

The exploration of optimized protocol for repetitive transcranial magnetic stimulation in the treatment of methamphetamine use disorder: A randomized sham-controlled study

Background

The prefrontal-striatal circuit is a core circuit related to substance dependence. Previous studies have found that repetitive transcranial magnetic stimulation (rTMS) targeting the dorsolateral prefrontal cortex (DLPFC) (key region of executive network) had limited responses, while inhibiting hyperactivation of ventromedial prefrontal cortex (vmPFC) (key region of limbic network) may be another strategy. However, there is currently no comparison between these two treatment locations.

Methods

Seventy-four methamphetamine-dependent patients were randomly assigned to one of treatment groups with two-week treatment: (1) Group A: intermittent theta-burst stimulation (iTBS) targeting the left DLPFC; (2) Group B: continuous theta-burst stimulation (cTBS) targeting the left vmPFC; (3) Group C: a combination of treatment protocol of Group A and Group B; (4) Group D: sham theta-burst stimulation. The primary endpoint was the change of cue-induced craving. The trial was registered at ClinicalTrials.gov (NCT03736317).

Findings

The three real TBS groups had more craving decrease effect than the sham group (p<0.01). The changes of craving were positively correlated with the improvement of anxiety and withdrawal symptom. With the highest respondence rate, group C also had shorter respondence time than Group A (p = 0.03). Group C was effective in improve depression symptoms (p = 0.04) and withdrawal symptom (p = 0.02) compared with Group D. Besides, Group C was significant in improve sleep quality (p = 0.04) compared with Group A. Baseline depression scores and spatial working memory were positively predicting the intervention response.

Interpretation

The rTMS paradigms involving vmPFC with cTBS are optimized protocols and well-tolerated for methamphetamine-dependent individuals, and they may have better efficacies compared with DLPFC iTBS. Emotion and cognitive function are rTMS treatment response predictors for methamphetamine-dependent patients.

Funding

This work was supported by the National Key R&D Program of China (2017YFC1310400), National Natural Science Foundation of China (81,771,436, 81,801,319, 81,601,164), Shanghai Municipal Health and Family Planning Commission (2017ZZ02021), Municipal Human Resources Development Program for Outstanding Young Talents in Medical and Health Sciences in Shanghai (2017YQ013), Qihang Project of Shanghai Mental Health Center (2019-QH-05), Shanghai Sailing Program (19YF1442100), Shanghai Key Laboratory of Psychotic Disorders (13DZ2260500), Program of Shanghai Academic Research Leader (17XD1403300), Shanghai Municipal Science and Technology Major Project (2018SHZDZX05), and Shanghai Clinical Research Center for Mental Health (19MC1911100).

Non-pharmacological interventions for methamphetamine use disorder: a systematic review

BACKGROUND

Methamphetamine (METH) use is on the rise globally, with the number of treatment seekers increasing exponentially across the globe. Evidence-based therapies are needed to meet rising treatment needs. This systematic review intends to appraise the existing evidence to identify effective non-pharmaceutical approaches for the treatment of METH use disorder.

METHODS

Five electronic bibliographic databases-Ovid (Medline), Embase, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Web of Science and PsycINFO- were searched to identify relevant studies that were published between January 1995 to February 2020. Studies were selected and assessed by two independent reviewers. A systematic review of data from both randomised control trials (RCT) and non-RCTs was conducted to appraise the evidence.

RESULTS

A total of 44 studies were included in the review. Behavioural interventions, i.e. cognitive behavioural therapy (CBT), contingency management (CM), exercise, residential rehabilitation based therapies, repetitive transcranial magnetic stimulation (rTMS), and matrix model demonstrated treatment efficacy in promoting abstinence, reducing methamphetamine use or craving in the participants. While CM interventions showed the strongest evidence favouring the outcomes assessed, tailored CBT alone or with CM was also effective in the target population.

CONCLUSIONS

Behavioural interventions should be considered as the first line of treatment for methamphetamine use disorder. Future studies should address the longevity of the effects, and limitations due to smaller sample sizes and high dropout rates to enable better assessment of evidence.

Disrupted brain network dynamics and cognitive functions in methamphetamine use disorder: insights from EEG microstates

BACKGROUND

Dysfunction in brain network dynamics has been found to correlate with many psychiatric disorders. However, there is limited research regarding resting electroencephalogram (EEG) brain network and its association with cognitive process for patients with methamphetamine use disorder (MUD). This study aimed at using EEG microstate analysis to determine whether brain network dynamics in patients with MUD differ from those of healthy controls (HC).

METHODS

A total of 55 MUD patients and 27 matched healthy controls were included for analysis. The resting brain activity was recorded by 64-channel electroencephalography. EEG microstate parameters and intracerebral current sources of each EEG microstate were compared between the two groups. Generalized linear regression model was used to explore the correlation between significant microstates with drug history and cognitive functions.

RESULTS

MUD patients showed lower mean durations of the microstate classes A and B, and a higher global explained variance of the microstate class C. Besides, MUD patients presented with different current density power in microstates A, B, and C relative to the HC. The generalized linear model showed that MA use frequency is negatively correlated with the MMD of class A. Further, the generalized linear model showed that MA use frequency, scores of Two-back task, and the error rate of MA word are correlated with the MMD and GEV of class B, respectively.

CONCLUSIONS

Intracranial current source densities of resting EEG microstates are disrupted in MUD patients, hence causing temporal changes in microstate topographies, which are correlated with attention bias and history of drug use.

γ-aminobutyric acid and glutamate/glutamine alterations of the left prefrontal cortex in individuals with methamphetamine use disorder: a combined transcranial magnetic stimulation-magnetic resonance spectroscopy study

Background

GABAergic and glutamatergic neurotransmitter systems are critical in the pathophysiology of addiction and represent potential targets for repetitive transcranial magnetic stimulation (rTMS). This study aims to investigate changes in γ-aminobutyric acid (GABA) levels, the combined resonance of glutamate and glutamine (Glx) in the left dorsolateral prefrontal cortex (DLPFC), and cognitive function of patients with methamphetamine dependence following rTMS intervention, using proton magnetic resonance spectroscopy (¹H MRS).

Methods

Fifty methamphetamine-dependent patients were randomized to a 4-week course of active or sham rTMS, with ¹H MRS measurement of DLPFC GABA and Glx levels relative to n-acetyl-aspartate (NAA) and craving and cognitive function measured at baseline and post-intervention.

Results

We observed significant reductions of GABA/NAA concentration in the active group and Glx/NAA concentration in the group receiving sham rTMS. There was a significant association between changes in GABA concentration and problem solving/error monitoring.

Conclusions

The effect of rTMS on cognitive function in individuals with methamphetamine dependence may be related to changes in GABA levels in the prefrontal cortex, and warrants further investigation.

Cognitive deficits in methamphetamine addiction: Independent contributions of dependence and intelligence

BACKGROUND

Methamphetamine's effects on brain function have been associated with cognitive deficits, which have a negative impact on clinical outcomes. However, it remains unclear if cognitive deficits relate to methamphetamine dependence (potentially amenable to abstinence and retraining) or background characteristics, mental health and other drug use. We tested the association between methamphetamine dependence and cognitive performance, while factoring in the impact of background characteristics, depressive symptoms and tobacco, alcohol and cannabis use.

METHOD

The sample comprised 108 treatment-seeking participants who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV TR) criteria for methamphetamine dependence and 50 socio-demographically matched controls. We administered a comprehensive neuropsychological test battery (delay discounting, decision making, disinhibition, episodic and working memory) and examined cognitive deficits in methamphetamine users after taking into account socio-demographic characteristics, tobacco, alcohol and cannabis use, and depressive symptoms.

RESULTS

Hierarchical multiple regression analyses showed that methamphetamine dependence was associated with poorer performance in decision-making and disinhibition over and above other predictors, while IQ better explained performance in episodic and working memory. Although duration of methamphetamine use was linked to disinhibition, other patterns of methamphetamine use (including dose and frequency) were not consistently related to performance.

CONCLUSIONS

Methamphetamine dependence impacts inhibitory control and decision-making, whereas lower IQ associates with memory/working memory deficits among methamphetamine users. Findings suggest the need to target disinhibition and impulsive decision-making as part of methamphetamine dependence treatment, while buffering the impact of IQ on memory systems.

Spending money to make change: Association of methamphetamine abstinence and voucher spending among contingency management pilot participants in South Africa

AIMS

Methamphetamine Use Disorder is prevalent in South Africa. This analysis uses data from a contingency management (CM) pilot study in South Africa to replicate and expand on a U.S.-based study showing that CM voucher spending was associated with drug abstinence behavior.

DESIGN

Participants with methamphetamine-use disorder were enrolled in an 8-week CM trial requiring thrice weekly visits and received cash vouchers in exchange for stimulant-negative urines at each visit.

PARTICIPANTS

Participants were 33 treatment-seeking individuals with methamphetamine use disorder including 22 men (66.7%) and 11 women (33.3%) with a mean age of 34 years (S.D. = 7.7). Participants reported using methamphetamine for a mean of 11.7 years (S.D. = 4.9).

SETTING

All study procedures took place in South Africa between August 2016 and May 2018.

MEASUREMENTS

A time-lagged counting process Cox Proportional Hazards model for recurrent event survival analysis examined the relationship between frequency of and participant-categorized type of CM expenditures (hedonic, utilitarian, consumable or durable) and drug abstinence.

FINDINGS

After controlling for severity of baseline methamphetamine use and accumulated CM earnings (proxied by cumulative negative urines), those spending CM earnings at a previous visit ("spenders") were more likely to produce stimulant-negative urine samples subsequently, compared to those who did not ("savers") [OR = 1.23, CI = 1.08-1.53, p = .002]. There were significantly more cumulative stimulant-negative results among spenders vs. savers, p < .001, although cumulative spending did not significantly predict abstinence once spending in the prior time period was controlled for, suggesting a recency effect tied to the underlying spending mechanism. When extending the original analyses to look at the effect of spending on current abstinence, controlling only for recent abstinence (rather than cumulative abstinence), spending was no longer a significant predictor. Spending type did not affect methamphetamine abstinence. Qualitative results suggest spending CM vouchers may support social reintegration over the course of the trial.

CONCLUSIONS

Abstinence outcomes are a function of CM spending in both the U.S. and South Africa. Findings of a significant relationship between contingency management spending and subsequent stimulant-negative urine samples across geographic locations provide guidance toward future work in optimizing CM efficacy.

Feasibility and acceptability of approach bias modification during methamphetamine withdrawal and related methamphetamine use outcomes

Approach bias modification (ApBM), a computerised cognitive training task which aims to reduce automatic, impulsive responding to drug-related cues, has been found to reduce alcohol consumption among individuals seeking treatment for their drinking. However, this approach has not been trialled in patients with methamphetamine use disorder (MUD), where altered impulsivity and reward processing are well-established. As such, this study aimed to examine the feasibility and acceptability of four consecutive days of ApBM training during a residential admission for methamphetamine withdrawal. Abstinence rates were examined 2-weeks and 3-months post-discharge. In terms of uptake, 52 of the 99 eligible patients approached agreed to participate and 47 of these 52 commenced training. Uptake and training completion rates (62%) were lower than those achieved in similar trials of ApBM for residential alcohol withdrawal, suggesting there are challenges to its delivery in this setting. This is likely due to the severity of acute methamphetamine withdrawal syndrome and associated behavioural characteristics. However, participants' ratings of the task and reports of post-session craving suggest acceptability was high. Abstinence rates were 61% at 2 weeks and 54% at 3-months, which compare favourably with the abstinence rates observed in a previous large treatment outcome study. The evidence of acceptability and apparent effectiveness suggest future trials of ApBM with MUD patients are warranted. However, ApBM may be more feasible in certain settings or among particular sub-groups where patients are more clinically stable and therefore more likely to complete the training (e.g., residential rehabilitation, after acute withdrawal has subsided).

Oxytocin-enhanced motivational interviewing group therapy for methamphetamine use disorder in men who have sex with men: study protocol for a randomized controlled trial

Background

The prevalence of methamphetamine use disorder (MUD) in the United States has risen dramatically in the past four decades and is concentrated in populations such as men who have sex with men (MSM). Despite the public health consequences of MUD, there are no FDA-approved psychopharmacological treatments. Psychosocial treatment alone has been shown to reduce methamphetamine use, but high attrition rates limit treatment efficacy. Promising findings from animal models of MUD using exogenous oxytocin, a social neuropeptide, have set the stage for translational work. Along with unique anti-addiction effects, oxytocin holds a primary role in enhancing social salience and modulating stress. In humans, oxytocin administration, combined with evidence-based psychosocial interventions, may act synergistically to improve addiction treatment outcomes and improve retention rates in current MUD treatment.

Methods/design

We are conducting a randomized, double-blind, placebo-controlled trial of oxytocin-enhanced motivational interviewing group therapy (MIGT). Oxytocin or placebo 40 IU is administered intranasally in conjunction with six, weekly MIGT sessions. We will recruit 50 MSM, initiating treatment for MUD from specialized community health programs in San Francisco, CA, USA. Individuals will be randomized (1:1) to receive six, weekly sessions of MIGT with or without oxytocin. Our primary outcome is session attendance. Other outcomes of interest include: measures of group cohesion, anxiety, psychophysiology, and stimulant craving and use.

Discussion

This will be the first study of oxytocin’s effects in humans with MUD. Findings from this novel protocol will attempt to bridge existing animal data with the need for innovative clinical treatments for MUD, inform the growing field of pharmacologically-enhanced psychotherapy, and help to elucidate mechanisms behind oxytocin’s potential anti-addiction effects.

Trial registration

ClinicalTrials.gov, ID: NCT02881177. Registered on 26 August 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3225-7) contains supplementary material, which is available to authorized users.

[Methamphetamine : Epidemiology, clinical importance and sequelae of abuse]

Methamphetamine (also known as meth and crystal meth) is a highly psychoactive synthetic amphetamine type stimulant, which falls under the German Federal Narcotics Law. The substance is similar to other stimulants but has distinct features with respect to psychoactive effects, clinical symptoms, user characteristics and short and long-term consequences including substance-induced problems and comorbidities. The consumption and misuse of crystal meth is still limited to certain regions in Germany; however, the substance causes significant clinical and public health concerns in the affected regions and beyond due to the associated high potential for misuse and dependence, neurotoxic and neurodegenerative effects as well as many other severe health risks. The new German guidelines for methamphetamine use disorders are now available to provide clinicians with the current knowledge on effective diagnostics and treatment planning.