Cognitive deficits in individuals with methamphetamine use disorder: A meta-analysis

The effect of the NLRP1 inflammasome on methamphetamine-induced cognitive impairment in rats

Methamphetamine (METH) use disorder has been shown to be in high comorbidity with cognitive deficits. METH-induced cognitive deficits are accompanied by neurotoxicity which could result from neuroinflammation. The potential role of NLRP1 inflammasome (NLRP1) and the downstream signalling pathway in METH-induced cognitive impairment was explored in the current study. Cognitive functions and the changes of NLRP1/Caspase-1/GSDMD signalling pathway were firstly determined in rats receiving daily injections of METH. Subsequently, the effects of aspirin-triggered-lipoxin A4 (ATL), a potent anti-inflammatory mediator, and NLRP1 siRNA was investigated were investigated in both METH-treated rats and HT22 cells. METH induces significant cognitive deficits in rats, using the NOR test. METH-induced cognitive impairment was in line with increased activities of NLRP1, cleaved-Caspase-11, IL-1β and TNF-α and the presence of GSDMD-mediated pyroptosis in the hippocampus of rats. NLRP1 inhibition by ATL significantly attenuated METH-induced cognitive impairment, in conjunction with the decreased activities of NLRP1 and cleaved-Caspase-1, IL-1β and TNF-α. ATL and NLRP1 siRNA also prevented the presence of apoptosis in the hippocampus of METH-treated rats and the cell death in METH-treated HT22 cells. These results reveal a novel role of NLRP1 and the downstream signaling pathways in the complex actions of METH-induced cognitive deficits.

Patients with Methamphetamine Use Disorder Show Highly Utilized Proactive Inhibitory Control and Intact Reactive Inhibitory Control with Long-Term Abstinence

Methamphetamine use disorder (MUD) is a chronic brain disorder that involves frequent failures of inhibitory control and relapses into methamphetamine intake. However, it remains unclear whether the impairment of inhibitory control in MUD is proactive, reactive or both. To address this issue, the current study used the conditional stop-signal task to assess proactive and reactive inhibitory control in 35 MUD patients with long-term abstinence and 35 matched healthy controls. The results showed that MUD patients with long-term abstinence had greater preparation costs than healthy controls, but did not differ in performance, implying a less efficient utilization of proactive inhibitory control. In contrast, MUD patients exhibited intact reactive inhibitory control; reactive but not proactive inhibitory control was associated with high sensation seeking in MUD patients with long-term abstinence. These findings suggest that proactive and reactive inhibitory control may be two different important endophenotypes of addiction in MUD patients with long-term abstinence. The current study provides new insight into the uses of proactive and reactive inhibitory control to effectively evaluate and precisely treat MUD patients with long-term abstinence.

Treatment outcome, cognitive function, and psychopathology in methamphetamine users compared to other substance users

BACKGROUND

The rising number of people using methamphetamine leads to an increasing need for treatment options for this patient group. Evidence-based research on the efficacy of treatment programs for methamphetamine users is limited. Due to specific characteristics of methamphetamine users, the question arises whether established treatment methods for individuals using other substances can be effective for the treatment of methamphetamine dependence as well. We hypothesize that there are significant differences between the two groups that may affect the effectiveness of treatment and worsen the prognosis of treatment outcomes for methamphetamine users compared to consumers of other substances.

AIM

To investigate potential differences in cognitive functioning and psychopathology between methamphetamine users and other substance users and possible correlations with treatment outcomes.

METHODS

A total of 110 subjects were recruited for an observational, longitudinal study from a German inpatient addiction treatment center: 55 patients with methamphetamine dependence and 55 patients with dependence of other substances (“OS group”). Both groups were examined at beginning (baseline) and end of treatment (after 6 mo) with regard to treatment retention, craving, cognitive functioning, psychosocial resources, personality traits, depression, and other psychiatric symptoms. Instruments used were Raven’s IQ test, Mannheimer craving scale, cognitrone cognitive test battery, NEO personality factors inventory, Hamilton depression scale, Becks depression inventory, and a symptom checklist. The statistical methods used were χ²-test, t-test and multiple mixed ANOVAs.

RESULTS

A total drop-out rate of 40% (methamphetamine-group: 36.4%; OS-group: 43.6%) was observed without significant differences between groups. At baseline, methamphetamine-group subjects significantly differed from OS-group individuals in terms of a lower intelligence quotient, fewer years of education, slower working speed, and decreased working accuracy, as well as less cannabinoid and cocaine use. Methamphetamine-group subjects further showed a significantly lower score of conscientiousness, depressive, and psychiatric symptoms than subjects from the OS-group. In both groups, a reduction of craving and depressive symptoms and an improvement of working speed and working accuracy was noted after treatment.

CONCLUSION

There are differences between methamphetamine users and users of other drugs, but not with regard to the effectiveness of treatment in this inpatient setting. There are differences in cognitive function and psychopathology between methamphetamine and other drugs users. The existing treatment options seem to be an effective approach in treating methamphetamine dependence.

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.

Differences in cognitive deficits in patients with methamphetamine and heroin use disorder compared with healthy controls in a Chinese Han population

BACKGROUND AND AIMS

To date, the pattern of heroin- and methamphetamine-induced cognitive impairment is unclear, especially in the Chinese population. The aim of this study was to compare the similarity and heterogeneity of cognitive impairment between heroin and methamphetamine-dependent patients and to link cognitive impairment to drug-related variables.

METHODS

567 pure methamphetamine patients, 78 pure heroin patients and 201 healthy volunteers participated in this study. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess cognitive function including immediate memory, visuospatial/constructional index, language, attention, delayed memory, and total scores.

RESULTS

Methamphetamine-dependent and heroin-dependent patients performed significantly worse on all RBANS subtest and total scores (all p < 0.05). Moreover, methamphetamine-dependent patients had more delayed memory impairment than heroin-dependent patients (p = 0.02). In addition, some drug-related variables, such as duration of abstinence, age at first drug use, and duration of drug use, were independently associated with memory and visuospatial/constructional index in methamphetamine patients (all p < 0.05). In contrast, none of the drug-related variables were associated with cognitive performance in heroin patients (all p > 0.05).

CONCLUSIONS

Chronic heroin and methamphetamine patients may exhibit different patterns of cognitive deficits.

Heroin Addiction Induces Axonal Transport Dysfunction in the Brain Detected by In Vivo MRI

Heroin is a highly addictive drug that causes axonal damage. Here, manganese-enhanced magnetic resonance imaging (MEMRI) was used to dynamically monitor axonal transport at different stages of heroin addiction. Rat models of heroin addiction (HA) and prolonged heroin addiction (PHA) were established by injecting rats with heroin at different stages. Heroin-induced learning and memory deficits were evaluated in the Morris water maze (MWM), and MEMRI was used to dynamically evaluate axonal transport in the olfactory pathway. The expression of proteins related to axonal structure and function was also assessed by Western blotting. Transmission electron microscopy (TEM) was used to observe ultrastructural changes, and protein levels of neurofilament heavy chain (NF-H) were analyzed by immunofluorescence staining. HA rats, especially PHA rats, exhibited worse spatial learning and memory than control rats. Compared with HA rats and control rats, PHA rats exhibited significantly longer escape latencies, significantly fewer platform-location crossings, and significantly more time in the target quadrant during the MWM test. Mn²⁺ transport was accelerated in HA rats. PHA rats exhibited severely reduced Mn²⁺ transport, and the axonal transport rate (ATR) was significantly lower in these rats than in control rats (P < 0.001). The levels of cytoplasmic dynein and kinesin-1 were significantly decreased in the PHA group than in the control group (P < 0.001); additionally, the levels of energy-related proteins, including cytochrome c oxidase (COX) IV and ATP synthase subunit beta (ATPB), were lower in the PHA group (P < 0.001). The brains of heroin-exposed rats displayed an abnormal ultrastructure, with neuronal apoptosis and mitochondrial dysfunction. Heroin exposure decreased the expression of NF-H, as indicated by significantly reduced staining intensities in tissues from HA and PHA rats (P < 0.05). MEMRI detected axonal transport dysfunction caused by long-term repeated exposure to heroin. The main causes of axonal transport impairment may be decreases in the levels of motor proteins and mitochondrial dysfunction. This study shows that MEMRI is a potential tool for visualizing axonal transport in individuals with drug addictions, providing a new way to evaluate addictive encephalopathy.

The Counterproductive Effect of Right Anodal/Left Cathodal Transcranial Direct Current Stimulation Over the Dorsolateral Prefrontal Cortex on Impulsivity in Methamphetamine Addicts

The current study aimed to evaluate the effect of transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) on behavioral impulsivity in methamphetamine addicts. Forty-five methamphetamine addicts were recruited and randomly divided into active tDCS and sham tDCS groups to receive a daily tDCS intervention for 5 days, with the intensity set to 2 mA for the active group and 0 mA for the sham group. Anodal and cathodal electrodes were, respectively, placed over the right and left DLPFC. Behavioral impulsivity in methamphetamine addicts was examined by the 2-choice oddball task at 3-time points: before tDCS intervention (baseline), after the first intervention (day 1), and after 5 repeated interventions (day 5). Besides, twenty-four healthy male participants were recruited as the healthy controls who completed a 2-choice oddball task. Analysis of accuracy for the 2-choice oddball task showed that behavioral impulsivity was counterproductively increased in the active group, which was shown by the decreased accuracy for the deviant stimulus. The results suggested that the present protocol may not be optimal and other protocols should be considered for the intervention of methamphetamine addicts in the future.

Dynamics of intrinsic whole-brain functional connectivity in abstinent males with methamphetamine use disorder

Background

The global prevalence of methamphetamine use disorder (MUD) and the associated economic burden are increasing, but effective pharmacological treatment is lacking. Therefore, understanding the neurological mechanisms underlying MUD is essential to develop clinical strategies and improve patient care. Individuals with MUD can show static brain network abnormalities during the resting state, but their alterations in dynamic functional network connectivity (dFNC) are unclear.

Methods

In this study, we obtained resting-state functional magnetic resonance imaging from 42 males with MUD and 41 healthy controls. Sliding-window and spatial independent component analyses with a k-means clustering algorithm were used to assess the recurring functional connectivity states. The temporal properties of the dFNC, including fraction and dwelling time of each state and the number of transitions between different states, were compared between the two groups. In addition, the relationships between the temporal properties of the dFNC and clinical characteristics of the MUDs, including their anxiety and depressive symptoms, were further explored.

Results

While the two groups shared many similarities in their dFNC, the occurrence of a highly integrated functional network state and a state featuring balanced integration and segregation in the MUDs significantly correlated with the total drug usage (Spearman's rho = 0.47, P = 0.002) and duration of abstinence (Spearman's rho = 0.38, P = 0.013), respectively.

Conclusions

The observed results in our study demonstrate that methamphetamines can affect dFNC, which may reflect the drug's influence on cognitive abilities. Our study justifies further studies into the effects of MUD on dynamic neural mechanisms.

Combined prior chronic methamphetamine treatment and gp120 expression reduce PPI in aged male but not female mice

Methamphetamine (METH) use disorder is highly prevalent among people with HIV and is a significant public health problem. Furthermore, people with HIV are living longer and using drugs such as METH even into old age, making it important to understand the effects of METH use and aging in this population. HIV, METH, and aging negatively impact a variety of brain functions, including sensorimotor gating (i.e. - automatic, pre-conscious information processing). Sensorimotor gating is often measured using prepulse inhibition (PPI), a paradigm that can be conducted in animals, thereby allowing for preclinical studies. Little is known about how HIV, METH, and aging interact to affect PPI. The goal of this study was therefore to examine how METH affects PPI in aged gp120 mice, a mouse model of HIV. PPI was measured at 8, 14, and 22 months in male and female wild type (WT) and gp120 mice. PPI was also measured during and after METH treatment at 23-24 months. Aging was associated with decreased PPI in both sexes and genotypes. Combined prior METH treatment and gp120 expression caused the greatest reduction in PPI in aged male mice. Prior METH treatment decreased PPI in aged WT female mice, but not aged gp120 female mice. Overall, these results suggest the effects of HIV and METH on information processing seem to be influenced by age and sex. Combined HIV and METH may impair information processing in older men, but not older women.

Cannabidiol inhibits methamphetamine-induced dopamine release via modulation of the DRD1-MeCP2-BDNF-TrkB signaling pathway

RATIONALE

Adaptive alteration of dopamine (DA) system in mesocorticolimbic circuits is an extremely intricate and dynamic process, which contributes to maintaining methamphetamine (METH)-related disorders. There are no approved pharmacotherapies for METH-related disorders. Cannabidiol (CBD), a major non-psychoactive constituent of cannabis, has received attention for its therapeutic potential in treating METH-related disorders. However, the major research obstacles of CBD are the yet to be clarified mechanisms behind its therapeutic potential. Recent evidence showed that DA system may be active target of CBD. CBD could be a promising dopaminergic medication for METH-related disorders.

OBJECTIVES

We investigated the role of the DA receptor D1 (DRD1)-methyl-CpG-binding protein 2 (MeCP2)-brain-derived neurotrophic factor (BDNF)-tyrosine receptor kinase B (TrkB) signaling pathway in DA release induced by METH. Investigating the intervention effects of CBD on the DRD1-MeCP2-BDNF-TrkB signaling pathway could help clarify the underlying mechanisms and therapeutic potential of CBD in METH-related disorders.

RESULTS

METH (400 μM) significantly increased DA release from primary neurons in vitro, which was blocked by CBD (1 μM) pretreatment. METH (400 μM) significantly increased the expression levels of DRD1, BDNF, and TrkB, but decreased the expression of MeCP2 in the neurons, whereas CBD (1 μM) pretreatment notably inhibited the protein changes induced by METH. In addition, DRD1 antagonist SCH23390 (10 μM) inhibited the DA release and protein change induced by METH in vitro. However, DRD1 agonist SKF81297 (10 μM) induced DA release and protein change in vitro, which was also blocked by CBD (1 μM) pretreatment. METH (2 mg/kg) significantly increased the DA level in the nucleus accumbens (NAc) of rats with activation of the DRD1-MeCP2-BDNF-TrkB signaling pathway, but these changes were blocked by CBD (40 or 80 mg/kg) pretreatment.

CONCLUSIONS

This study indicates that METH induces DA release via the DRD1-MeCP2-BDNF-TrkB signaling pathway. Furthermore, CBD significantly inhibits DA release induced by METH through modulation of this pathway.

Computational models of exploration and exploitation characterise onset and efficacy of treatment in methamphetamine use disorder

People with Methamphetamine Use Disorder (PwMUD) spend substantial time and resources on substance use, which hinders their ability to explore alternate reinforcers. Gold‐standard behavioural treatments attempt to remedy this by encouraging action towards non‐drug reinforcers, but substance use often persists. We aimed to unravel the mechanistic drivers of this behaviour by applying a computational model of explore/exploit behaviour to decision‐making data (Iowa Gambling Task) from 106 PwMUD and 48 controls. We then examined the longitudinal link between explore/exploit mechanisms and changes in methamphetamine use 6 weeks later. Exploitation parameters included reinforcement sensitivity and inverse decay (i.e., number of past outcomes used to guide choices). Exploration parameters included maximum directed exploration value (i.e., value of trying novel actions). The Timeline Follow Back measured changes in methamphetamine use. Compared to controls, PwMUD showed deficits in exploitative decision‐making, characterised by reduced reinforcement sensitivity, U = 3065, p = 0.009, and less use of previous choice outcomes, U = 3062, p = 0.010. This was accompanied by a behavioural pattern of frequent shifting between choices, which appeared consistent with random exploration. Furthermore, PwMUD with greater reductions of methamphetamine use at 6 weeks had increased directed exploration (β = 0.22, p = 0.045); greater use of past choice outcomes (β = −0.39, p = 0.002) and greater choice consistency (β = −0.39, p = 0.002). Therefore, limited computational exploitation and increased behavioural exploration characterise PwMUD's presentation to treatment, while increased directed exploration, use of past choice outcomes and choice consistency predict greater reductions of methamphetamine use.

Implication of thyroid hormone receptors in methamphetamine neurocognitive effects

Methamphetamine (MA) induces neurocognitive effects via several mechanisms. In the present study, we investigated the alteration of thyroid hormone receptor's expression in the context of MA-induced memory impairment and explored the protective effects of exogenous thyroid hormones (THs). Male wistar rats, received increasing regime of MA (1-10mg/kg, intraperitoneal, twice a day for 10 days), were treated with T3 (40μg/rat/day; intranasal, 2.5μl/nostril) or T4 (20µg/kg/day; intraperitoneal) for 7 days after MA cessation. All rats were subjected to novel object recognition memory test and then the mRNA levels of TH nuclear receptors (TRα1 and TRβ1) and seladin-1, an anti-apoptotic factor, and the protein level of TH cell surface receptor (integrin αvβ3) were measured in the hippocampus of rats. Our results showed that MA-induced memory impairment is concomitant with decreased level of TRα1 mRNA. T3 or T4 treatment significantly alleviated MA-induced memory impairment, but had no significant effect on the mRNA levels of TH nuclear receptors. However, T4 treatment significantly increased the protein level of cell surface receptor (av subunit) in MA-treated rats. These findings suggest that MA neurocognitive effects can be associated with impaired TH signaling in the brain and introduce this pathway as a promising therapeutic approach against MA-induced memory impairment.

Cellular messenger molecules mediating addictive drug-induced cognitive impairment: cannabinoids, ketamine, methamphetamine, and cocaine

Background

Cognitive impairment is a commonly reported symptom with increasing life spans. Numerous studies have focused on identifying precise targets to relieve or reduce cognitive impairment; however, its underlying mechanism remains elusive. Most patients or animals exposed to addictive drugs exhibit cognitive impairment. Accordingly, the present review discusses the molecular changes induced by addictive drugs to clarify potential mechanisms that mediate cognitive impairments.

Main body

We investigated changes in cognitive function using four drugs: cannabinoids, ketamine, methamphetamine, and cocaine. Chronic administration of most addictive drugs reduces overall cognitive functions, such as working, spatial, and long-term recognition memories. Levels of several transcription factors involved in neuronal differentiation, as well as functional components of neurotransmitter receptors in neuronal cells, are reportedly altered. In addition, inflammatory factors showed a generally increasing trend. These impairments could be mediated by neuroinflammation, synaptic activity, and neuronal plasticity.

Conclusion

This review outlines the effects of acute or chronic drug use and potential molecular alterations in the central nervous system. In the central nervous system, addictive drug-induced changes in molecular pathways associated with cognitive function might play a pivotal role in elucidating the pathogenesis of cognitive impairment.

Temporally dynamic neural correlates of drug cue reactivity, response inhibition, and methamphetamine-related response inhibition in people with methamphetamine use disorder

Cue-induced drug craving and disinhibition are two essential components of continued drug use and relapse in substance use disorders. While these phenomena develop and interact across time, the temporal dynamics of their underlying neural activity remain under-investigated. To explore these dynamics, an analysis of time-varying activation was applied to fMRI data from 62 men with methamphetamine use disorder in their first weeks of recovery in an abstinence-based treatment program. Using a mixed block-event, factorial cue-reactivity/Go-NoGo task and a sliding window across the task duration, dynamically-activated regions were identified in three linear mixed effects models (LMEs). Habituation to drug cues across time was observed in the superior temporal gyri, amygdalae, left hippocampus, and right precuneus, while response inhibition was associated with the sensitization of temporally-dynamic activations across many regions of the inhibitory frontoparietal network. Methamphetamine-related response inhibition was associated with temporally-dynamic activity in the parahippocampal gyri and right precuneus (corrected p-value < 0.001), which show a declining cue-reactivity contrast and an increasing response inhibition contrast. Overall, the declining craving-related activations (habituation) and increasing inhibition-associated activations (sensitization) during the task duration suggest the gradual recruitment of response inhibitory processes and a concurrent habituation to drug cues in areas with temporally-dynamic methamphetamine-related response inhibition. Furthermore, temporally dynamic cue-reactivity and response inhibition were correlated with behavioral and clinical measures such as the severity of methamphetamine use and craving, impulsivity and inhibitory task performance. This exploratory study demonstrates the time-variance of the neural activations undergirding cue-reactivity, response inhibition, and response inhibition during exposure to drug cues, and suggests a method to assess this dynamic interplay. Analyses that can capture temporal fluctuations in the neural substrates of drug cue-reactivity and response inhibition may prove useful for biomarker development by revealing the rate and pattern of sensitization and habituation processes, and may inform mixed cue-exposure intervention paradigms which could promote habituation to drug cues and sensitization in inhibitory control regions.

[Comorbidity of posttraumatic stress disorder and addiction from a biopsychosocial perspective]

Posttraumatic stress disorder and substance use disorder often co-occur within the health care system. Their comorbidity is associated with more serious acute clinical symptomatology, more frequent hospital admissions in state of emergency and significantly lower chances of improvement by psychological and pharmacological treatment. Their comorbidity contributes to dramatically unfavourable courses of illness as regards all biopsychosocial levels. The survey presented will discuss empirical findings from various perspectives: general epidemiology, substance use disorder as risk factor of trauma and PTSD, trauma and PTSD as risk factor of SUD, neurobiological effects of SUD converging towards neurobiology of PTSD, shared common factors of genetics/epigenetics, personality traits, and early developmental stress and trauma. The main focus of analysis will be put on processes that are intrinsically linked to the development and course of both disorders.

Neuronal Abnormalities Induced by an Intelligent Virtual Reality System for Methamphetamine Use Disorder

Methamphetamine use disorder (MUD) is a brain disease that leads to altered regional neuronal activity. Virtual reality (VR) is used to induce the drug cue reactivity. Previous studies reported significant frequency-specific abnormalities in patients with MUD during VR induction of drug craving. However, whether those patients exhibit neuronal abnormalities after VR induction that could serve as the treatment target remains unclear. Here, we developed an integrated VR system for inducing drug related changes and investigated the neuronal abnormalities after VR exposure in patients. Fifteen patients with MUD and ten healthy subjects were recruited and exposed to drug-related VR environments. Resting-state EEG were recorded for 5 minutes twice-before and after VR and transformed to obtain the frequency-specific data. Three self-reported scales for measurement of the anxiety levels and impulsivity of participants were obtained after VR task. Statistical tests and machine learning methods were employed to reveal the differences between patients and healthy subjects. The result showed that patients with MUD and healthy subjects significantly differed in, and power changes after VR. These neuronal abnormalities in patients were associated with the self-reported behavioral scales, indicating impaired impulse control. Our findings of resting-state EEG abnormalities in patients with MUD after VR exposure have the translation value and can be used to develop the treatment strategies for methamphetamine use disorder.

Disruption of regional homogeneity in the brains of chronic methamphetamine users

Previous studies have reported evidence supporting structural and functional alterations in the brains of methamphetamine (MA) users. The aim of the present study was to extend current knowledge regarding brain function(s) in MA users by examining regional homogeneity (ReHo). Chronic MA users (51 male, 46 female), who were undergoing supervised abstinence for 12 to 621 days, and 79 healthy controls (43 male, 36 female) underwent resting-state functional brain magnetic resonance imaging. Voxel-wise whole-brain scale group differences in ReHo were examined. The mean ReHo values of significant clusters were extracted, and linear regression was used to identify factors that contributed to these mean ReHo values. MA users exhibited lower ReHo values in the left orbital part of the inferior frontal gyrus extending to the left insula and left temporal pole, left amygdala, and left fusiform gyrus. MA users also exhibited greater ReHo values in the bilateral pre- and postcentral gyri and right cerebellum. Characteristics of MA use, including duration, duration of abstinence from MA, and age at onset of MA use, demonstrated no reliable contribution to ReHo of the significant clusters. Findings of the present study demonstrated that chronic MA use was associated with regional specific disruption of ReHo, which is relatively independent of structural and functional alterations and, apparently, does not recover after relatively long-term abstinence. This disruption may underlie overall neurocognitive deficits in MA users, which is difficult to recover.

Maybe It's Not the Meth: Considering Biopsychosocial Contributors to Cognitive Impairment in Methamphetamine Polydrug Use

OBJECTIVE

In considering the cognitive harms of methamphetamine (MA) use, there is currently a limited appreciation of the profile of pre-existing, comorbid, or modifiable risk factors for cognitive impairment in individuals with MA-polydrug use who present to clinical services. This is in contrast to the well-recognized evidence in alcohol use groups. The aim of this study was to investigate the biopsychosocial and neuropsychological profiles of MA-polysubstance using individuals reporting cognitive impairment in comparison to an alcohol-using group.

METHODS

A retrospective file audit was undertaken of individuals who presented for assessment to a specialist addiction neuropsychology service and reported either more than 1 year of heavy MA use as part of a polydrug use history (n = 40) or having only used alcohol (n = 27). Clinical histories including demographic, medical, mental health, substance use, and neuropsychological assessment results were extracted from medical records. Between group comparisons were conducted to explore differences in the MA-polydrug vs. the alcohol group.

RESULTS

Individuals in the MA-polydrug group were significantly younger, commenced substance use at an earlier age, were more likely to have an offending history, and experienced an overdose than those in the alcohol group. No differences in comorbid neurodevelopmental, psychiatric or acquired brain injury diagnoses were observed between groups. For neuropsychological functioning, significant group differences were observed in overall IQ, semantic verbal fluency, and psychomotor tracking, where individuals in the alcohol group performed significantly worse.

CONCLUSIONS

Neuropsychological profiles were largely equivalent between groups across cognitive domains, with minor differences in favor of the MA-polydrug group. Relative to the general population, cognitive functioning was reduced for both groups across a range of domains. High rates of comorbid mental health concerns were common across both groups, however, individuals in the MA-polydrug group presented with a higher risk of overall harm from substance use at a significantly younger age which is a unique concern for this group. These findings highlight the importance of considering the biopsychosocial factors, such as age of first use, emotional distress, indirect substance related harms including overdose and blood born virus infection that may be relevant to experiences of cognitive difficulty in MA-polydrug users.

Coenzyme Q10 reduces expression of apoptotic markers in adult rat nucleus accumbens dopaminergic neurons treated with methamphetamine

BACKGROUND

Abuse of addictive drugs such as methamphetamine (METH) has become a global problem, leading to many social, economic, and health disturbances, including neurological and cognitive disorders. Neuronal damage is reported in chronic METH abusers. The neuroprotective role of CoQ10 has been shown in many studies. In the present study, we aimed to assess the pre and post-efficacy of CoQ10 on the dopaminergic neurons of the Nucleus Accumbens (de Miranda et al. in Food Res Int 121:641-647, 2019) in the male adult rats treated with METH.

METHODS

80 rats were randomly divided into eight groups (n = 10), including: negative control (intact), positive control (received 5 mg/kg/day METH/IP), three post-treatment groups (METH + 5, 10, 20 mg/kg CoQ10) and three pre-treatment groups (received 5, 10, 20 mg/kg CoQ10 as pre-treatment for 14 days before METH injection). The expression of Bax, Bcl-2, Bax/Bcl-2 ratio, P53, Caspase-3 and tyrosine hydroxylase in NAc studied using western blotting. Nissl staining was used to study the neuronal density of NAc.

RESULTS

Our results showed that the different doses of CoQ10 in METH-treated animals significantly changed pro-apoptotic proteins' expression in the benefit of neuronal survival of NAc (P < 0.05). Neuronal density in NAc were significantly lower in the METH group compared to the control and CoQ10 treated groups. Pre- and post-treatment with different doses of CoQ10 restored the neuronal damage in NAc.

CONCLUSIONS

CoQ10 could decrease the activation of pro-apoptotic proteins and reduce the neurodegenerative effects induced by METH. From a clinical point of view, it seems that certain antioxidants such as CoQ10 should receive more attention in clinical trial research. We believe that antioxidants could be the promising for drug abuse treatment in the future.

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.

Impact of adolescent methamphetamine use on social cognition: A human-mice reverse translation study

BACKGROUND

Methamphetamine dependence is associated with social cognition deficits that may underpin negative social outcomes. However, there are considerable inter-individual differences in social cognition within people with methamphetamine dependence, with age of onset of methamphetamine use being a potential contributing factor.

MATERIALS AND METHODS

We conducted two sequential studies examining the link between age of onset of methamphetamine use (adolescence versus young adulthood) and performance in social cognition tests: (1) a human cross-sectional study in 95 participants with methamphetamine dependence varying in age of onset (38 with adolescent onset and 57 with adult onset) and 49 drug-naïve controls; (2) a mice study in which we tested the effects of methamphetamine exposure during adolescence versus young adulthood on social interaction and aggression, and their potential neurochemical substrates in the striatal dopaminergic system.

RESULTS

We initially showed that people with methamphetamine dependence who started use in adolescence had higher antisocial beliefs (p = 0.046, Cohen's d=0.42) and worse emotion recognition (p = 0.031, Cohen's d=0.44) than those who started use during adulthood. We reasoned that this could be due to either social cognition deficits leading to earlier onset of methamphetamine use, or methamphetamine-induced neuroadaptive effects specific to adolescence. Mice experiments showed that methamphetamine exposure during adolescence specifically decreased social investigation during social interaction and upregulated striatal tyrosine hydroxylase (p < 0.05, Bonferroni corrected). There was no evidence of adolescent-specific methamphetamine effects on aggression or other measures of dopaminergic function.

CONCLUSION

Together, translational findings demonstrate heightened sensitivity to methamphetamine effects on social cognition during adolescence.

Persistent Deficits in Self-Regulation as a Mediator between Childhood Attention-Deficit/Hyperactivity Disorder Symptoms and Substance Use Disorders

The link between attention-deficit/hyperactivity disorder (ADHD) and substance use disorders (SUDs) has been largely demonstrated. Some scholars have hypothesized that self-regulation mechanisms might play a key role in explaining this association. Objective(s): The current study tested the hypothesis that retrospective childhood ADHD symptoms might lead to more severe SUDs and this association should be mediated by current self-ratings of behavioral disinhibition, inattention, and emotional dysregulation among 204 treatment-seeking adults (male: 67.3%; female: 32.7%) with a primary diagnosis of alcohol use disorder and other SUDs. Methods: The mediational model was estimated through self-report measures of childhood ADHD symptoms (independent variable; WURS), current self-regulation mechanisms (mediators)-behavioral disinhibition (BIS-11 motor subscale), difficulties with attention regulation (MAAS) and emotion regulation (DERS)-and severity of SUDs (dependent variable; SPQ alcohol, illicit and prescribed drugs). Results: The analysis showed that alterations in the self-regulation system fully mediated the association between the severity of childhood ADHD symptoms and SUDs in adulthood. Behavioral disinhibition and difficulties in attention regulation were the most representative alterations in self-regulation processes that explained this association. Conclusions: These findings suggest it is useful to implement several therapeutic approaches (e.g. behavioral, mindfulness-based, and pharmacological) to increase the self-regulation abilities of children and adolescents with ADHD in order to reduce the probability of SUD onset in adulthood. However, future longitudinal neuroimaging and neuropsychological studies are needed to further support the role of self-regulation mechanisms in explaining the prospective association between childhood ADHD symptoms and SUDs in adulthood.

Training and transfer effects of working memory updating training in male abstinent long-term methamphetamine users

Methamphetamine use is associated with cognitive impairments, including executive functioning. These impairments might be cause and/or effect of the drug (re-)use and have, therefore, motivated interventions to improve cognitive functioning. Until now, only very few studies have examined the effect of training working memory updating (WMU), one of the core executive functions, in this population. In the present study, 32 long-term male abstinent methamphetamine inpatients received either a multiple-session WMU training or an active control treatment. All participants performed a number of tasks assessing WMU, inhibition, and task-switching ability- before and after treatment. The WMU-trained patients improved their performance on the trained task and on a non-trained WMU task, reflecting near transfer. However, there was no beneficial training-induced effect for the other tasks, indicating the absence of far transfer. Possible treatment implications of these findings were discussed.

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.

Effects of cytidine-5'-diphosphate choline on gray matter volumes in methamphetamine-dependent patients: A randomized, double-blind, placebo-controlled study

BACKGROUND

Cytidine-5'-diphosphate choline (CDP-choline) has been suggested to exert neuroprotective and neuroreparative effects and may be beneficial for patients with stimulant dependence. This randomized, double-blind, placebo-controlled study in methamphetamine (MA) dependence investigated effects of CDP-choline on the brain structures and their associations with craving and MA use.

METHODS

MA users (n = 44) were randomized to receive 2 g/day of CDP-choline (n = 22) or placebo (n = 22) for 8 weeks. Patients underwent brain magnetic resonance imaging (MRI) at baseline and 8-week follow-up. Healthy individuals (n = 27) were also examined using brain MRI at the same interval. Voxel-based morphometry analysis was conducted to examine changes in gray matter (GM) volumes and their associations with craving and MA use.

RESULTS

Craving for MA was significantly reduced after the 8 week-treatment with CDP-choline (p = 0.01), but not with the placebo treatment (p = 0.10). There was no significant difference in the total number of MA-negative urine samples between the two groups (p = 0.19). With CDP-choline treatment, GM volumes in the left middle frontal gyrus (p = 0.001), right hippocampus (p = 0.009), and left precuneus (p = 0.001) were significantly increased compared to the placebo and control groups. Increased GM volumes in the left middle frontal gyrus with CDP-choline treatment were associated with reduced craving for MA (Spearman's ρ = -0.56, p = 0.03). In addition, the right hippocampal volume increases were positively associated with the total number of MA-negative urine results in the CDP-choline group (Spearman's ρ = 0.67, p = 0.006).

CONCLUSION

Our findings suggest that CDP-choline may increase GM volumes of MA-dependent patients, which may be related to decreases in MA use and craving.

Oxytocin increases physiological linkage during group therapy for methamphetamine use disorder: a randomized clinical trial

Patients and psychotherapists often exhibit behavioral, psychological, and physiological similarity. Here, we test whether oxytocin—a neuropeptide that can enhance expressivity and social perception—influences time-lagged “linkage” of autonomic nervous system responses among participants and facilitators during group therapy. Physiological linkage estimates (n = 949) were created from ten cohorts, each with two facilitators (n = 5) and four to six participants (n = 48), over six weekly sessions of group therapy for methamphetamine use disorder. All participants of a cohort received oxytocin or placebo intranasally in a randomized double-blind procedure before each session. Cardiac interbeat intervals (IBI) were measured continuously during sessions to estimate physiological linkage, operationalized as one cohort-mate’s IBI reactivity during one minute predicting another cohort-mate’s IBI reactivity during the following minute. In oxytocin cohorts, participants and facilitators experienced significant physiological linkage to their cohort-mates (i.e., their physiological responses were predicted by the prior responses of their cohort-mates) and significantly more linkage than people in placebo cohorts. Both effects occurred during the first and second sessions but not later sessions. Results suggest that oxytocin may enhance psychosocial processes often associated with linkage—such as social engagement—in groups and highlight oxytocin’s potential to improve group cohesion during group therapy.

Clinical Trials Registration: NCT02881177, First published on 26/08/2016.

Effects of Acute Drug Administration on Emotion: A Review of Pharmacological MRI Studies

Purpose of review

Many drug users claim to use drugs to cope with negative emotions, which may, in turn, result in persistent emotional blunting or anhedonia even when they are not using drugs. The purpose of this review is to describe the ways acute administration of psychoactive drugs impacts brain regions during emotion-related tasks, as a first step in understanding how drugs influence emotion processing in the brain.

Recent findings

Drugs have varying effects on neural responses to emotional stimuli. In general, alcohol, analgesics, and psychedelics reduce neural reactivity to negative emotional stimuli in the amygdala and other brain regions. Other drugs produce mixed effects: Stimulants such as caffeine and modafinil increase brain activation while viewing emotional stimuli, whereas MDMA decreases activation during presentation of negative images. The effects of cannabinoids (cannabidiol and THC) are mixed. There are also inconsistent findings on the associations between neural responses to emotional stimuli and subjective drug effects.

Summary

Consistent with the notion that individuals might use drugs non-medically to diminish the experience of negative emotions, several drugs of abuse decrease neural responses to negative stimuli in limbic brain regions. These neural actions may underlie the reported 'emotional blunting' of drugs, which may contribute to drug-seeking behavior. Future work is needed to examine these limbic responses in relation to self-reports of changes in affect, both during acute administration and after extended drug use.

Cognition during active methamphetamine use versus remission

OBJECTIVE

To evaluate whether cognitive performance in adults with active methamphetamine use (MA-ACT) differs from cognitive performance in adults in remission from MA use disorder (MA-REM) and adults without a history of substance use disorder (CTLs).

METHOD

MA-ACT (n = 36), MA-REM (n = 48), and CTLs (n = 62) completed the Neuropsychological Assessment Battery (NAB).

RESULTS

The MA-ACT group did not perform significantly worse than CTLs on any NAB Index. The MA-REM group performed significantly (p < 0.050) worse than CTLs on the NAB Memory Index. The MA-ACT group performed significantly better than CTLs and the MA-REM group on the Executive Functions Index.

CONCLUSIONS

Some cognitive deficits are apparent during remission from MA use, but not during active use; this may result in clinical challenges for adults attempting to maintain recovery and continue with treatment.

Methamphetamine abuse disturbs the dopaminergic system to impair hippocampal-based learning and memory: An overview of animal and human investigations

Diverse intellectual functions including memory are some important aspects of cognition. Dopamine is a neurotransmitter of the catecholamine family, which contributes to the experience of pleasure and/or emotional states but also plays crucial roles in learning and memory. Methamphetamine is an illegal drug, the abuse of which leads to long lasting pathological manifestations in the brain. Chronic methamphetamine-induced neurotoxicity results in an alteration of various parts of the memory systems by affecting learning processes, an effect attributed to the structural similarities of this drug with dopamine. An evolving field of research established how cognitive deficits in abusers arise and how they could possibly trigger neurodegenerative disorders. Thus, the drugs-induced tenacious neurophysiological changes of the dopamine system trigger cognitive deficits, thereby affirming the influence of this addictive drug on learning, memory and executive function in human abusers. Here we present an overview of the effects of methamphetamine abuse on cognitive functions, dopaminergic transmission and hippocampal integrity as they have been validated in animals and in humans during the past 20 years.

Development of the Risk of Relapse Assessment Scale for methamphetamine abusers in China

BACKGROUND

Relapse to Methamphetamine (MA) use is among the public concerns nowadays, which result in adverse outcomes associated with physical and mental health problems. This study aimed to develop the Risk of Relapse Assessment Scale (RRAS) for Chinese MA abusers.

METHOD

A sample of 438 MA abusers aged between 17 and 58 years (M ± SD age = 34.08 ± 8.61 years) in compulsory detoxification institutes were randomly divided into sub-sample 1 (n = 223) and sub-sample 2 (n = 215) for conducting exploratory factor analysis and confirmatory factor analysis respectively.

RESULTS

Compared four-factor model with 19 items and three-factor model with 16 items using principal axis factoring, the three-factor solution showed better model fit. Three factors were identified in RRAS: Craving for MA, Social Recognition, and Attitude towards MA which accounted for 50.06 % of the variance in total. The results of confirmation factor analysis demonstrated good model fits (CFI = 0.95; TLI = 0.94; RMSEA = 0.050; GFI = 0.92). The internal consistency analysis indicated that the three-factor model had satisfactory reliability with Cronbach alphas ranging from 0.71 to 0.88 for different factors. Overall, the results showed that the RRAS had good construct validity and satisfactory reliability, suggesting that it was a good instrument for measuring the relapse of MA.

CONCLUSIONS

The RRAS with good psychometric properties provides a promising future for developing effective relapse prevention programs for MA abusers in China.

Methamphetamine use and technology-mediated psychosocial interventions: A mini-review

Engagement with face-to-face psychosocial interventions is often compromised in people using methamphetamine (MA), in the context of high rates of polysubstance use, mental health disorders, cognitive impairment and geographic isolation. Technology-mediated interventions offer flexible ways of engaging with treatment and are readily accessible. This mini-review evaluates evidence from eight studies for the effectiveness of telephone, mHealth (text-messaging and apps) and computer-based interventions for MA use. Two papers from one telephone counselling study showed a small improvement in MA-related outcomes, particularly for individuals in active use. However, a directive counselling style was associated with a higher likelihood of MA use during recovery for those higher in resistance to authority. Text-messaging interventions generally showed small but significant reductions in MA use in non-treatment seekers. When compared, there was no significant difference in level of MA use reduction between interactive, automated and self-monitoring text messages. Studies in other modalities (smartphone app, one trial; computer-based interventions, two trials) did not confer statistically significant reductions in MA use, though were likely impacted by app design and participant characteristics. Preliminary findings hint at the potential effectiveness of telephone counselling in aftercare and the capacity for text-messaging to reach those who are not in treatment. Given the small amount of existing literature, this review discusses the potential value of emerging interventions, the importance of adapting interventions to the characteristics of people who use MA and suggests specific directions for research in each technology modality.

Inhibition of Autophagy In Vivo Extends Methamphetamine Toxicity to Mesencephalic Cell Bodies

Methamphetamine (METH) is a widely abused psychostimulant and a stress-inducing compound, which leads to neurotoxicity for nigrostriatal dopamine (DA) terminals in rodents and primates including humans. In vitro studies indicate that autophagy is a strong modulator of METH toxicity. In detail, suppressing autophagy increases METH toxicity, while stimulating autophagy prevents METH-induced toxicity in cell cultures. In the present study, the role of autophagy was investigated in vivo. In the whole brain, METH alone destroys meso-striatal DA axon terminals, while fairly sparing DA cell bodies within substantia nigra pars compacta (SNpc). No damage to either cell bodies or axons from ventral tegmental area (VTA) is currently documented. According to the hypothesis that ongoing autophagy prevents METH-induced DA toxicity, we tested whether systemic injection of autophagy inhibitors such as asparagine (ASN, 1000 mg/Kg) or glutamine (GLN, 1000 mg/Kg), may extend METH toxicity to DA cell bodies, both within SNpc and VTA, where autophagy was found to be inhibited. When METH (5 mg/Kg × 4, 2 h apart) was administered to C57Bl/6 mice following ASN or GLN, a frank loss of cell bodies takes place within SNpc and a loss of both axons and cell bodies of VTA neurons is documented. These data indicate that, ongoing autophagy protects DA neurons and determines the refractoriness of cell bodies to METH-induced toxicity.

Lactoferrin Protects against Methamphetamine Toxicity by Modulating Autophagy and Mitochondrial Status

Lactoferrin (LF) was used at first as a vehicle to deliver non-soluble active compounds to the body, including the central nervous system (CNS). Nonetheless, it soon became evident that, apart from acting as a vehicle, LF itself owns active effects in the CNS. In the present study, the effects of LF are assessed both in baseline conditions, as well as to counteract methamphetamine (METH)-induced neurodegeneration by assessing cell viability, cell phenotype, mitochondrial status, and specific autophagy steps. In detail, cell integrity in baseline conditions and following METH administration was carried out by using H&E staining, Trypan blue, Fluoro Jade B, and WST-1. Western blot and immuno-fluorescence were used to assess the expression of the neurofilament marker βIII-tubulin. Mitochondria were stained using Mito Tracker Red and Green and were further detailed and quantified by using transmission electron microscopy. Autophagy markers were analyzed through immuno-fluorescence and electron microscopy. LF counteracts METH-induced degeneration. In detail, LF significantly attenuates the amount of cell loss and mitochondrial alterations produced by METH; and mitigates the dissipation of autophagy-related proteins from the autophagy compartment, which is massively induced by METH. These findings indicate a protective role of LF in the molecular mechanisms of neurodegeneration.

Cognitive effectiveness of high-intensity interval training for individuals with methamphetamine dependence: a study protocol for randomised controlled trial

INTRODUCTION

Cognitive deficit is a common syndrome of methamphetamine (MA) dependence. It is related to decision-making, control ability, and social functioning. High-intensity interval training (HIIT) is a training technique that requires people to work out at full intensity during a short period. Many studies have already shown the potential effects of HIIT on cognitive functions. The purpose of this trial is to evaluate the cognitive effects of HIIT on individuals with MA dependence.

METHODS AND ANALYSIS

A total of 240 individuals with MA dependence will be randomly assigned to the HIIT group, moderate-intensity continuous training (MICT) group and control (CON) group. HIIT will consist of a 24-min HIIT exercise on a treadmill. MICT will consist of a 1-h body-mind exercise. CON will be their traditional intervention. The experimental period will be 12 months with 3 interventions weekly for the first 6 months and follow-up for the next 6 months. All subjects will be given cognitive tests at baseline, after intervention and at follow-up. Cognitive performances will be compared by a mixed-model analysis for repeated measures.

DISCUSSION

HIIT training may reduce illicit drug cravings amongst individuals with MA dependence; hence, HIIT may have a good effect on the cognitive functions, such as memory and executive function, of individuals with MA dependence.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2000032492 . Registered on April 30, 2020 ( http://www.chictr.org.cn/edit.aspx?pid=52127&htm=4 ).

Altered fecal microbiota composition in individuals who abuse methamphetamine

As a severe public health problem, methamphetamine (METH) abuse places a heavy burden on families and society. A growing amount of evidence has indicated communication between gut microbiota and the CNS in drug addiction, with associations to neural, endocrine and immune pathways. Thus, we searched for alterations in the gut microbiota and their potential effects in METH users through 16S rRNA gene sequencing. A decreased Shannon index indicated lower bacterial diversity in the METH users than in the age-matched control group. The gut microbial community composition in the METH users was also altered, including reductions in Deltaproteobacteria and Bacteroidaceae abundances and increases in Sphingomonadales, Xanthomonadales, Romboutsia and Lachnospiraceae abundances. Moreover, the Fusobacteria abundance was correlated with the duration of METH use. Enterobacteriaceae, Ruminococcaceae, Bacteroides, and Faecalibacterium had statistically significant correlations with items related to the positive and negative symptoms of schizophrenia and to general psychopathology in the METH users, and all have previously been reported to be altered in individuals with psychotic syndromes, especially depression. Abstraction, one of the items of the cognitive assessment, was positively related to Blautia. These findings revealed alterations in the gut microbiota of METH users, and these alterations may play a role in psychotic syndrome and cognitive impairment. Although the mechanisms behind the links between these disorders and METH abuse are unknown, the relationships may indicate similarities in the pathogenesis of psychosis induced by METH abuse and other causes, providing a new paradigm for addiction and METH use disorder treatment.

Relapse prevention group therapy via video-conferencing for substance use disorder: protocol for a multicentre randomised controlled trial in Indonesia

BACKGROUND

Substance use disorder (SUD) is a leading contributor to the global burden of disease. In Indonesia, the availability of formal treatment for SUD falls short of the targeted coverage. A standardised therapeutic option for SUD with potential for widespread implementation is required, yet evidence-based data in the country are scarce. In this study, we developed a cognitive behavioural therapy (CBT)-based group telemedicine model and will investigate effectiveness and implementability in a multicentre randomised controlled trial.

METHODS

A total of 220 participants will be recruited from the social networks of eight sites in Indonesia: three hospitals, two primary healthcare centres and three rehabilitation centres. The intervention arm will participate in a relapse prevention programme called the Indonesia Drug Addiction Relapse Prevention Programme (Indo-DARPP), a newly developed 12-week module based on CBT and motivational interviewing constructed in the Indonesian context. The programme will be delivered by a healthcare provider and a peer counsellor in a group therapy setting via video-conferencing, as a supplement to participants' usual treatments. The control arm will continue treatment as usual. The primary outcome will be the percentage increase in days of abstinence from the primarily used substance in the past 28 days. Secondary outcomes will include addiction severity, quality of life, motivation to change, psychiatric symptoms, cognitive function, coping, and internalised stigma. Assessments will be performed at baseline (week 0), post-treatment (week 13), and 3 and 12 months post-treatment completion (weeks 24 and 60). Retention, participant satisfaction, and cost-effectiveness will be assessed as the implementation outcomes.

ETHICS AND DISSEMINATION

The study protocol was reviewed and approved by the Ethics Committees of Universitas Indonesia and Kyoto University. The results will be disseminated via academic journals and international conferences. Depending on trial outcomes, the treatment programme will be advocated for adoption as a formal healthcare-based approach for SUD.

TRIAL REGISTRATION NUMBER

UMIN000042186.

Cognitive improvement among abstinent methamphetamine users: A 2-year prospective longitudinal study

BACKGROUND AND OBJECTIVES

The adverse impact of chronic methamphetamine (MA) use on cognitive function has been described in previous studies, but limited evidence is available for abstinent users from prospective longitudinal studies. The aim of the present study was to assess cognitive function of varying abstinent duration.

METHODS

This prospective longitudinal study was conducted with baseline and four follow-up interviews every 6 months over 2 years in 358 MA users in Guangdong province, China. The Montreal Cognitive Assessment (MoCA) was used to measure cognitive function. Generalized estimating equation (GEE) analysis was used to examine within-subjects relationships between abstinence and cognitive consequences over time.

RESULTS

The repeated measure analysis of variance showed significant differences in the total MoCA score and all subscale scores (except Orientation) in the 24 months follow-up. The GEE model showed that abstinence from MA in the past 6 months predicted an increase of 0.66 (95% confidence interval [CI] = 0.29 to 1.05, p = .002) in MoCA score changes compared with the nonabstinence MA users. Abstinence in the past 12, 18, and 24 months predicted an increase in MoCA total score changes of 1.25 (95% CI = -0.23 to 2.74), 2.15 (95% CI = -0.79 to 5.09), and 5.28 (95% CI = -2.01 to 12.58), respectively, but none of these was statistically significant.

DISCUSSION AND CONCLUSIONS

Cognitive function was potentially improved following 6 months of MA abstinence.

SCIENTIFIC SIGNIFICANCE

This study extends prior research by long-term follow-up in big sample MA abstinence users. Findings from study support the need for a comprehensive measure to decrease MA use and promote the recovery of cognitive impairment.

Methamphetamine exacerbates pathophysiology of traumatic brain injury at high altitude. Neuroprotective effects of nanodelivery of a potent antioxidant compound H-290/51

Military personnel are often exposed to high altitude (HA, ca. 4500-5000m) for combat operations associated with neurological dysfunctions. HA is a severe stressful situation and people frequently use methamphetamine (METH) or other psychostimulants to cope stress. Since military personnel are prone to different kinds of traumatic brain injury (TBI), in this review we discuss possible effects of METH on concussive head injury (CHI) at HA based on our own observations. METH exposure at HA exacerbates pathophysiology of CHI as compared to normobaric laboratory environment comparable to sea level. Increased blood-brain barrier (BBB) breakdown, edema formation and reductions in the cerebral blood flow (CBF) following CHI were exacerbated by METH intoxication at HA. Damage to cerebral microvasculature and expression of beta catenin was also exacerbated following CHI in METH treated group at HA. TiO2-nanowired delivery of H-290/51 (150mg/kg, i.p.), a potent chain-breaking antioxidant significantly enhanced CBF and reduced BBB breakdown, edema formation, beta catenin expression and brain pathology in METH exposed rats after CHI at HA. These observations are the first to point out that METH exposure in CHI exacerbated brain pathology at HA and this appears to be related with greater production of oxidative stress induced brain pathology, not reported earlier.

Functional connectivity abnormalities underlying mood disturbances in male abstinent methamphetamine abusers

Anxiety and depression are the most common withdrawal symptoms of methamphetamine (METH) abuse, which further exacerbate relapse of METH abuse. To date, no effective pharmacotherapy exists for METH abuse and its withdrawal symptoms. Therefore, understanding the neuromechanism underlying METH abuse and its withdrawal symptoms is essential for developing clinical strategies and improving patient care. The aims of this study were to investigate brain network abnormalities in METH abusers (MAs) and their associations with affective symptoms. Forty-eight male abstinent MAs and 48 age-gender matched healthy controls were recruited and underwent resting state functional magnetic resonance imaging (fMRI). The severity of patient anxiety and depressive symptoms were measured by Hamilton anxiety and depression rating scales, which decreased across the duration of abstinence. Independent component analysis was used to investigate the brain network functional connectivity (FC) properties. Compared with healthy controls, MAs demonstrated hypo-intra-network FC in the cerebellar network and hyper-intra-network FC in the posterior salience network. A whole-brain regression analysis revealed that FC strength of clusters located in the right rostral anterior cingulate cortex (rACC) within the ventromedial network (VMN) was associated with affective symptoms in the patients. Importantly, the intra-network FC strength of the rACC in VMN mediated the association between abstinence duration and the severity level of affective symptoms. Our results demonstrate alterations in brain functional networks underlying METH abuse, and that the FC of rACC within VMN serve as a neural substrate in the association between abstinence length and affective symptom severity in the MAs.

The Role of HSP90α in Methamphetamine/Hyperthermia-Induced Necroptosis in Rat Striatal Neurons

Methamphetamine (METH) is one of the most widely abused synthetic drugs in the world. The users generally present hyperthermia (HT) and psychiatric symptoms. However, the mechanisms involved in METH/HT-induced neurotoxicity remain elusive. Here, we investigated the role of heat shock protein 90 alpha (HSP90α) in METH/HT (39.5°C)-induced necroptosis in rat striatal neurons and an in vivo rat model. METH treatment increased core body temperature and up-regulated LDH activity and the molecular expression of canonical necroptotic factors in the striatum of rats. METH and HT can induce necroptosis in primary cultures of striatal neurons. The expression of HSP90α increased following METH/HT injuries. The specific inhibitor of HSP90α, geldanamycin (GA), and HSP90α shRNA attenuated the METH/HT-induced upregulation of receptor-interacting protein 3 (RIP3), phosphorylated RIP3, mixed lineage kinase domain-like protein (MLKL), and phosphorylated MLKL. The inhibition of HSP90α protected the primary cultures of striatal neurons from METH/HT-induced necroptosis. In conclusion, HSP90α plays an important role in METH/HT-induced neuronal necroptosis and the HSP90α-RIP3 pathway is a promising therapeutic target for METH/HT-induced neurotoxicity in the striatum.

Effects of Aerobic Exercise on Cognitive Function in Women With Methamphetamine Dependence in a Detoxification Program in Tianjin, China: A Randomized Controlled Trial

BACKGROUND

Cognitive impairment is prevalent among individuals, especially women, with methamphetamine dependence. Although aerobic exercise has been shown to affect cognitive function in humans and animals, few related studies have focused on subjects with methamphetamine dependence.

PURPOSE

The aim of this study was to assess the detoxification-related effects of aerobic exercise on cognitive function in women with methamphetamine dependence.

METHODS

A randomized controlled trial was used with 98 women with methamphetamine dependence undergoing a detoxification program at a mental hospital. The women were distributed using a computer-generated grouping random method into either the study or control group. The investigator conducting the baseline questionnaire, the neuropsychologist assessing the cognitive function, and the data analyst were blinded to group assignment. In addition to hospital routine care, the study group received an aerobic exercise intervention for 3 months. The control group only received hospital routine care. Attention and working memory were measured using the Trail Making Test and Digit Span Test, verbal memory was measured using Logical Memory (LM) and Memory for Persons Data (MPD), and executive function was measured using the Color-Word Stroop Test.

RESULTS

Forty-nine participants were randomized into each group, and the valid data of 43 participants in the study group and 46 in the control group were analyzed. The study group showed significantly more improvement over time in terms of Digit Span Test, Trail Making Test, LM-delayed, MPD-5 minutes delayed, MPD-30 minutes delayed, and Color-Word Stroop Test than the control group (p < .05). LM-immediate and MPD-immediate scores showed that the effects of time and the interaction between time and group were significant but that the main effect of group was not.

CONCLUSIONS/IMPLICATIONS FOR PRACTICE

Women undergoing detoxification for methamphetamine dependence may practice aerobic exercise to improve attention, working memory, executive function, and parts of verbal memory. Aerobic exercise may be incorporated into detoxification treatment programs to facilitate the recovery of cognitive functions in women.

Methamphetamine in Orthopaedics: Considerations of an At-Risk Population

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Methamphetamine use by orthopaedic trauma patients has risen to epidemic proportions.

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Perioperative methamphetamine use by orthopaedic trauma patients requires physicians to consider both medical and psychosocial factors during treatment.

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Behavioral and psychosocial effects of methamphetamine use present barriers to care.

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Patients who use methamphetamine face elevated rates of complications.

Astrocyte-selective STAT3 knockdown rescues methamphetamine withdrawal-disrupted spatial memory in mice via restoring the astrocytic capacity of glutamate clearance in dCA1

Methamphetamine (METH) is a common abused drug. METH-triggered glutamate (Glu) levels in dorsal CA1 (dCA1) could partially explain the etiology of METH-caused abnormal memory, but the synaptic mechanism remains unclear. Here, we found that METH withdrawal disrupted spatial memory in mice, accompanied by the increases in Glu levels and postsynaptic neuronal activities at dCA1 synapses. METH withdrawal weakened the capacity of Glu clearance in astrocytes, as indicated by increasing the A1-like astrocytes and phosphorylated signal transducer and activator of transcription 3 (p-STAT3), decreasing the Glu transporter 1(GLT-1, also known as EAAT2 or SLC1A2), Glu-aspartate-transporter (GLAST also known as EAAT1 or SLC1A3) and astrocytic glutamine synthase (GS), but failed to affect the presynaptic Glu release from dCA3 within dCA1. Moreover, we identified that in vitro A1-like astrocytes exhibited an increased STAT3 activation and the impaired capacity of Glu clearance. Most importantly, selective knockdown of astrocytic STAT3 in vivo in dCA1 restored the astrocytic capacity of Glu clearance, normalized Glu levels at dCA1 synapses, and finally rescued METH withdrawal-disrupted spatial memory in mice. Thus, astrocytic Glu clearance system, especially STAT3, serves as a novel target for future therapies against METH neurotoxicity.

Current Practices of Electroconvulsive Therapy in Mental Disorders: A Systematic Review and Meta-Analysis of Short and Long-Term Cognitive Effects

ABSTRACT

Electroconvulsive therapy (ECT) remains one of the most effective treatments for major depressive disorder, but uncertainties persist regarding the cognitive tests to include in ECT follow-up. The current study is a systematic review and meta-analysis of the most frequent cognitive side effects after ECT. We also discuss the most common cognitive tests in ECT follow-up. We searched studies published from 2000 to 2017 in English and French language in Pubmed, EBM Reviews, EMBASE, and PsycINFO. Standardized cognitive tests were separated into 11 cognitive domains. Comparisons between cognitive measures included pre-ECT baseline with post-ECT measures at 3 times: PO1, immediately post-ECT (within 24 hours after last ECT); PO2, short term (1-28 days); and PO3, long term (more than 1 month). A total of 91 studies were included, with an aggregated sample of 3762 individuals. We found no significant changes in global cognition with Mini-Mental State Examination at PO1. Hedges g revealed small to medium effect sizes at PO2, with individuals presenting a decrease in autobiographical memory, verbal fluency, and verbal memory. Verbal fluency problems showed an inverse correlation with age, with younger adults showing greater deficits. At PO3, there is an improvement on almost all cognitive domains, including verbal fluency and verbal memory. There is a lack of standardization in the choice of cognitive tests and optimal cognitive timing. The Mini-Mental State Examination is the most common screening test used in ECT, but its clinical utility is extremely limited to track post-ECT cognitive changes. Cognitive assessment for ECT purposes should include autobiographical memory, verbal fluency, and verbal memory.

A unifying translational framework to advance treatment research for comorbid PTSD and substance use disorders

We provide a unifying translational framework that can be used to synthesize extant lines of human laboratory research in four neurofunctional domains that underlie the co-occurrence of posttraumatic stress and substance use disorders (PTSD+SUD). We draw upon the Alcohol and Addiction Research Domain Criteria (AARDOC) to include executive functioning, negative emotionality, reward, and added social cognition from the National Institute of Mental Health (NIMH) Research Domain Criteria into our framework. We review research findings across each of the four domains, emphasizing human experimental studies in PTSD, SUD, and PTSD+SUD for each domain. We also discuss the implications of research findings for treatment development by considering new ways of conceptualizing risk factors and outcomes at the level of the individual patient, which will enhance treatment matching and advance innovations in intervention.