Characterizing methamphetamine withdrawal in recently abstinent methamphetamine users: a pilot field study

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Neuropharmacological Evidence Implicating Drug-Induced Glutamate Receptor Dysfunction in Affective and Cognitive Sequelae of Subchronic Methamphetamine Self-Administration in Mice

Methamphetamine (MA) is a highly addictive drug, and MA use disorder is often comorbid with anxiety and cognitive impairment. These comorbid conditions are theorized to reflect glutamate-related neurotoxicity within the frontal cortical regions. However, our prior studies of MA-sensitized mice indicate that subchronic, behaviorally non-contingent MA treatment is sufficient to dysregulate glutamate transmission in mouse brain. Here, we extend this prior work to a mouse model of high-dose oral MA self-administration (0.8, 1.6, or 3.2 g/L; 1 h sessions × 7 days) and show that while female C57BL/6J mice consumed more MA than males, MA-experienced mice of both sexes exhibited some signs of anxiety-like behavior in a behavioral test battery, although not all effects were concentration-dependent. No MA effects were detected for our measures of visually cued spatial navigation, spatial learning, or memory in the Morris water maze; however, females with a history of 3.2 g/L MA exhibited reversal-learning deficits in this task, and mice with a history of 1.6 g/L MA committed more working-memory incorrect errors and relied upon a non-spatial navigation strategy during the radial-arm maze testing. Relative to naïve controls, MA-experienced mice exhibited several changes in the expression of certain glutamate receptor-related proteins and their downstream effectors within the ventral and dorsal areas of the prefrontal cortex, the hippocampus, and the amygdala, many of which were sex-selective. Systemic pretreatment with the mGlu1-negative allosteric modulator JNJ 162596858 reversed the anxiety-like behavior expressed by MA-experienced mice in the marble-burying test, while systemic pretreatment with NMDA or the NMDA antagonist MK-801 bi-directionally affected the MA-induced reversal-learning deficit. Taken together, these data indicate that a relatively brief history of oral MA is sufficient to induce some signs of anxiety-like behavior and cognitive dysfunction during early withdrawal that reflect, at least in part, MA-induced changes in the corticolimbic expression of certain glutamate receptor subtypes of potential relevance to treating symptoms of MA use disorder.

Methamphetamine Toxicities and Clinical Management

Methamphetamine Toxicities and Clinical ManagementMethamphetamine increases the release and blocks the uptake of norepinephrine, serotonin, and dopamine. This article reviews the morbidity and mortality associated with methamphetamine use and discusses prevention and treatment strategies.

Clinical management of psychostimulant withdrawal: review of the evidence

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

Effects of resilience on impulsivity, cognition and depression during protracted withdrawal among Chinese male methamphetamine users

BACKGROUND

Methamphetamine (METH) dependence is a complex and dynamic public health problem. Long-term abuse of METH can increase numerous risks of mental and physical problems. Currently, the methods to reduce METH dependence and improve the withdrawal symptoms are limited and ineffective. Resilience is seen as a multidimensional and dynamic capability to recover or bounce back from stressful events and is also generally considered as a protective factor against mental dysfunction.

METHODS

One hundred thirty-four males with METH dependence were consecutively recruited from Huanglong Compulsory Isolated Detoxification Center between 2019 and 2021, of whom 112 were into the group. The Connor-Davidson Resilience Scale (CD-RISC), Self-rating depression scale (SDS), Self-rating anxiety scale (SAS), Barratt Impulsiveness Scale-11(BIS-11), and the Repeatable Battery for the Assessment of Neuropsychological Status (Rbans) were used to evaluate resilience, depression, anxiety, impulsivity, and cognition respectively.

RESULTS

The results mainly indicated that high resilience group showed lower SDS, SAS and BIS-11 scores than low resilience group (all p < 0.05). Besides, the total scores of Rbans were higher in high resilience groups than low resilience group (both p < 0.05). Moreover, linear regression results showed that resilience may be influenced by the scores of SDS and SAS.

CONCLUSIONS

Resilience is negatively correlated with impulsivity and depression. Besides, it is also positively associated with cognitive function. Drug users with higher resilience may have a strong ability to mobilize psychological resources to create a good psychological environment, which may have a positive effect on the relief or improvement of symptoms.

Goofballing of Opioid and Methamphetamine: The Science Behind the Deadly Cocktail

Globally, millions of people suffer from various substance use disorders (SUD), including mono-and polydrug use of opioids and methamphetamine. Brain regions such as the cingulate cortex, infralimbic cortex, dorsal striatum, nucleus accumbens, basolateral and central amygdala have been shown to play important roles in addiction-related behavioral changes. Clinical and pre-clinical studies have characterized these brain regions and their corresponding neurochemical changes in numerous phases of drug dependence such as acute drug use, intoxication, craving, withdrawal, and relapse. At present, many studies have reported the individual effects of opioids and methamphetamine. However, little is known about their combined effects. Co-use of these drugs produces effects greater than either drug alone, where one decreases the side effects of the other, and the combination produces a prolonged intoxication period or a more desirable intoxication effect. An increasing number of studies have associated polydrug abuse with poorer treatment outcomes, drug-related deaths, and more severe psychopathologies. To date, the pharmacological treatment efficacy for polydrug abuse is vague, and still at the experimental stage. This present review discusses the human and animal behavioral, neuroanatomical, and neurochemical changes underlying both morphine and methamphetamine dependence separately, as well as its combination. This narrative review also delineates the recent advances in the pharmacotherapy of mono- and poly drug-use of opioids and methamphetamine at clinical and preclinical stages.

The Association of High-Frequency Nut Intake With a Low Risk of Psychological Problems in Female Methamphetamine Users

BACKGROUND

Recent years have witnessed a gradual increase in the number of female methamphetamine users. Meanwhile, female methamphetamine users are more likely to have psychological problems than male methamphetamine users. The association between diet and psychological problems have been found among non-methamphetamine user. The present study aims to investigate the relationship between dietary intake frequency and psychological problems in female methamphetamine users.

MATERIALS AND METHODS

A total of 109 female methamphetamine users, collected from a Compulsory Isolated Drug Rehabilitation Centre in northern China, participated in the study. All participants completed the Symptom Checklist 90 (SCL-90) questionnaire to assess psychological status. The relation of dietary intake frequency with the SCL-90 score was tested in partial correlation analysis. Multivariable regression models were used to calculate odds ratios to evaluate the association of dietary intake frequency with psychological problems.

RESULTS

Of the current female methamphetamine population, 33 participants were diagnosed with psychological problems using SCL-90. In the terms of dietary intake frequency, the frequency of nut intake in the psychiatric symptom group was significantly lower than that in the asymptomatic group. However, there was no difference in the frequency of other food intakes between the two groups. The frequency of nut intake was negatively correlated with the total score of SCL-90 and 8 different symptom clusters of psychopathologies on SCL-90. Logistic regression analysis indicated that the increased frequency of nut intake was associated with a lower risk of psychological problems.

CONCLUSION

In the female methamphetamine population, increasing the frequency of nut intake may reduce the risk of psychological problems for female methamphetamine users.

Utility of a controlled amphetamine withdrawal paradigm among adults who use methamphetamine: A pilot clinical trial

BACKGROUND

The continued increase in prevalence of methamphetamine use in the United States has resulted in a significant increase in the number of patients entering treatment for methamphetamine use. However, no robustly efficacious pharmacologic treatment for methamphetamine use or withdrawal has been identified to date after stopping methamphetamine use.

AIMS

Given the association between methamphetamine withdrawal and relapse during early treatment, this study tested a controlled d-amphetamine withdrawal paradigm among methamphetamine-using individuals.

METHODS

Treatment-seeking adults who used methamphetamine (N = 34; 47% female; 100% white) were enrolled in a 4-week, randomized, double-blind, placebo-controlled trial in a residential setting, in which all participants were maintained on d-amphetamine (30 mg BID) during week 1, then half were switched to placebo during weeks 2-3. All participants received placebo during week 4. Outcomes included vital signs, withdrawal, cravings for methamphetamine, mood, and cognition. Bivariate analyses tested treatment group differences on baseline demographic and outcome variables. Repeated measures models examined main and interaction effects of treatment over time.

RESULTS/OUTCOMES

Participants were successfully randomized and safely stabilized on d-amphetamine. Craving for methamphetamine increased during weeks 2-3 in the placebo group relative to those on d-amphetamine. Interactions with age and heart rate were noted.

CONCLUSIONS/INTERPRETATION

To our knowledge, this is the first double-blind, placebo-controlled trial measuring pharmacologic effects of abruptly stopping controlled d-amphetamine administration in adults who use methamphetamine. Results support the potential of this withdrawal paradigm to further examine the efficacy of pharmacologic agents in ameliorating methamphetamine withdrawal symptoms.

Methamphetamine and sleep impairments: neurobehavioral correlates and molecular mechanisms

Methamphetamine is a potent and highly addictive psychostimulant, and one of the most widely used illicit drugs. Over recent years, its global usage and seizure have been on a rapid rise, with growing detrimental effects on mental and physical health, and devastating psychosocial impact pressing for intervention. Among the unwanted effects of methamphetamine, acute and long-term sleep impairments are of major concern, posing a significant therapeutic challenge, and a cause of addiction relapse. Unraveling mechanisms and functional correlates of methamphetamine-related sleep and circadian disruption are, therefore, of key relevance to translational and clinical psychiatry. In this article, we review the mounting evidence for the acute and long-term impairements of sleep-wake behavior and circadian activity caused by single or recurring methamphetamine usage and withdrawal. Factors contributing to the severity of sleep loss and related cognitive deficit, with risks of relapse are discussed. Key molecular players mediating methamphetamine-induced dopamine release and neuromodulation are considered, with wake-promoting effects in mesolimbic circuits. The effects on various sleep phases and related changes in dopamine levels in selected subcortical structures are reviewed and compared to other psychostimulants with similar action mechanisms. A critical appraisal is presented of the therapeutic use of modafinil, countering sleep, and circadian rhythm impairments. Finally, emerging knowledge gaps and methodical limitations are highlighted along with the areas for future research and therapeutic translation.

Sleep and substance use disorder treatment: A preliminary study of subjective and objective assessment of sleep during an intensive outpatient program

BACKGROUND AND OBJECTIVES

Characteristics of sleep concerns and their relationship to mental health in heterogeneous substance use disorder (SUD) treatment settings are not well understood. The purpose of this preliminary study was to assess sleep using subjective and objective measures at two time points during SUD treatment and compare sleep changes to changes in mental health measures.

METHODS

Treatment-seeking participants completed an assessment battery at the beginning of treatment (Time 1, N = 30) and again upon treatment completion (Time 2, approximately 4 weeks later, N = 22). The majority of participants were White (80%), male (63%), and presenting for alcohol use disorder (60.0%), though almost half reported polysubstance abuse (43%). Comorbidity was common (53%). Sleep and mental health questionnaires with 1 week of actigraphy and sleep diaries were completed at both time points.

RESULTS

Most participants met the criteria for a sleep disorder and mean scores on questionnaires showed poor sleep quality, insomnia symptoms, and frequent nightmares, with sleep quality and insomnia improving over time but remaining clinically significant. Nightmares did not improve. Actigraphy indicated poor sleep at both time points. Improvement in insomnia was related to improvement in measures of mental health while changes in actigraphy variables were not related to these measures.

DISCUSSION AND CONCLUSIONS

Multiple types of sleep disturbance are prevalent in this population, with nightmares persisting throughout treatment and insomnia symptoms showing a relationship with mental health symptoms.

SCIENTIFIC SIGNIFICANCE

This was the first study to longitudinally assess mental health with subjective and objective measures of sleep across multiple types of SUDs in a community SUD treatment setting.

Immune to addiction: how immunotherapies can be used to combat methamphetamine addiction

Introduction: The concept of anti-methamphetamine (METH) immunotherapies is a few decades old. A substantial amount of information has been generated on the development of anti-METH immunotherapies, particularly in the preclinical stages of development of vaccines and monoclonal antibody (mAb) treatments. However, the concept of treating METH use addiction with anti-METH immunotherapies is not well understood by many researchers or general readers. A series of questions commonly arise regarding the concept: how does it work? What is the antigen used? How exactly does the vaccine prevent METH addiction?Areas covered: This paper reviews the published articles relating to the mechanisms of METH use disorders, strategies used in the development of anti-METH immunotherapies, and the mechanism of action of these treatments. It provides clear explanations to questions surrounding the basis of anti-METH immunotherapies and contextualizes their development. It also identifies areas for future investigation to speed their translation into clinical use.Expert opinion: While METH immunotherapies, including vaccines and mAbs, have progressed significantly in the last 30 years, there are newer approaches that should be evaluated to improve their translatability. Approaches including nanoparticle vaccines, virus-like particles, and other novel methods should be fully evaluated as means of generating anti-METH immunity.

Factors associated with methamphetamine withdrawal symptoms among people who inject drugs

BACKGROUND

Regular methamphetamine (MA) use can result in withdrawal syndrome characterized by fatigue, agitation, depression, and anxiety. No studies that we are aware of have examined the prevalence and predictors of MA withdrawal symptoms among people who inject drugs (PWID).

METHODS

PWID were recruited using targeted sampling methods in Los Angeles and San Francisco, California from 2016 to 2017. Survey questions included demographics, drug use, and MA withdrawal symptoms, frequency, and symptom severity. Participants who reported regular MA use (> 12 times in the last 30 days) were included in this analysis (N = 595). Multivariable regression models were developed to examine factors associated with any MA withdrawal, withdrawal frequency, symptom severity, and receptive syringe sharing.

RESULTS

MA withdrawal symptoms in the past 6 months were reported by 53 % of PWID, with 25 % reporting weekly withdrawal symptoms, and 20 % reporting very or extremely painful symptoms. In multivariable logistic regression, presence of any MA withdrawal symptoms was positively associated with more frequent MA use and non-injection tranquilizer use and inversely associated with crack cocaine use. Among those reporting any withdrawal, female sex was associated with more frequent withdrawal symptoms. Very or extremely painful withdrawal symptoms were associated with being in residential treatment. Receptive syringe sharing was associated with any MA withdrawal symptoms and weekly frequency of symptoms.

CONCLUSION

MA withdrawal symptoms are common among PWID and are associated with receptive syringe sharing. Strategies for implementing MA use treatment, safe supply programs, and syringe services programs targeting people who inject MA are indicated.

Prognostic plasma exosomal microRNA biomarkers in patients with substance use disorders presenting comorbid with anxiety and depression

Psychiatric disorders such as anxiety and depression precipitated by substance use occurred during both use and withdrawal. Exosomes play significant roles in biological functions and regulate numerous physiological and pathological processes in various diseases, in particular substance use disorders (SUDs) and other psychiatric disorders. To better understand the role of exosomal miRNAs in the pathology of symptoms of anxiety and depression in patients with SUDs, we first isolated circulating exosomes from heroin-dependent patients (HDPs) and methamphetamine-dependent patients (MDPs) and identified exosomal miRNAs that were differentially expressed between patients and healthy controls (HCs). Furthermore, the correlations between exosomal DE-miRNAs and symptoms of anxiety and depression which were measured using Hamilton-Anxiety (HAM-A)/Hamilton-Depression (HAM-D) Rating Scales in the participants. Notably, the expression level of exosomal hsa-miR-16-5p, hsa-miR-129-5p, hsa-miR-363-3p, and hsa-miR-92a-3p showed significantly negative correlations with HAM-A scores in both HDPs and MDPs. But all of the 4 DE-miRNAs lost significant correlations with HAM-D scores in HDPs. Functional annotation analyses showed that the target genes of the DE-miRNAs were mainly enriched for “synapse”, “cell adhesion”, “focal adhesion” and “MHC class II protein complex”. Our study suggests that a set of circulating exosomal miRNAs were associated with anxiety and depression in SUD patients and may have clinical utility as diagnostic and prognostic biomarkers.

Vaccine development against methamphetamine drug addiction

INTRODUCTION

There are currently no effective treatments for Methamphetamine (METH) addiction and psychotherapy remains the sole treatment option. The development of immunopharmacotherapies for the treatment of drug addiction, overdose, and relapse management appears to be promising alternative and a significant body of information has been generated using various vaccine development strategies. Herein, we present an update on the developments toward anti-METH vaccines and their study outcomes in preclinical and clinical studies.

AREAS COVERED

The scope of this article is to present an update on METH vaccine development strategies such as active vaccination through hapten design and the passive immunization through monoclonal antibodies along with preclinical and clinical studies. The relevant literatures and clinical trial outcomes were searched in databases including Google, Google Scholar, PubMed, Science Direct, ClinicalTrials.gov, and www.anzctr.org.au using specific keywords.

EXPERT OPINION

Significant improvements have been developed for immunopharmacotherapies for METH addiction over the last two decades. However, only one monoclonal antibody candidate has been evaluated in a phase I clinical trial. At this moment, it is essential to evaluate the safety and efficacy of potential candidates in clinical trials to validate the importance of this platform drug-vaccine conjugation in order to manage or overcome METH addiction.

TBHQ Attenuates Neurotoxicity Induced by Methamphetamine in the VTA through the Nrf2/HO-1 and PI3K/AKT Signaling Pathways

Methamphetamine (METH) leads to nervous system toxicity. Long-term exposure to METH results in damage to dopamine neurons in the ventral tegmental area (VTA), and depression-like behavior is a clinical symptom of this toxicity. The current study was designed to investigate whether the antioxidant tertiary butylhydroquinone (TBHQ) can alleviate neurotoxicity through both antioxidative stress and antiapoptotic signaling pathways in the VTA. Rats were randomly divided into a control group, a METH-treated group (METH group), and a METH+TBHQ-treated group (METH+TBHQ group). Intraperitoneal injections of METH at a dose of 10 mg/kg were administered to the rats in the METH and METH+TBHQ groups for one week, and METH was then administered at a dose that increased by 1 mg/kg per week until the sixth week, when the daily dosage reached 15 mg/kg. The rats in the METH+TBHQ group received 12.5 mg/kg TBHQ intragastrically. Chronic exposure to METH resulted in increased immobility times in the forced swimming test (FST) and tail suspension test (TST) and led to depression-like behavior. The production of reactive oxygen species (ROS) and apoptosis levels were increased in the VTA of animals in the METH-treated group. METH downregulated Nrf2, HO-1, PI3K, and AKT, key factors of oxidative stress, and the apoptosis signaling pathway. Moreover, METH increased the caspase-3 immunocontent. These changes were reversed by treatment with the antioxidant TBHQ. The results indicate that TBHQ can enhance Nrf2-induced antioxidative stress and PI3K-induced antiapoptotic effects, which can alleviate METH-induced ROS and apoptosis, and that the crosstalk between Nrf2 and PI3K/AKT is likely the key factor involved in the protective effect of TBHQ against METH-induced chronic nervous system toxicity.

Depression-like symptoms of withdrawal in a genetic mouse model of binge methamphetamine intake

Binge methamphetamine (MA) users have higher MA consumption, relapse rates and depression-like symptoms during early periods of withdrawal, compared with non-binge users. The impact of varying durations of MA abstinence on depression-like symptoms and on subsequent MA intake was examined in mice genetically prone to binge-level MA consumption. Binge-level MA intake was induced using a multiple-bottle choice procedure in which mice were offered one water drinking tube and three tubes containing increasing concentrations of MA in water, or four water tubes (control group). In two studies, depression-like symptoms were measured using a tail-suspension test and a subsequent forced-swim test, after forced abstinence of 6 and 30 hours from a 28-day course of chronic MA intake. An additional study measured the same depression-like symptoms, as well as MA intake, after prolonged abstinence of 1 and 2 weeks. MA high drinking mice and one of their progenitor strains DBA/2J escalated their MA intake with increasing MA concentration; however, MA high drinking mice consumed almost twice as much MA as DBA/2J mice. Depression-like symptoms were significantly higher early after MA access was withdrawn, compared to levels in drug-naïve controls, with more robust effects of MA withdrawal observed in MA high drinking than DBA/2J mice. When depression-like symptoms were examined after 1 or 2 weeks of forced abstinence in MA high drinking mice, depression-like symptoms dissipated, and subsequent MA intake was high. The MA high drinking genetic mouse model has strong face validity for human binge MA use and behavioral sequelae associated with abstinence.

Profile of psychiatric symptoms in methamphetamine users in China: Greater risk of psychiatric symptoms with a longer duration of use

Chronic methamphetamine (MA) use is associated with psychiatric symptoms. This study explored pattern of co-occurring psychiatric symptoms in MA users and their relationship to duration of MA use. A cross-sectional study was conducted among MA users at the Shenzhen Compulsory Drug Detoxification Center from April 2012 to October 2015. The Positive and Negative Syndrome Scale, Hamilton Anxiety Scale, and Beck Depression Inventory were used to assess psychiatric symptoms. Among 1277 MA users, 57.6% participants had any type of psychiatric symptoms including depressive, anxiety and psychotic symptoms. A dose-response relationship was found between duration of MA use and risk of psychiatric symptoms. The odds ratios (OR) of depressive symptoms increased with the duration of MA use (1-5 years vs. < 1 year: 1.74 [95% CI, 1.24-2.42]; ≥ 5 years vs. < 1 year: 2.07 [1.19-3.61]), so did the ORs of co-occurring anxiety and depressive symptoms (1-5 years: 1.74 [1.20-2.51]; ≥ 5 years: 3.09 [1.76-5.40]). Methamphetamine-dependent individuals were four-times more likely to experience any type of psychiatric symptoms than non-dependent users. The prevalence of psychiatric symptoms was high in chronic MA users and increased with MA use duration. Early prevention and treatment strategies targeting both MA use and associated psychiatric symptoms are needed.

Role of Prefrontal Serotonergic and Dopaminergic Systems in Encounter-Induced Hyperactivity in Methamphetamine-Sensitized Mice

BACKGROUND

Isolation-reared mice show social encounter-induced hyperactivity with activation of prefrontal serotonergic and dopaminergic systems, but it is not known whether this stress response is observed in other pathological conditions. Here we examined whether the social encounter stimulation induces abnormal behavior during withdrawal in chronic methamphetamine-treated mice.

METHODS

To induce methamphetamine-induced behavioral sensitization, male mice were injected with methamphetamine (1 mg/kg) once daily for 7 days.

RESULTS

The encounter with an intruder elicited hyperactivity 24 h after the last injection of methamphetamine in methamphetamine-sensitized mice. This response was observed even as long as 2 weeks after withdrawal of methamphetamine. The encounter increased c-Fos expression in the prefrontal cortex, dorsal raphe nucleus and ventral tegmental area in methamphetamine-sensitized mice, while it did not in control mice. Furthermore, the encounter increased extracellular serotonin (5-HT) and dopamine, but not noradrenaline, levels in the prefrontal cortex in methamphetamine-sensitized mice. Local injection of 5,7-dihydroxytryptamine and 6-hydroxydopamine into the prefrontal cortex attenuated encounter-induced hyperactivity in methamphetamine-sensitized mice and it markedly decreased prefrontal 5-HT and dopamine levels, respectively. Pharmacological analysis showed that the encounter-induced hyperactivity is mediated by dopamine D1 receptors and 5-HT2A receptors and attenuated by anxiolytics and antidepressants such as diazepam, osemozotan and selective 5-HT reuptake inhibitors. The effect of paroxetine was blocked by the 5-HT3 receptor antagonist azasetron.

CONCLUSIONS

The present study shows that psychological stress elicits hyperactivity with activation of prefrontal 5-HT and dopamine systems in methamphetamine-dependent mice and suggests that the abnormal behavior is associated with anxiety and depression.

Importance of Urinary Drug Screening in the Multiple Sleep Latency Test and Maintenance of Wakefulness Test

STUDY OBJECTIVES

Multiple sleep latency testing (MSLT) and the maintenance of wakefulness test (MWT) are gold-standard objective tests of daytime sleepiness and alertness; however, there is marked variability in their interpretation and practice. This study aimed to determine the incidence of positive drug screens and their influence on MSLT, MWT, and polysomnographic variables.

METHODS

All patients attending Eastern Health Sleep Laboratory for MSLT or MWT over a 21-mo period were included in the study. Urinary drug screening for amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, methadone, and opiates was performed following overnight polysomnography (PSG). Demographics and PSG variables were compared.

RESULTS

Of 69 studies, MSLT (43) and MWT (26), 16% of patients had positive urinary drug screening (7 MSLT; 4 MWT). Drugs detected included amphetamines, cannabinoids, opiates, and benzodiazepines. No patient self-reported use of these medications prior to testing. No demographic, MSLT or MWT PSG data or overnight PSG data showed any statistical differences between positive and negative drug screen groups. Of seven MSLT patients testing positive for drug use, one met criteria for the diagnosis of narcolepsy and five for idiopathic hypersomnia. On MWT, three of the four drug-positive patients had a history of a motor vehicle accident and two patients were occupational drivers.

CONCLUSIONS

These findings indicate drug use is present in patients attending for daytime testing of objective sleepiness and wakefulness. These data support routine urinary drug screening in all patients undergoing MSLT or MWT studies to ensure accurate interpretation in the context of illicit and prescription drug use.

Reduced sleep duration mediates decreases in striatal D2/D3 receptor availability in cocaine abusers

Neuroimaging studies have documented reduced striatal dopamine D2/D3 receptor (D2/D3R) availability in cocaine abusers, which has been associated with impaired prefrontal activity and vulnerability for relapse. However, the mechanism(s) underlying the decreases in D2/D3R remain poorly understood. Recent studies have shown that sleep deprivation is associated with a downregulation of striatal D2/D3R in healthy volunteers. As cocaine abusers have disrupted sleep patterns, here we investigated whether reduced sleep duration mediates the relationship between cocaine abuse and low striatal D2/D3R availability. We used positron emission tomography with [(11)C]raclopride to measure striatal D2/D3R availability in 24 active cocaine abusers and 21 matched healthy controls, and interviewed them about their daily sleep patterns. Compared with controls, cocaine abusers had shorter sleep duration, went to bed later and reported longer periods of sleep disturbances. In addition, cocaine abusers had reduced striatal D2/D3R availability. Sleep duration predicted striatal D2/D3R availability and statistically mediated the relationship between cocaine abuse and striatal D2/D3R availability. These findings suggest that impaired sleep patterns contribute to the low striatal D2/D3R availability in cocaine abusers. As sleep impairments are similarly observed in other types of substance abusers (for example, alcohol and methamphetamine), this mechanism may also underlie reductions in D2/D3R availability in these groups. The current findings have clinical implications suggesting that interventions to improve sleep patterns in cocaine abusers undergoing detoxification might be beneficial in improving their clinical outcomes.

The implications of sleep disruption for cognitive and affective processing in methamphetamine abuse

Sleep is disrupted during active use of methamphetamine (MA), during withdrawal from the drug, and during abstinence from its use. However, relatively little is known about possible mediatory functions of disrupted sleep in the emergence, manifestation, and maintenance of cognitive and affective symptoms of MA abuse. We hypothesise that sleep functions as a mediator for stimulant drug effects. Specifically, we propose that objectively-measured sleep parameters can be used to explain some of the variability in the experience and presentation of memory deficits and emotion dysregulation in MA abusers. After describing how important healthy sleep is to unimpaired cognitive and affective functioning, we review literature describing how sleep is disrupted in MA abuse. Then, we provide a conceptual framework for our hypothesis by explaining the relationship between MA abuse, sleep disruption, memory deficits, emotion dysregulation, and changes in reward-related brain networks. We conclude by discussing implications of the hypothesis for research and treatment.

Effect of Abstinence on Depression, Anxiety, and Quality of Life in Chronic Methamphetamine Users in a Therapeutic Community

Background:

During withdrawal, patients experience different symptoms. These symptoms are associated with relapse. Understanding different outcomes of methamphetamine abstinence is useful for finding better treatments for dependence.

Objectives:

This study aimed to show the effects of abstinence on depression, anxiety, and quality of life in methamphetamine users.

Patients and Methods:

A prospective quasi-experimental (before and after study) method was used to show the effect of 3 weeks abstinence on depression, anxiety, and quality of life. A convenient sample of addicted people entered into the study and 34 people completed the study. Beck Depression Scale, Cattell Anxiety Inventory and Short Form Health Survey (SF-36) (for assessing quality of life), were used for outcome assessments.

Results:

The mean depression score after abstinence decreased significantly (P < 0.001). Both hidden and obvious anxiety and total anxiety had a high level at admission and after 3 weeks of abstinence, the mean level of anxiety did not change significantly (P < 0.096). However, the quality of life increased after 3 weeks of abstinence (P < 0.001).

Conclusions:

Depression and anxiety are prevalent in methamphetamine users. Short-term abstinence improves depression and quality of life but does not improve anxiety in methamphetamine abusers. During follow up of these patients, addressing depression and anxiety is important to achieve better results.

A stress steroid triggers anxiety via increased expression of α4βδ GABAA receptors in methamphetamine dependence

Methamphetamine (METH) is an addictive stimulant drug. In addition to drug craving and lethargy, METH withdrawal is associated with stress-triggered anxiety. However, the cellular basis for this stress-triggered anxiety is not understood. The present results suggest that during METH withdrawal (24h) following chronic exposure (3mg/kg, i.p. for 3-5weeks) of adult, male mice, the effect of one neurosteroid released by stress, 3α,5α-THP (3α-OH-5α-pregnan-20-one), and its 3α,5β isomer reverse to trigger anxiety assessed by the acoustic startle response (ASR), in contrast to their usual anti-anxiety effects. This novel effect of 3α,5β-THP was due to increased (three-fold) hippocampal expression of α4βδ GABAA receptors (GABARs) during METH withdrawal (24h-4weeks) because anxiogenic effects of 3α,5β-THP were not seen in α4-/- mice. 3α,5β-THP reduces current at these receptors when it is hyperpolarizing, as observed during METH withdrawal. As a result, 3α,5β-THP (30nM) increased neuronal excitability, assessed with current clamp and cell-attached recordings in CA1hippocampus, one CNS site which regulates anxiety. α4βδ GABARs were first increased 1h after METH exposure and recovered 6weeks after METH withdrawal. Similar increases in α4βδ GABARs and anxiogenic effects of 3α,5β-THP were noted in rats during METH withdrawal (24h). In contrast, the ASR was increased by chronic METH treatment in the absence of 3α,5β-THP administration due to its stimulant effect. Although α4βδ GABARs were increased by chronic METH treatment, the GABAergic current recorded from hippocampal neurons at this time was a depolarizing, shunting inhibition, which was potentiated by 3α,5β-THP. This steroid reduced neuronal excitability and anxiety during chronic METH treatment, consistent with its typical effect. Flumazenil (10mg/kg, i.p., 3×) reduced α4βδ expression and prevented the anxiogenic effect of 3α,5β-THP after METH withdrawal. Our findings suggest a novel mechanism underlying stress-triggered anxiety after METH withdrawal mediated by α4βδ GABARs.

Driving on ice: impaired driving skills in current methamphetamine users

RATIONALE

Previous research indicates a complex link between methamphetamine (METH) and driving performance. Acute dosing with amphetamines has improved driving-related performance in some laboratory studies, while epidemiological studies suggest an association between METH use, impaired driving, and accident culpability.

METHODS

Current METH users were compared to a control group of nonusers on driving simulator performance. Groups were matched for age, gender, and driving experience. Subjects were assessed for current drug use, drug dependence, and drug levels in saliva/blood as well as personality variables, sleepiness, and driving performance.

RESULTS

METH users, most of whom met the criteria for METH dependence, were significantly more likely to speed and to weave from side to side when driving. They also left less distance between their vehicle and oncoming vehicles when making a right-hand turn. This risky driving was not associated with current blood levels of METH or its principal metabolite, amphetamine, which varied widely within the METH group. Other drugs were detected (principally low levels of THC or MDMA) in some METH users, but at levels that were unlikely to impair driving performance. There were higher levels of impulsivity and antisocial personality disorder in the METH-using cohort.

CONCLUSIONS

These findings confirm indications from epidemiological studies of an association between METH use and impaired driving ability and provide a platform for future research to further explore the factors contributing to increased accident risk in this population.

Chronic Methamphetamine Causes Differential Expression of Immediate Early Genes in the Nucleus Accumbens and Midbrain of Rats

The present study investigated whether chronic methamphetamine (METH) would suppress METH-induced mRNA expression of immediate early genes (IEGs) in the rat brain. Rats were given METH or saline over two weeks. After an overnight withdrawal, saline- and METH-pretreated rats received an acute saline or METH challenge. The acute METH challenge increased expression of members of activator protein 1 (AP-1) and Nr4a IEG families in the nucleus accumbens (NAc) and midbrain of saline-pretreated rats. Chronic METH exposure attenuated the effects of acute METH challenge on AP-1 IEG expression in the NAc. However, chronic METH failed to attenuate acute METH-induced increases of Nr4a1 and Nr4a3 expression in the NAc. In contrast to observations in the NAc, chronic METH did not prevent acute METH-induced changes in IEG expression in the midbrain. These results suggest that these two brain regions that are implicated in neuroplastic effects of illicit substances might be differentially affected by psychostimulants.