Modeling methamphetamine use disorder in mammals: Sex differences in behavioral, biochemical, and transcriptional consequences.

Methamphetamine (METH) is the most commonly misused amphetamine-type stimulant throughout the globe. METH is very rewarding, and its misuse can lead to a diagnosis of METH use disorder (MUD). Although METH use is observed in both sexes, there are, however, reported differences in the clinical manifestations of METH use and its consequences. These observations indicate the need for more research on the long-term sex-dependent consequences of METH taking in both preclinical and clinical settings. In effect, sex is a biological variable that can impact conclusions drawn from various basic and clinical studies. Thus, the present chapter provides a succinct review of the current state of the research on METH and its sex-associated consequences. In addition to behavioral and cognitive aspects of METH use, we discuss METH-induced changes in neurotransmitter systems and structures in the brain. Thus, the book chapter serves to highlight the significance of sex as a critical element that needs to be considered during discussions of novel therapeutic approaches to MUD.

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

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

The interplay of childhood trauma, oxytocin, and impulsivity in predicting the onset of methamphetamine use.

BACKGROUND: Childhood trauma is associated with substance use disorders, including methamphetamine use disorder (MUD). Oxytocin, involved in social bonding, stress regulation, and reward processing, may influence addiction vulnerability and impulsivity in individuals with a history of childhood trauma. OBJECTIVE: To investigate the relationships among childhood trauma, oxytocin levels, impulsivity, and the age of first methamphetamine use in individuals with MUD. PARTICIPANTS AND SETTING: The study included 298 male participants (148 individuals with MUD and 150 healthy controls) from both probation offices and psychiatric clinics. METHODS: Childhood trauma was assessed using the Childhood Trauma Questionnaire-Short Form (CTQ-SF), impulsivity with the Barratt Impulsiveness Scale-11 (BIS-11), and plasma oxytocin levels were obtained. RESULTS: Individuals with MUD exhibited higher levels of childhood trauma, impulsivity, and lower plasma oxytocin levels compared to healthy controls. Childhood trauma was associated with a younger age of first methamphetamine use, higher impulsivity, and lower oxytocin levels among individuals with MUD. Plasma oxytocin levels partially mediated the relationship between childhood trauma and both the age of first methamphetamine use and impulsivity. Serial mediation analysis demonstrated that oxytocin levels and impulsivity sequentially mediated the relationship between childhood trauma and the age of first methamphetamine use. CONCLUSIONS: The findings reveal the complex interplay among childhood trauma, oxytocin, impulsivity, and methamphetamine use, emphasizing the importance of considering these factors in prevention and intervention strategies for MUD. Future research should explore oxytocin and impulsivity-focused interventions to mitigate the effects of childhood trauma and reduce MUD development risk.

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

BACKGROUND: Regular methamphetamine use can cause a range of physical, psychological and social harms. Stigma is one factor that impacts engagement and successful completion of treatment. In Australia, Aboriginal and Torres Strait Islander people who regularly use methamphetamine experience multiple stigmas, which further compounds access to treatment and quality of life. This paper explores the cumulative and compounding effects of participating in a stigmatised activity such as illicit drug use in relation to the stigma experienced by Aboriginal and Torres Strait Islander people as a population marginalised through colonisation. METHODS: Ten sites nationally participated in a cross-sectional survey measuring a range of factors including psychosocial stress in methamphetamine users. The survey sample size was 734, with 59% identifying as Aboriginal and Torres Strait Islander (n = 433). In addition, a total of 147 mainly Aboriginal and Torres Strait Islander people who use methamphetamine, community and family members, and service providers took part in a total of 19 focus groups and 7 interviews. RESULTS: Aboriginal and Torres Strait Islander participants experienced multiple psychosocial stressors at significantly higher rates than non-Indigenous participants. These stressors include diminished access to health care (33%), experiences of racism (34%), grief and sorrow (39%), worry for family (46%), and child welfare experiences (46%). The qualitative findings highlight the cumulative impact of historical, political and social stressors on an already stigmatised population. CONCLUSIONS: The findings of this unique analysis demonstrate the disruptive impact of methamphetamine use on the lives of those who use methamphetamines and their family members. They also illustrate challenges, such as stigma, that may confront those seeking assistance for drug-related issues. Aboriginal and Torres Strait Islander community involvement is necessary to provide support and education for the individual, the family, and the community as a whole. Stigma reduction is therefore a worthy target for intervention.

Applying computerized adaptive testing to the Desires for Speed Questionnaire in the Chinese population: A simulation study.

The current methods for measuring patient-reported outcomes for amphetamine (speed) craving have limitation ability to adapt to the needs of individual patients while maintaining consistency in their scores. This study aimed to investigate whether the 40-item Desires for Speed Questionnaire (DSQ) could be improved for assessing clinical subjects using computerized adaptive testing (CAT). A sample of 677 participants from four drug addiction treatment centers in China was utilized in the study. Two types of analysis were conducted using the response data. First, the psychometric properties of all items were evaluated to meet the requirements of CAT. Second, multiple CAT simulations were carried out using real response data. The results indicated that the CAT method, which only required a small number of items (50%-75%), produced results that were only slightly different from the full DSQ assessment in terms of measuring amphetamine craving and criterion validity. In conclusion, this study suggests that developing a DSQ CAT for clinical subjects is useful as it leads to more efficient measurement without compromising the reliability of the test outcomes. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

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

Background: The transition from methamphetamine (MA) casual use (MCU) to compulsive use is enigmatic as some MA users can remain in casual use, but some cannot. There is a knowledge gap if gut microbiota (GM) play a role in differing MCU from MA use disorder (MUD). We aimed to investigate the clinical features and GM differences between individuals with MCU and MUD. Method: We recruited two groups of MA users -MCU and MUD - and matched them according to age and body mass index (n=21 in each group). Participants were accessed using the Semi-Structured Assessment for Drug Dependence and Alcoholism, and their fecal samples were undergone 16S ribosomal DNA sequencing. We compared the hosts' clinical features and GM diversity, composition, and structure (represented by enterotypes) between the two groups. We have identified differential microbes between the two groups and performed network analyses connecting GM and the clinical traits. Result: Compared with the casual users, individuals with MUD had higher incidences of MA-induced neuropsychiatric symptoms (e.g., paranoia, depression) and withdrawal symptoms (e.g., fatigue, drowsiness, and increased appetite), as well as stronger cravings for and intentions to use MA, and increased MA tolerance. The GM diversity showed no significant differences between the two groups, but four genera (Halomonas, Clostridium, Devosia, and Dorea) were enriched in the individuals with MUD (p<0.05). Three distinct enterotypes were identified in all MA users, and Ruminococcus-driven enterotype 2 was dominant in individuals with MUD compared to the MCU (61.90% vs. 28.60%, p=0.03). Network analysis shows that Devosia is the hub genus (hub index = 0.75), which is not only related to the counts of the MUD diagnostic criteria (ρ=0.40; p=0.01) but also to the clinical features of MA users such as reduced social activities (ρ=0.54; p<0.01). Devosia is also associated with the increased intention to use MA (ρ=0.48; p<0.01), increased MA tolerance (ρ=0.38; p=0.01), craving for MA (ρ=0.37; p=0.01), and MA-induced withdrawal symptoms (p<0.05). Conclusion: Our findings suggest that Ruminococcus-driven enterotype 2 and the genera Devosia might be two influential factors that differentiate MA casual use from MUD, but further studies are warranted.

A Pilot Assessment of the Effects of HIV and Methamphetamine Dependence on Socially Dysregulated Behavior in the Human Behavioral Pattern Monitor.

Deficits in social cognition are seen in both people living with HIV (PWH) and people with a history of methamphetamine (METH) dependence. Dually affected individuals may experience additive negative effects on social cognition due to these conditions. We evaluated social cognition in 4 diagnostic groups (HIV-/METH-, HIV-/METH+, HIV+/METH-, HIV+/METH+). First, we used traditional social-emotional functioning assessments, the Difficulties in Emotion Regulation Scale and the Faux Pas Task, to determine any significant effects of METH dependence and HIV on social cognition. Next, we quantified social cognition using the Human Behavioral Pattern Monitor by evaluating social behavior represented by interaction with novel objects. METH dependence significantly affected social-emotional functions and HIV significantly affected on object interactions, however no significant additive effects were observed using these methods. The nuanced relationship between HIV and METH dependence suggests that other factors (i.e., adaptive life skills) likely mediate social cognition-related behaviors.

RESUMEN: Los déficits en la cognición social se observan tanto en las personas que viven con el VIH (PWH) como en las personas con antecedentes de dependencia de la metanfetamina (METH). Las personas con ambas condiciones pueden experimentar efectos negativos aditivos en la cognición social. Evaluamos la cognición social en 4 grupos de diagnóstico (VIH−/METH−, VIH−/METH+, VIH+/METH−, VIH+/METH+). En primer lugar, utilizamos evaluaciones tradicionales del funcionamiento socioemocional, la Escala de Dificultades en la Regulación Emocional y la Prueba de Faux Pas, para determinar efecto significativo debido a la dependencia de METH y el VIH en la cognición social. Entonces, cuantificamos la cognición social utilizando el Monitor de Patrones de comportamiento humano mediante la evaluación del comportamiento social representado por la interacción con objetos novedosos. La dependencia de METH afectó significativamente las funciones socioemocionales y el VIH afectó significativamente las interacciones con los objetos, sin embargo, no se observaron efectos aditivos significativos al usar estos métodos. La relación compleja entre el VIH y la dependencia de METH sugiere que otros factores (i.e., habilidades adaptativas) probablemente regulan los comportamientos relacionados con la cognición social.

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

BACKGROUND: Substance use disorder is one of the severe public health problems worldwide. Inequitable resources, discrimination, and physical distances limit patients' access to medical help. Automated conversational agents have the potential to provide in-home and remote therapy. However, automatic dialogue agents mostly use text and other methods to interact, which affects the interaction experience, treatment immersion, and clinical efficacy. OBJECTIVE: The aim of this paper is to describe the design and development of Echo-APP, a tablet-based app with the function of a virtual digital psychotherapist, and to conduct a pilot study to explore the feasibility and preliminary efficacy results of Echo-APP for patients with methamphetamine use disorder. METHODS: Echo-APP is an assessment and rehabilitation program developed for substance use disorder (SUD) by a team of clinicians, psychotherapists, and computer experts. The program is available for Android tablets. In terms of assessment, the focus is on the core characteristics of SUD, such as mood, impulsivity, treatment motivation, and craving level. In terms of treatment, Echo-APP provides 10 treatment units, involving awareness of addiction, motivation enhancement, emotion regulation, meditation, etc. A total of 47 patients with methamphetamine dependence were eventually enrolled in the pilot study to receive a single session of the Echo-APP-based motivational enhancement treatment. The outcomes were assessed before and after the patients' treatment, including treatment motivation, craving levels, self-perception on the importance of drug abstinence, and their confidence in stopping the drug use. RESULTS: In the pilot study, scores on the Stages of Change Readiness and Treatment Eagerness Scale and the questionnaire on motivation for abstaining from drugs significantly increased after the Echo-APP-based treatment (P<.001, Cohen d=-0.60), while craving was reduced (P=.01, Cohen d=0.38). Patients' baseline Generalized Anxiety Disorder-7 assessment score (ß=3.57; P<.001; 95% CI 0.80, 2.89) and Barratt Impulsiveness Scale (BIS)-motor impulsiveness score (ß=-2.10; P=.04; 95% CI -0.94, -0.02) were predictive of changes in the patients' treatment motivation during treatment. Moreover, patients' baseline Generalized Anxiety Disorder-7 assessment score (ß=-1.607; P=.03; 95% CI -3.08, -0.14), BIS-attentional impulsivity score (ß=-2.43; P=.004; 95% CI -4.03, -0.83), and BIS-nonplanning impulsivity score (ß=2.54; P=.002; 95% CI 0.98, 4.10) were predictive of changes in craving scores during treatment. CONCLUSIONS: Echo-APP is a practical, accepted, and promising virtual digital psychotherapist program for patients with methamphetamine dependence. The preliminary findings lay a good foundation for further optimization of the program and the promotion of large-scale randomized controlled clinical studies for SUD.

Effectiveness of Mindfulness - Based Therapy and Counseling programs (MBTC) on relapses to methamphetamine dependence at a substance dependency treatment center.

This non-concurrent controlled intervention study aimed to examine the effectiveness of the Mindfulness - Based Therapy and Counseling programs (MBTC) on the treatment of methamphetamine use disorder among 70 individuals (37 females) receiving methamphetamine dependency treatment. Participants were divided into a control group undergoing the usual program and an experimental group using MBTC plus the usual program at a treatment center in Thailand. The study was conducted using the Methamphetamine Craving Questionnaire, urine Color Immunochromatographic Assay and the Mini-International Neuropsychiatric Interview. Stress, depression, and mindfulness were also assessed. MBTC comprised of practicing mindfulness for 90-120 min weekly for eight weeks. Participants were assessed before and after the treatment(s) and at follow-ups visits at 2, 4, 8, 12, and 24 weeks. Mean age (30.3 ± 5.8 years), age of first methamphetamine use (18.2 ± 4.5 years) and other demographics did not differ between groups. At six-month follow-up, the experimental group had significantly lower craving (-7.89, 95%CI = -15.47, -0.32), stress (-7.44, 95%CI = -12.21, -2.67), and depression (-2.95, 95%CI = -5.31, -0.6) and statistically significant higher mindfulness scores (12.86, 95%CI = 9.37, 16.35) than the control group. In addition, methamphetamine relapse in the MBTC group (5/35, 14.3%) was significantly lower than the control group (16/35, 45.7%).

Executive function in methamphetamine users with and without psychosis.

Methamphetamine abuse is associated with cognitive deficits across a wide range of domains. It is unclear, however, whether methamphetamine-dependent individuals with co-occurring psychosis are more impaired than those without psychosis on tests assessing executive function. We therefore aimed to compare the executive function performance of three groups: methamphetamine-dependent individuals with methamphetamine-induced psychosis (MA+; n = 20), methamphetamine-dependent individuals without psychosis (MA-; n = 19), and healthy controls (HC; n = 20). All participants were administered a neuropsychological test battery that assessed executive functioning across six sub domains (problem solving, working memory, verbal generativity, inhibition, set switching, and decision making). Analyses of covariance (controlling for between-group differences in IQ) detected significant between-group differences on tests assessing verbal generativity and inhibition, with MA+ participants performing significantly more poorly than HC. The finding that methamphetamine-induced psychosis is associated with performance impairments in particular subdomains of executive function may have implications for treatment adherence and relapse prevention.

The Effects of Oxytocin on Craving, Mental Health Parameters, and Stress Hormones in Methamphetamine-Dependent Patients Undergoing Matrix Treatment Model: A Randomized, Double-Blind Clinical Trial.

BACKGROUND: Methamphetamine (METH) dependence is an increasing public health problem with a wide range of mental and physical adverse effects. Recent studies report that oxytocin (OXT) has potential therapeutic properties in drug dependence. Hence, the present study was designed to evaluate the effects of OXT on craving, mental health (depression and anxiety), and stress hormones (ACTH and cortisol) in METH-dependent patients undergoing matrix treatment model (MTM), an intensive outpatient approach for stimulant abuse treatment. METHODS: This randomized placebo-controlled clinical trial was conducted in 42 METH-dependent patients undergoing MTM to receive either intranasal OXT 40 IU (n = 21) or normal saline as placebo (n = 21) for 4 weeks. Clinical and biochemical parameters were measured at baseline and end of trials in METH-dependent patients. RESULTS: Our findings indicated that OXT administration for 4 weeks is associated with a significant improvement in the craving and depression scores, respectively (p < 0.001 and p < 0.001), but there was no significant difference for anxiety scores compared with the placebo group. In addition, OXT administration significantly decreased cortisol (p < 0.001) and ACTH levels (p < 0.002). CONCLUSIONS: These findings suggest that OXT can be considered as a new potential therapeutic for the treatment of METH-dependent patients undergoing MTM. Further studies are required to explore the effectiveness and safety of OXT.

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.

The relationship between serum brain-derived neurotrophic level and neurocognitive functions in chronic methamphetamine users.

Methamphetamine (METH) is a highly addictive psychostimulant with serious neurotoxic effects. Given evidence indicating that brain-derived neurotrophic factor (BDNF) is associated with addictive behaviors, this study aimed to investigate the serum level of BDNF and cognitive functions in chronic METH users and healthy participants. Thirty-seven chronic METH users and 37 healthy participants were recruited in this study. Cognitive functioning, including executive functions and working memory, were assessed using the Wisconsin Card Sorting Test (WCST) and Wechsler Memory Scale (WMS), respectively. The levels of serum BDNF were also examined using an enzyme-linked immunosorbent assay kit. METH users showed significant impairment in executive function and working memory compared to healthy participants. The serum BDNF concentrations of METH users were significantly higher than healthy participants (42 ± 13.34 ng/ml vs. 24 ± 7 ng/ml). BDNF concentration was significantly correlated with duration (r = 0.37, p = 0.02) and dose of METH use (r = 0.35, p = 0.02). Besides, the BDNF level was not associated with any subscales of WCST and WMS. These results provide further evidence regarding the role of BDNF in the pathophysiology of METH addiction. Besides, these findings suggest that increased BDNF level is not related to cognitive impairments in METH users.

Loneliness, Risky Beliefs and Intentions about Practicing Safer Sex among Methamphetamine Dependent Individuals.

BACKGROUND: Methamphetamine use is a known predictor of riskier sexual behaviors, which can have important public health implications (e.g., HIV-transmission risk). Loneliness also is associated with riskier sexual behaviors, though the relationship between loneliness and beliefs and/or intentions to practice safer sex has not been examined among people dependent on methamphetamine. MATERIALS AND METHODS: Individuals who met DSM-IV criteria for lifetime methamphetamine dependence and current (≤ 18-months) methamphetamine abuse or dependence (METH+ n = 56) were compared to those without severity and recency of methamphetamine use (METH- n = 59). These groups did not differ on social network size or proportion of people with HIV (∼58% HIV+). Participants completed the NIH Toolbox Loneliness Scale and the Sexual Risks Scale's "Norms" and "Intentions" subscales. RESULTS: METH+ individuals were significantly lonelier than METH- controls (t(113) = 2.45, p = .02). Methamphetamine dependence remained significantly associated with greater loneliness, after controlling for HIV status and other relevant covariates (e.g., neurocognitive impairment, history of mood disorder, social network size; F = 3.70, Adjusted R2 = 0.18, p = .0009). Loneliness, above and beyond the aforementioned covariates, was significantly associated with riskier beliefs and intentions to practice safer sex among METH+, but not METH-, individuals (ß = 2.92, p = .02). CONCLUSIONS: Loneliness is prevalent among individuals dependent on methamphetamine, and is uniquely associated with riskier beliefs and intentions regarding practicing safer sex. Findings may aid in identifying individuals at-risk of engaging in riskier sexual behaviors and guide risk prevention strategies.

Prior Methamphetamine Use Disorder History Does Not Impair Interoceptive Processing of Soft Touch in HIV Infection.

INTRODUCTION: Interoception, defined as the sense of the internal state of one's body, helps motivate goal-directed behavior. Prior work has shown that methamphetamine (METH) use disorder is associated with altered interoception, and that this may contribute to risky behavior. As people with HIV (PWH) may also experience disrupted bodily sensations (e.g., neuropathy), an important question is whether PWH with a history of METH use disorder might exhibit greater impairment of interoceptive processing. METHODS: Eighty-three participants stratified by HIV infection and a past history of methamphetamine use disorder experienced a soft touch paradigm that included slow brush strokes on the left forearm and palm during blood-oxygen level-dependent functional MRI acquisition. To assess differences in interoception and reward, voxelwise analyses were constrained to the insula, a hub for the evaluation of interoceptive cues, and the striatum, which is engaged in reward processing. RESULTS: Overall, individuals with a history of METH use disorder had an attenuated neural response to pleasant touch in both the insula and striatum. Longer abstinence was associated with greater neural response to touch in the insula, suggesting some improvement in responsivity. However, only PWH with no METH use disorder history had lower brain activation in the insula relative to non-using seronegative controls. CONCLUSIONS: Our findings suggest that while METH use disorder history and HIV infection independently disrupt the neural processes associated with interoception, PWH with METH use disorder histories do not show significant differences relative to non-using seronegative controls. These findings suggest that the effects of HIV infection and past methamphetamine use might not be additive with respect to interoceptive processing impairment.

Survival Probabilities and Predictors of Major Depressive Episode Incidence Among Individuals With Various Types of Substance Use Disorders.

Objective: This study aimed to estimate the survival probabilities related to the occurrence of major depressive episodes (MDEs) after the onset of substance use disorders (SUDs) using data from the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions-III.Methods: The Alcohol Use Disorder and Associated Disabilities Interview Schedule-5 was used to diagnose SUD, and psychiatric diagnoses were based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Individuals with incidents of various SUDs with no prior history of MDEs (n = 5,987 with alcohol use disorder [AUD], 1,353 with cannabis use disorder [CUD], 351 with opioid use disorder [OUD], 827 with stimulant use disorder [STUD], and 5,363 with nicotine use disorder [NUD]) were included. The survival probabilities of these groups were compared to those of a control group without an SUD (n = 20,034). Outcome measures included the number of years from the age at SUD onset until MDE occurrence or the time of the interview.Results: The probabilities of experiencing MDEs after 1 year were 3.56%, 4.80%, 7.78%, 8.46%, and 5.31% for AUD, CUD, OUD, STUD, and NUD, respectively. The groups differed statistically significantly from each other and from the control group (P < .0001). Individuals with AUD and STUD, respectively, had a lower and higher probability of having an MDE compared to those with other SUDs. Young age, family history of depression, anxiety disorder presence, and failure to achieve full remission consistently predicted an MDE for all substances.Conclusions: The findings highlight that users of all studied substances have an increased probability of having an MDE over the lifespan.

Changes of BDNF exon IV DNA methylation are associated with methamphetamine dependence.

Aim: We investigated DNA methylation of BDNF in methamphetamine (METH) dependence in humans and an animal model. Materials & methods:BDNF methylation at exon IV was determined by pyrosequencing of blood DNA from METH-dependent and control subjects, and from rat brain following an escalating dose of METH or vehicle. Bdnf expression was determined in rat brain. Results:BDNF methylation was increased in human METH dependence, greatest in subjects with psychosis and in prefrontal cortex of METH-administered rats; rat hippocampus showed reduced Bdnf methylation and increased gene expression. Conclusion:BDNF methylation is abnormal in human METH dependence, especially METH-dependent psychosis, and in METH-administered rats. This may influence BDNF expression and contribute to the neurotoxic effects of METH exposure.

Lay abstract The effects of methamphetamine (METH), an addictive psychostimulant drug, on changes of DNA methylation of an important regulator of neuronal survival, BDNF, were examined in blood of METH-dependent patients and in the brain of METH-administered rats. BDNF methylation was increased in patients and in the prefrontal cortex of METH-administered rats, while rat hippocampus showed a reduction of Bdnf methylation, with an equivalent increase in gene expression. The methylation increases in humans were greatest in those with a METH-induced psychosis. Although a relationship between Bdnf methylation and its expression has not been proven, changes of BDNF DNA methylation are associated with METH dependence, especially METH-dependent psychosis, suggesting that METH neurotoxicity may relate to the effects of changes in BDNF methylation.

A mindfulness-based, stress and coping model of craving in methamphetamine users.

There is increasing interest in the role of mindfulness and mindfulness-based interventions to optimize recovery from a substance use disorder (SUD). However, relatively little is known about the theory-based psychological and social pathways whereby mindfulness could have beneficial effects for managing a chronic, relapsing SUD. Informed by Revised Stress and Coping Theory, the present cross-sectional study examined affective, cognitive, and social pathways whereby mindfulness is associated with lower methamphetamine craving. A total of 161 HIV-positive, methamphetamine-using sexual minority men completed a screening visit for a randomized controlled trial. Using a hybrid structural equation model, we examined pathways whereby mindfulness is associated with lower methamphetamine craving. We found that greater mindfulness was directly associated with lower negative affect and higher positive affect as well as indirectly associated with less methamphetamine craving. Interestingly, the indirect association between mindfulness and methamphetamine craving appeared to be uniquely attributable to positive affect. Only positive affect was indirectly associated with lower methamphetamine craving via higher positive re-appraisal coping and greater self-efficacy for managing triggers for methamphetamine use. Methamphetamine craving was supported by moderate associations with greater substance use severity and more frequent methamphetamine use. These findings support the role of mindfulness in cultivating positive affect, which could be crucial to build the capacity of individuals to manage methamphetamine craving as a chronic stressor that threatens recovery from SUD.

It is never as good the second time around: Brain areas involved in salience processing habituate during repeated drug cue exposure in treatment engaged abstinent methamphetamine and opioid users.

The brain response to drug-related cues is an important marker in addiction-medicine. However, the temporal dynamics of this response in repeated exposure to cues are not well known. In an fMRI drug cue-reactivity task, the presence of rapid habituation or sensitization was investigated by modeling time and its interaction with condition (drug>neutral) using an initial discovery-sample. Replication of this temporal response was tested in two other clinical populations all abstinent during their early recovery (treatment). Sixty-five male participants (35.8 ± 8.4 years-old) with methamphetamine use disorder (MUD) were recruited as the discovery-sample from an abstinence-based residential treatment program. A linear mixed effects model was used to identify areas with a time-by-condition interaction in the discovery-sample. Replication of these effects was tested in two other samples (29 female with MUD from a different residential program and 22 male with opioid use disorder from the same residential program as the discovery sample). The second replication sample was re-tested within two weeks. In the discovery-sample, clusters within the VMPFC, amygdala and ventral striatum showed both a main effect of condition and a condition-by-time interaction, indicating a habituating response to drug-related but not neutral cues. The estimates for the main effects and interactions were generally consistent between the discovery and replication-samples across all clusters. The re-test data showed a consistent lack of drug > neutral and habituation response within all selected clusters in the second cue-exposure session. The VMPFC, amygdala and ventral striatum show habituation in response to drug-related cues which is consistent among different clinical populations. This habituated response in the first session of cue-exposure and lack of reactivity in the second session of exposure may be important for informing the development of cue-desensitization interventions.

Cue Exposure Triggers Inhibitory Deficits in Individuals With Methamphetamine Use Disorder.

OBJECTIVE: Inhibitory deficits contribute to impulsive drug-seeking behavior in individuals with methamphetamine use disorder (MUD). Whether abstinent individuals with MUD exhibit greater cognitive disinhibition when the suppressed response is associated with drug-related images is not fully known. This study evaluated the potency of drug-associated cue exposure in this process. METHOD: We recruited 54 abstinent men with MUD and 46 healthy control (HC) subjects to complete a novel go/no-go task in which drug-associated cues were presented in 240 trials. RESULTS: Upon exposure to drug-associated cues, the numbers of commission errors increased significantly only in the abstinent MUD group (p < .001), and the abstinent MUD group produced higher levels of commission errors than the HC group (p = .009). When drug-associated cues were not available (in scrambled trials), the abstinent MUD group produced similar levels of commission errors when compared with the HC group (p = .336). The reaction times in drug cue exposure trials were longer than in scrambled trials across groups (p < .001), whereas the abstinent MUD group produced shorter reaction times than HCs, regardless of trial conditions (p = .004). CONCLUSIONS: The novel go/no-go task is a useful method for detecting impulsivity in abstinent individuals with MUD. Cue exposure triggers impairment of inhibitory control in individuals with MUD at abstinence.