Modulation of Methamphetamine-Related Attention Bias by Intermittent Theta-Burst Stimulation on Left Dorsolateral Prefrontal Cortex.

BACKGROUND: Previous studies have identified the treatment effect of repetitive transcranial magnetic stimulation (rTMS) on cravings of patients with methamphetamine use disorder (MUD). However, the mechanism underlying the treatment effect remains largely unknown. A potential candidate mechanism could be that rTMS over the dorsolateral prefrontal cortex (DLPFC) modulates the attention bias to methamphetamine-related cues. The purpose of this study is therefore to determine the modulation of rTMS on methamphetamine-related attention bias and the corresponding electrophysiological changes. METHODS: Forty-nine patients with severe MUD were included for analysis. The subjects were randomized to receive the active intermittent theta-burst stimulation (iTBS) or sham iTBS targeting DLPFC for 20 sessions. Participants performed the Addiction Stroop Task before and after the treatment while being recorded by a 64-channel electroencephalogram. Baseline characteristics were collected through the Addiction Severity Index. RESULTS: Post-treatment evaluations showed a reduced error rate in discriminating the color of methamphetamine words in the active iTBS group compared with the sham iTBS group. Following rTMS treatment, we found the significant time-by-group effect for the N1 amplitude (methamphetamine words > neutral words) and P3 latency (methamphetamine words > neutral words). The change of N1 amplitude was positively correlated with cravings in the active group. Moreover, reduced power of neural oscillation in the beta band, manifesting at frontal central areas, was also found in the active group. CONCLUSION: This study suggests that attention bias and the beta oscillation during the attentional processing of methamphetamine words in patients with MUD could be modulated by iTBS applied to left DLPFC.

Current Situation of Methamphetamine Abuse and Related Research Progress.

Drug problem is a major social and public security problem in the world. Drug abuse poses a great threat to economic development, social stability and public health. In recent years, synthetic drugs represented by methamphetamine have surpassed traditional drugs such as morphine, heroin, ketamine and become one of the most abused drugs in the world. In order to solve the problem of drug abuse, it is of great theoretical value and practical significance to carry out all-round and multi-level scientific research on drug-related issues. Based on the current situation of drug abuse, this article reviews research progresses on the epidemiology of methamphetamine abuse, the monitoring technology, the basic researches on toxicity damage, the withdrawal drug screening, the related clinical comorbidity and the testing technologies, comprehensively presenting the development trend of methamphetamine abuse related issues.

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

BACKGROUND: Dysfunction in brain network dynamics has been found to correlate with many psychiatric disorders. However, there is limited research regarding resting electroencephalogram (EEG) brain network and its association with cognitive process for patients with methamphetamine use disorder (MUD). This study aimed at using EEG microstate analysis to determine whether brain network dynamics in patients with MUD differ from those of healthy controls (HC). METHODS: A total of 55 MUD patients and 27 matched healthy controls were included for analysis. The resting brain activity was recorded by 64-channel electroencephalography. EEG microstate parameters and intracerebral current sources of each EEG microstate were compared between the two groups. Generalized linear regression model was used to explore the correlation between significant microstates with drug history and cognitive functions. RESULTS: MUD patients showed lower mean durations of the microstate classes A and B, and a higher global explained variance of the microstate class C. Besides, MUD patients presented with different current density power in microstates A, B, and C relative to the HC. The generalized linear model showed that MA use frequency is negatively correlated with the MMD of class A. Further, the generalized linear model showed that MA use frequency, scores of Two-back task, and the error rate of MA word are correlated with the MMD and GEV of class B, respectively. CONCLUSIONS: Intracranial current source densities of resting EEG microstates are disrupted in MUD patients, hence causing temporal changes in microstate topographies, which are correlated with attention bias and history of drug use.

Cognitive and emotional predictors of real versus sham repetitive transcranial magnetic stimulation treatment response in methamphetamine use disorder.

BACKGROUND AND AIMS: Repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (DLPFC) can effectively reduce cravings in methamphetamine use disorder (MUD). However, a considerable group still fails to respond. Cognitive and emotional disturbance, as well as impulsive features, are widespread in patients with MUD and might mediate the treatment response of rTMS. The purpose of this study is to figure out whether these variables can help predicting patients' responses to rTMS treatment. METHODS: Ninety-seven patients with severe MUD and thirty-one gender- and age-matched healthy subjects were included. Patients were randomized to receive 20 sessions of real or sham rTMS. Intermittent theta burst protocols (iTBS) or sham iTBS were applied every weekday over the DLPFC for 20 daily sessions. Both groups received regular treatment. Craving induced by drug-related cue was measured before and after stimulation. Cognition was evaluated by using the CogState Battery. Baseline characteristics were collected through the Addiction Severity Index, Patient Health Questionnaire-9, General Anxiety Disorder Scale-7, and Barrett Impulsivity Scale-11. RESULTS: Results showed that patients with MUD have worse spatial working memory, problem-solving ability, as well as depression and anxiety symptoms compared with healthy controls. Cognition and emotion differed between responders (craving decrease ≥60%) and non-responders in real rTMS group but not in the sham group. Better cognitive and emotional functions means that patients have higher possibility for better response to real rTMS treatment. CONCLUSIONS: This study suggests that cognitive, emotional and impulsive features could be used to predict the prospective treatment responses of rTMS in patients with MUD.

Monitoring consumption of methadone and heroin in major Chinese cities by wastewater-based epidemiology.

BACKGROUND: Methadone maintenance treatment (MMT) services have been used in China for treatment of heroin dependence. But no study has been conducted to assess the appropriateness of MMT distribution and the potential abuse of methadone in China. This study aims to do that through a nationwide estimation of methadone consumption in China via wastewater-based epidemiology and subsequently compare it with MMT data and level of heroin abuse. METHODS: Wastewater samples were collected from 53 wastewater treatment plants in 27 major cities that cover all geographic regions of China. Methadone and pure heroin consumptions were estimated based on influent concentrations of methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), morphine and codeine. RESULTS: Drug residues were detected in most samples. The ratio of EDDP/methadone was around 2 in influents and methadone and EDDP loads were strongly correlated, indicating that they originated from human consumption. Both influent methadone and EDDP loads in Southwest and Northwest China were significantly higher than those in other regions. The highest estimated consumptions of methadone and heroin in China were 22.0 ±â€¯2.1 mg/1000 in./d and 263.9 ±â€¯115.9 mg/1000 in./d, respectively. There was a significant positive correlation between methadone and heroin consumptions. CONCLUSIONS: Consumption of methadone in China was primarily from MMT services. The use of methadone and heroin displayed a clear geographical pattern: it is higher in the western inland regions than in the eastern regions. This study has shown that the distribution of MMT services is reflective of the level of heroin abuse in different regions of China.

Factors associated with depression and anxiety among patients attending community-based methadone maintenance treatment in China.

AIM: To estimate the prevalence of, and identify factors associated with, depression and anxiety among community-based methadone maintenance treatment (MMT) clients in China. DESIGN: A cross-sectional survey. SETTING: Nine MMT clinics, three each from three Chinese provinces (Yunnan, Anhui and Jiangsu) between October 2008 and February 2009. PARTICIPANTS: A total of 1301 MMT clients. MEASUREMENTS: A questionnaire, including the Zung Self-Rating Depression Scale (SDS) and Zung Self-Rating Anxiety Scale (SAS), and on-site urine drug testing. FINDINGS: The prevalence of depression (SDS score≥53) and anxiety (SAS score≥50) in our sample was 38.3% [95% confidence interval (CI)=35.7, 40.9] and 18.4% (95% CI=16.3, 20.5), respectively, with 14.2% (95% CI=12.3, 16.1) displaying symptoms of both. Sample prevalence rates for depression [mean=49.69, standard deviation (SD)=10.34] and anxiety (mean=40.98, SD=10.66) were higher than the national average for each (t(0.05/2, 1300)=19.2, P<0.001 and t(0.05/2, 1300)=8.0, P<0.001, respectively). Employing multi-level modelling techniques, gender (P=0.03) and employment status (P<0.001) were found to be associated significantly with depression in a single-level model; however, in a multi-level mixed model, only employment status (P<0.001) was associated with depression. Gender (P=0.03), education level (P=0.02), marital status (P=0.04), employment status (P<0.001), positive urine drug test results (P=0.02) and daily methadone dose (P<0.001) were found to be associated significantly with anxiety in a single-level model, while only employment status (P<0.01) and positive results for the urine drug test (P=0.04) were associated with anxiety in a multi-level mixed model. CONCLUSIONS: A considerable proportion of methadone maintenance treatment clients in China have experienced depression and anxiety during treatment. There is a need to provide tailored mental health interventions for this high-risk population.

Prevalence and correlates of HIV and HCV infection among amphetamine-type stimulant users in 6 provinces in China.

BACKGROUND: China has experienced an epidemic of amphetamine-type stimulant (ATS) use in recent years. The present study explored the status and correlates of HIV and hepatitis C virus (HCV) infection among ATS users in China. METHODS: A multicenter cross-sectional study of HIV and HCV status and associated behaviors among ATS users was conducted in 6 provinces from September 2009 to December 2010. Socioeconomic/behavioral risk factors were measured. Blood samples were collected to test for HIV and HCV antibodies. RESULTS: Of the 1327 ATS users, the prevalence of HIV and exposure to HCV were 4.5% and 43.5%, respectively, with large geographic variations (0%-20.3% and 8.6%-67.1%, respectively). HIV infection was independently associated with living in Yunnan province [adjusted odds ratio = 15.8; 95% confidence interval (CI): 2.0 to 125.1), polydrug use (adjusted odds ratio = 2.6; 95% CI: 1.3 to 5.4), increased frequency of sexual behavior (adjusted odds ratio = 2.0; 95% CI: 1.1 to 4.1), history of sex with sexually transmitted infection-positive persons (adjusted odds ratio = 11.4; 95% CI: 1.3 to 98.9), and HCV infection (adjusted odds ratio = 2.8; 95% CI: 1.2 to 6.7). HCV was associated with study site, marital status, unemployment (adjusted odds ratio = 1.8; 95% CI: 1.3 to 2.4), a longer duration of ATS use, and history of injection use of ATS (adjusted odds ratio = 13.3; 95% CI: 1.5 to 116.1). CONCLUSIONS: The prevalence of HIV was high among ATS users in Yunnan province but quite rare elsewhere, and the prevalence of exposure to HCV was high in 6 provinces. Risk factors emphasize the need for new prevention strategies toward this population at risk in China.

Effects of a randomized contingency management intervention on opiate abstinence and retention in methadone maintenance treatment in China.

AIMS: Methadone maintenance treatment has been made available in China in response to the rapid spread of human immunodeficiency virus (HIV), but high rates of dropout and relapse are problematic. The aim of this study was to apply and test if a contingency management (or motivational incentives) intervention can improve treatment retention and reduce drug use. DESIGN: Random assignment to usual care with (n = 160) or without (n = 159) incentives during a 12-week trial. Incentives participants earned draws for a chance to win prizes on two separate tracks targeting opiate-negative urine sample or consecutive attendance; the number of draws increased with continuous abstinence or attendance. SETTING: Community-based methadone maintenance clinics in Shanghai and Kunming. PARTICIPANTS: The sample was 23.8% female, mean age was 38, mean years of drug use was 9.4 and 57.8% had injected drugs in the past 30 days. MEASUREMENTS: Treatment retention and negative drug urine. FINDINGS: Relative to the treatment-as-usual (control) group, better retention was observed among the incentive group in Kunming (75% versus 44%), but no difference was found in Shanghai (90% versus 86%). Submission of negative urine samples was more common among the incentive group than the usual care (74% versus 68% in Shanghai, 27% versus 18% in Kunming), as was the longest duration of sustained abstinence (7.7 weeks versus 6.5 in Shanghai, 2.5 versus 1.6 in Kunming). The average total prize amount was 371 Yuan (or $55) per participant (527 for Shanghai versus 216 in Kunming). CONCLUSIONS: Contingency management improves treatment retention and drug abstinence in methadone maintenance treatment clinics in China, although there can be considerable site differences in magnitude of effects.

[Risk factors which were associated with heroin use during the methadone maintenance treatment among 1301 patients in 9 cities of China.].

OBJECTIVE: To determine the proportion of heroin use among patients who were involved in community-based methadone maintenance treatment (MMT) program and to identify the risk factors associated with heroin use. METHODS: This study was conducted in 9 MMT clinics within 3 provinces. Thirteen hundred and one patients who met the study criteria were selected from each of the five groups with different dosages of methadone users. An administrative questionnaire was applied to explore the demographics, drug abuse-related behaviors and MMT services received by the clients, etc. The prevalence of depression and anxiety among the clients were also collected by SAS and SDS. Urine samples were collected as a biological marker to indicate if heroin had been used. RESULTS: Of the 1301 patients, 76.2% were males. The mean age was (34.6 +/- 6.5) years while 71.7% had an education level of primary school or below. The average daily dosage of methadone was (48.1 +/- 29.4) mg and self-satisfied evaluation score on treatment was 8.6. On average, 27.7% urine samples showed positive opiate evidence. Marital status, employment status, treatment retention, self-satisfied evaluation score on dosage and dropout history were found to be significantly associated with heroin use, while gender, education level and dosage had no significant association with heroin use. It seemed that risk factors that associated with heroin use were different from areas to areas. CONCLUSION: High quality MMT clinic services, high self-satisfied score, longer treatment retention and low dropout rate seemed to have the effects of reducing the risk of ongoing heroin abuse under the methadone maintenance treatment program.