During the recent years, there is a profound change in the profile of drug abuse in China: psychoactive substances, including crystal methamphetamine , 3,4-Methylenedioxy-N-methylamphetamine , as well as ketamine and others, have surpassed heroin and become the most popular drug choice in China . As of 2014, the number of drug users officially documented by the Chinese public security department was 2.955 million, among whom approximately half were psychoactive substance users . Among the 480 thousand drug users newly reported in 2014, psychoactive substance users accounted for near 80% . Psychoactive substances are neurotoxic, and long term use may induce cognitive and behavioral implications . In addition, its attendant behaviors, including high risk sexual behaviors and injection drug use, place the users at elevated risk for HIV infection . Therefore, the increasing trends in psychoactive substance use are of particular public health concern in China. Methadone maintenance therapy could block the effects of opiate withdrawal symptoms and the euphoria produced by opioids, such as heroin, so it could reduce or even eliminate opiate use . However, its impact on psychoactive substance abuse is not as clear . As a matter of fact, psychoactive substance use has been a serious concern among MMT patients in other countries . Reasons for using psychoactive substances during MMT included negative attitudes toward methadone, increased euphoria, enhanced energetic level and sexual performance, and self-medication for depression . To combat the substance abuse issue in the country, Chinese government started piloting MMT in 2004 . During the past decade, China has established the largest MMT program worldwide . By August of 2014, 756 methadone maintenance clinics and more than 300 outreach clinics have been established in 28 provinces,flood grow tables autonomous regions and municipalities, cumulatively treating 410 thousand opiate users .
While the program has generally been successful, the issue of psychoactive substance use exists in MMT clinics in China. A pilot study indicated that a proportion of clients who attend MMT shifted their substance use habit from opiate to psychoactive substances . A cross-sectional study conducted in eastern China revealed that 6.8% and 6.2% of the current MMT clients were tested positive for methamphetamine and MDMA, respectively . Because of the newness of the drug use trend, psychoactive substance use, particularly within MMT settings, has previously received little systematic investigation. Literature has documented factors correlated psychoactive substance use, which included demographic characteristics , mental health status, alcohol and other illicit drug use , yet these associations have not been confirmed among MMT clients in China. This aim of this study was to examine the prevalence, patterns, and correlates of psychoactive substance use among MMT clients in China. We hypothesized that psychoactive substance use would be associated with a client’s demographic characteristics, drug use related factors, and his or her mental health status. The study used baseline data from a randomized controlled intervention trial before any intervention activities were delivered. In order to increase the representativeness of the study sample, MMT clients were recruited from five provinces with varying economic and drug use conditions. Only the MMT clinics with more than 80 current clients were included to ensure enough eligible participants at each clinic. A total of 68 MMT clinics were randomly selected out of 110 clinics that meet our selection criteria in the five provinces. Using a random number table, about 36 clients were randomly selected from each of the 68 participating clinics, rendering a total sample size of 2,448 clients. According to the country’s national guidelines, all MMT clients must be at least 20 years of age with opiate dependence, excluding those who are currently convicted of criminal or civil charges, and those who have severe mental disabilities .
This study included only the clients who met these criteria and were receiving MMT from the participating clinics at the time of the study. The data were collected between September 2012 and August 2013. The selected clients were approached by our project outreach staff when they came into the clinic for daily treatment. Using a standard script, our project staff explained the study purpose, procedure, risks, and benefits to the study participants. Each participant was assured of confidentiality and their right to refuse participation without affecting their treatment services. The refusal rate was less than 5%. Written informed consent was obtained from each of the participants. The study was reviewed and approved by the Institutional Review Boards of the participating institutes in the U.S. and China. The survey questionnaire was administered face-to-face using the Computer Assisted Personal Interview method, with trained interviewers reading questions to the participants and recording their responses on laptop computers. The CAPI database was developed to automatically incorporate skip patterns and logistic check to reduce human errors. The survey took place in a private office within a MMT clinic and lasted about 45 to 60 minutes. The participants received 30 yuan for their time spent on the assessment. The statistical analyses were performed using the SAS 9.4 statistical software package . Firstly, descriptive statistics and frequency distribution for demographic and drug use related factors were summarized. These characteristics were compared between psychoactive substance users and non-users. Due to the study design, the participants were clustered within MMT clinics. Participants within a particular clinic may tend to be more similar to each other than to participants from different clinics, so we used mixed-effect models with clinic-level random effects to account for the clustering effect within a clinic . Second, we descriptively analyzed the proportion of each type of psychoactive substance use during the last 30 days and in lifetime. Lastly, in order to examine the factors associated with psychoactive substance use, mixed-effect models were built for the participants’ psychoactive substance use during the past 30 days and in lifetime .
The factors included in the models were: age , gender , marital status , education , personal income during the last 30 days , duration of heroin use , duration of MMT use , heroin use in the last 30 days , lifetime alcohol use , if have friend uses drug other than heroin and alcohol , and depressive symptoms . The selection the covariates was based on our prior understanding of the population and the correlates of psychoactive substance use suggested by literature . The models included clinic-level random effects to account for correlation within the clinics.Table 1 summarizes the characteristics of the study population. Among the 2448 participants, the majority were men. The average age was 40.6 years, with about half of the participants being between the ages of 36 to 45. More than half of the participants were married or living with a regular partner at the time of the study. Approximately one third had a high school or above education. The average monthly income was 2070.0 yuan , and 763 of the participants had no income during the previous 30 days. At the time of the study,greenhouse grow table the average duration of heroin use was 14.9 years and the average duration of MMT was 3.6 years. The average daily methadone dose was 54.0 ml. Half of the participants have used alcohol in their lifetime, and 14.2% self-reported heroin use in the previous 30 days. About one tenth of the participants had friend who used drugs other than heroin and alcohol. Among the 2448 participants, 158 have used psychoactive substance use during the past 30 days, and 933 did so in lifetime. Among the 158 lifetime users, 148 reported using psychoactive substance during the past 30 days. Table 2 presents the types of psychoactive substance used in the last 30 days and in lifetime. Sedative/hypnotic/ antidiarrheal agent was the most commonly used psychoactive substance , followed by amphetamine and hallucinogens . The frequency distribution of psychoactive substance use and its cross tabulation with background characteristics are also presented in Table 1. Participants who were 35 years or younger reported more psychoactive substance use in lifetime than older participants . Those who were married or living with a regular partner were less likely to report psychoactive substance use than those who were single, divorced, separated or widowed .
Lifetime psychoactive substance use was found to be the highest among those who had used heroin for 11–20 years .Having psychoactive substances using friends was positively correlated with psychoactive substance use in lifetime and in the past 30 days . Those who had used psychoactive substances in the last 30 days reported significantly higher level of depressive symptoms than those who had not ; this was also true for lifetime users . Table 3 summarizes the results of mixed model for psychoactive substance use in the last 30 days and in lifetime. When all were held constant, heroin use in the past 30 days was the most important factor in association with psychoactive substance use in the past 30 days . Other covariate significantly associated with psychoactive substance use in the last 30 days include younger age , having psychoactive substances using friend , and having higher level of depressive symptoms . Factors associated with lifetime psychoactive substance use included having psychoactive substance using friend , heroin use in the last 30 days , lifetime alcohol use , duration of heroin use , depressive symptoms , and age . The paper reported that a substantial proportion of the MMT clients in China either have initiated or are currently involved in psychoactive substance use. The number indicates a need for increased attention to this issue. As previous studies suggested, after cessation of opioid abuse, MMT clients might seek psychoactive substances as an attempt to achieve alternative rewarding effect . The concomitant use of psychoactive substances may lead to poor MMT adherence and compromise the treatment outcome , so the issue is in an urgent need to be prevented and controlled. The current Chinese national MMT guideline requires MMT clients to receive urine morphine test on both regular and random basis during the maintenance treatment to monitor the use of heroin . However, the guideline did not specify the testing of non-opiate substances, so urine psychoactive substance screening is not consistently performed in MMT clinics . Given the considerable prevalence of psychoactive substance use among MMT clients, urinalysis of psychoactive substances should be incorporated and routinely administered in the MMT clinics, so that psychoactive substance users could be detected and linked to treatment and care. More importantly, behavioral, psychological, and medical interventions are warranted to be integrated into the current MMT to protect the clients from the negative impacts of psychoactive substance use and to maintain the benefits of MMT . The study revealed several factors associated with psychoactive substance use among MMT clients. More psychoactive substance use was found to be associated with younger age, which was consistent with the literature which indicated that psychoactive substances were primarily popular among young people . The study also found a strong correlation between recent heroin use and recent psychoactive substance use, which suggested that client who was detected to use heroin should simultaneously receive psychoactive substance screening and interventions. In this study, high dose of methadone did not show to have a protective effect against psychoactive substance use, which was supported by previous studies . Findings also confirmed that having a psychoactive substances using friend increased the MMT clients’ likelihood of psychoactive substance use . As reported by numerous literatures, social network had an impact on psychoactive substance using behaviors by making drugs more available and emitting environmental cues to trigger craving and withdrawal . In order to reduce psychoactive substance use, intervention effort should aim to supplant the harmful friendship with non-drug-using supportive networks .The interplay between psychoactive substance use and mental illnesses has been documented by numerous studies . In particular, psychoactive substances have direct effect on monoamine regulation within the brain, producing various depressive symptoms including low mood, fatigue, sleeping disorder, appetite changes, irritability, and/or poor concentration . Conversely, depressive symptoms can reduce adherence to addiction treatment and elevate the risk of psychoactive substance use . The finding implies that the MMT services providers should closely monitor the clients’ mental health status to identify early signs of psychoactive substance use, so that interventions can be delivered in a timely manner.