Access to Office-Based Buprenorphine Treatment in Areas With High Rates of Opioid-Related Mortality: An Audit Study.

Background: Improving access to treatment for opioid use disorder is a national priority, but little is known about the barriers encountered by patients seeking buprenorphine-naloxone ("buprenorphine") treatment. Objective: To assess real-world access to buprenorphine treatment for uninsured or Medicaid-covered patients reporting current heroin use. Design: Audit survey ("secret shopper" study). Setting: 6 U.S. jurisdictions with a high burden of opioid-related mortality (Massachusetts, Maryland, New Hampshire, West Virginia, Ohio, and the District of Columbia). Participants: From July to November 2018, callers contacted 546 publicly listed buprenorphine prescribers twice, posing as uninsured or Medicaid-covered patients seeking buprenorphine treatment. Measurements: Rates of new appointments offered, whether buprenorphine prescription was possible at the first visit, and wait times. Results: Among 1092 contacts with 546 clinicians, schedulers were reached for 849 calls (78% response rate). Clinicians offered new appointments to 54% of Medicaid contacts and 62% of uninsured-self-pay contacts, whereas 27% of Medicaid and 41% of uninsured-self-pay contacts were offered an appointment with the possibility of buprenorphine prescription at the first visit. The median wait time to the first appointment was 6 days (interquartile range [IQR], 2 to 10 days) for Medicaid contacts and 5 days (IQR, 1 to 9 days) for uninsured-self-pay contacts. These wait times were similar regardless of clinician type or payer status. The median wait time from first contact to possible buprenorphine induction was 8 days (IQR, 4 to 15 days) for Medicaid and 7 days (IQR, 3 to 14 days) for uninsured-self-pay contacts. Limitation: The survey sample included only publicly listed buprenorphine prescribers. Conclusion: Many buprenorphine prescribers did not offer new appointments or rapid buprenorphine access to callers reporting active heroin use, particularly those with Medicaid coverage. Nevertheless, wait times were not long, implying that opportunities may exist to increase access by using the existing prescriber workforce. Primary Funding Source: National Institute on Drug Abuse.

Prescribing diamorphine in the United States: Insights from a nationally representative survey.

BACKGROUND: Some countries allow physicians to prescribe pharmaceutical-grade diamorphine to dependent users who have previously undergone treatment but are still using street-sourced heroin; this is not allowed in the US. This study provides the first nationally representative US data concerning public support for prescribing diamorphine to dependent users. We also test the hypothesis that calling it "diamorphine" instead of "heroin" increases support for this approach. METHODS: The RAND American Life Panel is a nationally representative, probability-based survey of US adults. Of the 3345 panel members invited to take the survey, 2530 (75.6%) provided a valid response to our question module. Respondents were randomly assigned to have the question refer to the prescribed drug as either "heroin" or "diamorphine." The groups did not significantly differ on sex, age, race/ethnicity, or education. We compare the distribution of responses for the two groups and conduct Pearson's chi-squared test with the Rao-Scott correction. RESULTS: For those asked whether the US should try prescribing pharmaceutical-grade "heroin," the share answering "Yes" (20.8%) was 15 percentage points lower than those responding "No" (35.8%). When the question asked about "diamorphine," the results were nearly reversed: the share answering "Yes" (30.6%) was almost 12 percentage points higher than those responding "No" (18.9%). The distributions of responses were significantly different (p < 0.001). CONCLUSIONS: Support for prescribing diamorphine to dependent users is low in the US. While the results are consistent with the hypothesis that referring to heroin as diamorphine may reduce stigma associated with the substance and increase support for prescribing it, opinions may change as individuals learn they are different names for the same substance.

A longitudinal and case-control study of dropout among drug users in methadone maintenance treatment in Haiphong, Vietnam.

BACKGROUND: Vietnam began providing methadone maintenance therapy (MMT) in 2008; as of June 2016, 44,479 persons who inject drugs (PWID) were in treatment in 57 provinces. However, 10-23% of patients were estimated to have dropped out of treatment during the first 2 years. We evaluated dropout and factors associated with quitting treatment. METHODS: We followed clients ≥ 18 years old enrolled in five MMT clinics in Haiphong for 3 years. Persons who missed a consecutive month of methadone treatment were considered to have dropped out and were not allowed to return; those who missed greater than five consecutive doses were considered to be non-compliant but were allowed to restart treatment at their initial dose. Clients who dropped out or who were non-compliant during their third year of MMT (cases) were traced and matched with two clients who remained in treatment (controls) by gender, age, and length of time in the program. Cases and controls were interviewed. Additional data on levels of yearly retention were abstracted from clinic records. RESULTS: Among the 1055 patients initially enrolled in MMT, dropout and non-compliance combined was 13.6% during the first year, 16.5% during the second year, and 22.3% during the third year. By 36 months, 33.3% of clients had dropped out, of whom 10.6% had died and 24% had been arrested. We traced and interviewed 81 clients who dropped out or who were non-compliant during year 3 as well as 161 controls. The primary reasons for dropping out included claiming no dependence on heroin (22.2%), conflict with work (21.0%), health problems (16.0%), and inability to afford the methadone co-payment of approximately 0.5 USD/day (14.8%). Independent factors associated with non-compliance included continuing to use heroin (aOR = 12.4, 95% CI 4.2-36.8) and missing greater than three doses during the previous 3 months (aOR = 18.5, 95% CI 7.4-47.1); receiving a daily dose of > 120 mg of methadone was associated with a lower odds ratio of dropping out (aOR = 0.3, 95% CI 0.1-0.9). CONCLUSION: By 3 years, one third of all patients in treatment had permanently dropped out. Ensuring that methadone dosing is adequate and reducing or eliminating the co-payment fee for those who cannot afford it could improve retention.

Effectiveness and cost-effectiveness of unsupervised buprenorphine-naloxone for the treatment of heroin dependence in a randomized waitlist controlled trial.

BACKGROUND: Access to opioid agonist treatment can be associated with extensive waiting periods with significant health and financial burdens. This study aimed to determine whether patients with heroin dependence dispensed buprenorphine-naloxone weekly have greater reductions in heroin use and related adverse health effects 12-weeks after commencing treatment, compared to waitlist controls and to examine the cost-effectiveness of this strategy. METHODS: An open-label waitlist RCT was conducted in an opioid treatment clinic in Newcastle, Australia. Fifty patients with DSM-IV-TR heroin dependence (and no other substance dependence) were recruited. The intervention group (n=25) received take-home self-administered sublingual buprenorphine-naloxone weekly (mean dose, 22.7±5.7mg) and weekly clinical review. Waitlist controls (n=25) received no clinical intervention. The primary outcome was heroin use (self-report, urine toxicology verified) at weeks four, eight and 12. The primary cost-effectiveness outcome was incremental cost per additional heroin-free-day. RESULTS: Outcome data were available for 80% of all randomized participants. Across the 12-weeks, treatment group heroin use was on average 19.02days less/month (95% CI -22.98, -15.06, p<0.0001). A total 12-week reduction in adjusted costs including crime of $A5,722 (95% CI 3299, 8154) in favor of treatment was observed. Excluding crime, incremental cost per heroin-free-day gained from treatment was $A18.24 (95% CI 4.50, 28.49). CONCLUSION: When compared to remaining on a waitlist, take-home self-administered buprenorphine-naloxone treatment is associated with significant reductions in heroin use for people with DSM-IV-TR heroin dependence. This cost-effective approach may be an efficient strategy to enhance treatment capacity.

Oral health assessment for users of marijuana and cocaine/crack substances

Abstract: The objective of this study was to assess the oral health status of users of illicit drugs such as marijuana and cocaine/crack and compare it with individuals not using these chemical substances. Questionnaires were applied to 35 illicit drugs users to gather information on demographic status, general health, and use of drugs. Then, a clinical assessment of the oral health condition was performed to collect data on decayed, missing and filled teeth (DMFT) index, salivary flow rate (SFR), and mucosal lesions. The control group was composed of 35 non-illicit drug users. In the experimental group, 91.43% were males, 80% were smokers, and 42.85% were alcoholics. Cocaine was the most common drug used (77.15%), followed by marijuana (68.6%), and crack (51.4%). The average DMFT index was 9.8 and the SFR was reduced in 60% of subjects. Mucosal alterations were detected, but no potentially malignant disorders or oral cancer were diagnosed. Compared to control group, significantly higher values for gender (40%, p = 0.0001), smoking (22.86%) and heavy drinking (5.7%) habits (p = 0.0001), SFR (31.4%; p = 0.0308), and oral lesions (p = 0.0488) were found for the experimental group, although significantly higher values were found in the control group for DMFT index (p = 0.0148). It can be concluded that the use of illicit drugs contributed to an increased prevalence of oral mucosa lesions. In addition, a decline on SFR and a reduced DMFT index was observed for illicit drug users.

Conspicuous by their abstinence: The limited engagement of heroin users in English and Welsh Drug Recovery Wings.

BACKGROUND: In recent years, an abstinence-focused, 'recovery' agenda has emerged in UK drug policy, largely in response to the perception that many opioid users had been 'parked indefinitely' on opioid substitution therapy (OST). The introduction of ten pilot 'Drug Recovery Wings' (DRWs) in 2011 represents the application of this recovery agenda to prisons. This paper describes the DRWs' operational models, the place of opiate dependent prisoners within them, and the challenges of delivering 'recovery' in prison. METHODS: In 2013, the implementation and operational models of all ten pilot DRWs were rapidly assessed. Up to three days were spent in each DRW, undertaking semi-structured interviews with a sample of 94 DRW staff and 102 DRW residents. Interviews were fully transcribed, and coded using grounded theory. Findings from the nine adult prisons are presented here. RESULTS: Four types of DRW were identified, distinguished by their size and selection criteria. Strikingly, no mid- or large-sized units regularly supported OST recipients through detoxification. Type A were large units whose residents were mostly on OST with long criminal records and few social or personal resources. Detoxification was rare, and medication reduction slow. Type B's mid-sized DRW was developed as a psychosocial support service for OST clients seeking detoxification. However, staff struggled to find such prisoners, and detoxification again proved rare. Type C DRWs focused on abstinence from all drugs, including OST. Though OST clients were not intentionally excluded, very few applied to these wings. Only Type D DRWs, offering intensive treatment on very small wings, regularly recruited OST recipients into abstinence-focused interventions. CONCLUSION: Prison units wishing to support OST recipients in making greater progress towards abstinence may need to be small, intensive and take a stepped approach based on preparatory motivational work and extensive preparation for release. However, concerns about post-release deaths will remain.

Multiple imputation strategies for zero-inflated cost data in economic evaluations: which method works best?

Cost and effect data often have missing data because economic evaluations are frequently added onto clinical studies where cost data are rarely the primary outcome. The objective of this article was to investigate which multiple imputation strategy is most appropriate to use for missing cost-effectiveness data in a randomized controlled trial. Three incomplete data sets were generated from a complete reference data set with 17, 35 and 50 % missing data in effects and costs. The strategies evaluated included complete case analysis (CCA), multiple imputation with predictive mean matching (MI-PMM), MI-PMM on log-transformed costs (log MI-PMM), and a two-step MI. Mean cost and effect estimates, standard errors and incremental net benefits were compared with the results of the analyses on the complete reference data set. The CCA, MI-PMM, and the two-step MI strategy diverged from the results for the reference data set when the amount of missing data increased. In contrast, the estimates of the Log MI-PMM strategy remained stable irrespective of the amount of missing data. MI provided better estimates than CCA in all scenarios. With low amounts of missing data the MI strategies appeared equivalent but we recommend using the log MI-PMM with missing data greater than 35 %.

Heroin-assisted treatment: has a controversial treatment come of age?†.

This editorial considers the findings of the systematic review of heroin-assisted treatment, with six different studies from six different countries, published in this issue. The meta-analysis focuses on supervised injected heroin and reports significant crime reduction and an overall cost-effectiveness of treatment. Despite this body of evidence, policy makers remain reluctant to develop this treatment further. The question remains, what else is required to convince policy makers of the value of such treatment for severe and refractory heroin dependence?

Delivering opioid maintenance treatment in rural and remote settings.

OBJECTIVE: This study explored the delivery of opioid maintenance treatment (OMT) from a specialist program in rural and remote New South Wales (NSW), focusing on the viability of the model and strategies for its improvement. DESIGN: Program evaluation examining configuration and delivery, client characteristics and trends in demand, using policy documents, service data and stakeholder consultations (n = 28). SETTING: The Greater Western Area Health Service, a sparsely populated and large geographic area in NSW. RESULTS: There were four service hubs or primary sites. Three sites were co-located with hospitals and one within community health, with all sites providing assessment, prescribing, dispensing and limited case management. Staff were mainly trained nurses, while prescribers were visiting specialists or sessional GPs. There was minimal OMT provision by community prescribers and dispensers. In 2009, there were 638 clients. They were younger on average than those in OMT across Australia. The most common principal drug of concern was heroin (37-85% of clients), while around one-fifth of clients identified prescription opioids (18-23%). There was a substantial increase in OMT provision between 2006 and 2009 at three program sites. Staff at the sites had limited capacity to engage primary health services and thus reduce their client load. CONCLUSIONS: Findings indicate the need to adjust funding to account for increased demand for OMT and to establish a financial incentive for GP prescribers. Dedicated resourcing is needed for a capacity building role to support the uptake of prescribing and dispensing in community services.

Psychometric evaluation, using Rasch analysis, of the WHOQOL-BREF in heroin-dependent people undergoing methadone maintenance treatment: further item validation.

BACKGROUND: The brief version of World Health Organization Quality of Life assessment (WHOQOL-BREF), a useful outcome measure for clinical decision making, has been evaluated using classical test theory (CTT) for psychometric properties on heroin-dependent patients. However, CTT has a major disadvantage of invalid summated score, and using Rasch models can overcome the shortcoming. The purpose of this study was using Rasch models to evaluate the psychometric properties of the WHOQOL-BREF for heroin-dependent patients, and the hypothesis was that each WHOQOL-BREF domain is unidimensional. METHODS: Two hundred thirty six participants (24 females, mean [SD] age = 38.07 [7.44] years, first used heroin age = 26.13 [6.32] years), with a diagnosis of opioid dependence, were recruited from a methadone maintenance treatment program. Each participant filled out the WHOQOL-BREF. Parallel analysis (PA) and Rasch rating scale models were used for statistical analyses. RESULTS: Based on the PA analyses, four domains of the WHOQOL-BREF were unidimensional. The Rasch analyses showed three negatively worded items (2 in Physical and 1 in Psychological) reported as misfits that may not contribute to the Physical and Psychological domains; one positively worded item in the Physical domain may be redundant. All values for the separation indices were above 2 except for the person separation index in the Physical domain (1.93). Category functioning and item independency of four WHOQOL-BREF domains were supported by the Rasch analyses, and there were 5 items showing the differential item function (DIF) for positive versus negative HIV (human immunodeficiency virus) infection. CONCLUSIONS: The WHOQOL-BREF is a valid outcome measure for assessing general quality of life for substance abusers in terms of physical, psychological, social, and environmental factors. It can also be used as a treatment outcome measure to evaluate the effect of treatments for substance abusers. However, the three misfit negatively worded items should be used with caution because the substance abuser may not fully understand their meaning. Future research may apply cognitive interviews to determine the cognitive functioning of substance abusers and their interpretation of negatively worded items.

Substance use and hepatitis C: an ecological momentary assessment study.

OBJECTIVE: The objective of this study was to assess craving and mood related to opioid and cocaine use among asymptomatic hepatitis C virus (HCV)+ and HCV- methadone patients who have not started antiviral treatment. METHODS: In this 28-week prospective ecological momentary assessment (EMA) study, 114 methadone-maintained, heroin- and cocaine-abusing individuals reported from the field in real time on their mood, craving, exposure to drug-use triggers, and drug use via handheld computers. RESULTS: Sixty-one percent were HCV+; none were overtly symptomatic or receiving HCV treatment. HCV status was not associated with age, sex, race, or past-30-day or lifetime heroin or cocaine use. In event-contingent EMA entries, HCV+ individuals more often attributed use to having been bored, worried, or sad; feeling uncomfortable; or others being critical of them compared with HCV- participants. In randomly prompted EMA entries, HCV+ participants reported significantly more exposure to drug-use triggers, including handling ≥$10, seeing cocaine or heroin, seeing someone being offered/use cocaine or heroin, being tempted to use cocaine, and wanting to see what would happen if they used just a little cocaine or heroin. CONCLUSIONS: HCV+ individuals experienced more negative moods and more often cited these negative moods as causes for drug use. HCV+ individuals reported greater exposure to environmental drug-use triggers, but they did not more frequently cite these as causes for drug use. The EMA data reported here suggest that HCV+ intravenous drug users may experience more labile mood and more reactivity to mood than HCV- intravenous drug users. The reason for the difference is not clear, but HCV status may be relevant to tailoring of treatment.

Assessment of CYP450 genetic variability effect on methadone dose and tolerance.

AIM: Methadone dose is related to treatment success in individuals under methadone maintenance treatment (MMT). We constructed a gene matrix using previously identified genetic polymorphisms in CYP450 and determined their genetic influence on methadone dose or tolerance. MATERIALS & METHODS: The allelic combinations of CYP450 genetic variants (two from CYP2C19, four from CYP2B6 and five from CYP3A4) were analyzed in 366 MMT heroin dependent patients as possible determinants of methadone dose and tolerance using analysis of covariance. RESULTS: Methadone dose (p = 0.007) and tolerance (p = 0.06) were mainly influenced by CYP2C19 gene dose. Moreover, dominant influence of the CYP2C19 gene dose on methadone dose and tolerance was only found among MMT patients with negative urine morphine test results, but not among those with positive results. CONCLUSION: The findings suggest that CYP2C19 gene dose may serve as a potential indicator for assessing methadone dose and tolerance in MMT patients.

Work and the journey to recovery: exploring the implications of welfare reform for methadone maintenance clients.

BACKGROUND: An emphasis on welfare reform has been a shared concern of recent UK governments, with the project of transforming the provision of welfare gathering pace over the past six years. Replicating active labour market policies pursued across the globe, successive governments have used welfare-to-work programmes as mechanisms to address worklessness. Since 2008, problem drug users (PDUs) have been added to a list of groups for whom intervention is deemed necessary to encourage, enable, and sometimes coerce them into paid employment. This approach is underpinned by three beliefs relating to paid work: it sustains recovery, has a transformative potential and should be the primary duty of the responsible citizen. Using policy developments in the UK as a case study, the article explores the implications for methadone maintenance clients of connecting drug policy (premised on the belief that work is central to recovery) with welfare policy (which at present is preoccupied with reducing worklessness). METHODS: A critical analysis of policy documents, including drug strategies, Green and White papers and welfare reform legislation, alongside a review of relevant academic literature. RESULTS: The 'work first' approach which underpins current labour market activation policies in the UK and elsewhere is insufficiently flexible to accommodate the diverse needs of PDUs in recovery, and is particularly particular problematic when combined with a 'social deficit' model which concentrates on individual rather than structural barriers to employability. The use of payment-by-results mechanisms to provide employment services, coupled with the use of sanctions for those who do not engage, is likely to be particularly problematic for methadone maintenance clients. CONCLUSION: Welfare reform in the UK is likely to undermine the recovery of methadone maintenance clients. Further research is urgently needed to explore its impact on this sub-group of PDUs, alongside comparative studies to determine best practice in integrating drug and welfare policies.

Methadone, a contested substance: Danish methadone policy in the 1970s.

BACKGROUND: During the 1970s in Denmark, there was a great deal of controversy about the role of methadone in Danish drug policy. At stake were not just epistemological issues about how to explain drug problems or indeed technical issues about the best possible treatment for such problems, but also social issues about how drug problems and drug treatment affected and were affected by social change. The paper uses an analytical framework in which drugs are co-constructed with their social worlds. It uses this framework to investigate how conflicts emerged about the different ways of conceiving of the relationship between methadone and Danish society. METHODS: Documentary data from the archives of a pressure group of parents of children with drug problems, the archives of an addiction doctor, newspaper articles, and policy documents from that time were coded in order to identify and analyze central controversies. RESULTS: The methadone controversy of the 1970s was not just about the best treatment methods, but also a matter of the future of the Danish welfare state. The nation debated whether it should medicalise a social problem or solve it through social reform. CONCLUSION: Drug treatment is not just a technical issue, but also a political issue and this needs to be accounted for when making drug policy.

From political controversy to a technical problem? Fifteen years of opioid substitution treatment in Finland.

BACKGROUND: The aim of the article is to analyze changes in opioid substitution treatments (OST) in Finland. OST spread in Finland in the late 1990s and early 2000s (Phase 1). Since then, OST has become an integrated part of Finnish drug policy and is provided in various substance abuse treatment units as well as in municipal health centers (Phase 2). METHODS: The paper analyses the policy around the implementation of opioid substitution treatment in Finland, focusing on identifying the key factors and the relations between them that have contributed to the implementation of OST in Finland. RESULTS: OST has become accepted in Finland during the past ten years as a crucial element of a harm reduction strategy. Present incentives behind this development are not as clearly related to drug-specific policies as in the late 1990s; rather, they stem from both the restructuring of health care services (e.g. cost-effectiveness) and the strengthening of the medical or technico-administrative approach to the development of OST. CONCLUSION: Since the early 2000s, the development of substitution treatment in Finland has not taken place under explicit drug-political guidance, but largely as a result of many differing intended and unintended effects. One of the unintended effects is the fact that buprenorphine has replaced heroin as the most commonly misused opioid in Finland.

Assessment of attitudes towards methadone maintenance treatment between heroin users at a compulsory detoxification centre and methadone maintenance clinic in Ningbo, China.

BACKGROUND: In China, the Compulsory Detoxification Centres are the main response for people who use illegal drugs. Due to high relapse rates among people released from the Compulsory Detoxification Centres, it is likely that they may seek medical help, including Methadone Maintenance Treatment (MMT) services, at some point. Therefore, better understanding of the attitudes and beliefs of people in the Compulsory Detoxification Centres can help to provide more adequate response to opioid dependence. METHODS: In total, 329 detained heroin users and 112 active MMT clients were recruited from a local Compulsory Detoxification Centre and MMT clinic, respectively. The survey contained specific questions relating to attitudes and beliefs regarding MMT. RESULTS: Participants at the Compulsory Detoxification Centre and the MMT clinic expressed different opinions, regarding positive and negative attitudes and beliefs towards MMT. In addition, participants from both sites hold certain negative attitudes and beliefs about methadone despite their acknowledgement of the positive effects of MMT. Finally, participants at the Compulsory Detoxification Centre and the MMT clinic reported distinctive treatment preferences, with the former preferring community-based treatment and the latter MMT. CONCLUSIONS: Developing targeted education about MMT for people at the Compulsory Detoxification Centres could help improve access to accurate and evidence-based health and treatment information. The study may also help providers understand and adjust services needed for target population in the future.

Impact of methadone maintenance on health utility, health care utilization and expenditure in drug users with HIV/AIDS.

BACKGROUND: This study assessed the impact of methadone maintenance treatment (MMT) on health utility, health care service utilization, and out-of-pocket (OOP) health expenditure in drug users with HIV/AIDS in Vietnam. METHODS: Using the 2012 Vietnam HIV Service Users Survey data, a post-evaluation was designed to compare 121 MMT patients with 347 non-MMT patients who were matched using propensity scores of MMT covariates. Health utility was measured using the EuroQOL - five dimensions - five levels (EQ-5D-5L) and a visual analogue scale (EQ-VAS). RESULTS: The mean EQ-5D-5L single index and EQ-VAS score of MMT patients were 0.68 (95% CI=0.64-0.73) and 71.5% (95% CI=68.2-74.9). Compared with the control group, the adjusted differences in health utility were 0.08 and 4.43% (p=0.07), equivalent to 12.1% and 6.5% increases during MMT. There was a 45.9% decrease in the frequency of health care service utilization that was attributable to MMT. Although, antiretroviral treatment and MMT services were free-of-charge, MMT and non-MMT patients still paid their OOP for health care for averagely US$ 16.3/month and US$ 28.9/month. The adjusted difference between the two groups was US$ 19.3/month ($ 231.6/year) that equivalents to a reduction of 66.7% in OOP health expenditure related to MMT. CONCLUSION: MMT was associated with a clinically important difference in health utility, large reductions in health care service utilization and OOP health expenditure in HIV-positive drug users. Scaling up MMT in large drug-using population could help improve the outcomes of HIV/AIDS interventions and reduce economic vulnerability of affected households.

Associations among hypothalamus-pituitary-adrenal axis function, novelty seeking, and retention in methadone maintenance therapy for heroin dependency.

OBJECTIVE: The efficacy of methadone maintenance therapy for heroin dependence is compromised by the low retention rate. Hypothalamus-pituitary-adrenal (HPA) axis function, which is associated with stress response, and novelty seeking (NS), a personality trait associated with low dopaminergic activity, may play roles in retention. METHOD: We conducted a prospective study in which HPA axis function and NS were assessed by the dexamethasone suppression test and the Tridimensional Personality Questionnaire at baseline, respectively. The retention rate was assessed at the half- and 1-year points of methadone maintenance therapy. RESULTS: A low suppression rate of dexamethasone suppression test (D%) was associated with a high level of NS. A low D% was associated with half-year dropout, whereas a high level of NS was associated with 1-year dropout. Survival analysis confirmed that D% and NS were significant time-dependent covariates for retention. CONCLUSION: The findings showed that HPA axis function and NA were associated with retention at different time points.