Drug Abuse Treatment Clinical Trials Research Articles

Mortality Rates Among Substance Use Disorder Participants in Clinical Trials: Pooled Analysis of Twenty-Two Clinical Trials Within the National Drug Abuse Treatment Clinical Trials Network

BackgroundMost substance use disorders (SUD) treatment clinical trials are too short and small to reliably estimate the incidence of rare events like death. ObjectiveThe aim of this study is to estimate the overall mortality rates among a SUD treatment-seeking population by pooling participants from multiple clinical trials conducted through the National Institute on Drug Abuse (NIDA)-sponsored National Drug Abuse Treatment Clinical Trials Network (CTN). ParticipantsDrug and or alcohol users (N=9866) who sought treatment and participated in one of the twenty-two CTN trials. MeasurementsData were collected through randomized clinical trials in national community treatment programs for SUD. Pooled analysis was performed to assess age- and gender-standardized mortality rate(s) (SM rate(s)), and mortality ratio(s) (SM ratio(s)) of CTN trial participants compared to the U.S. general population. ResultsThe age- and gender-SM rate among CTN trials participants was 1403 (95% CI: 862–2074) per 100,000 person years (PY) compared to 542 (95% CI: 541–543) per 100,000 PY among the U.S. general population in 2005. By gender, age-adjusted SM ratio for female CTN trial participants was over five times (SM ratio=5.35, 95% CI: 3.31–8.19)), and for male CTN trial participants, it was over three times (SM ratio=3.39, 95% CI: 2.25–4.90) higher than their gender comparable peers in the U.S. general population. ConclusionsAge and gender-standardized mortality rates and ratios among NIDA CTN SUD treatment-seeking clinical trial participants are higher than the age and gender comparable U.S. general population. The overall mortality rates of CTN trial participants are similar to in-treatment mortality reported in large U.S. and non-U.S. cohorts of opioid users. Future analysis with additional CTN trial participants and risk times will improve the stability of estimates, especially within subgroups based on primary substance of abuse. These SUD mortality rates can be used to facilitate safety monitoring within SUD clinical trials.

Hair analysis and its concordance with self-report for drug users presenting in emergency department

BackgroundSecondary analysis using data from the National Drug Abuse Treatment Clinical Trials Network randomized trial (NCT # 01207791), in which 1285 adult ED patients endorsing moderate to severe problems related to drug use were recruited from 6 US academic hospitals. Objective: To investigate the utility of hair analysis in drug use disorder trials with infrequent visits, and its concordance with Timeline Follow Back (TLFB). Methods: This study compared the self-reported drug use on the TLFB instrument with the biological measure of drug use from hair analysis for four major drug classes (Cannabis, Cocaine, Prescribed Opioids and Street Opioids). Both hair analysis and TLFB were conducted at 3, 6 and 12 month follow-up visit and each covered a 90-day recall period prior to the visit. Results: The concordance between the hair sample results and the TLFB was high for cannabis and street opioids, but was low to moderate for cocaine and prescribed opioids. Under-reporting of drug use given the positive hair sample was always significantly lower for the drug the study participant noted as their primary drug of choice compared with other drugs the participant reported taking, irrespective of whether the drug of choice was cannabis, cocaine, street opioids and prescribed opioids. Over-reporting of drug use given the negative hair sample was always significantly higher for the drug of choice, except for cocaine. Conclusions: This study extends the literature on hair analysis supporting its use as a secondary outcome measure in clinical trials.

Design of the NIDA clinical trials network validation study of tobacco, alcohol, prescription medications, and substance use/misuse (TAPS) tool

BackgroundSubstance use and its associated use disorders are under-detected and under-treated in primary care. There is a need for a clinically useful brief screening and assessment instrument to identify primary care patients with substance use, sub-threshold substance use disorder (SUD), and SUD to facilitate brief intervention and treatment. MethodsWe describe the design of the recently completed National Drug Abuse Treatment Clinical Trials Network's tobacco, alcohol, prescription medications, and substance use/misuse screen and brief assessment tool validation study. Study aims included to: develop a 2-stage screening and brief assessment tool (TAPS Tool) to detect substance use, problem use, and SUD among adult primary care patients; examine the validity of both the screen component and the TAPS Tool by comparing them to reference standard screening and assessment measures of no use, problem use, and SUD; and determine the feasibility and acceptability of the self-administration and interviewer-administration of the tool. The design included a pilot testing phase (n=30) and the main study of 2000 adult primary care participants who were randomly assigned in counter-balanced order to have the interviewer-administration or the self-administration of the TAPS Tool followed by the other administration format. Participants' views of feasibility, acceptability and preference for format of self-administration versus interviewer-administration of the TAPS Tool were assessed. Criterion measures of use and DSM-5 SUDs were administered. DiscussionThe TAPS Tool study builds on prior work to develop a 2-stage clinical tool for facilitating the adoption of screening, brief assessment and treatment for SUDs in primary care.

Smoking among patients in substance use disorders treatment: associations with tobacco advertising, anti-tobacco messages, and perceived health risks

ABSTRACTBackground: Although tobacco control efforts have contributed to an overall decline in smoking, individuals with substance use disorders (SUDs) continue to smoke at high rates and remain targets of advertising to vulnerable groups, including those with mental health disorders and SUDs. Objectives: We examined associations of tobacco advertising exposure and receptivity, anti-tobacco message awareness, and health-risk perception with smoking status and cigarettes-per-day (CPD) in a national sample of SUD treatment patients. Methods: The patients (N = 1,113) in 24 programs chosen randomly, stratified by program type, from among publicly funded adult treatment programs within the National Drug Abuse Treatment Clinical Trials Network completed surveys of smoking, advertising exposure and receptivity, anti-tobacco message awareness, and perceived health risks. Results: Current smokers (77.9% of the sample) smoked a daily median of 10 cigarettes (IQR = 13). The participants reporting daily advertising exposure were 1.41 times more likely to be smokers (p = 0.019) than others. Those highly receptive to advertising were 2.34 times more likely to be smokers (p < 0.001) than those with low/moderate receptivity. Higher perceived health risk was associated with lower odds of smoking (OR = 0.99, 95% CI: 0.98–0.99, p < 0.001). CPD for smokers highly receptive to advertising was 11.1% (95% CI: 2.8%–20.0%) higher than for smokers with low/moderate advertising receptivity. Anti-tobacco message awareness was not associated with smoking status or CPD. Conclusion: The high rate of smoking among SUD treatment patients is associated with daily exposure and high receptivity to tobacco advertisements and lower perception of health-related smoking risks. Tobacco control efforts should target this vulnerable population.

Gender Differences in HIV Sexual Risk Behaviors Among Clients of Substance Use Disorder Treatment Programs in the U.S.

This study examined differences in sexual risk behaviors by gender and over time among 1281 patients (777 males and 504 females) from 12 community-based substance use disorder treatment programs throughout the United States participating in CTN-0032, a randomized control trial conducted within the National Drug Abuse Treatment Clinical Trials Network. Zero-inflated negative binomial and negative binomial models were used in the statistical analysis. Results indicated significant reductions in most types of sexual risk behaviors among substance users regardless of the intervention arms. There were also significant gender differences in sexual risk behaviors. Men (compared with women) reported more condomless sex acts with their non-primary partners (IRR=1.80, 95% CI 1.21-2.69) and condomless anal sex acts (IRR=1.74, 95% CI 1.11-2.72), but fewer condomless sex partners (IRR=0.87, 95% CI 0.77-0.99), condomless vaginal sex acts (IRR=0.83, 95% CI 0.69-1.00), and condomless sex acts within 2h of using drugs or alcohol (IRR=0.70, 95% CI 0.53-0.90). Gender-specific intervention approaches are called for in substance use disorder treatment.

Gender Differences in Internalizing Symptoms and Suicide Risk Among Men and Women Seeking Treatment for Cannabis Use Disorder from Late Adolescence to Middle Adulthood

Cannabis continues to rise in popularity as the perception of its harmfulness decreases and evidence of its deleterious developmental effect increases. While internalizing distress and suicide risk have been linked with cannabis use problems [DSM-5 cannabis use disorder (CUD); DSM-IV cannabis abuse and dependence] it remains unclear how this association varies over the course of development in treatment-seeking men and women. The current study utilized the National Drug Abuse Treatment Clinical Trials Network (NIDA CTN) to conduct a cross-sectional comparison of internalizing distress and suicide risk among men (n=437) and women (n=163) spanning ages 18–50 who met DSM-5 criteria for CUD. Interactions between gender and developmental stage (i.e., late adolescence, early adulthood, and middle adulthood) were observed for suicide risk and anxiety but not depression problems. Specifically, women seeking CUD treatment in late adolescence and middle adulthood exhibited significantly higher rates of anxiety and suicide risk compared to men seeking treatment during the same developmental stages. Internalizing distress and suicide risk did not differ between treatment-seeking men and women in the early adult stage. Overall, results suggest that the structure of risk for CUD may differ in men and women across the lifespan and that women presenting for CUD treatment during late adolescence and middle adulthood may uniquely benefit from intervention designed to address these elevations in anxiety and suicide risk.

Using electronic health record data for substance use Screening, Brief Intervention, and Referral to Treatment among adults with type 2 diabetes: Design of a National Drug Abuse Treatment Clinical Trials Network study

BackgroundThe Affordable Care Act encourages healthcare systems to integrate behavioral and medical healthcare, as well as to employ electronic health records (EHRs) for health information exchange and quality improvement. Pragmatic research paradigms that employ EHRs in research are needed to produce clinical evidence in real-world medical settings for informing learning healthcare systems. Adults with comorbid diabetes and substance use disorders (SUDs) tend to use costly inpatient treatments; however, there is a lack of empirical data on implementing behavioral healthcare to reduce health risk in adults with high-risk diabetes. Given the complexity of high-risk patients' medical problems and the cost of conducting randomized trials, a feasibility project is warranted to guide practical study designs. MethodsWe describe the study design, which explores the feasibility of implementing substance use Screening, Brief Intervention, and Referral to Treatment (SBIRT) among adults with high-risk type 2 diabetes mellitus (T2DM) within a home-based primary care setting. Our study includes the development of an integrated EHR datamart to identify eligible patients and collect diabetes healthcare data, and the use of a geographic health information system to understand the social context in patients' communities. Analysis will examine recruitment, proportion of patients receiving brief intervention and/or referrals, substance use, SUD treatment use, diabetes outcomes, and retention. DiscussionBy capitalizing on an existing T2DM project that uses home-based primary care, our study results will provide timely clinical information to inform the designs and implementation of future SBIRT studies among adults with multiple medical conditions.

Functional and behavioral consequences of DRD4 genetic variation in macaques

Functional and behavioral consequences of DRD4 genetic variation in macaques

Long-term outcomes from the National Drug Abuse Treatment Clinical Trials Network prescription opioid addiction treatment study

Long-term outcomes from the National Drug Abuse Treatment Clinical Trials Network prescription opioid addiction treatment study

Item banks for substance use from the Patient-Reported Outcomes Measurement Information System (PROMIS®): Severity of use and positive appeal of use

BackgroundTwo item banks for substance use were developed as part of the Patient-Reported Outcomes Measurement Information System (PROMIS®): severity of substance use and positive appeal of substance use. MethodsQualitative item analysis (including focus groups, cognitive interviewing, expert review, and item revision) reduced an initial pool of more than 5300 items for substance use to 119 items included in field testing. Items were written in a first-person, past-tense format, with 5 response options reflecting frequency or severity. Both 30-day and 3-month time frames were tested. The calibration sample of 1336 respondents included 875 individuals from the general population (ascertained through an internet panel) and 461 patients from addiction treatment centers participating in the National Drug Abuse Treatment Clinical Trials Network. ResultsFinal banks of 37 and 18 items were calibrated for severity of substance use and positive appeal of substance use, respectively, using the two-parameter graded response model from item response theory (IRT). Initial calibrations were similar for the 30-day and 3-month time frames, and final calibrations used data combined across the time frames, making the items applicable with either interval. Seven-item static short forms were also developed from each item bank. ConclusionsTest information curves showed that the PROMIS item banks provided substantial information in a broad range of severity, making them suitable for treatment, observational, and epidemiological research in both clinical and community settings.

Examining the factor structure of the Clinical Opiate Withdrawal Scale: A secondary data analysis from the National Drug Abuse Treatment Clinical Trials Network (CTN) 0003

BackgroundThe Clinical Opiate Withdrawal Scale (COWS) is used to assess withdrawal in clinical trials and practice. The aims of this study were to examine the inter-item correlations and factor structure of the COWS in opioid-dependent men and women. MethodsThis is a secondary data analysis of the National Drug Abuse Treatment Clinical Trials Network 0003, a randomized clinical trial that compared buprenorphine/naloxone tapering strategies. The trial included 11 sites in 10 US cities. Participants were opioid-dependent individuals (n=516) that had data on the COWS. The COWS at study baseline was analyzed in this study. ResultsInter-item correlations showed weak to moderate relationships among the items. A 1-factor model did not fit the data for men (comparative fit index (CFI)=.801, root mean square error of approximation (RMSEA)=.073, weighted root mean square residual (WRMR)=1.132) or women (CFI=.694, RMSEA=.071, WRMR=.933), where resting pulse rate was not related to withdrawal for men, and yawning and gooseflesh skin was not related to withdrawal for women. A reduced model comprised of only the 8 items that were significantly related to the construct of withdrawal in both men and women, and an exploratory 2-factor model, were also assessed but not retained due to inconsistencies across gender. ConclusionsWhen traditional psychometric models are applied to the COWS, it appears that the scale may not relate to a single underlying construct of withdrawal. Further research testing the hypothesized factor structure in other opioid-dependent samples is needed.

Maximizing Effectiveness Trials in PTSD and SUD Through Secondary Analysis: Benefits and Limitations Using the National Institute on Drug Abuse Clinical Trials Network "Women and Trauma" Study as a Case Example

Recent federal legislation and a renewed focus on integrative care models underscore the need for economical, effective, and science-based behavioral health care treatment. As such, maximizing the impact and reach of treatment research is of great concern. Behavioral health issues, including the frequent co-occurrence of substance use disorders (SUD) and posttraumatic stress disorder (PTSD), are often complex, with a myriad of factors contributing to the success of interventions. Although treatment guides for comorbid SUD/PTSD exist, most patients continue to suffer symptoms following the prescribed treatment course. Further, the study of efficacious treatments has been hampered by methodological challenges (e.g., overreliance on “superiority” designs (i.e., designs structured to test whether or not one treatment statistically surpasses another in terms of effect sizes) and short term interventions). Secondary analyses of randomized controlled clinical trials offer potential benefits to enhance understanding of findings and increase the personalization of treatment. This paper offers a description of the limits of randomized controlled trials as related to SUD/PTSD populations, highlights the benefits and potential pitfalls of secondary analytic techniques, and uses a case example of one of the largest effectiveness trials of behavioral treatment for co-occurring SUD/PTSD conducted within the National Drug Abuse Treatment Clinical Trials Network (NIDA CTN) and producing 19 publications. The paper concludes with implications of this secondary analytic approach to improve addiction researchers' ability to identify best practices for community-based treatment of these disorders. Innovative methods are needed to maximize the benefits of clinical studies and better support SUD/PTSD treatment options for both specialty and non-specialty healthcare settings. Moving forward, planning for and description of secondary analyses in randomized trials should be given equal consideration and care to the primary outcome analysis.

Long-term outcomes from the National Drug Abuse Treatment Clinical Trials Network Prescription Opioid Addiction Treatment Study

BackgroundDespite the growing prevalence of prescription opioid dependence, longitudinal studies have not examined long-term treatment response. The current study examined outcomes over 42 months in the Prescription Opioid Addiction Treatment Study (POATS). MethodsPOATS was a multi-site clinical trial lasting up to 9 months, examining different durations of buprenorphine-naloxone plus standard medical management for prescription opioid dependence, with participants randomized to receive or not receive additional opioid drug counseling. A subset of participants (N=375 of 653) enrolled in a follow-up study. Telephone interviews were administered approximately 18, 30, and 42 months after main-trial enrollment. Comparison of baseline characteristics by follow-up participation suggested few differences. ResultsAt Month 42, much improvement was seen: 31.7% were abstinent from opioids and not on agonist therapy; 29.4% were receiving opioid agonist therapy, but met no symptom criteria for current opioid dependence; 7.5% were using illicit opioids while on agonist therapy; and the remaining 31.4% were using opioids without agonist therapy. Participants reporting a lifetime history of heroin use at baseline were more likely to meet DSM-IV criteria for opioid dependence at Month 42 (OR=4.56, 95% CI=1.29–16.04, p<.05). Engagement in agonist therapy was associated with a greater likelihood of illicit-opioid abstinence. Eight percent (n=27/338) used heroin for the first time during follow-up; 10.1% reported first-time injection heroin use. ConclusionsLong-term outcomes for those dependent on prescription opioids demonstrated clear improvement from baseline. However, a subset exhibited a worsening course, by initiating heroin use and/or injection opioid use.

Pathways to change: Use trajectories following trauma-informed treatment of women with co-occurring post-traumatic stress disorder and substance use disorders.

Despite advances towards integration of care for women with co-occurring substance use disorder (SUD) and post-traumatic stress disorder (PTSD), low abstinence rates following SUD/PTSD treatment remain the norm. The utility of investigating distinct substance use trajectories is a critical innovation in the detection and refining of effective interventions for this clinical population. The present study reanalysed data from the largest randomised clinical trial to date for co-occurring SUD and PTSD in women (National Drug Abuse Treatment Clinical Trials Network; Women and Trauma Study). Randomised participants (n = 353) received one of two interventions in addition to treatment as usual for SUD: (i) trauma-informed integrative treatment for PTSD/SUD; or (ii) an active control psychoeducation course on women's health. The present study utilised latent growth mixture models (LGMM) with multiple groups to estimate women's substance use patterns during the 12-month follow-up period. Findings provided support for three different trajectories of substance use in the post-treatment year: (i) consistently low likelihood and use frequency; (ii) consistently high likelihood and use frequency; and (iii) high likelihood and moderate use frequency. Covariate analyses revealed improvement in PTSD severity was associated with membership in a specific substance use trajectory, although receiving trauma-informed treatment was not. Additionally, SUD severity, age and after-care efforts were shown to be related to trajectory membership. Findings highlight the necessity of accounting for heterogeneity in post-treatment substance use, relevance of trauma-informed care in SUD recovery and benefits of incorporating methodologies like LGMM when evaluating SUD treatment outcomes.

The relationship of therapeutic alliance and treatment delivery fidelity with treatment retention in a multisite trial of twelve-step facilitation.

This study examined associations of therapeutic alliance and treatment delivery fidelity with treatment retention in Stimulant Abusers to Engage in Twelve-Step (STAGE-12), a community-based trial of 12-Step Facilitation (TSF) conducted within the National Drug Abuse Treatment Clinical Trials Network (CTN). The STAGE-12 trial randomized 234 stimulant abusers enrolled in 10 outpatient drug treatment programs to an eight-session, group and individual TSF intervention. During the study, TSF participants rated therapeutic alliance using the Helping Alliance questionnaire-II. After the study, independent raters evaluated treatment delivery fidelity of all TSF sessions on adherence, competence, and therapist empathy. Poisson regression modeling examined relationships of treatment delivery fidelity and therapeutic alliance with treatment retention (measured by number of sessions attended) for 174 participants with complete fidelity and alliance data. Therapeutic alliance (p = .005) and therapist competence (p = .010) were significantly associated with better treatment retention. Therapist adherence was associated with poorer retention in a nonsignificant trend (p = .061). In conclusion, stronger therapeutic alliance and higher therapist competence in the delivery of a TSF intervention were associated with better treatment retention whereas treatment adherence was not. Training and fidelity monitoring of TSF should focus on general therapist skills and therapeutic alliance development to maximize treatment retention. (PsycINFO Database Record

Cigarette Smoking During Substance Use Disorder Treatment: Secondary Outcomes from a National Drug Abuse Treatment Clinical Trials Network study

IntroductionThe majority of patients enrolled in treatment for substance use disorders (SUDs) also use tobacco. Many will continue to use tobacco even during abstinence from other drugs and alcohol, often leading to smoking-related illnesses. Despite this, little research has been conducted to assess the influence of being a smoker on SUD treatment outcomes and changes in smoking during a treatment episode. MethodsIn this secondary analysis, cigarette smoking was evaluated in participants completing outpatient SUD treatment as part of a multi-site study conducted by the National Drug Abuse Treatment Clinical Trials Network. Analyses included the assessment of changes in smoking and nicotine dependence via the Fagerström Test for Nicotine Dependence during the 12-week study among all smokers (aim #1), specifically among those in the experimental treatment group (aim #2), and the moderating effect of being a smoker on treatment outcomes (aim #3). ResultsParticipants generally did not reduce or quit smoking throughout the course of the study. Among a sub-set of participants with higher baseline nicotine dependence scores randomized to the control arm, scores at the end of treatment were lower compared to the experimental arm, though measures of smoking quantity did not appear to decrease. Further, being a smoker was associated with poorer treatment outcomes compared to non-smokers enrolled in the trial. ConclusionsThis study provides evidence that patients enrolled in community-based SUD treatment continue to smoke, even when abstaining from drugs and alcohol. These results add to the growing literature encouraging the implementation of targeted, evidence-based interventions to promote abstinence from tobacco among SUD treatment patients.

Expanding the National Drug Abuse Treatment Clinical Trials Network to address the management of substance use disorders in general medical settings.

The Patient Protection and Affordable Care Act (2010) and the Mental Health Parity and Addiction Equity Act (2008) expand substance use disorder (SUD) care services in the USA into general medical settings. Care offered in these settings will engage substance-using patients in an integrated and patient-centered environment that addresses physical and mental health comorbidities and follows a chronic care model. This expansion of SUD services presents a great need for evidence-based practices useful in general medical settings, and reveals several research gaps to be addressed. The National Drug Abuse Treatment Clinical Trials Network of the National Institute on Drug Abuse can serve an important role in this endeavor. High-priority research gaps are highlighted in this commentary. A discussion follows on how the National Drug Abuse Treatment Clinical Trials Network can transform to address changing patterns in SUD care to efficiently generate evidence to guide SUD treatment practice within the context of recent US health care legislation.

Is level of exposure to a 12-step facilitation therapy associated with treatment outcome?

This study examined whether level of exposure to Stimulant Abuser Groups to Engage in 12-Step (STAGE-12), a 12-Step facilitative therapy, is related to treatment outcome. Data were from a large National Drug Abuse Treatment Clinical Trials Network (CTN) study comparing STAGE-12 combined with treatment-as-usual (TAU) to TAU alone. These analyses include only those randomized to STAGE-12 (n=234). Assessments occurred at baseline and 30, 60, 90, and 180days following randomization. High-exposure patients (n=158; attended at least 2 of 3 individual, and 3 of 5 group, sessions), compared to those with less exposure (n=76), demonstrated: (1) higher odds of self-reported abstinence from, and lower rates of, stimulant and non-stimulant drug use; (2) lower probabilities of stimulant-positive urines; (3) more days of attending and lower odds of not attending 12-Step meetings; (4) greater likelihood of reporting no drug problems; (5) more days of duties at meetings; and (6) more types of 12-Step activities. Many of these differences declined over time, but several were still significant by the last follow-up. Treatment and research implications are discussed.

Research staff training in a multisite randomized clinical trial: Methods and recommendations from the stimulant reduction intervention using dosed exercise (STRIDE) trial

Background: Descriptions of and recommendations for meeting the challenges of training research staff for multisite studies are limited despite the recognized importance of training on trial outcomes. The STRIDE (Stimulant Reduction Intervention using Dosed Exercise) study is a multisite randomized clinical trial that was conducted at nine addiction treatment programs across the United States within the National Drug Abuse Treatment Clinical Trials Network (CTN) and evaluated the addition of exercise to addiction treatment as usual (TAU), compared to health education added to TAU, for individuals with stimulant abuse or dependence. Research staff administered a variety of measures that required a range of interviewing, technical, and clinical skills. Purpose: In order to address the absence of information on how research staff are trained for multisite clinical studies, the current manuscript describes the conceptual process of training and certifying research assistants (RAs) for STRIDE. Methods: Training was conducted using a three-stage process to allow staff sufficient time for distributive learning, practice, and calibration leading up to implementation of this complex study. Results: Training was successfully implemented with staff across nine sites. Staff demonstrated evidence of study and procedural knowledge via quizzes and skill demonstration on six measures requiring certification. Overall, while the majority of staff had little to no experience in the six measures, all RAs demonstrated ability to correctly and reliably administer the measures throughout the study. Conclusions: Practical recommendations are provided for training research staff and are particularly applicable to the challenges encountered with large, multisite trials.

The National Drug Abuse Treatment Clinical Trials Network Data Share project: Website design, usage, challenges, and future directions

There are many benefits of data sharing, including the promotion of new research from effective use of existing data, replication of findings through re-analysis of pooled data files, meta-analysis using individual patient data, and reinforcement of open scientific inquiry. A randomized controlled trial is considered as the 'gold standard' for establishing treatment effectiveness, but clinical trial research is very costly, and sharing data is an opportunity to expand the investment of the clinical trial beyond its original goals at minimal costs. We describe the goals, developments, and usage of the Data Share website (http://www.ctndatashare.org) for the National Drug Abuse Treatment Clinical Trials Network (CTN) in the United States, including lessons learned, limitations, and major revisions, and considerations for future directions to improve data sharing. Data management and programming procedures were conducted to produce uniform and Health Insurance Portability and Accountability Act (HIPAA)-compliant de-identified research data files from the completed trials of the CTN for archiving, managing, and sharing on the Data Share website. Since its inception in 2006 and through October 2012, nearly 1700 downloads from 27 clinical trials have been accessed from the Data Share website, with the use increasing over the years. Individuals from 31 countries have downloaded data from the website, and there have been at least 13 publications derived from analyzing data through the public Data Share website. Minimal control over data requests and usage has resulted in little information and lack of control regarding how the data from the website are used. Lack of uniformity in data elements collected across CTN trials has limited cross-study analyses. The Data Share website offers researchers easy access to de-identified data files with the goal to promote additional research and identify new findings from completed CTN studies. To maximize the utility of the website, ongoing collaborative efforts are needed to standardize the core measures used for data collection in the CTN studies with the goal to increase their comparability and to facilitate the ability to pool data files for cross-study analyses.