Contingency management is effective across cocaine-dependent outpatients with different socioeconomic status

Predictors of cocaine use disorder treatment outcomes: a systematic review

BACKGROUND

Psychosocial approaches are the first-line treatments for cocaine dependence, although they still present high dropout and relapse rates. Thus, there is a pressing need to understand which variables influence treatment outcomes to improve current treatments and prevent dropout and relapse rates. The aim of this study is to explore predictors of treatment retention and abstinence in CUD.

METHODS

This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We searched three databases-PubMed, PsychINFO and Web of Science-for randomized clinical trials (RCTs) published in English and Spanish from database inception through April 1, 2023. We selected all studies that met the inclusion criteria (adults aged ≥ 18, outpatient treatment, CUD as main addiction, and no severe mental illness) to obtain data for the narrative synthesis addressing cocaine abstinence and treatment retention as main outcome variables. After data extraction was completed, risk of bias was assessed using the Cochrane risk-of-bias tool for randomized trials (RoB-2).

RESULTS

A total of 566 studies were screened, and, of those, 32 RCTs were included in the synthesis. Younger age, more years of cocaine use, and craving levels were significant predictors of relapse and treatment dropout. Fewer withdrawal symptoms, greater baseline abstinence, greater treatment engagement, and more self-efficacy were all predictors of longer duration of abstinence. The role of impulsivity as a predictor of CUD is unclear due to conflicting data, although the evidence generally suggests that higher impulsivity scores can predict more severe addiction and withdrawal symptoms, and earlier discontinuation of treatment.

CONCLUSION

Current evidence indicates which variables have a direct influence on treatment outcomes, including well-studied cocaine use-related variables. However, additional variables, such as genetic markers, appear to have a high impact on treatment outcomes and need further study.

SYSTEMATIC REVIEW REGISTRATION

This systematic review is registered at PROSPERO (ID: CRD42021271847). This study was funded by the Spanish Ministry of Science, Innovation and Universities, Instituto Carlos III (ISCIII) (FIS PI20/00929) and FEDER funds and Fundació Privada Hospital de la Santa Creu i Sant Pau (Pla d'acció social 2020).

Psychosocial interventions for stimulant use disorder

BACKGROUND

Stimulant use disorder is a continuously growing medical and social burden without approved medications available for its treatment. Psychosocial interventions could be a valid approach to help people reduce or cease stimulant consumption. This is an update of a Cochrane review first published in 2016.

OBJECTIVES

To assess the efficacy and safety of psychosocial interventions for stimulant use disorder in adults.

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, three other databases, and two trials registers in September 2023. All searches included non-English language literature. We handsearched the references of topic-related systematic reviews and the included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing any psychosocial intervention with no intervention, treatment as usual (TAU), or a different intervention in adults with stimulant use disorder.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included a total of 64 RCTs (8241 participants). Seventy-three percent of studies included participants with cocaine or crack cocaine use disorder; 3.1% included participants with amphetamine use disorder; 10.9% included participants with methamphetamine use disorder; and 12.5% included participants with any stimulant use disorder. In 18 studies, all participants were in methadone maintenance treatment. In our primary comparison of any psychosocial treatment to no intervention, we included studies which compared a psychosocial intervention plus TAU to TAU alone. In this comparison, 12 studies evaluated cognitive behavioural therapy (CBT), 27 contingency management, three motivational interviewing, one study looked at psychodynamic therapy, and one study evaluated CBT plus contingency management. We also compared any psychosocial intervention to TAU. In this comparison, seven studies evaluated CBT, two contingency management, two motivational interviewing, and one evaluated a combination of CBT plus motivational interviewing. Seven studies compared contingency management reinforcement related to abstinence versus contingency management not related to abstinence. Finally, seven studies compared two different psychosocial approaches. We judged 65.6% of the studies to be at low risk of bias for random sequence generation and 19% at low risk for allocation concealment. Blinding of personnel and participants was not possible for the type of intervention, so we judged all the studies to be at high risk of performance bias for subjective outcomes but at low risk for objective outcomes. We judged 22% of the studies to be at low risk of detection bias for subjective outcomes. We judged most of the studies (69%) to be at low risk of attrition bias. When compared to no intervention, we found that psychosocial treatments: reduce the dropout rate (risk ratio (RR) 0.82, 95% confidence interval (CI) 0.74 to 0.91; 30 studies, 4078 participants; high-certainty evidence); make little to no difference to point abstinence at the end of treatment (RR 1.15, 95% CI 0.94 to 1.41; 12 studies, 1293 participants; high-certainty evidence); make little to no difference to point abstinence at the longest follow-up (RR 1.22, 95% CI 0.91 to 1.62; 9 studies, 1187 participants; high-certainty evidence); probably increase continuous abstinence at the end of treatment (RR 1.89, 95% CI 1.20 to 2.97; 12 studies, 1770 participants; moderate-certainty evidence); may make little to no difference in continuous abstinence at the longest follow-up (RR 1.14, 95% CI 0.89 to 1.46; 4 studies, 295 participants; low-certainty evidence); reduce the frequency of drug intake at the end of treatment (standardised mean difference (SMD) -0.35, 95% CI -0.50 to -0.19; 10 studies, 1215 participants; high-certainty evidence); and increase the longest period of abstinence (SMD 0.54, 95% CI 0.41 to 0.68; 17 studies, 2118 participants; high-certainty evidence). When compared to TAU, we found that psychosocial treatments reduce the dropout rate (RR 0.79, 95% CI 0.65 to 0.97; 9 studies, 735 participants; high-certainty evidence) and may make little to no difference in point abstinence at the end of treatment (RR 1.67, 95% CI 0.64 to 4.31; 1 study, 128 participants; low-certainty evidence). We are uncertain whether they make any difference in point abstinence at the longest follow-up (RR 1.31, 95% CI 0.86 to 1.99; 2 studies, 124 participants; very low-certainty evidence). Compared to TAU, psychosocial treatments may make little to no difference in continuous abstinence at the end of treatment (RR 1.18, 95% CI 0.92 to 1.53; 1 study, 128 participants; low-certainty evidence); probably make little to no difference in the frequency of drug intake at the end of treatment (SMD -1.17, 95% CI -2.81 to 0.47, 4 studies, 479 participants, moderate-certainty evidence); and may make little to no difference in the longest period of abstinence (SMD -0.16, 95% CI -0.54 to 0.21; 1 study, 110 participants; low-certainty evidence). None of the studies for this comparison assessed continuous abstinence at the longest follow-up. Only five studies reported harms related to psychosocial interventions; four of them stated that no adverse events occurred.

AUTHORS' CONCLUSIONS

This review's findings indicate that psychosocial treatments can help people with stimulant use disorder by reducing dropout rates. This conclusion is based on high-certainty evidence from comparisons of psychosocial interventions with both no treatment and TAU. This is an important finding because many people with stimulant use disorders leave treatment prematurely. Stimulant use disorders are chronic, lifelong, relapsing mental disorders, which require substantial therapeutic efforts to achieve abstinence. For those who are not yet able to achieve complete abstinence, retention in treatment may help to reduce the risks associated with stimulant use. In addition, psychosocial interventions reduce stimulant use compared to no treatment, but they may make little to no difference to stimulant use when compared to TAU. The most studied and promising psychosocial approach is contingency management. Relatively few studies explored the other approaches, so we cannot rule out the possibility that the results were imprecise due to small sample sizes.

Implementing an evidence-based prize contingency management protocol for stimulant use

INTRODUCTION

Contingency management (CM) is an efficacious treatment for stimulant use disorders. Research has developed support materials for the clinical delivery of prize-based CM and they are widely accessible, but few resources are available to support design and preparation for CM implementation. This guide aims to fill that gap.

METHOD/RESULTS

The article outlines a suggested prize CM protocol and discusses the best practices most aligned with evidence-based practices and acceptable-if-necessary modifications. The article also highlights modifications that are not evidence-based and not recommended. In addition, I discuss practical and clinical aspects of preparing for CM implementation.

CONCLUSIONS

Deviations from evidence-based practices are common, and poorly designed CM is unlikely to impact patient outcomes. This article provides planning stage guidance to support programs' adoption of evidence-based prize CM for the treatment of stimulant use disorders.

Vouchers versus reminders to prevent dropout: Findings from the randomized youth drug abuse treatment project (youthDAT project)

BACKGROUND

Over the last few decades, evidence-based treatments for emerging adults with drug use disorder (DUD) have been developed, but dropout and inconsistent session attendance persist. This study assessed the efficacy of voucher reinforcement and/or text reminders for treatment attendance and completion in emerging adults with DUD in Denmark.

METHODS

The study compared four levels of treatment intensity, with participants randomly assigned to standard outpatient counseling only (STD), outpatient counseling plus vouchers for attendance (VOU), outpatient counseling plus text reminders (REM), or outpatient counseling plus vouchers and text reminders (REM + VOU). A total of 460 individuals aged 15-25 years seeking treatment for DUD were randomly assigned to the four treatment conditions across nine sites.

RESULTS

STD counseling had the lowest completion rate (25%), followed by REM (39%), VOU (46%), and REM + VOU (49%). Additionally, post hoc comparisons indicated that clients randomized to the REM + VOU condition differed in terms of zero no-shows from clients who were randomized to the VOU condition (χ2(1) = 6.90, p = 0.009) and the REM condition (χ2(1) = 5.87, p = 0.015).

CONCLUSIONS

Vouchers and text reminders contribute to reduced dropout and increased treatment attendance in emerging adults with DUD. The combination of vouchers and reminders in particular has the potential to reduce the number of no-shows.

Contingency management treatment for methamphetamine use disorder in South Africa

INTRODUCTION AND AIMS

As South Africa, especially the Western Cape Province, faces an epidemic of methamphetamine use disorder, therapeutic approaches suited to the South African context are needed. This secondary analysis assessed retention and methamphetamine abstinence outcomes in response to an 8-week pilot contingency management (CM) intervention trial of neural correlates of methamphetamine abstinence, exploring sociodemographic and clinical differences between responders and non-responders.

DESIGN AND METHODS

Research participants provided thrice-weekly monitored urine samples, which were analysed by qualitative radioimmunoassay. The primary outcome for this analysis was therapeutic response, defined as abstinence from methamphetamine (≥23 of 24 possible methamphetamine-negative urine samples).

RESULTS

Data from 30 adults living in Cape Town, South Africa (34 ± 6.1 years of age, mean age ± SD, 21 men) were included. Sixty-three percent (12 men) were responders. In bivariate comparisons, baseline measurements showed fewer responders reported monthly household income ≥25 000+ South African Rand (ZAR; ~USD $1880; vs. ZAR < 25 000) than non-responders (15.8% vs. 63.6%; P = 0.007). Furthermore, responders had higher median years of education (12 vs. 10; Kruskal-Wallis χ² = 4.25, DF = 1, P = 0.039) and lower median body mass index than non-responders (19 vs. 24; Kruskal-Wallis χ² = 6.84, P = 0.008).

DISCUSSION AND CONCLUSIONS

Therapeutic response in this study were comparable to those obtained with CM for methamphetamine use disorder in North America and Europe. Our findings suggest that CM may be a useful component of treatment strategies to boost retention and continuous abstinence from methamphetamine in Cape Town, South Africa. Larger efficacy studies are needed in this setting.

Considerations for Implementing Contingency Management in Substance Abuse Treatment Clinics: The Veterans Affairs Initiative as a Model

Contingency management (CM) is an efficacious intervention for the treatment of substance use disorders that is widely applicable across a range of client populations and characteristics. Despite its strong evidence base, CM remains underutilized in real world practice. This article introduces CM for clinicians interested in adopting CM and briefly reviews this research evidence. In addition, CM protocols are described, with emphasis on the specific design considerations important to CM's efficacy. The recent Department of Veterans Affairs (VA) initiative, which represents the first successful large-scale implementation effort, is presented. It provides a model for the training and supervision components that may be critical to implementation with fidelity. Continued research in this area, as well as further demonstrations of successful dissemination and implementation, will be critical for improving the adoption of this intervention in clinical, nonresearch settings.

"I's" on the prize: A systematic review of individual differences in Contingency Management treatment response

Contingency Management is an evidence-based treatment for substance use disorders with strong potential for measurement-based customization. Previous work has examined individual difference factors in Contingency Management treatment response of potential relevance to treatment targeting and adaptive implementation; however, a systematic review of such factors has not yet been conducted. Here, we summarize and evaluate the existing literature on patient-level predictors, mediators, and moderators of Contingency Management treatment response in stimulant and/or opioid using outpatients - clinical populations most frequently targeted in Contingency Management research and clinical practice. Our search strategy identified 648 unique, peer-reviewed publications, of which 39 met full inclusion criteria for the current review. These publications considered a variety of individual difference factors, including (1) motivation to change and substance use before and during treatment (8/39 publications), (2) substance use comorbidity and chronicity (8/39 publications), (3) psychiatric comorbidity and severity (8/39 publications), (4) medical, legal, and sociodemographic considerations (15/39 publications), and (5) cognitive-behavioral variables (1/39 publications). Contingency Management was generally associated with improved treatment outcomes (e.g., longer periods of continuous abstinence, better retention), regardless of individual difference factors; however, specific patient-level characteristics were associated with either an enhanced (e.g., more previous treatment attempts, history of sexual abuse, diagnosis of antisocial personality disorder) or diminished (e.g., complex post-traumatic stress symptoms, pretreatment benzodiazepine use) response to Contingency Management. Overall, the current literature is limited but existing evidence generally supports greater benefits of Contingency Management in patients who would otherwise have a poorer prognosis in standard outpatient care. It was also identified that the majority of previous work represents a posteriori analysis of pre-existing clinical samples and has therefore rarely considered pre-specified, hypothesis-driven individual difference factors. We therefore additionally highlight patient-level factors that are currently understudied, as well as promising future directions for measurement-based treatment adaptations that may directly respond to patient traits and states to improve Contingency Management effectiveness across individuals and over time.

Comparative efficacy and acceptability of psychosocial interventions for individuals with cocaine and amphetamine addiction: A systematic review and network meta-analysis

BACKGROUND

Clinical guidelines recommend psychosocial interventions for cocaine and/or amphetamine addiction as first-line treatment, but it is still unclear which intervention, if any, should be offered first. We aimed to estimate the comparative effectiveness of all available psychosocial interventions (alone or in combination) for the short- and long-term treatment of people with cocaine and/or amphetamine addiction.

METHODS AND FINDINGS

We searched published and unpublished randomised controlled trials (RCTs) comparing any structured psychosocial intervention against an active control or treatment as usual (TAU) for the treatment of cocaine and/or amphetamine addiction in adults. Primary outcome measures were efficacy (proportion of patients in abstinence, assessed by urinalysis) and acceptability (proportion of patients who dropped out due to any cause) at the end of treatment, but we also measured the acute (12 weeks) and long-term (longest duration of study follow-up) effects of the interventions and the longest duration of abstinence. Odds ratios (ORs) and standardised mean differences were estimated using pairwise and network meta-analysis with random effects. The risk of bias of the included studies was assessed with the Cochrane tool, and the strength of evidence with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. We followed the PRISMA for Network Meta-Analyses (PRISMA-NMA) guidelines, and the protocol was registered in PROSPERO (CRD 42017042900). We included 50 RCTs evaluating 12 psychosocial interventions or TAU in 6,942 participants. The strength of evidence ranged from high to very low. Compared to TAU, contingency management (CM) plus community reinforcement approach was the only intervention that increased the number of abstinent patients at the end of treatment (OR 2.84, 95% CI 1.24-6.51, P = 0.013), and also at 12 weeks (OR 7.60, 95% CI 2.03-28.37, P = 0.002) and at longest follow-up (OR 3.08, 95% CI 1.33-7.17, P = 0.008). At the end of treatment, CM plus community reinforcement approach had the highest number of statistically significant results in head-to-head comparisons, being more efficacious than cognitive behavioural therapy (CBT) (OR 2.44, 95% CI 1.02-5.88, P = 0.045), non-contingent rewards (OR 3.31, 95% CI 1.32-8.28, P = 0.010), and 12-step programme plus non-contingent rewards (OR 4.07, 95% CI 1.13-14.69, P = 0.031). CM plus community reinforcement approach was also associated with fewer dropouts than TAU, both at 12 weeks and the end of treatment (OR 3.92, P < 0.001, and 3.63, P < 0.001, respectively). At the longest follow-up, community reinforcement approach was more effective than non-contingent rewards, supportive-expressive psychodynamic therapy, TAU, and 12-step programme (OR ranging between 2.71, P = 0.026, and 4.58, P = 0.001), but the combination of community reinforcement approach with CM was superior also to CBT alone, CM alone, CM plus CBT, and 12-step programme plus non-contingent rewards (ORs between 2.50, P = 0.039, and 5.22, P < 0.001). The main limitations of our study were the quality of included studies and the lack of blinding, which may have increased the risk of performance bias. However, our analyses were based on objective outcomes, which are less likely to be biased.

CONCLUSIONS

To our knowledge, this network meta-analysis is the most comprehensive synthesis of data for psychosocial interventions in individuals with cocaine and/or amphetamine addiction. Our findings provide the best evidence base currently available to guide decision-making about psychosocial interventions for individuals with cocaine and/or amphetamine addiction and should inform patients, clinicians, and policy-makers.

Cost-effective way to reduce stimulant-abuse among gay/bisexual men and transgender women: a randomized clinical trial with a cost comparison

OBJECTIVES

A randomized controlled study was conducted with 422 homeless, stimulant-using gay/bisexual (G/B) men and 29 transgender women (n = 451) to assess two community-based interventions to reduce substance abuse and improve health: (a) a nurse case-managed program combined with contingency management (NCM + CM) versus (b) standard education plus contingency management (SE + CM).

STUDY DESIGN

Hypotheses tested included: a) completion of hepatitis A/B vaccination series; b) reduction in stimulant use; and c) reduction in number of sexual partners.

METHODS

A deconstructive cost analysis approach was utilized to capture direct costs associated with the delivery of both interventions. Based on an analysis of activity logs and staff interviews, specific activities and the time required to complete each were analyzed as follows: a) NCM + CM only; b) SE + CM only; c) time to administer/record vaccines; and d) time to receive and record CM visits. Cost comparison of the interventions included only staffing costs and direct cash expenditures.

RESULTS

The study outcomes showed significant over time reductions in all measures of drug use and multiple sex partners, compared to baseline, although no significant between-group differences were detected. Cost analysis favored the simpler SE + CM intervention over the more labor-intensive NCM + CM approach. Because of the high levels of staffing required for the NCM relative to SE, costs associated with it were significantly higher.

CONCLUSIONS

Findings suggest that while both intervention strategies were equally effective in achieving desired health outcomes, the brief SE + CM appeared less expensive to deliver.

Income Levels and Response to Contingency Management for Smoking Cessation

BACKGROUND

Contingency management (CM) has demonstrated its efficacy in treating many drug addictions, including nicotine. However, one of the most commonly perceived limitations with regard to its dissemination into community settings is whether this protocol could be equally effective for treating patients across different income levels.

OBJECTIVE

This study aimed to examine whether individuals' income levels affect treatment success in a cognitive behavioral treatment (CBT) that included a voucher-based CM protocol for smoking cessation.

METHODS

A total of 92 treatment-seeking smokers in a community setting were randomly assigned to a CBT group (N = 49) or to a CBT plus CM group (N = 43). The CM procedure included a voucher program through which smoking abstinence was reinforced on a schedule of escalating magnitude of reinforcement with a reset contingency. We analyzed the impact of self-reported monthly income, alone and in combination with treatment condition, on short-term (treatment retention) and long-term (self-reported number of days of continuous smoking abstinence at 6-month follow-up) results.

RESULTS

Income had no effect on treatment retention and continuous abstinence outcomes at 6-month follow-up in either treatment condition. Treatment modality emerged as the only significant predictor of treatment success.

CONCLUSIONS

Our findings suggest that treatment-seeking smokers from the general population respond equally well to CM regardless of their income levels. The results of this randomized controlled trial support the generalizability of this evidenced-based program into community settings.

Cocaine-using substance abuse treatment patients with and without HIV respond well to contingency management treatment

HIV is common among individuals with substance use disorders, but relatively few studies have examined the impact of HIV status on response to substance abuse treatment. This secondary analysis compared patients seeking treatment for cocaine use with and without HIV in terms of substance use treatment outcomes. Primary treatment outcomes included treatment retention, longest duration of abstinence, and percent of negative samples; both substance use outcomes reflect abstinence from cocaine, alcohol and opioids concurrently. Participants (N=432) were enrolled in randomized clinical trials comparing contingency management (CM) to standard care, and 32 (7%) reported being positive for HIV. Overall, CM improved both treatment retention (average of 8.2weeks compared to 6.0weeks in the standard care condition) and longest duration of abstinence (average of 5.8weeks compared to 2.8weeks in the standard care condition). HIV status was not associated with treatment outcomes as a main effect, nor did it have an interaction effect with treatment condition. These results suggest a benefit of CM in substance abuse treatment irrespective of HIV status.

Impact of Tailored Interventions to Reduce Drug Use and Sexual Risk Behaviors Among Homeless Gay and Bisexual Men

A randomized controlled trial was conducted with homeless gay and bisexual men to assess the impact of two culturally sensitive intervention programs on reduction of drug use and risky sexual behavior. In this study, gay and bisexual men between 18 and 46 years of age were randomly assigned to one of two culturally sensitive behavioral intervention programs: a Nurse Case Management Plus Contingency Management (NCM + CM; n = 204) or a Standard Education Plus Contingency Management (SE + CM; n = 210) program. Regardless of group assignment, significant and clinically relevant reductions were observed in stimulant use over time. Multivariable predictors of stimulant use at 4- and 8-month follow-up evaluations were recent injection drug use, tested positive for HIV, or for use of amphetamine. Data revealed a significant linear decline over time for those who had sex with multiple partners. Furthermore, being HIV positive was associated with reporting multiple partners, while higher homophobia scores and having children were inversely related to reports of having sex with multiple partners at follow-up. Culturally sensitive approaches are needed to successfully reduce drug use and risky sexual activities among gay and bisexual populations.

Contingency Management: New Directions and Remaining Challenges for An Evidence-Based Intervention

This article introduces the special issue on contingency management (CM), an efficacious intervention for the treatment of substance use disorders with low uptake in clinical settings that is not commensurate with evidence for efficacy. In this special issue of the Journal of Substance Abuse Treatment, we present 16 articles representing the latest research in efficacy, implementation, and technological advances related to CM. Combined, this collection of articles highlights the diverse populations, settings, and applications of CM in the treatment of substance use disorders. We conclude by highlighting directions for future research, particularly those that may increase CM's appeal and uptake in routine clinical care.

A review of the literature on contingency management in the treatment of substance use disorders, 2009-2014

This report describes a systematic literature review of voucher and related monetary-based contingency management (CM) interventions for substance use disorders (SUDs) over 5.2years (November 2009 through December 2014). Reports were identified using the search engine PubMed, expert consultations, and published bibliographies. For inclusion, reports had to (a) involve monetary-based CM; (b) appear in a peer-reviewed journal; (c) include an experimental comparison condition; (d) describe an original study; (e) assess efficacy using inferential statistics; (f) use a research design allowing treatment effects to be attributed to CM. Sixty-nine reports met inclusion criteria and were categorized into 7 research trends: (1) extending CM to special populations, (2) parametric studies, (3) extending CM to community clinics, (4) combining CM with pharmacotherapies, (5) incorporating technology into CM, (6) investigating longer-term outcomes, (7) using CM as a research tool. The vast majority (59/69, 86%) of studies reported significant (p<0.05) during-treatment effects. Twenty-eight (28/59, 47%) of those studies included at least one follow-up visit after CM was discontinued, with eight (8/28, 29%) reporting significant (p<0.05) effects. Average effect size (Cohen's d) during treatment was 0.62 (95% CI: 0.54, 0.70) and post-treatment it was 0.26 (95% CI: 0.11, 0.41). Overall, the literature on voucher-based CM over the past 5years documents sustained growth, high treatment efficacy, moderate to large effect sizes during treatment that weaken but remain evident following treatment termination, and breadth across a diverse set of SUDs, populations, and settings consistent with and extending results from prior reviews.

Psychosocial interventions for psychostimulant misuse

BACKGROUND

Psychostimulant misuse is a continuously growing medical and social burden. There is no evidence proving the efficacy of pharmacotherapy. Psychosocial interventions could be a valid approach to help patients in reducing or ceasing drug consumption.

OBJECTIVES

To assess the effects of psychosocial interventions for psychostimulant misuse in adults.

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Group Specialised Register (via CRSLive); Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CINAHL; Web of Science and PsycINFO, from inception to November 2015. We also searched for ongoing and unpublished studies via ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (apps.who.int/trialsearch/).All searches included non-English language literature. We handsearched references of topic-related systematic reviews and the included studies.

SELECTION CRITERIA

We included randomised controlled trials comparing any psychosocial intervention with no intervention, treatment as usual (TAU) or a different intervention in adults with psychostimulant misuse or dependence.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included a total of 52 trials (6923 participants).The psychosocial interventions considered in the studies were: cognitive behavioural therapy (19 studies), contingency management (25 studies), motivational interviewing (5 studies), interpersonal therapy (3 studies), psychodynamic therapy (1 study), 12-step facilitation (4 studies).We judged most of the studies to be at unclear risk of selection bias; blinding of personnel and participants was not possible for the type of intervention, so all the studies were at high risk of performance bias with regard to subjective outcomes; the majority of studies did not specify whether the outcome assessors were blind. We did not consider it likely that the objective outcomes were influenced by lack of blinding.The comparisons made were: any psychosocial intervention versus no intervention (32 studies), any psychosocial intervention versus TAU (6 studies), and one psychosocial intervention versus an alternative psychosocial intervention (13 studies). Five of included studies did not provide any useful data for inclusion in statistical synthesis.We found that, when compared to no intervention, any psychosocial treatment: reduced the dropout rate (risk ratio (RR): 0.83, 95% confidence interval (CI) 0.76 to -0.91, 24 studies, 3393 participants, moderate quality evidence); increased continuous abstinence at the end of treatment (RR: 2.14, 95% CI 1.27 to -3.59, 8 studies, 1241 participants, low quality evidence); did not significantly increase continuous abstinence at the longest follow-up (RR: 2.12, 95% CI 0.77 to -5.86, 4 studies, 324 participants, low quality evidence); significantly increased the longest period of abstinence: (standardised mean difference (SMD): 0.48, 95% CI 0.34 to 0.63, 10 studies, 1354 participants, high quality evidence). However, it should be noted that the in the vast majority of the studies in this comparison the specific psychosocial treatment assessed in the experimental arm was given in add on to treatment as usual or to another specific psychosocial or pharmacological treatment which was received by both groups. So, many of the control groups in this comparison were not really untreated. Receiving some amount of treatment is not the same as not receiving any intervention, so we could argue that the overall effect of the experimental psychosocial treatment could be smaller if given in add on to TAU or to another intervention than if given to participants not receiving any intervention; this could translate to a smaller magnitude of the effect of the psychosocial intervention when it is given in add on.When compared to TAU, any psychosocial treatment reduced dropout rate (RR: 0.72, 95% CI 0.59 to 0.89, 6 studies, 516 participants, moderate quality evidence), did not increase continuous abstinence at the end of treatment (RR: 1.27, 95% CI 0.94 to 1.72, 2 studies, 224 participants, low quality evidence), did not increase longest period of abstinence (MD -3.15 days, 95% CI -10.35 to 4.05, 1 study, 110 participants, low quality evidence). No studies in this comparison assessed the outcome of continuous abstinence at longest follow-up.There were few studies comparing two or more psychosocial interventions, with small sample sizes and considerable heterogeneity in terms of the types of interventions assessed. None reported significant results.None of the studies reported harms related to psychosocial interventions.

AUTHORS' CONCLUSIONS

The addition of any psychosocial treatment to treatment as usual (usually characterised by group counselling or case management) probably reduces the dropout rate and increases the longest period of abstinence. It may increase the number of people achieving continuous abstinence at the end of treatment, although this might not be maintained at longest follow-up. The most studied and the most promising psychosocial approach to be added to treatment as usual is probably contingency management. However, the other approaches were only analysed in a few small studies, so we cannot rule out the possibility that the results were not significant because of imprecision. When compared to TAU, any psychosocial treatment may improve adherence, but it may not improve abstinence at the end of treatment or the longest period of abstinence.The majority of the studies took place in the United States, and this could limit the generalisability of the findings, because the effects of psychosocial treatments could be strongly influenced by the social context and ethnicity. The results of our review do not answer the most relevant clinical question, demonstrating which is the most effective type of psychosocial approach.Further studies should directly compare contingency management with the other psychosocial approaches.

Contingency management is effective in promoting abstinence and retention in treatment among crack cocaine users in Brazil: A randomized controlled trial

Crack cocaine dependence has become a severe public health problem in Brazil, and current psychosocial approaches to this problem have shown little or no effectiveness. Although contingency management is among the most effective behavioral treatments for substance use disorders, it has never been applied in the treatment of crack cocaine-dependent individuals in Brazil. The aim of this study was to evaluate the efficacy of incorporating contingency management into standard outpatient treatment for crack cocaine dependence, as well as the impact that doing so has on treatment attendance, retention in treatment, maintenance of abstinence, and the frequency of substance use. We evaluated 65 treatment-seeking, crack cocaine-dependent individuals, randomized to receive 12 weeks of standard treatment plus contingency management (STCM; n = 33) or 12 weeks of standard treatment alone (STA; n = 32). Those in the STCM group received monetary incentives for being abstinent, earning up to US$235.50 if they remained abstinent throughout the entire treatment period. The STCM group participants attended a mean of 19.5 (SD = 14.9) treatment sessions, compared with 3.7 (SD = 5.9) for the STA group participants (p < .01). Those in the STCM group were 3.8, 4.6, and 68.9 times more likely to be retained in treatment at weeks 4, 8, and 12 than were those in the STA group. The likelihood of detecting 4, 8, and 12 weeks of continuous abstinence was 17.7, 9.9, and 18.6 times higher in the STCM group than in the STA group (p < .05). Compared to the STA group, the STCM group submitted a significantly higher proportion of negative samples for crack cocaine, delta-9-tetrahydrocannabinol, and alcohol (p < .001) when all expected samples were included in the denominator but not when only submitted samples were considered. The average monthly cost/participant for incentives was $29.00. Contingency management showed efficacy in a sample of Brazilian crack cocaine users. The intervention holds promise for broader application in international settings. (PsycINFO Database Record

Interest and preferences for contingency management design among addiction treatment clientele

BACKGROUND

Despite strong support for its efficacy, debates persist about how dissemination of contingency management is most effectively undertaken. Currently-promoted contingency management methods are empirically-validated, yet their congruence with interests and preferences of addiction treatment clientele is unknown. Such client input is a foundational support for evidence-based clinical practice.

OBJECTIVE

This study documented interest in incentives and preferences for fixed-ratio vs. variable-ratio and immediate vs. distal distribution of earned incentives among clients enrolled at three community programs affiliated with the National Institute on Drug Abuse Clinical Trials Network.

METHODS

This multi-site study included anonymous survey completion by an aggregate sample of 358 treatment enrollees. Analyses first ruled out site differences in survey responses, and then tested age and gender as influences on client interest in financial incentives, and preferences for fixed-ratio vs. variable-ratio reinforcement and immediate vs. distal incentive distribution.

RESULTS

Interest in different types of $50 incentives (i.e. retail vouchers, transportation vouchers, cash) was highly inter-correlated, with a mean sample rating of 3.49 (0.83) on a five-point scale. While consistent across client gender, age was an inverse predictor of client interest in incentives. A majority of clients stated preference for fixed-ratio incentive magnitude and distal incentive distribution (67% and 63%, respectively), with these preferences voiced by a larger proportion of females.

CONCLUSION

Sample preferences contradict currently-promoted contingency management design features. Future efforts to disseminate contingency management may be more successful if flexibly undertaken in a manner that incorporates the interests and preferences of local client populations.

Contingency management for substance use disorders in Spain: Implications for research and practice

OBJECTIVE

We provide a narrative review of published studies evaluating voucher-based contingency management (CM) treatment for cocaine, nicotine and cannabis use disorders in Spain and discuss the concerns and future challenges.

METHOD

Published studies between 2008 and 2015 that evaluated the impact of incentives for SUD in Spain and included an appropriate control or comparison condition were identified and reviewed.

RESULTS

Adding voucher-based CM to standard treatments obtained better treatment retention and cocaine abstinence than standard care alone. CM also improved psychosocial functioning. Economic status or depressive symptoms did not affect the results of CM treatment for cocaine dependence. The addition of a CM protocol to cognitive behavioral treatment (CBT) also improved treatment effectiveness for smoking cessation. Available data on the effect of CM on cannabis use disorders (CUD) with young people did not allow confirmation of its superiority to date.

CONCLUSION

The research conducted to date in Spain confirms and expands the findings of studies conducted in the US supporting the effectiveness of CM in the context of community settings with cocaine- and nicotine-dependents. However, CM has not yet been readily adopted into general clinical practice in Spain or the rest of Europe. The limited effectiveness of CM for CUD is likely due to the scarcity of data and may change with more studies, taking into account recent research on this topic in the US. Continued efforts are warranted to further develop and disseminate incentive-based treatments for SUD across clinical settings and populations in Spain.

Contingency Management Abstinence Incentives: Cost and Implications for Treatment Tailoring

OBJECTIVE

To examine prize-earning costs of contingency management (CM) incentives in relation to participants' pre-study enrollment drug use status (baseline (BL) positive vs. BL negative) and relate these to previously reported patterns of intervention effectiveness.

METHODS

Participants were 255 substance users entering outpatient treatment who received the therapeutic educational system (TES), in addition to usual care counseling. TES included a CM component such that participants could earn up to $600 in prizes on average over 12-weeks for providing drug negative urines and completing web-based cognitive behavior therapy modules. We examined distribution of prize draws and value of prizes earned for subgroups that were abstinent (BL negative; N=136) or not (BL positive; N=119) at study entry based on urine toxicology and breath alcohol screen.

RESULTS

Distribution of draws earned (median=119 vs. 17; p<.0001) and prizes redeemed (median=54 vs. 9; p<.001) for drug abstinence differed significantly for BL negative compared to BL positive participants. BL negative earned on average twice as much in prizes as BL positive participants ($245 vs. $125). Median value of prizes earned was 5.4 times greater for BL negative compared to BL positive participants ($237 vs. $44; p<.001).

CONCLUSIONS

Two-thirds of expenditures in an abstinence incentive program were paid to BL negative participants. These individuals had high rates of drug abstinence during treatment and did not show improved abstinence outcomes with TES versus usual care (Campbell et al., 2014). Effectiveness of the abstinence-focused CM intervention included in TES may be enhanced by tailoring delivery based on patients' drug use status at treatment entry.

Initial abstinence status and contingency management treatment outcomes: does race matter?

OBJECTIVE

Limited research has evaluated African American substance users' response to evidence-based treatments. This study examined the efficacy of contingency management (CM) in African American and White cocaine users.

METHOD

A secondary analysis evaluated effects of race, treatment condition, and baseline cocaine urine sample results on treatment outcomes of African American (n = 444) and White (n = 403) cocaine abusers participating in one of six randomized clinical trials comparing CM to standard care.

RESULTS

African American and White patients who initiated treatment with a cocaine-negative urine sample remained in treatment for similar durations and submitted a comparable proportion of negative samples during treatment regardless of treatment type; CM was efficacious in both races in terms of engendering longer durations of abstinence in patients who began treatment abstinent. Whites who began treatment with a cocaine positive sample remained in treatment longer and submitted a higher proportion of negative samples when assigned to CM than standard care. African Americans who initiated treatment with a cocaine positive sample, however, did not remain in treatment longer with CM compared with standard care, and gains in terms of drug use outcomes were muted in nature relative to Whites. This interaction effect persisted through the 9-month follow-up period.

CONCLUSIONS

CM is not equally effective in reducing drug use among all subgroups, specifically African American patients who are using cocaine upon treatment entry. Future research on improving treatment outcomes in this population is needed.

The future potential for cocaine vaccines

INTRODUCTION

Addiction to cocaine is a major problem around the world, but especially in developed countries where the combination of wealth and user demand has created terrible social problems. Although only some users become truly addicted, those who are often succumb to a downward spiral in their lives from which it is very difficult to escape. From the medical perspective, the lack of effective and safe, non-addictive therapeutics has instigated efforts to develop alternative approaches for treatment, including anticocaine vaccines designed to block cocaine's pharmacodynamic effects.

AREAS COVERED

This paper discusses the implications of cocaine pharmacokinetics for robust vaccine antibody responses, the results of human vaccine clinical trials, new developments in animal models for vaccine evaluation, alternative vaccine formulations and complementary therapy to enhance anticocaine effectiveness.

EXPERT OPINION

Robust anti-cocaine antibody responses are required for benefit to cocaine abusers, but since any reasonably achievable antibody level can be overcome with higher drug doses, sufficient motivation to discontinue use is also essential so that the relative barrier to cocaine effects will be appropriate for each individual. Combining a vaccine with achievable levels of an enzyme to hydrolyze cocaine to inactive metabolites, however, may substantially increase the blockade and improve treatment outcomes.

Psychostimulant addiction treatment

Treatment of psychostimulant addiction has been a major, and not fully met, challenge. For opioid addiction, there is strong evidence for the effectiveness of several medications. For psychostimulants, there is no corresponding form of agonist maintenance that has met criteria for regulatory approval or generally accepted use. Stimulant-use disorders remain prevalent and can result in both short-term and long-term adverse consequences. The mainstay of treatment remains behavioral interventions. In this paper, we discuss those interventions and some promising candidates in the search for pharmacological interventions. This article is part of the Special Issue entitled 'CNS Stimulants'.

Income received during treatment does not affect response to contingency management treatments in cocaine-dependent outpatients

BACKGROUND

Prior studies find no effect of baseline income on response to contingency management (CM) interventions. However, income among substance disordered patients is variable, particularly at treatment entry. This study investigated the impact of during-treatment income, a more proximal estimate of economic resources at the time that CM is in effect, on response to standard treatment or the standard treatment plus CM.

METHOD

These secondary analyses included 418 cocaine dependent participants initiating community intensive outpatient treatment. We examined whether differences were present in pretreatment and during-treatment overall income, as well as specific income sources. We then conducted a series of regression models to investigate the impact of during-treatment income on treatment outcome.

RESULTS

Participants' during-treatment income was significantly lower compared to pretreatment income, and this difference was largely attributable to decreases in earned income, illegal income, and support from friends and family. Neither the main effect of income, nor the interaction of income and treatment condition, was significantly associated with treatment outcome. CM, however, was a significant predictor of improved treatment outcome relative to standard treatment. Income sources and some demographic characteristics were also significant predictors of outcomes; public assistance income was associated with improved outcomes and illegal income was associated with poorer outcomes.

CONCLUSIONS

These results suggest that substance abusers benefit from CM regardless of their income level, and these data add to the growing literature supporting the generalizability of CM across a variety of patient characteristics.