Neurophysiological and cognitive effects of smoked marijuana in frequent users

Rationale

Previously, we reported that acute marijuana intoxication minimally affected complex cognitive performance of daily marijuana smokers. It is possible that the cognitive tests used were insensitive to marijuana-related cognitive effects.

Objectives

In the current study, electroencephalographic (EEG) signals were recorded as daily marijuana users performed additional tests of immediate working memory and delayed episodic memory, before and after smoking marijuana.

Methods

Research volunteers (N = 24), who reported smoking ∼ 24 marijuana cigarettes/week, completed this study. Participants completed baseline computerized cognitive tasks, smoked a single marijuana cigarette (0%, 1.8%, or 3.9% ?⁹-THC w/w), and completed additional cognitive tasks; sessions were separated by at least 72-hours. Cardiovascular and subjective effects were also assessed throughout sessions.

Results

Overall performance accuracy was not significantly altered by marijuana, although the drug increased response times during task performance and induced a response bias towards labeling “new” words as having been previously seen in the verbal episodic memory task. Marijuana reduced slow wave evoked potential amplitude in the episodic memory task and decreased P300 amplitude and EEG power in the alpha band in the spatial working memory task. Heart rate and “positive” subjective-effect ratings were increased in a ?⁹-THC concentration-dependent manner.

Conclusions

Relative to previous findings with infrequent marijuana users, the frequent users in the current study exhibited similar neurophysiological effects but more subtle performance effects. These data emphasize the importance of taking into account the drug-use histories of research participants and examining multiple measures when investigating marijuana-related effects on cognitive functioning.     

Abstinence and psychological distress in co-morbid smokers using various pharmacotherapies

Background

Existing trials of varenicline have typically excluded smokers with concurrent medical and psychiatric illnesses and no data exist comparing effectiveness of varenicline with combination pharmacotherapy. This study evaluated abstinence and psychiatric outcomes of various tobacco dependence medications, including varenicline.

Methods

Retrospective cohort of 723 smokers, most with significant medical and psychiatric comorbidity, was evaluated at the UMDNJ-Tobacco Dependence Clinic from 2006 to 2008. Demographics, measures of tobacco dependence and co-morbidities, and a validated instrument measuring psychological distress (Kessler-6) were obtained. Primary outcome was 7-day point abstinence at 6 months after target quit date.

Results

Cessation medications used included combination pharmacotherapy (39%), single nicotine replacement therapy (NRT) or bupropion (29%), and varenicline (23%), with 9% using no medications. Overall, 23% of patients were abstinent at 6 months. In an adjusted regression model, smokers using varenicline or combination medications were more likely abstinent at 6 months than those using no medications (adjusted odds ratio = 2.99; 95% confidence interval = 1.20-7.47 and 2.80; 1.15-6.82, respectively), but not statistically higher than those using single medications (AOR = 1.70). Age, gender, education, marital status, cigarettes per day, time to first cigarette, night smoking, and menthol smoking were not significantly related to abstinence. Varenicline or combination medications did not significantly increase serious psychological distress over the treatment period compared to other medication options.

Conclusions

Both varenicline and combination pharmacotherapy were effective and did not increase psychological distress for up to 6 months in smokers with co-morbidities treated at a specialty clinic.     

Contingency management is efficacious and improves outcomes in cocaine patients with pretreatment marijuana use

Background

Marijuana use is common in patients seeking treatment for cocaine use. Nevertheless, few studies have examined effects of marijuana use on treatment outcomes in general, and even fewer with respect to contingency management (CM) treatment, which has been criticized for potentially increasing non-reinforced drug use.

Methods

Data from three randomized clinical trials of CM versus standard treatment (ST) in cocaine-abusing patients were examined ( [Petry et al., 2004], [Petry et al., 2005a] and [Petry et al., 2006a]; N = 393) to assess effects of pretreatment marijuana use on outcomes. Patients were divided into two groups: (1) no self-reported marijuana use (No Pre-M; n = 315) and (2) any self-reported marijuana use (Pre-M; n = 78) in the 30 days pretreatment.

Results

CM was especially efficacious in enhancing retention in Pre-M patients such that retention nearly doubled among Pre-M patients assigned to CM versus those assigned to ST. In contrast, CM exerted only modest benefits on retention in No Pre-M patients. Pretreatment marijuana use was not related to during-treatment abstinence from cocaine, opioids, and alcohol, or abstinence at a Month 9 follow-up. However, CM treatment and longest duration of abstinence achieved during treatment were significant predictors of Month 9 abstinence. Pre-M patients also evidenced more improvements in drug problems over time when randomized to CM.

Conclusions

CM was especially efficacious in facilitating retention and improving severity of drug-related problems in those who used marijuana in the month before initiating treatment.     

Young adults who smoke cigarettes and marijuana: Analysis of thoughts and behaviors

Introduction

Smoking both cigarettes and marijuana is increasingly common among young adults, yet little is known about use patterns, motivations, or thoughts about abstinence. In a U.S. sample, this study explored young adults' severity of cigarette and marijuana co-use, quit attempts, and thoughts about use.

Methods

Young adults age 18-to-25 who had smoked at least one cigarette in the past 30 days completed an anonymous online survey.

Results

Of 1987 completed surveys, 972 participants reported both past-month cigarette and marijuana use (68% male, 71% Caucasian, mean age 20.4 years [SD = 2.0]). Frequency of use, temptations to use, measures of dependence, decisional balance, and past-year quit attempts were associated across the two substances (all p < .05), but not motivation to quit. Relative to marijuana, participants reported greater desire and a later stage of change for quitting cigarettes and were more likely to endorse a cigarette abstinence goal, yet they had lower expectancy of success with quitting cigarettes and with staying quit (all p < .001).

Conclusions

Cigarette and marijuana use, temptations to use, and pros/cons of using were related in this young adult sample. Differences in motivation and thoughts about abstinence, however, suggest that young adults may be more receptive to interventions for tobacco than marijuana use. Use patterns and cognitions for both substances should be considered in prevention and intervention efforts.     

Contingency management with community reinforcement approach or twelve-step facilitation drug counseling for cocaine dependent pregnant women or women with young children

Background

Cocaine abuse among women of child-bearing years is a significant public health problem. This study evaluated the efficacy of contingency management (CM), the community reinforcement approach (CRA), and twelve-step facilitation (TSF) for cocaine-dependent pregnant women or women with young children.

Methods

Using a 2 × 2 study design, 145 cocaine dependent women were randomized to 24 weeks of CRA or TSF and to monetary vouchers provided contingent on cocaine-negative urine tests (CM) or non-contingently but yoked in value (voucher control, VC). Primary outcome measures included the longest consecutive period of documented abstinence, proportion of cocaine-negative urine tests (obtained twice-weekly), and percent days using cocaine (PDC) during treatment. Documented cocaine abstinence at baseline and 3, 6, 9 and 12 months following randomization was a secondary outcome.

Findings

CM was associated with significantly greater duration of cocaine abstinence (p < .01), higher proportion of cocaine-negative urine tests (p < 0.01), and higher proportion of documented abstinence across the 3-, 6-, 9- and 12-month assessments (p < 0.05), compared to VC. The differences between CRA and TSF were not significant for any of these measures (all p values ≥0.75). PDC decreased significantly from baseline during treatment in all four groups (p < 0.001) but did not differ significantly between CM and VC (p = 0.10) or between TSF and CRA (p = 0.23).

Interpretation

The study findings support the efficacy of CM for cocaine dependent pregnant women and women with young children but do not support greater efficacy of CRA compared to TSF or differential efficacy of CM when paired with either CRA or TSF.     

Violence among men and women in substance use disorder treatment: A multi-level event-based analysis

Background

This study examined associations between acute alcohol and drug use and violence towards others in conflict incidents (overall, partner, and non-partner conflict incidents) by men and women recruited from substance use disorder (SUD) treatment.

Methods

Semi-structured interviews were used to obtain details about interpersonal conflict incidents (substance use, whether specific conflicts were with intimate partners or non-partners) in the 180 days pre-treatment. Participants for this study were selected for screening positive for past-year violence (N = 160; 77% men, 23% women).

Results

Multi-level multinomial regression models showed that after adjusting for clustering within individual participants, the most consistent predictors of violence across models were acute cocaine use (significant for overall, intimate partner and non-partner models), acute heavy alcohol use (significant for overall and non-partner models), and male gender (significant in all models).

Conclusions

This study was the first to explicitly examine the role of acute alcohol and drug use across overall, partner and non-partner conflict incidents. Consistent with prior studies using a variety of methodologies, alcohol, cocaine use and male gender was most consistently and positively related to violence severity (e.g., resulting in injury). The results provide important and novel event-level information regarding the relationship between acute alcohol and specific drug use and the severity of violence in interpersonal conflict incidents.     

A systematic review of the impact of alcohol use disorders on HIV treatment outcomes, adherence to antiretroviral therapy and health care utilization

Background

Alcohol use disorders (AUDs) are highly prevalent and associated with non-adherence to antiretroviral therapy, decreased health care utilization and poor HIV treatment outcomes among HIV-infected individuals.

Objectives

To systematically review studies assessing the impact of AUDs on: (1) medication adherence, (2) health care utilization and (3) biological treatment outcomes among people living with HIV/AIDS (PLWHA).

Data sources

Six electronic databases and Google Scholar were queried for articles published in English, French and Spanish from 1988 to 2010. Selected references from primary articles were also examined.

Review methods

Selection criteria included: (1) AUD and adherence (N = 20); (2) AUD and health services utilization (N = 11); or (3) AUD with CD4 count or HIV-1 RNA treatment outcomes (N = 10). Reviews, animal studies, non-peer reviewed documents and ongoing studies with unpublished data were excluded. Studies that did not differentiate HIV+ from HIV− status and those that did not distinguish between drug and alcohol use were also excluded. Data were extracted, appraised and summarized.

Data synthesis and conclusions

Our findings consistently support an association between AUDs and decreased adherence to antiretroviral therapy and poor HIV treatment outcomes among HIV-infected individuals. Their effect on health care utilization, however, was variable.     

5-HT induces temporomandibular joint nociception in rats through the local release of inflammatory mediators and activation of local β adrenoceptors

Objectives

The present studies assessed the effects of adolescent and adult ethanol exposure on the rewarding effects of cocaine as measured with the conditioned place preference procedure.

Methods

Male rats were exposed to intraperitoneal (IP) injections of ethanol or vehicle for 10 days [postnatal days (PNDs) 30-39 or PNDs 70-79; 2 mg/kg]. Place preference conditioning began on PND 65 or PND 105, respectively, and consisted of a baseline test followed by four conditioning cycles with either 0, 5, 10 or 20 mg/kg cocaine. Following the fourth conditioning cycle a final preference test was performed. Changes in time on the drug-paired side between the baseline and final test were analyzed.

Results

Animals exposed to vehicle (during adolescence or adulthood) showed a significant place preference at 20 mg/kg cocaine. Animals exposed to ethanol (during adolescence or adulthood) showed a significant place preference at 10 mg/kg cocaine.

Conclusions

Exposure to ethanol (adolescents or adults) sensitized the rewarding effects of cocaine. This may indicate an increase in the abuse liability of cocaine following a history of ethanol exposure.     

Psychosocial treatments for cocaine dependence: the role of depressive symptoms

Background

The association between cocaine use and depression has been frequently observed. However, less is known about the significance of depression in the treatment of cocaine use disorders. This study examined possible interrelations between drug use and depression severity among cocaine-dependent patients in psychosocial treatments for cocaine dependence.

Methods

Monthly assessed drug use and depression severity scores of N = 487 patients during 6-month psychosocial treatments for cocaine dependence were analyzed using hybrid latent growth models.

Results

Results indicated a moderate but statistically significant (z = 3.13, p < .01) influence of depression severity on increased drug use in the upcoming month, whereas drug use did not affect future depression severity.

Conclusions

Findings suggest that depression symptoms are an important predictor of drug use outcomes during psychosocial treatments for cocaine dependence and, hence, underline the importance of adequately addressing depression symptoms to improve treatment outcomes.     

Can intranasal drug use reduce HCV infection among injecting drug users?

Background

Preventing HCV infection among people who inject drugs is a difficult public health challenge. We examined the potential role of intranasal drug use in reducing HCV acquisition.

Methods

Subjects were recruited from IDUs entering the Beth Israel drug detoxification program from 2005 to 2010. A structured interview was administered and serum samples were collected for HCV testing.

Results

726 active injecting drug users were recruited from 2005 to 2010. HCV prevalence was 71%, 90% reported recent heroin injection and 44% reported recent intranasal heroin use. In a multiple logistic regression analysis, being HCV seropositive was associated with more years injecting, Latino ethnicity, previous testing for HCV, and recent injection of speedball, and negatively associated with recent intranasal use of heroin (AOR = 0.52, 95% CI 0.33-0.82) and intranasal use of speedball (AOR = 0.41, 95% CI 0.31-0.80). The association between intranasal heroin use and lower HCV seroprevalance was observed among both new injectors and persons with long injecting histories (16+ years since first injection).

Conclusion

Encouraging intranasal use as an alternative to injection among persons currently injecting drugs may be a viable strategy for reducing HCV transmission.     

Associations among types of impulsivity, substance use problems and neurexin-3 polymorphisms

Background

Some of the genetic vulnerability for addiction may be mediated by impulsivity. This study investigated relationships among impulsivity, substance use problems and six neurexin-3 (NRXN3) polymorphisms. Neurexins (NRXNs) are presynaptic transmembrane proteins that play a role in the development and function of synapses.

Methods

Impulsivity was assessed with the Barratt Impulsiveness Scale Version 11 (BIS-11), the Boredom Proneness Scale (BPS) and the TIME paradigm; alcohol problems with the Michigan Alcoholism Screening Test (MAST); drug problems with the Drug Abuse Screening Test (DAST-20); and regular tobacco use with a single question. Participants (n = 439 Caucasians, 64.7% female) donated buccal cells for genotyping. Six NRXN3 polymorphisms were genotyped: rs983795, rs11624704, rs917906, rs1004212, rs10146997 and rs8019381. A dual luciferase assay was conducted to determine whether allelic variation at rs917906 regulated gene expression.

Results

In general, impulsivity was significantly higher in those who regularly used tobacco and/or had alcohol or drug problems. In men, there were modest associations between rs11624704 and attentional impulsivity (p = 0.005) and between rs1004212 and alcohol problems (p = 0.009). In women, there were weak associations between rs10146997 and TIME estimation (p = 0.03); and between rs1004212 and drug problems (p = 0.03). The dual luciferase assay indicated that C and T alleles of rs917906 did not differentially regulate gene expression in vitro.

Conclusions

Associations between impulsivity, substance use problems and polymorphisms in NRXN3 may be gender specific. Impulsivity is associated with substance use problems and may provide a useful intermediate phenotype for addiction.     

"It's not rocket science, what I do": Self-directed harm reduction strategies among drug using ethno-racially diverse gay and bisexual men

Background

Research on harm reduction has typically focused on broad-based or organisational strategies such as needle exchange and opiate substitute programmes. Less attention has been paid to the self-directed harm reduction practices of substance users themselves. Few studies have focused on sexual minority populations such as gay and bisexual men and fewer still on the marginalised groups that constitute these populations. This paper identifies self-directed harm reduction strategies among substance using ethno-racially diverse gay and bisexual men.

Methods

This article presents findings from the Party Drugs Study in Toronto's gay dance club scene, a community-based qualitative study in Toronto, Canada. We present a thematic analysis of interviews with 43 gay and bisexual men from diverse ethno-racial backgrounds about their substance use in the gay dance club scene.

Findings

We identify five self-directed harm reduction strategies: rationing, controlling or avoiding mixing, controlling quality, maintaining a healthy lifestyle, and following guidelines during substance use.

Conclusions

We discuss our findings in relation to prior research and to critical theory. We suggest that drug users’ awareness of possible harm, and their personal investment in harm reduction, constitute a viable platform from which community-based and public health organisations may promote and strengthen harm reduction among gay and bisexual men from ethno-racially diverse backgrounds.     

Methadone maintenance and the cost and utilization of health care among individuals dependent on opioids in a commercial health plan

Background

Few health plans provide maintenance medication for opioid dependence. This study assessed the cost of treating opioid-dependent members in a commercial health plan and the impacts of methadone maintenance on costs of care.

Methods

Individuals with diagnoses of opioid dependence (two or more diagnoses per year) and at least 9 months of health plan eligibility each year were extracted from electronic health records for the years 2000 through 2004 (1,518 individuals and 2,523 observations across the study period—some individuals were in multiple years). Analyses examined the patterns and costs of health care for three groups of patients: (1) one or more methadone visits during the year (n = 1,298; 51%); (2) no methadone visits and 0 or 1 visits in the Addiction Medicine Department (n = 370; 15%); (3) no methadone visits and 2 or more visits in addiction medicine (n = 855; 34%).

Results

Primary care (86%), emergency department (48%) and inpatient (24%) visits were common. Mean total annual costs to the health plan were $11,200 (2004 dollars) per member per year. The health plan's costs for members receiving methadone maintenance were 50% lower ($7,163) when compared to those with two or more outpatient addiction treatment visits but no methadone ($14,157) and 62% lower than those with one or zero outpatient addiction treatment visits and no methadone treatment ($18,694).

Conclusions

Use of opioid maintenance services was associated with lower total costs of care for opioid-dependent members in a commercial health plan.     

Epidural, intrathecal and plasma pharmacokinetic study of epidural ropivacaine in PLGA-microspheres in sheep model

Background

Microparticulate local anesthetics-loaded delivery systems are known to provide a controlled release of drug and to reduce systemic toxicity resulting from transient high plasma concentrations. The aim of this study was to evaluate epidural, intrathecal and plasma pharmacokinetics of ropivacaine following epidural administrations of repeated boluses or infusions and to compare them with the epidural administration of polylactide-co-glycolide ropivacaine-loaded microspheres.

Methods

In the first step, the epidural and intrathecal pharmacokinetics was evaluated in 3 Lacaunes ewes, receiving epidural continuous infusion of ropivacaine with increasing doses (20, 50 and 100 mg/h). Then, six animals received an epidural administration of ropivacaine-loaded microspheres (500 mg), three others received ropivacaine in epidural bolus (30 mg) followed by infusion (2 mg/ml during 6 h), and the last three animals received three successive epidural boluses of ropivacaine (50 mg) at 2 h interval. A simultaneous microdialysis technique was used to measure epidural and intrathecal concentrations of ropivacaine.

Results

After epidural administration of ropivacaine-loaded microspheres, Cmax in plasma was around 100 ng/ml while epidural and intrathecal Cmax of ropivacaine were close to 600 and 150 μg/ml, respectively. The ratios of intrathecal to epidural AUC (AUCit/AUCepi) for bolus administration, bolus + infusion administration, and for microspheres were 13.4 ± 2.4; 14.1 ± 6.1 and 33.9 ± 22.6%, respectively. This suggested that administration of ropivacaine as microspheres increased the transmeningeal passage of ropivacaine in comparison to other administration regimens.

Conclusions

Epidural administration of ropivacaine-loaded microspheres led to the sustained levels of ropivacaine in the intrathecal space compared to the boluses of ropivacaine solution. Moreover, epidural administration of microspheres resulted in the highest efficiency in intrathecal uptake of ropivacaine compared to administration in solution.     

Binge drinking and marijuana use among menthol and non-menthol adolescent smokers: Findings from the Youth Smoking Survey

Introduction

Research has shown that smoking menthol cigarettes induces smoking initiation and hinders cessation efforts especially among youth. The objective of this paper is to examine the association between menthol cigarette smoking and substance use among adolescent students in Canada.

Methods

A nationally representative cross-sectional sample of 4466 Canadian students in grades 7 to 12 from the 2010–2011 Youth Smoking Survey is analyzed. A bivariate probit model is used jointly to examine the association of menthol smoking status with binge drinking and marijuana use.

Results

32% of the current smokers in grades 7 to 12 smoke mentholated cigarettes, 73% are binge drinkers and 79% use marijuana. Results of the bivariate probit regression analysis, controlling for other covariates, show statistically significant differences in the likelihood of binge drinking and marijuana use between menthol and non-menthol smokers. Menthol cigarette smokers are 6% (ME = 0.06, 95% CI = 0.03–0.09) more likely to binge drink and 7% (ME = 0.07, 95% CI = 0.05–0.10) more likely to use marijuana.

Conclusion

Smoking menthol cigarettes is associated with a higher likelihood of binge drinking and marijuana use among Canadian adolescents. Banning menthol in cigarettes may be beneficial to public health.     

Percutaneous penetration of 5-methoxypsoralen in rhesus monkeys

Objective and design

5-methoxypsoralen (bergapten) has been used in the treatment of psoriasis and vitiligo, and as a sun tanning accelerator. While low plasma concentrations have previously been detected, there is no data on its dermatopharmacokinetics.

Materials and methods

Three rhesus monkeys were used as a model for human skin. [14C]-5-methoxypsoralen, as a parenteral excretion control, was injected in propylene glycol with an activity of 1.12 uCi/ml at a concentration of 80 mcg/ml and urine was collected at 4, 8, 12, 24 h, and then daily for a total of 6 days. [14C]-5-methoxypsoralen was then applied topically in acetone with a dose of 1.19 mc (72 mcg) and urine was collected at 4 and 24 h and then daily for a total of 7 days. The amount excreted was corrected for the previously determined parenteral excretion kinetics.

Results

Intramuscular [14C]-5-methoxypsoralen had an average of 71.87 ± 7.77% of excretion and percutaneously applied [14C]-5-methoxypsoralen had an average of 58.4 ± 11.8% of excretion.

Conclusion

A high percentage of the administered 5-methoxypsoralen was absorbed. This provides a foundation of methodology to evaluate the efficacy of other delivery vehicles for 5-methoxypsoralen and serves as part of its dermatotoxic profile.     

Validation of the Cannabis Expectancy Questionnaire (CEQ) in adult cannabis users in treatment

Background

Outcome expectancies are a key cognitive construct in the etiology, assessment and treatment of Substance Use Disorders. There is a research and clinical need for a cannabis expectancy measure validated in a clinical sample of cannabis users.

Method

The Cannabis Expectancy Questionnaire (CEQ) was subjected to exploratory (n = 501, mean age 27.45, 78% male) and confirmatory (n = 505, mean age 27.69, 78% male) factor analysis in two separate samples of cannabis users attending an outpatient cannabis treatment program. Weekly cannabis consumption was clinically assessed and patients completed the Severity of Dependence Scale-Cannabis (SDS-C) and the General Health Questionnaire (GHQ-28).

Results

Two factors representing Negative Cannabis Expectancies and Positive Cannabis Expectancies were identified. These provided a robust statistical and conceptual fit for the data. Internal reliabilities were high. Negative expectancies were associated with greater dependence severity (as measured by the SDS) and positive expectancies with higher consumption. The interaction of positive and negative expectancies was consistently significantly associated with self-reported functioning across all four GHQ-28 scales (Somatic Concerns, Anxiety, Social Dysfunction and Depression). Specifically, within the context of high positive cannabis expectancy, higher negative expectancy was predictive of more impaired functioning. By contrast, within the context of low positive cannabis expectancy, higher negative expectancy was predictive of better functioning.

Conclusions

The CEQ is the first cannabis expectancy measure to be validated in a sample of cannabis users in treatment. Negative and positive cannabis expectancy domains were uniquely associated with consumption, dependence severity and self-reported mental health functioning.     

Depressive mood and tobacco use: moderating effects of gender and emotional attention

Introduction

Depressive symptomatology is a predictive variable of tobacco use. The objective of the present study was to evaluate the influence that this symptomatology has on tobacco use when moderated by emotional attention.

Methods

A total of 289 participants (127 males, 162 females) completed a survey to measure perceived emotional intelligence, depressive symptomatology, tobacco use and sociodemographic variables. Results were analyzed using a multiple regression model that included self-perceived emotional attention as a moderating variable.

Results

In women, an interaction was found between depressive symptomatology and gender for predicting the number of cigarettes smoked (t = 2.45; p = .01), but not in men (t = −.74; p = .45). This interaction was moderated by emotional attention (t = 2.83; p = .005), such that women with medium and high levels of attention consumed a larger number of cigarettes.

Conclusions

In women, the effect of depressive symptomatology on tobacco use was moderated by the amount of attention that women paid to those symptoms. Such a moderating effect of attention was not observed in men. We recommend that smoking cessation programs incorporate interventions designed specifically for women, in particular to help them manage depressive symptomatology.     

Moderating effects of race in clinical trial participation and outcomes among marijuana-dependent young adults

Background

Few studies have examined clinical trial participation rates and treatment outcomes among underserved young adults who are dependent on marijuana, the most commonly abused illicit drug.

Method

The present study was a secondary analysis of a trial of court-referred marijuana-dependent young adults (ages 18–25) randomized to one of four treatment conditions: Motivational Enhancement Therapy/Cognitive Behavioral Therapy (MET/CBT), MET/CBT + Contingency Management (CM), Drug Counseling (DC) or DC + CM. African American (N = 81) participants were compared to White (N = 31) participants with respect to rates of participation in phases of treatment and substance use outcomes. In addition, the interaction of race and treatment condition was examined to ascertain if the interventions yielded different effects based on race.

Results

Among those who started treatment, African American young adults were significantly less likely to complete the treatment and posttreatment phases of the clinical trial than their White counterparts. Irrespective of treatment type, substance use outcomes (i.e., percentage of marijuana-negative specimens and longest duration of continuous abstinence) did not vary by race. However, there was a significant interaction effect between treatment type and race; African American young adults did not benefit differentially from any specific type of treatment, but CM was effective in reducing proportion of marijuana positive samples among White young adults.

Conclusions

Findings suggest that clinical trial treatment and posttreatment completion rates vary by race in this population, as does response to specific treatment types. More treatment research focusing specifically on African American marijuana-dependent young adults is warranted.     

Internet-based group contingency management to promote abstinence from cigarette smoking: a feasibility study

Background

In contingency management (CM) interventions, monetary consequences are contingent on evidence of drug abstinence. Typically, these consequences are contingent on individual performance. Consequences contingent on group performance may promote social support (e.g., praise).

Methods

Thus, to combine social support with the monetary incentives of CM, we integrated independent and interdependent group contingencies of reinforcement into an Internet-based intervention to promote smoking abstinence. Breath carbon monoxide (CO) measures were compared between treatment conditions and a baseline control condition. Thirteen participants were divided into 5 groups or “teams” (n = 2-3 per team). Each participant submitted video recordings of CO measurement twice daily via the Internet. Teammates could monitor each other's progress and communicate with one another through an online peer support forum. During a 4-day tapering condition, vouchers exchangeable for goods were contingent on gradual reductions in breath CO. During a 10-day abstinence induction condition, vouchers were contingent on abstinence (CO ≤ 4 ppm). In both treatment conditions, concurrent independent and interdependent group contingencies were arranged (i.e., a mixed contingency arrangement).

Results

Less than 1% of CO samples submitted during baseline were ≤ 4 ppm, compared to 57% submitted during abstinence induction. Sixty-five percent of participants’ comments on the online peer support forum were rated as positive by independent observers. Participants rated the intervention favorably on a treatment acceptability questionnaire.

Conclusion

The results suggest that the intervention is feasible and acceptable for promoting abstinence from cigarette smoking.