Research Findings - Research on Behavioral and Combined Treatments for Drug Abuse
Intermittent Marijuana Use is Associated with Improved Retention in Naltrexone Treatment for Opiate-Dependence
Naltrexone is a theoretically promising alternative to agonist substitution treatment for opioid dependence, but its effectiveness has been severely limited by poor adherence. This study examined, in an independent sample, a previously observed association between moderate cannabis use and improved retention in naltrexone treatment. Opioid dependent patients (N = 63), admitted for inpatient detoxification and induction onto oral naltrexone, and randomized into a six-month trial of intensive behavioral therapy (Behavioral Naltrexone Therapy) versus a control behavioral therapy (Compliance Enhancement), were classified into three levels of cannabis use during treatment based on biweekly urine toxicology: abstinent (0% cannabis positive urine samples); intermittent use (1% to 79% cannabis positive samples); and consistent use (80% or greater cannabis positive samples). Intermittent cannabis users showed superior retention in naltrexone treatment (median days retained = 133), compared to abstinent (median = 35) or consistent users (median = 35). Intermittent cannabis use was also associated with greater adherence to naltrexone pill-taking. Treatment interacted with cannabis use level, such that intensive behavioral therapy appeared to moderate the adverse prognosis in the consistent cannabis use group. Experimental studies are needed to directly test the hypothesis that cannabinoid agonists exert a beneficial pharmacological effect on naltrexone maintenance and to understand the mechanism. Raby WN, Carpenter KM, Rothenberg J, Brooks AC, Jiang H, Sullivan M, Bisaga A, Comer S, Nunes EV. Intermittent marijuana use is associated with improved retention in naltrexone treatment for opiate-dependence. Am J Addict. 2009 Jul-Aug;18(4):301-308.
Extended Treatment of Older Cigarette Smokers
Dr. Sharon Hall and colleagues at the University of California San Francisco conducted the present study to determine the efficacy of extended cognitive behavioral and pharmacological interventions in older smokers (greater than 49 years of age) and to determine if gender differences in efficacy existed. Participants who smoked at least 10 cigarettes per day received a 12-week treatment that included group counseling, nicotine replacement therapy (NRT) and bupropion. After initial treatment, participants were randomized to one of four conditions, independent of smoking status. The four conditions were: 1) Standard Treatment (ST; no further treatment; 2) Extended NRT (E-NRT; 40 weeks of nicotine gum availability); 3) Extended Cognitive Behavioral Therapy (E-CBT; 11 cognitive behavioral sessions over a 40-week period); or 4) E-CBT plus E-NRT (E-Combined: 11 cognitive behavioral sessions plus 40 weeks nicotine gum availability). Participants were assessed at weeks 24, 52, 64, and 104 for smoking abstinence. The E-CBT condition produced high abstinence rates that were maintained throughout the two year study period and was significantly more effective than E-NRT and ST across that period. The authors concluded that extended cognitive behavioral treatments can produce high and stable cigarette abstinence rates for both men and women. NRT does not add to the efficacy of extended CBT, and may hamper its' efficacy. Further research is needed to determine if these results can be replicated in a sample with a greater range of ages, and improved upon with the addition of medications other than NRT. Hall SM, Humfleet GL, Munoz RF, Reus VI, Robbins JA, Prochaska JJ. Extended treatment of older cigarette smokers. Addiction. 2009 Jun;104(6):1043-1052.
Contingency Management and Motivational Enhancement for College Student Smokers
Dr. Tevyaw and colleagues at Brown University conducted this study to examine the efficacy of Motivational Enhancement Therapy (MET) and Contingency Management (CM) for college student smokers. In a 2 x 2 experimental design, 110 nontreatment-seeking daily smokers were randomly assigned to three weeks of CM vs. noncontingent reinforcement (NR) and to three individual sessions of MET vs. a relaxation control. Carbon monoxide (CO) samples were collected twice daily for three weeks. Participants earned $5 for providing each sample and those randomized to CM earned escalating monetary rewards based on CO reductions (week 1) and smoking abstinence (weeks 2-3). The participants assigned to the CM condition had significantly lower CO levels than those assigned to NR. Those in the CM and MET groups reported greater interest in quitting smoking post-treatment, but rates of abstinence at follow-up were very low (4% at 6-month follow-up) and did not differ by group. The authors suggest that the short-term efficacy of CM is supported for college students. However future research should explore enhancements to CM, including a longer intervention period and the recruitment of smokers who are motivated to quit. Tevyaw T, Colby SM, Tidey JW, Kahler CW, Rohsenow DJ, Barnett NP, Gwaltney CJ, Monti PM. Contingency management and motivational enhancement: A randomized clinical trial for college student smokers. Nicotine & Tobacco Research. 2009, Jan;11(6): 739-749.
Mediators of the Relationship Between NRT and Smoking Abstinence Among People Living with HIV/AIDS
Researchers at Brown University conducted this study to determine if psychosocial variables, such as self-efficacy and decisional balance, mediated the relationship between nicotine replacement therapy (NRT) and long-term abstinence. Multivariate analyses identified self-efficacy to refuse cigarettes and decisional balance (beliefs about smoking) as predictors of 6-month abstinence and therefore potential mediators of the NRT treatment effect found in this sample. Findings of this study provide evidence that improving self-efficacy to resist smoking temptations may be a psychological mechanism that results from the success experiences boosted by NRT treatments. Racial/ethnic differences were found among participants. Hispanic Americans were almost three times as likely to be abstinent compared with European American participants, which was due in part to larger gains in self-efficacy from baseline to 6-month follow-up. African Americans' self-efficacy to quit was of comparable magnitude to Hispanics. However, those improvements did not translate into improved abstinence rates. In sum, this study found the efficacy of NRT compliance on 6-month quit rates to be mediated by positive changes in self-efficacy to resist temptations to smoke and, to a lesser extent, changes in beliefs about the pros and cons of quitting smoking. This was the case for all ethnic-racial groups, with the exception of African Americans in which increased self-efficacy did not translate to abstinence. Specific psychosocial factors should be addressed with greater awareness of how cultural and social contextual factors impact treatment response. Stanton CA, Lloyd-Richardson EE, Papandonatos GD, de Dios MA, Niaura R. Mediators of the relationship between nicotine replacement therapy and smoking abstinence among people living with HIV/AIDS. AIDS Education and Prevention. 2009;21:Supplement A: 65-80.
Depressive Symptoms Predict Smoking Status among Pregnant Women
This study conducted by researchers at the University of Vermont compared smokers and spontaneous quitters on psychological functioning. Data were obtained from 127 women enrolled in a trial to test smoking cessation and relapse prevention interventions during pregnancy and postpartum. Smokers and spontaneous quitters differed on sociodemographic and smoking characteristics. In terms of psychological functioning, smokers reported significantly more depression/anxiety symptoms and withdrawn behavior than spontaneous quitters. Higher depression scores were associated with increased odds of continued smoking, even after controlling for sociodemographic and smoking variables in multivariate analyses. These results suggest that depressive symptoms may be an independent contributor to the problem of continued smoking during pregnancy, which may have implications for smoking-cessation interventions among pregnant women. Linares Scott TJ, Heil SH, Higgins ST, Badger GJ, Bernstein IM. Depressive symptoms predict smoking status among pregnant women. Addictive Behaviors. 2009;34:705-708.
Short-Term Weight Gain by Menstrual Phase Following Smoking Cessation in Women
Dr. Sharon Allen and colleagues at the University of Minnesota conducted this trial to examine short-term weight gain by menstrual phase following a quit attempt. The aim of the study was to assess whether greater weight gain, due to smoking abstinence, occurs during luteal verses follicular phase. Women were randomized to quit smoking during the follicular or luteal phase of their cycle and followed for four weeks. The results showed that participants who quit smoking experienced significantly more weight gain than those who quit for less than 24 hours. However, if smoking abstinence is achieved, the menstrual phase in which a woman quits does not play a role in short-term weight gain. Allen SS, Allen AM, Mooney M, Bade T. Short-term weight gain by menstrual phase following smoking cessation in women. Eating Behaviors. 2009; 10:52-55.
Stigma, Disclosure, and Depressive Symptoms Among Informal Caregivers of People Living with HIV/AIDS
Informal care receipt is associated with better HIV treatment outcomes among patients vulnerable to treatment failure. Yet, informal caregiving can be highly stressful, leading to distress and cessation of caregiving. Research on factors contributing to informal caregivers' psychological distress may advance our understanding of how to improve caregivers' well-being and sustained HIV caregiving for a vulnerable population. The authors examined relationships among caregiver stigma, disclosure, and depressive symptoms in a cross-sectional sample of 207 informal caregivers of people living with HIV/AIDS (PLWHAs) in Baltimore, Maryland. Caregivers were primarily African American, low-income, urban adults participating in the Action, Resources, and Knowledge (ARK) study, which recruited urban PLWHAs and their main supporters. Results indicated that among caregivers, HIV caregiving-related stigma was associated with more depressive symptoms, while disclosure of caregiving status was associated with fewer symptoms. The authors also explored the buffering effect of disclosure in the relationship between stigma and depressive symptoms. Results indicated that among those who reported greater stigma, there was a significant decrease in depressive symptoms as the number of disclosures increased. In contrast, participants who indicated lower stigma had consistently fewer depressive symptoms regardless of number of disclosures. These results suggest the need for interventions to address high levels of depressive symptoms among informal HIV caregivers, particularly those who report greater caregiving stigma and less disclosure of their caregiver status. In addition, future research should examine these relationships further using longitudinal data from informal caregivers and their care recipients. Mitchell MM, Knowlton A. Stigma, disclosure, and depressive symptoms among informal caregivers of people living with HIV/AIDS. AIDS Patient Care STDS. 2009 July. [E-pub ahead of print].
Developing an Integrated Treatment for Substance Use and Depression using Cognitive–Behavioral Therapy
Providing a unified treatment approach to meet the substance abuse and mental health needs of clients is the preferred model for addressing co-occurring disorders. The authors developed a group-based cognitive-behavioral (CBT) integrated treatment for depression and substance use disorders (SUD) that could be delivered by counselors in SUD treatment settings and evaluated its feasibility and acceptability. The authors conducted an in-depth case study examining one implementation of the treatment using 15 focus groups with clients and semistructured interviews with counselors and administrators. Using CBT as a treatment approach to integrate the treatment was widely accepted by clients, counselors, and administrators. Clients stated the treatment was applicable to multiple aspects of their lives and allowed them to recognize their clinical improvements over time. Counselors and administrators discussed challenges for long-term feasibility. Key decisions used to develop the treatment and recommendations for implement-ting integrated care in SUD settings are discussed. Osilla KC, Hepner KA, Munoz RF, Woo SW, Watkins K. Developing an integrated treatment for substance use and depression using cognitive–behavioral therapy. Journal of Substance Abuse Treatment. 2009 June [E-pub ahead of print].
A Randomized Controlled Trial of a Money Management-Based Substance Use Intervention
Money management has been implemented, often in bundled interventions, as a strategy to counteract spending of public support checks and other funds on drugs and alcohol. The authors conducted a randomized controlled trial of a voluntary money management program as an adjunctive treatment for patients in treatment for mental illness, substance use disorders, or both. In the advisor-teller money manager (ATM) intervention, a money manager stores patients' checkbooks and automated bank cards, trains patients to manage their own funds, and links spending to activities related to their treatment goals. Eighty-five veterans with recent use of alcohol or cocaine were randomly assigned to 36 weeks of the ATM intervention or a control intervention (completion of a simple financial workbook). With ATM, 75% of veterans gave their checkbook to their money manager to hold, and participants attended significantly more therapy sessions than those assigned to the control therapy (mean of 20.6 versus 8.1 sessions). Although participants assigned to ATM did not show significantly greater improvement over time on the primary outcomes (self-reported abstinence from alcohol and cocaine and negative urine tests for cocaine metabolite), they reduced their Addiction Severity Index drug and alcohol use composite scale scores more rapidly than the control group. High rates of abstinence in both groups created a ceiling effect, limiting the power to detect improved abstinence rates. In this relatively small trial, ATM, a money management intervention, showed promise in engaging patients, improving their money management, and improving some substance abuse outcomes. Rosen MI, Carroll KM, Stefanovics E, Rosenheck RA. A randomized controlled trial of a money management-based substance use intervention. Psychiatric Services. 2009 Apr;60(4): 498-504.
Depression Among Methamphetamine Users: Association with Outcomes from the Methamphetamine Treatment Project at 3-Year Follow-Up
Although depression is highly comorbid with substance use disorders, little is known about the clinical course and outcomes of methamphetamine (MA) users with depressive symptoms and syndromes. In this study of MA-dependent individuals entering psychosocial treatment, the authors predicted that (1) depressive symptoms would decline during treatment, an effect that would vary as a function of MA use and (2) depression diagnoses post-treatment would be associated with poorer outcomes. Participants (N = 526) were assessed for depression, substance use, and psychosocial outcomes at baseline, treatment discharge, and 3-year follow-up. Depressive symptoms declined significantly during treatment, an effect that was greatest among those who abstained from MA. Major depression at follow-up was associated with poorer MA use outcomes and impairment across multiple domains of functioning. The findings highlight the relationship of depressive symptoms and diagnoses to treatment outcomes, and suggest a need for further studies of depression in populations using MA. Glasner-Edwards S, Marinelli-Casey P, Hillhouse M, Ang A, Mooney LJ, Rawson R, Methamphetamine Treatment Project Corporate Authors. Depression among methamphetamine users: Association with outcomes from the methamphetamine treatment project at 3-year follow-up. Journal of Nervous and Mental Dis. 2009 Apr;197(4):225-231.
The Need for Smoking Cessation Among HIV-Positive Smokers
Most HIV-positive persons in the U.S. smoke cigarettes. Despite substantial clinical advances in HIV care in the era of highly active antiretroviral therapy (HAART), HIV-positive persons are at high risk of tobacco-related disease and death. HIV-positive persons have complex social, economic, psychiatric, and medical needs that may impact smoking behavior and response to smoking cessation interventions, but there is a dearth of research on smoking cessation interventions tailored to HIV-positive persons. HIV care providers should treat tobacco use with the array of evidence-based smoking cessation treatments available, updating their clinical practice as new data emerge. This article reviews the literature on the health consequences of tobacco use in HIV-positive persons, the treatment of tobacco dependence, and the research to date on smoking cessation interventions in HIV-positive persons, and it presents recommendations for future research and intervention. Nahvi, S, Cooperman, NA. Review: The need for smoking cessation among HIV-positive smokers. AIDS Education and Prevention. 2009 Jun;21(3 Suppl):14-27.
Self-Management of Injection-Related Wounds Among Injecting Drug Users Injection-related wounds are an important complication of injection drug use
This study describes behaviors related to self-management of injection-related wounds and identifies factors associated with behaviors that may increase the potential for harm. The authors conducted interviews with 101 injecting drug users in Washington, DC. A total of 82 (81.2%) injecting drug users reported ever having an injection-related wound, and of these 93.9% reported self-management of their wounds. The most commonly reported behaviors were cleaning and applying ointment to wounds; however, several participants engaged in behaviors determined to be more potentially harmful, including acquiring antibiotics without prescriptions and manipulating their wounds. In multivariate analysis, injecting drug users who had ever injected amphetamines were more likely to engage in potentially harmful self-management behaviors (adjusted odds ratio = 4.38; 95% confidence interval = 1.15-16.64). Self-management of injection-related wounds is common and certain behaviors may increase the potential for harm. Further research is needed to best focus efforts to improve wound care for injecting drug users. Roose RJ, Hayashi AS, Cunningham CO. Self-management of injection related wounds among injecting drug users. J Addict Dis. 2009;28(1):74-80.
Successful Treatment of Chronic Hepatitis C with Pegylated Interferon in Combination with Ribavirin in a Methadone Maintenance Treatment Program
Injection drug users constitute 60% of the more than 4 million people in the United States with hepatitis C virus (HCV), including many methadone maintenance patients. Few data exist describing clinical outcomes for patients receiving HCV treatment on-site in methadone maintenance settings. In this retrospective study, the authors describe clinical outcomes for 73 patients receiving HCV treatment on-site in a methadone maintenance treatment program. Fifty-five percent of patients achieved end-of-treatment response, and 45% achieved sustained viral response. These treatment response rates are nearly equivalent to previously published HCV treatment response rates, despite high prevalence of ongoing drug use (49%), psychiatric comorbidity (67%), and HIV coinfection (32%). These data show that on-site HCV treatment with pegylated interferon and ribavirin is effective in methadone-maintained patients, many of whom are active drug users, psychiatrically ill, or HIV coinfected, and that methadone maintenance treatment programs represent an opportunity to safely treat chronic hepatitis C. Litwin AH, Harris Jr. KA, Nahvi S, Zamor PJ, Soloway IJ, Tenore PL, Kaswan D, Gourevitch, MN, Arnsten JH. Successful treatment of chronic hepatitis C with pegylated interferon in combination with ribavirin in a methadone maintenance treatment program. Journal of Substance Abuse Treatment 2009 Jul;37(1):32-40.
A Treatment for Substance Abusing Pregnant Women
The authors describe the adaptation of a manualized behavioral treatment for substance using pregnant women that includes components of motivational interviewing and cognitive therapy. In a pilot study conducted in 2006-2007, five non-behavioral health clinicians were trained to provide the treatment to 14 women. Therapy was administered concurrent with routine prenatal care at inner-city maternal health clinics in New Haven and Bridgeport, Connecticut, small urban cities in the USA. Substance use was monitored by self report, and urine and breath tests. Treatment fidelity was assessed using the Yale Adherence and Competence System. Behavioral treatment delivery in this setting is feasible and is being evaluated in a randomized, controlled, clinical trial. Yonkers KA, Howell HB, Allen AE, Ball SA, Pantalon MV, Rounsaville BJ. A treatment for substance abusing pregnant women. Archives of Women's Mental Health. 2009 Aug;12(4):221-227.
Beck Depression Inventory for Depression Screening in Substance-Abusing Adolescents
Co-occurring major depressive disorder (MDD) in adolescents with substance use disorders (SUD) has been linked to poor treatment outcomes. Use of validated depression screens in adolescent SUD populations may improve the detection of depression. In this secondary analysis of data, the authors evaluated the diagnostic efficiency of the Beck Depression Inventory (BDI) in detecting MDD, as assessed by psychiatrists administering the Diagnostic Interview for Children and Adolescents, and its factor structure, internal consistency, and discriminant validity in a clinical sample of treatment-seeking adolescents with SUD (n = 145). Results indicate that BDI scores of 12 and higher had the optimal sensitivity (73%), whereas BDI scores of 17 and higher, the most optimal specificity (75%). Five factors accounted for approximately 56% of the variance. Overall, internal consistency was high, and the BDI adequately discriminated MDD from non-MDD cases. Results support the use of BDI as a screen for MDD with moderate to high psychometric properties in an adolescent SUD sample. Subramaniam G, Harrell P, Huntley E, Tracy M. Beck Depression Inventory for depression screening in substance-abusing adolescents. J Subst Abuse Treat. 2009 Jul;37(1):25-31.
Troubled Parents, Motivated Adolescents: Predicting Motivation to Change Substance Use among Runaways
Runaway adolescents engage in high rates of substance use and report significant family and individual problems. However, in general, adolescents report low motivation to change their substance use. Because a higher level of motivation for changing substance use is associated with greater substance abuse treatment success, identifying variables associated with motivation for change can be useful for enhancing treatment success. In this study, predictors of motivation for changing substance use were examined among 140 shelter-recruited adolescents and their parents/primary caretakers. Several findings were noteworthy. A perceived negative family environment increased parents' and adolescents' depressive symptoms, which increased adolescents' motivation to change. Also, greater severity of adolescent substance use predicted higher motivation to change. Consideration of the family environment and parent problems when addressing motivation for changing substance use among these adolescents might be important foci for motivational interventions and future research. Slesnick N, Bartle-Haring S, Erdem G, Budde H, Letcher A, Bantchevska D, Patton R. Troubled parents, motivated adolescents: Predicting motivation to change substance use among runaways. Addict Behav. 2009 Aug;34(8):675-684.
Culturally Informed and Flexible Family-Based Treatment for Adolescents: A Tailored and Integrative Treatment for Hispanic Youth
The increasing utilization of evidence-based treatments has highlighted the need for treatment development efforts that can craft interventions that are effective with Hispanic substance abusing youth and their families. The list of evidence-based treatments is extremely limited in its inclusion of interventions that are explicitly responsive to the unique characteristics and treatment needs of young Hispanics and that have been rigorously tested with this population. Some treatments that have been tested with Hispanics do not articulate the manner in which cultural characteristics and therapy processes interact. Other treatments have emphasized the important role of culture but have not been tested rigorously. A focus on how treatment processes interact with patient characteristics is particularly relevant in the Hispanic population because of the considerable heterogeneity beneath the Hispanic umbrella. The authors describe a new program of clinical research that focuses on articulating how the varied profiles with regard to immigration stressors, acculturation processes, values clashes, sense of belonging to the community, discrimination, and knowledge about issues important to adolescent health can be more effectively addressed by a culturally informed treatment. Santisteban DA, Mena MP. Culturally informed and flexible family-based treatment for adolescents: A tailored and integrative treatment for Hispanic youth. Family Process. 2009 Jun;48(2):253-268.
Methamphetamine Users Explain Continuing Drug Use and Relapse
A variety of theories exist about why drug abusers relapse including avoiding withdrawal or pain, positive reinforcement or "pleasure seeking", craving, habits, and impulsivity. Researchers at Baylor College of Medicine surveyed methamphetamine users about why they continued to use following a period of cessation. In general pleasure seeking was the dominant reason for resuming methamphetamine use followed by impulsivity and habits. Craving and avoidance of pain were the least frequent reasons for relapse. This is significant because it suggests that new treatments should target habits, impulsivity and especially alternative sources of pleasure. Newton TF, De La Garza R II, Kalechstein AD, Tziortzis D, Jacobsen CA. Theories of addiction: Methamphetamine users' explanations for continuing drug use and relapse. Am J Addict 2009 Jul-Aug;18(4):294-300.
Congruence of BOLD Response across Intertemporal Choice Conditions: Fictive and Real Money Gains and Losses
Delay (or temporal) discounting refers to the devaluation of an outcome as a function of the time to the delivery of that outcome. Delay discounting has been proposed to underlie impulsive decision making, with increased levels of discounting observed in drug-dependent cohorts. Intertemporal choice is predicated on the valuation of commodities with respect to delay until their receipt. Subjective value of a future outcome decreases, or is discounted, as a function of that delay. Although behavioral studies suggest no difference between the devaluation of real and fictive outcomes, no neuroimaging studies have investigated potential differences in the underlying deliberative process. Dr. Bickel and colleagues at the University of Arkansas for Medical Sciences compared behavioral and neural correlates of intertemporal valuation of real and hypothetical monetary gains as well as hypothetical losses, which have been posited to involve different mechanisms. Behavioral and neuroimaging sessions were conducted in which participants made intertemporal choice decisions in a gains condition using both real and hypothetical $100 money and in a loss condition using a fictive $100 money. Within-subject comparison of behavioral data revealed no significant difference between levels of discounting across the three conditions. Random-effects analysis of functional magnetic resonance imaging (fMRI) data of each of the three discounting conditions independently revealed significant signal change in limbic (anterior ingulate, striatum, posterior cingulate) and executive functioning areas (lateral prefrontal cortex). These data support a concordance between real and hypothetical conditions from delay-discounting studies and further suggest a congruence of the fMRI blood oxygen level-dependent signal across brain regions associated with the deliberative process of different forms of intertemporal choice. Bickel WK, Pitcock JA, Yi R, Angtuaco EJ. Congruence of BOLD response across intertemporal choice conditions: Fictive and real money gains and losses. J Neurosci. 2009 Jul 8;29(27):8839-8846.
Temporal Horizon: Modulation by Smoking Status and Gender
Recently, delay discounting has been argued to be conceptually consistent with the notion of temporal horizon. Cigarette smokers discount past and future rewards symmetrically and more than controls: is discounting a measure of impulsivity? Temporal horizon refers to the temporal distance over which behavioral events or objects can influence behavior. This study examined the results on two putative measures of temporal horizon, future time perspective (FTP) and delay discounting, collected over three separate studies (n=227), to determine the influence of smoking and gender on temporal horizon. By comparing the results on these temporal horizon measures they addressed an underserved population: women who smoke. One of the measures of FTP indicates that smoking women have a shorter temporal horizon than their nonsmoking counterparts. Additionally, the story completion measures of FTP are positively correlated with delay discounting. In contrast, results of delay discounting measures showed no difference between smoking women and nonsmoking women, while results of delay discounting measures indicated smoking men have a shorter temporal horizon than non-smoking men. Additionally, the results of the FTP story completion measure indicated that lower third income earners had a shortened temporal horizon compared to upper third income earners. A possible explanation for these results is explored, and the implications of the modulation of temporal horizon by gender and smoking are discussed. Jones BA, Landes RD, Yi R, Bickel WK. Temporal horizon: Modulation by smoking status and gender. Drug Alc Depend. 2009 May [E-pub ahead of print].
Latent Structure of Facets of Alcohol Reinforcement from a Behavioral Economic Demand Curve
Behavioral economic demand curves are quantitative representations of the relationship between consumption of a drug and its cost. Demand curves provide a multidimensional assessment of reinforcement, but the relationships among the various indices of reinforcement have been largely unstudied. The objective of the study was to use exploratory factor analysis to examine the underlying factor structure of the facets of alcohol reinforcement generated from an alcohol demand curve. Participants were 267 weekly drinkers who underwent a single group assessment session. Alcohol demand curves were generated via an alcohol purchase task, which assessed consumption at 14 levels of prices from $0 to $9. The results revealed a clear two-factor solution, which were interpreted as "Persistence," reflecting sensitivity to escalating price, and "Amplitude," reflecting the amount consumed and spent. These findings suggest that alcohol reinforcement as measured via a demand curve is binary in nature, with separate dimensions of price-sensitivity and volumetric consumption. If supported, these findings may contribute theoretically and experimentally to a reinforcement-based approach to alcohol use and misuse. Mackillop J, Murphy JG, Tidey JW, Kahler CW, Ray LA, Bickel WK. Latent structure of facets of alcohol reinforcement from a behavioral economic demand curve. Psychopharmacology. 2009 Mar14;203(1):33-40.
Cost Analysis of Clinic and Office-Based Treatment of Opioid Dependence: Results with Methadone and Buprenorphine in Clinically Stable Patients
The cost of providing and receiving treatment for opioid dependence can determine its adoption. To compare the cost of clinic-based methadone (MC), office-based methadone (MO), and office-based buprenorphine (BO) an analysis of treatment and patient costs over 6 months of maintenance in patients who had previously been stabilized for at least 1 year was performed. Dr. Schottenfeld and colleagues from Yale University did statistical comparisons using ANOVA and chi-square tests and performed a sensitivity analysis varying cost estimates and intensity of clinical contact. The cost of providing 1 month of treatment per patient was $147 (MC), $220 (MO) and $336 (BO). Mean monthly medication cost was $93 (MC), $86 (MO) and $257 (BO). The cost to patients was $92 (MC), $63 (MO) and $38 (BO). Sensitivity analyses, varying cost estimates and clinical contact, result in total monthly costs of $117 to $183 (MC), $149 to $279 (MO), $292 to $499 (BO). Monthly patient costs were $84 to $133 (MC), $55 to $105 (MO) and $34 to $65 (BO). The authors conclude that providing clinic-based methadone is least expensive. The price of buprenorphine accounts for a major portion of the difference in costs. For patients, office-based treatment may be less expensive. Jones ES, Moore BA, Sindelar JL, O'Connor PG, Schottenfeld RS, Fiellin DA. Cost analysis of clinic and office-based treatment of opioid dependence: Results with methadone and buprenorphine in clinically stable patients. Drug Alcohol Depend. 2009 Jan 1;99(1-3):132-140.
Relations among Psychopathology, Substance Use, and Physical Pain Experiences in Methadone-Maintained Patients
Dr. Schottenfeld and colleagues from Yale University conducted this study to examine differences in psychiatric distress and substance use (licit and illicit) in methadone maintenance treatment (MMT) patients with a variety of pain experiences. Parametric and nonparametric statistical tests were performed on data obtained from 150 patients currently enrolled in MMT. Results suggested that, in comparison to MMT patients reporting no pain in the previous week, those with chronic severe pain (CSP; i.e., pain lasting at least 6 months with moderate to severe pain intensity or significant pain interference) exhibited significantly higher levels of depression, anxiety, somatization, overall psychiatric distress, and personality disorder criteria but reported comparable rates of substance use. A third group, i.e., non-CSP MMT patients reporting some pain in the past week, differed significantly from the other 2 pain groups on somatization and global psychiatric distress but reported comparable rates of substance use. Pain-related differences in psychiatric problems exist in MMT patients and may have implications for program planning and outreach efforts. Barry DT, Beitel M, Garnet B, Joshi D, Rosenblum A, Schottenfeld RS. Relations among psychopathology, substance use, and physical pain experiences in methadone-maintained patients. J Clin Psychiatry. 2009; Jul 14. [E-pub ahead of print].
Caffeine Withdrawal, Acute Effects, Tolerance, and Absence of Net Beneficial Effects of Chronic Administration: Cerebral Blood Flow Velocity, Quantitative EEG, and Subjective Effects
Although the subjective effects of caffeine abstinence, acute and chronic administration, and tolerance are well described, the corresponding neurophysiological effects are not. In the current study, caffeine withdrawal, acute caffeine effects, caffeine tolerance, and net beneficial effects of chronic caffeine administration were investigated using cerebral blood flow velocity, quantitative electroencephalography (EEG), and subjective effects. Specifically, sixteen regular caffeine users participated in this double-blind, within-subject study during which they received acute caffeine and placebo challenges (1) while maintained on 400 mg caffeine daily for > 14 days and (2) while maintained on placebo for > 14 days. Blood flow velocity was determined for the middle (MCA) and anterior (ACA) cerebral arteries using pulsed transcranial Doppler sonography. EEG was recorded from 16 scalp sites. Subjective effects were assessed with questionnaires. Acute caffeine abstinence (evaluated 24 h after placebo substitution) increased mean, systolic, and diastolic velocity in the MCA and ACA and decreased pulsatility index in the MCA. Acute caffeine abstinence increased EEG theta and decreased beta 2 power. Acute caffeine abstinence also increased measures of Tired, Fatigue, Sluggish, and Weary and decreased ratings of Energetic, Friendly, Lively, and Vigor. Acute caffeine effects were demonstrated across a wide range of measures, including cerebral blood flow, EEG, and subjective effects. Tolerance and "complete" tolerance were observed on subjective but not physiological measures. Chronic caffeine effects were demonstrated only on the measure of EEG beta 2 power. Acute caffeine abstinence and administration produced changes in cerebral blood flow velocity, EEG, and subjective effects. Tolerance to subjective but not physiological measures was demonstrated. There was almost no evidence for net effects of chronic caffeine administration on these measures. Overall, these findings provide the most rigorous demonstration to date of physiological effects of caffeine withdrawal. Sigmon SC, Herning RI, Better W, Cadet JL, Griffiths RR. Caffeine withdrawal, acute effects, tolerance, and absence of net beneficial effects of chronic administration: Cerebral blood flow velocity, quantitative EEG, and subjective effects. Psychopharm. 2009 Jul;204(4):573-585.
Increased Drinking in a Trial of Treatments for Marijuana Dependence: Substance Substitution?
Dr. Kadden and others at the University of Connecticut examined the extent to which participants in a study of treatments for marijuana dependence may have increased their use of alcohol when they reduced or ceased marijuana use. Specifically, participants were randomly assigned to one of four psychosocial treatments and followed at 3-month intervals for 1 year. The authors found that of the 207 participants with data at post-treatment and at least one other follow-up, 73% reported an increase of at least 10% in drinking days over their level at intake, and 65% reported an increase of at least 10% in drinks per drinking day. Drinking increases were not related to treatment condition or to change in marijuana use, but were related to baseline drinking. For example, those with less baseline drinking tended to increase their drinking during treatment and those with more baseline drinking reported less drinking during treatment. Thereafter, drinking levels remained fairly stable throughout the follow-up year. The results suggest that use of alcohol and marijuana are independent of one another. Kadden RM, Litt MD, Kabela-Cormier E, Petry NM. Increased drinking in a trial of treatments for marijuana dependence: Substance substitution? Drug Alcohol Depend. 2009; Jul 14. [E-pub ahead of print].