Reduction of cocaine seeking by a food-based inhibitor in rats.

Environmental stimuli can exert a powerful influence over drug seeking and taking. For example, previous experiments found that combining multiple drug-related stimuli tripled drug seeking and doubled drug intake (L. V. Panlilio, S. J. Weiss, & C. W. Schindler, 1996, 2000), whereas a signal for the absence of cocaine (i.e., a drug-related inhibitor) dramatically reduced cocaine seeking in rats by over 90% (D. N. Kearns, S. J. Weiss, C. W. Schindler, & L. V. Panlilio, 2005). In the present experiment, a signal for the absence of food created through the A+/AB- conditioned inhibition paradigm also suppressed responding for cocaine by approximately 90%. Symmetrically, a signal for the absence of cocaine (i.e., a cocaine-based inhibitor) suppressed food seeking to a similar degree. These findings, consistent with the appetitive-aversive interaction theory of motivation, suggest that using inhibitors based on nondrug appetitive reinforcers might be a practical method of reducing drug seeking in human drug abusers and should be seriously considered for clinical test and application. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of oral caffeine pretreatment on response to intravenous nicotine and cocaine.

Previous research suggests that under conditions of chronic daily caffeine administration, caffeine increases the effects of nicotine. Little is known about the effects of caffeine pretreatment on response to nicotine under infrequent caffeine administration conditions. The present study examined whether infrequent (not on consecutive days) acute oral caffeine administration alters subject-rated, physiological, and monetary value effects of intravenous nicotine in regular users of caffeine, tobacco, and cocaine. To determine the specificity of effects of caffeine on response to nicotine, the effects of caffeine administration on response to intravenous cocaine (another short-acting stimulant) were also studied. Fourteen (1 woman) volunteers participated in this 3–4 week, double-blind, inpatient study. Volunteers participated in 10 experimental conditions in pseudo-randomized order, in which oral caffeine (250 mg/70 kg) or placebo was administered 1 hr before an intravenous injection, consisting of nicotine (1 or 2 mg/70 kg), cocaine (15 or 30 mg/70 kg), or saline. Infrequent acute caffeine pretreatment attenuated the increase resulting from 2 mg/70 kg nicotine administration on ratings of “rush,” “good effects,” “liking,” “high,” and “drowsy/sleepy.” Caffeine had no significant effect on physiological response to nicotine. Caffeine had no significant effect on subject-rated and physiological response to cocaine, with the exception that caffeine significantly augmented blood pressure response to cocaine. In contrast to the previous research using chronic caffeine maintenance, these data suggest that infrequent acute caffeine administration may attenuate nicotine effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of oral cocaine on intravenous cocaine discrimination in humans.

This study was designed to evaluate the drug discrimination paradigm as a model for assessing the ability of potential agonist medications to block the effects of intravenous cocaine. Previous research has demonstrated that oral cocaine attenuated the subjective and physiological effects of intravenous cocaine injections, and in the absence of a known efficacious medication for cocaine use disorders, a proof-of-concept approach was used in which cocaine was acutely administered orally to block intravenous cocaine's discriminative-stimulus effects. During training, 11 cocaine-dependent participants were able to discriminate between intravenous saline and 20 mg/70 kg iv cocaine, and 8 of these participants completed the study. After training, participants ingested capsules containing either placebo or 300 mg/70 kg cocaine 60 min prior to the intravenous injection of different doses of cocaine during test sessions with no contingencies in place. Each cocaine dose was administered twice, once under each oral pretreatment condition. Training sessions were interspersed among the test sessions. Physiological and subjective effects were measured throughout each session. Oral cocaine moderately increased some of the subjective and physiological effects of the lower doses of intravenous cocaine, whereas effects at the higher doses were unaltered. Similar changes were seen for the discrimination results. Thus, although oral cocaine given acutely likely is not a viable treatment medication for cocaine dependence, the usefulness of the drug discrimination model in the evaluation of agonist treatment medications remains unclear. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contingency management is efficacious for cocaine abusers with prior treatment attempts.

Efforts are underway to detect subgroups who may be more or less responsive to contingency management (CM) substance abuse treatments. This study examined the impact of prior treatment attempts on primary and posttreatment outcomes in a combined sample of cocaine abusers randomized to standard care substance abuse outpatient treatment (SC) or SC plus CM. Participants (N = 393) were categorized according to self-reported prior treatment attempts (0-1, ≥2). Participants with multiple prior treatment attempts were older, had more severe alcohol and cocaine use disorders, and had greater employment-related problems. Participants with 0?1 prior treatment attempts had comparable treatment retention, regardless of treatment condition; however, among participants with multiple prior treatment attempts, retention was greater for CM than SC. A similar, but nonsignificant (p = .08) pattern was evident for longest duration of abstinence (LDA). LDA was a significant predictor of negative (for cocaine, alcohol, and opiates) specimen results at Month 9. The results provide support for CM as an advantageous option for individuals with multiple prior treatment attempts, as well as for substance abuse treatment patients in general. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The value of nonhuman primates in drug abuse research.

The use of nonhuman primates (NHP) is invaluable for drug abuse research. The laboratory animals most closely related to humans are NHP. The phylogeny, anatomy, physiology, neurochemistry, and behavior of NHP are more similar to humans than other laboratory species. There is now an extensive body of literature documenting the neuroanatomical, neurochemical, and neuropharmacological similarities between NHP and humans and the differences between NHP and other laboratory species in dopamine, norepinephrine, serotonin, opioid, and gamma aminobutyric acid systems. Comprehensive studies comparing pharmacokinetics in humans, monkeys, dogs, and rats have shown that data in monkeys are the most predictive of human pharmacokinetic parameters. The long life span and extended adolescent period for NHP permits intensive, long-term investigations and the use of within-subject experimental designs similar to those used in human laboratory studies. Within-subject designs require fewer subjects than standard between-group designs and permit the careful evaluation of individual differences. NHP have been used extensively in drug abuse research for over 40 years and have provided useful information on the behavioral processes associated with drug abuse and addiction as well as drug abuse liability in humans. This review focuses on important species differences between rodents and NHP and on the value of NHP in bridging the gap between rodents and humans to enhance the ability to generalize preclinical findings to human drug abuse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vocher-based reinforcement of opiate plus cocaine abstinence in treatment-resistant methadone patients: Effects of reinforcer magnitude.

The study tested a voucher-based abstinence reinforcement procedure for reducing opiate and cocaine use in a population of treatment-resistant opiate- and cocaine-abusing methadone patients. Vouchers exchangeable for goods and services were contingent on abstinence from both opiates and cocaine. In two conditions, participants could earn up to $374 or $3,369 in vouchers for providing opiate- and cocaine-free urine samples. Participants received a daily 60-mg dose of methadone. The dose was increased in a second phase, and the voucher conditions were replicated. Analyses of both phases revealed trends toward greater abstinence under the high voucher condition and suggested that higher doses may enhance the efficacy of voucher reinforcement. The results show that reinforcement for abstinence from 2 drugs simultaneously can be effective even in a treatment-resistant population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of homework in cognitive-behavioral therapy for cocaine dependence.

This study examines the effect of homework compliance on treatment outcome in 123 participants receiving cognitive-behavioral therapy (CBT) for cocaine dependence. Regression analyses revealed a significant relationship between homework compliance and cocaine use that was moderated by readiness to change. Homework compliance predicted less cocaine use during treatment but only for participants higher in readiness to change. For those lower in readiness to change, homework compliance was not associated with cocaine use during treatment. Homework compliance early in therapy was associated with better retention in treatment. Homework compliance was not predicted by participants' level of education or readiness to change. These findings support the use of homework during CBT for substance use disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Supportive-expressive psychodynamic therapy for cocaine dependence: A closer look.

Using data from the National Institute on Drug Abuse Collaborative Cocaine Treatment Study, this article focuses on the outcomes of patients who received supportive-expressive (SE) psychodynamically oriented psychotherapy (plus group drug counseling; GDC). Short-term SE for cocaine dependent individuals, while not the most efficacious treatment examined in the study (individual drug counseling [IDC] plus GDC was), produced large improvements in cocaine use. In addition, there was evidence that SE was superior to IDC on change in family/social problems at the 12-month follow-up assessment, particularly for those patients with relatively more severe difficulties in this domain at baseline. For patients who achieved abstinence early in treatment, SE produced comparable drug use outcomes to IDC, with mean drug use scores numerically lower for SE at all of the follow-up assessments (9, 12, 15, and 18 months). SE patients who achieved initial abstinence decreased cocaine use from a mean 10.1 day per month at baseline to a mean of 1.3 days at 12 months. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Day treatment with contingency management for cocaine abuse in homeless persons: 12-month follow-up.

Abstinence, employment, and homelessness treatment outcomes at 12-month follow-up are presented from a study comparing behavioral day treatment plus abstinence-contingent housing and work therapy with behavioral day treatment only among homeless persons who abuse crack cocaine. Within-group improvements were revealed, but group differences for drug abstinence found in J. B. Milby et al. (2000) failed to persist at 12 months. Drug use measurement and treatment termination explanations are discussed. Within- but not between-group differences were found for employment and homelessness outcomes at long-term follow-up. Research extending abstinence contingencies and continuous drug use monitoring is recommended. Questions about effectiveness of contingency management alone, role of coexisting psychiatric disorders on treatment outcome, and individualized treatment dosing are offered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contingency management improves abstinence and quality of life in cocaine abusers.

Contingency management (CM) treatments enhance drug abstinence. This study evaluated whether CM also improves quality of life and if these effects are mediated by abstinence. Across 3 independent trials, cocaine abusers in intensive outpatient treatment (n = 387) were randomly assigned to 12 weeks of standard treatment as usual or standard treatment with CM. The Quality Of Life Inventory (QOLI) was administered at baseline and at Months 1, 3, 6, and 9. Changes in QOLI scores over time differed significantly by treatment, with QOLI scores rising over time in CM participants and remaining stable in standard treatment participants. CM participants also achieved greater durations of abstinence, and duration of abstinence was correlated with posttreatment QOLI scores. During-treatment abstinence mediated the relationship between treatment condition and QOLI scores over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Cocaine: A clinician's handbook.

Reviews the book, Cocaine: A clinician's handbook edited by Arnold M. Washton and Mark S. Gold (see record 1987-98183-000). Washton and Gold point out that the goal of this text is to provide "clinicians with information that is directly relevant to the treatment of cocaine abusers." I feel they accomplished their goal, by concentrating on various aspects of theory, research, and treatment of cocaine abuse. The book is divided into three major sections: Basic and Biomedical Issues, Treatment Approaches, and Special Topics. Overall, this text examines a range of topics. This book can be extremely valuable to physicians, psychiatrists, psychologists, social workers, counselors in the drug and alcohol fields, and students. The book is comprehensive in what it covers and well organized. Even experienced professionals in this field will be hard pressed to find flaws with this resource. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Risk factors in the relationship between gender and crack/cocaine.

Female inner-city substance users evidence greater crack/cocaine use and are more likely to be dependent on this drug than on any other drug. Additionally, female inner-city substance users evidence greater crack/cocaine use and are more likely to be dependent on this drug than their male counterparts, despite no consistent difference demonstrated in use and dependence across other drugs. Because no published work has empirically examined the factors underlying this link between females and crack/cocaine, the current study examined the role of theoretically relevant personality and environmental variables. Among 152 (37% female) individuals in a residential substance-use treatment program, females evidenced greater use of crack/cocaine (current and lifetime heaviest) and were significantly more likely to evidence crack/cocaine dependence than their male counterparts. In contrast, no gender differences were found for any other substance across alcohol, cannabis, and hallucinogens (including PCP). Surprisingly, females were more impulsive than their male counterparts, with impulsivity serving as a risk factor in the relationship between gender and crack/cocaine dependence and lifetime heaviest use. Females also evidenced higher levels of negative emotionality and childhood abuse, but neither variable served as a risk factor in the relationship between gender and crack/cocaine dependence or use. Limitations and future directions are discussed, including the need for further exploration of impulsivity across its various dimensions as well as the inclusion of additional variables such as social context variables to account more fully for this complex link between gender and crack/cocaine. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contingency management is especially efficacious in engendering long durations of abstinence in patients with sexual abuse histories.

Exposure to sexual victimization is prevalent among persons with substance use disorders (SUDs). Contingency management (CM) treatments utilize concrete and relatively immediate positive reinforcers to retain patients in treatment and reduce substance use, and CM may have particular benefits for patients with histories of sexual victimization. Using data from three randomized trials of CM (N = 393), this study evaluated main and interactive effects of sexual abuse history and treatment condition (standard care versus CM) with respect to during treatment outcomes (retention, proportion of negative urine samples submitted, and longest duration of abstinence) and abstinence at a nine-month follow-up. Compared to patients without sexual abuse histories (N = 316), those with sexual abuse histories (N = 77) submitted a significantly higher proportion of negative samples in treatment. In CM, but not in standard care, patients with sexual abuse histories achieved significantly longer durations of abstinence during treatment than those without sexual abuse histories. Although sexual abuse history was not associated with abstinence at nine-month follow-up evaluations, longest duration of abstinence during treatment was significantly associated with this long-term outcome. Results suggest that SUD patients with sexual abuse histories may accrue particular benefits during CM treatment that are associated with long-term abstinence. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Acceptability and availability of harm-reduction interventions for drug abuse in American substance abuse treatment agencies.

[Correction Notice: An erratum for this article was reported in Vol 18(1) of Psychology of Addictive Behaviors (see record 2007-16711-001). On page 208, the first sentence in the note of Table 4 incorrectly reads as follows: "Numbers in parentheses are ns of respondents who provided an 'other' reason for this specific intervention." The sentence should read as follows: "Numbers in parentheses are ns of respondents whose agencies do not offer this intervention."] This study assessed acceptability, availability, and reasons for nonavailability of interventions designed to prevent drug use related harm by substituting pharmaceuticals for illicit drugs; facilitating detoxification; and reducing the occurrence of HIV transmission, relapse, and opiate overdose. A survey was mailed to a sample of 500 randomly selected American substance abuse treatment agencies. Of 435 potentially eligible respondents, 222 (51%) returned usable data. A subset of interventions--including harm reduction education, cue exposure therapy, needle exchange, substitute opiate prescribing, various detoxification regimes, and complementary therapies--were rated as somewhat or completely acceptable by 50% or more of the respondents. Regardless of their acceptability, listed interventions were generally not available from responding agencies; respondents typically attributed unavailability to lack of resources and inconsistency of an intervention with agency philosophy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Progesterone effects on cocaine use in male cocaine users maintained on methadone: A randomized, double-blind, pilot study.

Previously, the authors reported that progesterone treatment attenuated reports of cocaine-induced high in male and female cocaine users. In this pilot clinical trial, the authors tested the safety and efficacy of oral progesterone as a treatment for cocaine dependence in methadone-stabilized male cocaine users. This was a 10-week, randomized, double-blind, placebo-controlled trial. Forty-five male methadone-stabilized cocaine users were randomized to receive placebo (n=15) or progesterone (n=30) for 9 weeks. The progesterone dose was gradually increased from 100 mg to 300 mg twice daily by Week 4 and maintained through Week 10. Treatment retention for the clinical trial was 80%, without significant group differences (log rank=2.4, p=.12). Hierarchical linear modeling estimates of obtaining a cocaine positive urine result across 10 weeks showed a very slight reduction in cocaine use for the progesterone group (Z=-2.89, p     

Cognitive-behavioral therapy plus contingency management for cocaine use: Findings during treatment and across 12-month follow-up.

Contingency management (CM) rapidly reduces cocaine use, but its effects subside after treatment. Cognitive-behavioral therapy (CBT) produces reductions months after treatment. Combined, the 2 might be complementary. One hundred ninety-three cocaine-using methadone-maintained outpatients were randomly assigned to 12 weeks of group therapy (CBT or a control condition) and voucher availability (CM contingent on cocaine-negative urine or noncontingent). Follow-ups occurred 3, 6, and 12 months posttreatment. Primary outcome was cocaine-negative urine (urinalysis 3 times/week during treatment and once at each follow-up). During treatment, initial effects of CM were dampened by CBT. Posttreatment, there were signs of additive benefits, significant in 3- versus 12-month contrasts. Former CBT participants were also more likely to acknowledge cocaine use and its effects and to report employment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discriminative and reinforcing stimulus effects of nicotine, cocaine, and cocaine + nicotine combinations in rhesus monkeys.

Concurrent cigarette smoking and cocaine use is well documented. However, the behavioral pharmacology of cocaine and nicotine combinations is poorly understood, and there is a need for animal models to examine this form of polydrug abuse. The purpose of this study was twofold: first to assess the effects of nicotine on the discriminative stimulus effects of cocaine, and second, to study self-administration of nicotine/cocaine combinations in a novel polydrug abuse model. In drug discrimination experiments, nicotine increased the discriminative stimulus effects of low cocaine doses in two of three monkeys, but nicotine did not substitute for cocaine in any monkey. Self-administration of cocaine and nicotine alone, and cocaine + nicotine combinations was studied under a second-order fixed ratio 2, variable ratio 16 (FR2[VR16:S]) schedule of reinforcement. Cocaine and nicotine alone were self-administered in a dose-dependent manner. The combination of marginally reinforcing doses of cocaine and nicotine increased drug self-administration behavior above levels observed with the same dose of either cocaine or nicotine alone. These findings indicate that nicotine may increase cocaine's discriminative stimulus and reinforcing effects in rhesus monkeys, and illustrate the feasibility of combining cocaine and nicotine in a preclinical model of polydrug abuse. Further studies of the behavioral effects of nicotine + cocaine combinations will contribute to our understanding the pharmacology of dual nicotine and cocaine dependence, and will be useful for evaluation of new treatment medications. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Experience-dependent effects of cocaine self-administration/conditioning on prefrontal and accumbens dopamine responses.

Experiments were performed to examine the effects of cocaine self-administration and conditioning experience on operant behavior, locomotor activity, and nucleus accumbens (NAcc) and prefrontal cortex (PFC) dopamine (DA) responses. Sensory cues were paired with alternating cocaine and nonreinforcement during 12 (limited training) or 40 (long-term training) daily operant sessions. After limited training, NAcc DA responses to cocaine were significantly enhanced in the presence of cocaine-associated cues compared with nonreward cues and significantly depressed after cocaine-paired cues accompanied a nonreinforced lever response. PFC DA levels were generally nonresponsive to cues after the same training duration. However, after long-term training, cocaine-associated cues increased the magnitude of cocaine-stimulated PFC DA levels significantly over levels observed with nonreinforcement cues. Conversely, conditioned cues no longer influenced NAcc DA levels after long-term training. In addition, cocaine-stimulated locomotor activity was enhanced by cocaine-paired cues after long-term, but not after limited, training. Findings demonstrate that cue-induced cocaine expectation exerts a significant impact on dopaminergic and behavioral systems, progressing from mesolimbic to mesocortical regions and from latent to patent behaviors as cocaine and associative experiences escalate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion-focused coping as a mediator of maternal cocaine abuse and antisocial behavior.

A great deal of data implicate parental drug use as a potential risk factor for child abuse, however, theories for understanding the links between maternal drug use and antisocial behavior have yet to be examined empirically. This case-control study investigated correlates of adult antisocial behavior among 279 inner-city mothers in 3 comparison groups: drug abusers, (n = 112), depressed mothers (n = 73), and nonsubstance abusing controls (n = 94). Using hierarchical regression techniques and mediational analyses controlling for ethnicity, current depression, and family history of substance abuse, support was provided for an emotion-focused coping style as a link between addictive and antisocial behavior. These results highlight the importance of focusing on emotion regulation models in the prevention and treatment of violence in drug-abusing women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of voucher-based intervention on abstinence and retention in an outpatient treatment for cocaine addiction: A randomized controlled trial.

The aims of this study were to assess whether voucher magnitude improved cocaine abstinence and retention in an outpatient treatment for cocaine dependence, and to determine the effectiveness of a contingency management intervention in a European cultural context. A randomized controlled trial was conducted in which 96 participants who were randomly assigned to 1 of 3 treatment conditions in a community setting: standard outpatient treatment, community reinforcement approach (CRA) plus low monetary value vouchers (each point earned was equivalent to 0.125? US$ 0.18), and CRA plus high monetary value vouchers (each point was worth 0.25? US$ 0.36). In the standard treatment group, mean percentage of cocaine-negative samples was 88.45%, versus 96.09% in the CRA plus low-vouchers group, and 97.07% in the CRA plus high-vouchers group. Retention rate at 6 months was 36.5% in the standard treatment group, 53.3% in the CRA plus low-vouchers group, and 69.0% in the CRA plus high-vouchers group. The CRA plus vouchers groups obtained better results than the standard program. This study showed that treating cocaine addiction by combining CRA with vouchers was more effective than standard treatment in community outpatient programs in Spain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)