Behavioral pharmacological similarities between methylphenidate and cocaine in cocaine abusers.

Six human participants with recent histories of cocaine use were trained to discriminate 200 mg oral cocaine hydrochloride. A range of doses of oral cocaine (50–300 mg), methylphenidate (15–90 mg), triazolam (0.125–0.75 mg), and placebo were then tested to determine whether they shared discriminative–stimulus and participant-rated effects with 200 mg cocaine. Cocaine and methylphenidate dose-dependently increased cocaine-appropriate responding, produced prototypical stimulant-like participant-rated drug effects (e.g., increased participant ratings of Drug Liking), and increased heart rate and blood pressure. Triazolam produced low levels of cocaine-appropriate responding and impaired performance. Thus, consistent with previous studies, humans can reliably discriminate oral cocaine. Consistent with in vivo behavioral neuropharmacological data, the discriminative–stimulus, participant-rated, and physiological effects of oral cocaine and methylphenidate were similar. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The validity of self-reported cocaine use in two groups of cocaine abusers.

To evaluate the validity of 2 self-report methods for estimating cocaine use, Timeline Follow-Back (TLFB) and weekly calendar reports from 65 patients with a cocaine use disorder were compared with urine drug test results. The TLFB showed fair to moderate validity, and the weekly calendar showed moderate to high validity in measuring the frequency of cocaine use. Similar results were obtained when the self-report measures were used to time specific cocaine use episodes. In addition to evidence for superiority of the weekly calendar, the validity of self-reports was inversely related to the percentage of positive urine test results. Furthermore, there was some evidence that validity increased as the time window over which the comparisons were drawn increased. Given the central role of self-reports in the clinical and research evaluation of drug use, factors affecting their validity warrant further investigation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparing self-reported cocaine use with repeated urine tests in outpatient cocaine abusers.

Sixty-one participants in outpatient therapy for cocaine dependence provided urine samples and self-reports of cocaine use 3 times a week for 4 weeks. Participants later gave a retrospective self-report of cocaine use for the month on the Addiction Severity Index (ASI). Comparisons with urine test values revealed substantial underreporting of cocaine use on both measures, and results from the 2 forms of self-report were only imperfectly correlated. More participants admitted to at least 1 cocaine use episode on the ASI than on the repeated self-reports, but the repeated reports provided a more accurate index of the relative frequency of cocaine use during the month. Self-reports can enhance cocaine use detection when urines are infrequently collected and can help determine whether consecutive positive urine samples represent elevated metabolite levels from a single drug use episode. However, self-reports cannot substitute for regular urine sampling. (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)     

Random versus nonrandom assignment in the evaluation of treatment for cocaine abusers.

Cocaine-abusing patients randomly assigned to day-hospital or inpatient rehabilitation were compared with patients who self-selected these treatment settings to examine differences in substance use and psychosocial outcomes under experimental and nonexperimental designs. There was little evidence of setting or assignment effects or Setting?×?Assignment interactions over the 12-month follow-up period. However, Assignment?×?Time interactions were obtained with 2 measures of cocaine use and measures of family-social and psychiatric problem severity. These interactions indicated greater problem severity at intake among the randomized patients coupled with greater improvements by the 3-month follow-up relative to the nonrandomized patients. Findings suggest that randomized studies of treatment for cocaine abuse may produce somewhat larger estimates of improvement than what is observed in more typical treatment situations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depression among cocaine abusers in treatment: relation to cocaine and alcohol use and treatment outcome

Recent studies indicate that immature B cells compete with recirculating B cells for survival signals. The signals, delivered through the B-cell receptor for antigen, induce immature cells to differentiate into recirculating cells and maintain the survival of recirculating cells. They do not induce proliferation or differentiation to antibody-producing cells.     

Concentration and occupancy of dopamine transporters in cocaine abusers with [11C]cocaine and PET

The concentration (Bmax) of the dopamine transporter (DAT) and the maximum and effective occupancies by cocaine doses of 0.1 mg/kg or 0.05 mg/kg were measured in the striatum of cocaine abusers (n = 12) by using [11C]cocaine as a radiotracer for the DAT and positron emission tomography (PET). Two methods based on a three-compartment model with one binding site (the nonlinear least squares (NLSQ) and the Farde pseudoequilibrium method) were used to estimate Bmax. Effective occupancies and maximum occupancies were calculated from the distribution volume ratios (DVR) and a three-compartment model, respectively. The NLSQ and Farde methods gave similar values of Bmax (average, 650 +/- 350 pmol/ml and 776 +/- 400 pmol/ml, respectively), but the individual estimates of Bmax were found to be very sensitive to small variations in other model parameters and were not correlated with the parameter Bmax/Kd (r = .07). The average maximum (and effective) occupancies were found to be 67% (50%) and 52% (39%) for the 0.1-mg/kg and the 0.05-mg/kg studies, respectively. The ED50 based on the effective occupancy corresponds to 0.1 mg/kg, which is significantly smaller than the ED50 of 3 mg/kg calculated from studies in which [123]beta-CIT is displaced by cocaine. The effect on the Bmax estimate of two binding sites with different Kd's is also considered by simulation. We conclude (1) that the lack of robustness in the Bmax estimate limits the usefulness of any one subject's Bmax and suggests that the combination parameter Bmax/Kd (or the DVR), which has been used extensively, is a more stable measure of free receptor/transporter concentration. The average Bmax may, however, provide an estimate of the expected concentration in humans. (2) The DVR can be used as a measure of DAT occupancy without applying an explicit model.     

Cocaine use is associated with increased craving in outpatient cocaine abusers

Continuous treatment with transdermal nitroglycerin leads to tolerance development within the first day of application. Effective long-term therapy can be provided by interval treatment with nightly patch removal, but even during the hours of intermittent patch application there is rapid attenuation of initial effects. To assess whether an unattenuated antiischemic and antianginal efficacy during the hours of intermittent dosing can be maintained, a modified drug-release profile with increasing plasma concentrations was evaluated using a double-blind, placebo-controlled crossover protocol. Eleven patients with documented coronary artery disease received, in a randomized order, a total of four low-dose nitroglycerin patches (5 mg/24 h each) or placebo, respectively, at intervals of 3 hours. After a treatment interval of 12 hours, all patches were removed for an equally long patch-free interval prior to renewed application of one patch the next morning. At a comparable workload, reductions of ST-segment depression of 65%, 63%, and 56% were found at 2.5 hours, 8 hours, and 12 hours after application of the first patch on day 1, respectively (all significant vs. placebo; 2.5 hours vs. 12 hours, n.s.). On day 2, the comparable reduction of 63% at 2.5 hours after renewed application indicates prevention of tolerance development during subchronic treatment. Effects on exercise capacity and angina pectoris paralleled those on exercise-induced ST-segment depression. Plasma concentrations of nitroglycerin increased from 223 pg/mL to 558 and 803 pg/mL on day 1 and amounted to 205 ng/mL at 2.5 hours on day 2. Thus, interval therapy with increasing nitroglycerin concentrations provides unattenuated antiischemic and antianginal efficacy during the hours of treatment and circumvention of early tolerance during subchronic application. This modified pharmacokinetic profile can be regarded as a model for an improved dosage regimen in nitrate interval therapy.     

Subtypes of cocaine abusers: Support for a Type A–Type B distinction.

The dysfunction and generalizability of a multidimensional alcoholism typological system was systematically assessed in 399 inpatient, outpatient, and non-treatment-seeking cocaine abusers. Two different cluster-analytic procedures supported the construct, concurrent, and predictive validity of the Type A–Type B distinction in cocaine abusers. Participants classified as Type B (33%) cocaine abusers exhibited higher rates of premorbid risk factors (family history, childhood behavior problems, personality, age of onset), more severe drug and alcohol abuse, more addiction-related psychosocial impairment, more antisocial behavior, and more comorbid psychiatric problems than Type A participants (67%). Multidimensional typological systems have had a major impact on the alcoholism field and may be equally important for the assessment, prevention, treatment, and theoretical understanding of other substance use disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Superior efficacy of cognitive-behavioral therapy for urban crack cocaine abusers: main and matching effects

This study evaluated the efficacy of cognitive-behavioral therapy (CBT) and 12-step facilitation (12SF) in treating cocaine abuse. Participants (N = 128) were randomly assigned to treatment conditions and assessed at baseline and at Weeks 4, 8, 12, and 26. Treatment lasted for 12 weeks. It was hypothesized that participants treated with CBT would be significantly more likely to achieve abstinence from cocaine than participants treated with 12SF. A series of patient-treatment matching hypotheses was also proposed. Across 2 different outcome variables, it was found that participants in CBT were significantly more likely to achieve abstinence than participants in 12SF. In addition, some support for matching hypotheses was found, suggesting that both psychotherapies may be differentially effective for identified subgroups of persons that abuse cocaine.     

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)     

The validity of an alternative five-factor measure of personality in cocaine abusers.

The validity of an alternative 5-factor measure of personality, the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ), was assessed in 450 cocaine abusers seeking outpatient treatment. As predicted, the ZKPQ Impulsive Sensation Seeking (ImpSS), Neuroticism-Anxiety (N-Anx), and Aggression-Hostility (Agg-Hos) scales were associated with greater drug abuse and psychiatric severity and symptoms and worse outcome (p?     

MMPI diagnostic classification of substance abusers of the 1970s

Retrospective analysis of the MMPI profiles of 160 substance abusers tested in the 1970s showed that 54% were classified as showing signs of characterological disorder, 32% thinking disturbance, and 9% emotional disturbance. Four percent of the profiles were asymptomatic. These findings are presented both to confirm the wider variety of psychopathology in substance abusers of the 1970s than earlier and to provide current researchers with comparative data.     

Group comparisons of coping self-efficacy between alcohol and cocaine abusers seeking treatment.

The Drug-Taking Confidence Questionnaire (DTCQ; H. M. Annis & G. Martin, 1985) assesses situation-specific coping self-efficacy for resisting the use of a particular substance of abuse. This article extends previous research (S. M. Sklar, H. M. Annis, & N. E. Turner, see record 1998-10850-009) by testing the factorial invariance of the DTCQ on a sample of 344 alcohol and 253 cocaine clients. The results confirmed that the 8-factor model based on G A. Marlatt and J. R. Gordon's (1985) high-risk categories for relapse provided a remarkably similar fit across both samples. Alcohol clients were less confident in their ability to resist using than cocaine clients in interpersonal conflict situations, whereas cocaine clients expressed less confidence in temptation-related situations. For both samples, women were more confident than men in positive situations. The findings demonstrate that the DTCQ is sensitive to different situational patterns of self-efficacy between alcohol and cocaine clients and between men and women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Concurrent alcohol dependence among methadone-maintained cocaine abusers is associated with greater abstinence.

Concurrent alcohol dependence (AD) among polysubstance abusers has been associated with negative consequences, although it may not necessarily lead to poor treatment outcomes. One of the most efficacious treatments for cocaine abuse is contingency management (CM), but little research has explored the impact of AD on abstinence outcomes, particularly among patients in methadone maintenance. Using data from three trials of CM for cocaine use, we compared baseline characteristics and posttreatment and follow-up cocaine outcomes between methadone-maintained, cocaine-dependent patients (N = 193) with and without concurrent AD, randomized to standard care (SC) with or without CM. Patients with and without concurrent AD had similar baseline characteristics, with the exception that AD patients reported more alcohol use. AD patients achieved longer durations of cocaine abstinence and were more likely to submit a cocaine-negative sample at follow-up than non-AD patients. Patients randomized to CM achieved better outcomes than those randomized to SC, but there was no interaction between treatment condition and AD status. These findings suggest that cocaine-using methadone patients with AD achieve greater cocaine abstinence than their non-AD counterparts and should not necessarily be viewed as more difficult to treat. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Contingency management in cocaine abusers: A dose-effect comparison of goods-based versus cash-based incentives.

Goods-based contingency management interventions (e.g., those using vouchers or prizes as incentives) have demonstrated efficacy in reducing cocaine use, but cost has limited dissemination to community clinics. Recent research suggests that development of a cash-based contingency management approach may improve treatment outcomes while reducing operational costs of the intervention. However, the clinical safety of providing cash-based incentives to substance abusers has been a concern. The present 16-week study compared the effects of goods-based versus cash-based incentives worth $0, $25, $50, and $100 on short-term cocaine abstinence in a small sample of cocaine-dependent methadone patients (N = 12). A within-subject design was used; a 9-day washout period separated each of 8 incentive conditions. Higher magnitude ($50 and $100) cash-based incentives (checks) produced greater cocaine abstinence compared with the control ($0) condition, but a magnitude effect was not seen for goods-based incentives (vouchers). A trend was observed for greater rates of abstinence in the cash-based versus goods-based incentives at the $50 and $100 magnitudes. Receipt of $100 checks did not increase subsequent rates of cocaine use above those seen in control conditions. The efficacy and safety data provided in this and other recent studies suggest that use of cash-based incentives deserves consideration for clinical applications of contingency management, but additional confirmation in research using larger samples and more prolonged periods of incentive delivery is needed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensation seeking, substance abuse, and psychopathology in treatment-seeking and community cocaine abusers.

Sensation seeking, substance abuse severity, and psychiatric disorders were systematically assessed in a clinical and a community sample of 335 cocaine abusers. In contrast to low-sensation-seeking cocaine abusers, high-sensation seekers exhibited more severe symptoms of substance abuse, exhibited more severe psychosocial impairment, were more likely to be polysubstance abusers, and had an earlier age of onset for substance use and abuse. High-sensation seekers were more likely to report both a lifetime history and family history of antisocial personality, attention deficit disorders and conduct disorder. Sensation seeking was related to several dimensions that are important for defining subtypes of substance abusers and was consistent with other features of a Type II classification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Causal uncertainty beliefs and diagnostic information seeking.

This study examined the extent to which chronic causal uncertainty beliefs influence diagnostic information seeking. Situational factors intended to increase the excitation level of causal uncertainty beliefs and the intensity of goal-directed behavior also were investigated. Participants expected to interview either a gender in-group or a gender out-group member, and half of them expected to be held accountable for their understanding of the interviewee. For out-group conditions, those accountable participants who possessed chronically accessible causal uncertainty beliefs revealed the greatest preference for diagnostic information. For in-group conditions, no differential pattern of information seeking as a function of chronic causal uncertainty beliefs or goal importance were found. Results are discussed in terms of a recent model of motivated social cognition proposed by G. Weary and J. A. Edwards (1996). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Disposition and metabolism of [3H]cocaine in acutely and chronically treated dogs

1. Beagle dogs were chronically treated with cocaine, 5 mg/kg subcutaneously twice daily for 6 weeks, followed by same dose of [3H]cocaine given intravenously. 2. The t1/2 values of cocaine in plasma, liver, spleen and heart, in acutely and chronically treated dogs, were: 1-2, 1-1; 2-2, 1-8; 1-8, 1-3; 2-0, 1-2 h, respectively. In both groups, cocaine disappeared from all areas of the central nervous system 12-24 h after injection but significant amounts of radioactivity due to benzoylnorecgonine and benzoylecgonine persisted in the CNS even 1 week after administration of cocaine. Brain-to-plasma ratios of cocaine were lower in chronically-treated than in acutely-treated dogs 2 and 4 h after injection. 3. Norcocaine, benzoylnorecgonine, benzoylecgonine and ecgonine were metabolites of cocaine in dog brain in both groups. Norcocaine and benzoylnorecgonine were present in higher amounts in brains of chronically treated dogs. Rate of disappearance of norcocaine was similar to cocaine in both groups. 4. The amounts of cocaine excreted in urine and faeces as percentage of dose were 0-9-5-0, 1-1-6 in the acute and 2-2-3-3 and 0-2-0-3 in the chronically treated dogs. Major excretion of radiactivity occurred in urine within 24 h in both groups. Total radioactivity (65% of dose) in urine plus faeces was similar in both groups. 5. Norcocaine, benzoylnorecgonine, benzoylecgonine, ecgonine, norecgonine, ecgonine methyl ester and unidentified compounds were urinary metabolites of cocaine in both groups. Benzoylnorecgonine and ecgonine were excreted in higher amounts and benzoylecgonine and norecgonine in lower amounts in the acute than in the chronically treated dogs. 6. The possible role of persistence of benzoylnorecgonine and benzoylecgonine (which possessed potent stimulant activity intracisternally) in the CNS is discussed.