Psychostimulant abuse: the case for combined behavioral and pharmacological treatments

Systematic review of cognitive and behavioral strategies used in effective harm reduction interventions for people who use cocaine

OBJECTIVE

The aim of this systematic review is to identify cognitive and behavioral strategies that have been used in effective harm reduction interventions for people who use cocaine.

METHOD

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the search was performed on February 26, 2023 across databases including PsycInfo, PubMed, Scopus, and Web of Science. Studies were included if they (1) report the use of one cognitive or behavioral strategy, (2) have harm reduction as the objective, (3) involve participants who used cocaine as at least one of their substances, (4) be published within the last 10 years, and (5) have a randomized controlled trial design. The Cochrane RoB 2.0 Tool was used to assess risk of bias. The cognitive and behavioral strategies were extracted and organized based on their frequency of use in the studies and their corresponding outcomes.

RESULTS

The final synthesis included k = 10 studies with N = 3,567 participants. Psychoeducation strategies, influence on social norms, personalized feedback, increased self-efficacy and motivational interviewing were the most frequently used promising strategies across studies.

CONCLUSIONS

This review underscores the significance of incorporating cognitive and behavioral strategies within harm reduction interventions, as they represent a promising domain that could enhance the effectiveness of addressing cocaine use.

Interventions to Reduce Drug Use Among Methamphetamine Users at Risk for HIV

PURPOSE OF REVIEW

This paper reports on the results of a study comparing two behavioral treatments for methamphetamine users. The outcome was the effectiveness of the interventions in reducing meth use. The interventions were contingency management (CM) and contingency management plus strengths-based case management (CM/SBCM).

RECENT FINDINGS

CM/SBCM was found to be associated with attending more sessions for people who reported being in a couple. Also, participants who earned more money in the first part of the study were more likely to have more clean urinalysis in the second part of the study. Latent class analysis identified a class of participants who were in a couple, without sexual abuse history, and less meth use at baseline. This class tended to have more clean urinalysis in the CM/SBCM intervention. These results indicate that incentive-based interventions with case management may be useful for helping meth users reduce their drug use.

Reinstatement of nicotine seeking is mediated by glutamatergic plasticity

Nicotine abuse and addiction is a major health liability. Nicotine, an active alkaloid in tobacco, is self-administered by animals and produces cellular adaptations in brain regions associated with drug reward, such as the nucleus accumbens. However, it is unknown whether, akin to illicit drugs of abuse such as cocaine or heroin, the adaptations endure and contribute to the propensity to relapse after discontinuing nicotine use. Using a rat model of cue-induced relapse, we made morphological and electrophysiological measures of synaptic plasticity, as well as quantified glutamate overflow, in the accumbens after 2 wk of withdrawal with extinction training. We found an enduring basal increase in dendritic spine head diameter and in the ratio of AMPA to NMDA currents in accumbens spiny neurons compared with yoked saline animals at 2 wk after the last nicotine self-administration session. This synaptic potentiation was associated with an increase in both AMPA (GluA1) and NMDA (GluN2A and GluN2B) receptor subunits, and a reduction in the glutamate transporter-1 (GLT-1). When nicotine seeking was reinstated by presentation of conditioned cues, there were parallel increases in behavioral responding, extracellular glutamate, and further increases in dendritic spine head diameter and ratio of AMPA to NMDA currents within 15 min. These findings suggest that targeting glutamate transmission might inhibit cue-induced nicotine seeking. In support of this hypothesis, we found that pharmacological inhibition of GluN2A with 3-Chloro-4-fluoro-N-[4-[[2-(phenylcarbonyl)hydrazino]carbonyl]benzyl]benzenesulfonamide (TCN-201) or GluN2B with ifenprodil abolished reinstated nicotine seeking. These results indicate that up-regulated GluN2A, GluN2B, and rapid synaptic potentiation in the accumbens contribute to cue-induced relapse to nicotine use.

Influence of acute bupropion pre-treatment on the effects of intranasal cocaine

AIMS

The aim of this experiment was to determine the influence of acute bupropion pre-treatment on subject-rated effects and choice of intranasal cocaine versus money.

DESIGN

A randomized, within-subject, placebo-controlled, double-blind experiment.

SETTING

An out-patient research unit.

PARTICIPANTS

Eight cocaine-using adults.

MEASUREMENTS

Subjects completed nine experimental sessions in which they were pre-treated with 0, 100 or 200 mg oral immediate release bupropion. Ninety minutes later they sampled an intranasal cocaine dose [4 (placebo), 15 or 45 mg] and made six choices between that dose and an alternative reinforcer (US$0.25), available on independent, concurrent progressive ratio schedules. Subjects also completed a battery of subject-rated, performance and physiological measures following the sample doses of cocaine.

FINDINGS

After 0 mg bupropion, the high dose of cocaine (45 mg) was chosen five of six times on average compared to 2.25 of six choices for placebo cocaine (4 mg) (P < 0.05). Active bupropion reduced choice of 45 mg cocaine to 3.13 (100 mg) or 4.00 (200 mg) out of six drug choices on average. Bupropion also consistently enhanced positive subject-rated effects of cocaine (e.g. good effects; willing to take again) while having no effects of its own.

CONCLUSIONS

The atypical antidepressant, bupropion, acutely appears to reduce preference for intranasal cocaine versus a small amount of money but to increase reported positive experiences of the drug.

Monetary alternative reinforcers more effectively decrease intranasal cocaine choice than food alternative reinforcers

Cocaine dependence continues to be a significant public health concern. Contingency management, wherein alternative reinforcers are made available upon cocaine abstinence, has shown promise for decreasing cocaine use. Other research has modeled this effect and demonstrated that alternative reinforcers also reduce cocaine self-administration in the laboratory. Results from both clinical and laboratory studies suggest that the type and value of alternative reinforcers influences their ability to decrease drug choice. The purpose of the present experiment was to determine the effect of money or food alternative reinforcers, valued at $0.01, 0.25, 0.50 and 1.00, on intranasal cocaine (4 [placebo] and 30 mg) choice. Cocaine was chosen to a greater extent than placebo across alternative reinforcer types and values, but the monetary alternative reinforcer suppressed drug choice to a greater degree than the food reinforcer. These results are concordant with previous findings and suggest that money may be a more effective alternative reinforcer for decreasing cocaine use. Future research should determine the sensitivity of this model to specific behavioral aspects of contingency management and whether food could compete with drugs as reinforcers in humans under laboratory conditions.

Toward a nonhuman model of contingency management: effects of reinforcing abstinence from nicotine self-administration in rats with an alternative nondrug reinforcer

RATIONALE

Reinforcing abstinence from drug use with alternative nondrug reinforcers (e.g., contingency management) is one of the most effective interventions for drug abuse. While nonhuman studies have also shown that access to alternative nondrug reinforcers reduces drug self-administration, this effect has not been examined in nicotine self-administration models. Moreover, abstinence contingencies per se under free-operant conditions have not been examined.

OBJECTIVE

The objective of this experiment was to begin development of a model of contingency management interventions by employing a differential-reinforcement-of-alternative-behavior (DRA) schedule of alternative nondrug reinforcement in rats self-administering nicotine.

METHODS

Two groups of rats were trained to self-administer nicotine under a multiple schedule of nicotine and sucrose delivery. The DRA-group was then exposed to an interlocking FR3 nicotine DRA t-sec sucrose schedule. Under this schedule, nicotine continued to be available under the FR schedule while a sucrose pellet was made available contingent upon every pause in self-administration responding (DRA interval) of 40, 80, or 160 s. The FT-group was exposed to noncontingent delivery of sucrose under fixed time (FT) schedules at an average rate equal to that obtained under the DRA schedule in the DRA-group.

RESULTS

The DRA schedule significantly reduced NSA by 73, 69, and 59% at the DRA 40, 80, and 160 s intervals, respectively, compared to baseline, while noncontingent sucrose had no significant effect. The effect of the DRA schedule was apparent throughout the NSA sessions.

CONCLUSIONS

The present assay approximates the abstinence contingencies arranged in contingency management interventions for drug abuse and provides a preliminary nonhuman model of such interventions.

Levodopa pharmacotherapy for cocaine dependence: choosing the optimal behavioral therapy platform

BACKGROUND

The dopamine precursor levodopa has shown some, albeit relatively weak, promise in treating cocaine dependence. This study sought to identify the most appropriate behavioral therapy platform for levodopa pharmacotherapy by evaluating its effect when administered in combination with behavioral platforms of varying intensities.

METHOD

A total of 161 treatment-seeking cocaine dependent subjects received sustained release levodopa/carbidopa (400/100mg bid, Sinemet) or placebo delivered in combination with Clinical Management (ClinMan); ClinMan+cognitive behavioral therapy (CBT); or ClinMan+CBT+voucher-based reinforcement therapy (VBRT) in a 12-week randomized, placebo-controlled, double-blind (for medication condition) trial. Medication compliance was monitored with riboflavin (100mg/capsule) and the Medication Event Monitoring System. Protocol compliance was addressed in weekly, 10-min nurse-delivered ClinMan sessions. Weekly, 1-h CBT sessions focused on coping skills training. VBRT (with escalating reinforcer value) provided cash-valued vouchers contingent on cocaine-negative urine toxicology results. Urine benzoylecgonine assays collected thrice-weekly were analyzed by intention-to-treat criteria using generalized linear mixed models.

RESULTS

Levodopa main effects were found on all outcome measures of cocaine use. Contrasts testing the levodopa-placebo difference within each behavioral platform found reliable effects, favoring levodopa, only in the VBRT platform. Levodopa treatment with vouchers produced higher proportions of cocaine-negative urines and longer periods of consecutive abstinence compared to other treatment combinations.

CONCLUSION

This is the first study to find a significant treatment effect for levodopa and, in doing so, to demonstrate that the magnitude of this effect is dependent upon conditions of the behavioral therapy platform. The data support use of levodopa with abstinence-based reinforcement therapy as one efficacious combination in cocaine dependence disorder treatment.

Psychosocial approaches to psychostimulant dependence: A systematic review

This review examines the nature and evidence for the effectiveness of psychosocial interventions for psychostimulant dependence. Psychostimulant dependence and related harms continue to increase in many parts of the world, while treatment responses are predominantly limited to psychosocial interventions. The effectiveness of psychosocial interventions is compromised by poor rates of treatment induction and retention. As with other substance use disorders, increasing the diversity of treatment options is likely to improve treatment coverage and outcomes across a broader range of users. Identifying medications that might enhance treatment induction and retention would also enhance the effectiveness of psychosocial programs. It is concluded that psychosocial interventions are moderately effective in reducing psychostimulant use and related harms among psychostimulant-dependent persons.

Behavioral economic analysis of opioid consumption in heroin-dependent individuals: effects of unit price and pre-session drug supply

Behavioral economic analysis has been used to investigate factors underlying drug consumption in laboratory animals and, increasingly, in human drug abusers. However, there are few studies in heroin abusers, especially those who are not in treatment; such studies may be valuable for understanding the mechanisms of persistent drug use. This study investigated effects of unit price (UP) and pre-session supply of hydromorphone (HYD) on choice and consumption of HYD. Heroin-dependent research volunteers (n=13) stabilized on buprenorphine 8 mg/day completed this eight-session inpatient study. In sessions 1-2, participants sampled two total HYD doses (12 and 24 mg IM) that could be earned in later sessions. In each of the final six sessions, volunteers were given access to a 12-trial choice progressive ratio schedule lasting 3h. On each trial, volunteers could earn a HYD unit dose (1 or 2 mg, for a maximum of 12 or 24 mg, respectively) or money (US dollars 2, for a maximum of US dollars 24). Fixed ratio requirements increased exponentially, generating 24 unit prices for behavioral economic analysis. Before some choice sessions, volunteers could choose (FR 1) to receive extra HYD (12 or 24 mg; at 0915), whereas on other days no supplement was available. HYD choice and peak responding (breakpoint, O(max)) measures increased with unit dose, decreased with pre-session supplements, and were greater among volunteers who used cocaine prior to the experiment. Taking pre-session supplements decreased P(max) and made group-percent HYD consumption more demand-elastic. Consumption was functionally equivalent at differing FR/unit dose combinations. Thus, opioid demand in heroin-dependent individuals not in treatment is a function of drug supply, unit price, and cocaine use.

Time-dependent effects of repeated cocaine administration on dopamine transmission in the medial prefrontal cortex

The medial prefrontal cortex (mPFC) has been implicated in the development of behavioral sensitization, which is the progressive enhancement of locomotor activity that occurs with repeated administration of psychostimulants. Previous data suggest that mPFC dopamine (DA) transmission may be attenuated in cocaine-sensitized animals, but the onset and duration of this effect have not been investigated. After recovery from stereotaxic surgeries, animals were given four daily injections of saline (1 ml/kg, i.p.) or cocaine (15 mg/kg, i.p.) and were subsequently challenged with saline or cocaine after 1, 7 or 30 d of withdrawal, on which days in vivo microdialysis of the mPFC was conducted simultaneously with monitoring of locomotor activity. Compared to acutely administered controls, the results in cocaine-pretreated animals were as follows: 1d of withdrawal was associated with a significant attenuation in cocaine-induced locomotion and mPFC DA overflow; after 7d, behavioral sensitization was accompanied by a significant attenuation in cocaine-induced elevations in mPFC DA levels; 30 d of withdrawal led to the expression of sensitized behaviors paralleled by an augmentation in cocaine-induced mPFC DA. These data suggest that repeated cocaine produces temporally distinct behavioral effects associated with alterations in mPFC DA responsiveness to cocaine that may be involved in the development of behavioral sensitization.

Tobacco abstinence symptom suppression: the role played by the smoking-related stimuli that are delivered by denicotinized cigarettes

AIMS

Cigarette smoking causes cancer and disease, yet people find quitting difficult due to aversive symptoms that accompany tobacco abstinence. Understanding how to suppress these symptoms is critical in developing effective smoking cessation treatments. Pharmacologically, pure nicotine suppresses tobacco abstinence symptoms partially, and non-nicotine, smoking-related stimuli suppress these abstinence symptoms fully, at least for 24 hours. The current study was designed to clarify the impact of smoking-related stimuli on tobacco withdrawal, and to explore the duration of their ability to suppress withdrawal in smokers.

DESIGN

Three double-blind, within-subjects, Latin square-ordered, 5-day conditions in which participants smoked nicotinized, denicotinized or no cigarettes.

SETTING

Out-patient laboratory at Virginia Commonwealth University.

PARTICIPANTS

Thirteen women and 19 men.

MEASUREMENTS

Subjective, physiological and performance measures were collected daily and compliance with study conditions was verified objectively.

FINDINGS

Smoking-related stimuli are sufficient for suppressing some symptoms of tobacco abstinence over a 5-day period [i.e. Questionnaire of Smoking Urges (QSU) factor 1, 'Desire for sweets', 'Hunger' and 'Urges to smoke'], while in this study a combination of nicotine and smoking-related stimuli suppressed other symptoms (i.e. 'Difficulty concentrating', 'Increased eating', 'Restlessness' and 'Impatient').

CONCLUSIONS

These results indicate that, while some tobacco abstinence symptoms may be suppressed with nicotine, suppressing others may also require strategies that address the absence of smoking-related stimuli.

Investigations using immunization to attenuate the psychoactive effects of nicotine

Despite the enormous health risks, people continue to smoke and use tobacco primarily as a result of nicotine addiction. As part of our immunopharmacotherapy research, the effects of active and passive immunizations on acute nicotine-induced locomotor activity in rats were investigated. To this end, rats were immunized with either a NIC-KLH immunoconjugate vaccine designed to elicit an antinicotine immune response, or were administered an antinicotine monoclonal antibody, NIC9D9, prior to a series of nicotine challenges and testing sessions. Vaccinated rats showed a 45% decrease in locomotor activity compared to a 16% decrease in controls. Passive immunization with NIC9D9 resulted in a 66.9% decrease in locomotor activity versus a 3.4% decrease in controls. Consistent with the behavioral data, much less nicotine was found in the brains of immunized rats. The results support the potential clinical value of immunopharmacotherapy for nicotine addiction in the context of tobacco cessation programs.

Acute Exacerbation of COPD

Nurses in acute care settings play a vital role in caring for individuals during an acute exacerbation of chronic obstructive pulmonary disease (COPD), the fourth leading cause of death in the United States. In addressing this health concern, the Global Initiative for Chronic Obstructive Lung Disease Report summarized the goals for COPD management and recommended treatment supported by current data and research. It is imperative that our clinical nursing practice is based upon research-supported interventions: use of appropriate medications, monitoring acid-base status, administering controlled oxygen therapy, assessing the need for mechanical ventilation, and close monitoring of comorbid illnesses. Health promotion includes patient and family education on early recognition of symptoms, smoking cessation strategies, and participation in pulmonary rehabilitation that can reduce long-term morbidity from this chronic disease.

Cigarette smoking and its relationship to other substance use among eating disordered inpatients

OBJECTIVE

The present study examines prevalence rates of tobacco, caffeine, alcohol and other substance use and abuse among eating disordered inpatients and compares smokers (regular vs occasional vs non-smokers) and eating disorder (ED) subtypes [anorexia nervosa (AN) vs bulimia nervosa (BN); restrictors vs purgers] on substance use behaviors, family history, depressive symptoms and impulsivity.

METHOD

Participants were 100 ED inpatients who completed assessment upon treatment entry.

RESULTS

A high incidence of regular cigarette smoking (29%) and occasional smoking (13%) was detected and associations were found with caffeine abuse, alcohol and marijuana use, family history and depression. BNs were more likely to smoke occasionally and use alcohol than ANs, while Purgers demonstrated higher caffeine and alcohol use than Restrictors.

DISCUSSION

Comprehensive assessment and intervention for smoking, caffeine and other substance use among ED patients is clearly indicated.

Preclinical research on cocaine self-administration: environmental determinants and their interaction with pharmacological treatment

It has been asserted that any comprehensive understanding of cocaine abuse and its treatment will require attention to both behavioral and pharmacological variables. Although the preclinical literature evaluating the effects of pharmacological variables on cocaine self-administration has been extensively reviewed, no comprehensive review of the effects of environmental variables on cocaine self-administration has been published. The present review summarizes and critiques the preclinical findings on environmental determinants of cocaine self-administration. The influence of environmental variables on the effects of pharmacological interventions on cocaine self-administration are also described. Several environmental variables have been shown to affect cocaine self-administration, including unit dose, schedule of cocaine delivery, schedules of nondrug stimuli, behavioral history, conditioned stimuli, food deprivation, exposure to stress, and rearing environment. Among these variables, unit dose, schedule of cocaine delivery, availability of alternative nondrug reinforcers, food deprivation, and rearing environment have also been shown to alter pharmacological treatment effects on cocaine self-administration. Thus, drug effects on cocaine self-administration are malleable and dependent upon the environmental context within which they occur. Suggestions for future research on the effects of these and other environmental variables on cocaine self-administration and its pharmacological treatment are presented.