Alcohol Administration Increases Cocaine Craving But Not Cocaine Cue Attentional Bias

Direct Effects of Cannabis Intoxication on Motivations for Softer and Harder Drug Use: An Experimental Approach to the Gateway Hypothesis

Aims: This study experimentally tested whether there is a gateway-type effect of cannabis administration on tobacco and cocaine motivation and whether motivational responses predicted use 6 months later. Methods: A 2 (condition: active cannabis vs. placebo joint)×3 (substance stimulus type: tobacco, cannabis, and cocaine) factor within-subjects design for both implicit and explicit motivation. Both experimental sessions were conducted in a cannabis dispensary ("coffeeshop") in Amsterdam and were separated by ∼1 week, followed by a 6-month online follow-up. Eighty-five participants between 18 and 27 years of age (57% male), who used cannabis, tobacco, and cocaine <15 times per month, participated in session 1 (session 2: N=79 and follow-up: N=81). Counterbalanced over sessions, participants smoked an active and a placebo joint following a paced puffing procedure. Before and after smoking, craving and avoidance (explicit motivation) were assessed using visual analog scales, and after smoking, the stimulus response compatibility test was completed to assess approach biases (implicit motivation). Self-reported intoxication and similarity to their usual smoking experience were assessed at the end of both sessions. Self-reported frequency/quantity and dependence symptoms for tobacco, cannabis, and cocaine were assessed at all time points. A linear mixed model approach was used to assess the effects of condition, substance stimulus type, and their interactions on explicit and implicit motivation. Results: In the active condition, participants reported higher levels of intoxication and an experience more similar to their usual smoking experience than in the placebo condition. There was no significant effect of condition, substance type, or their interaction on approach bias. Participants exhibited increased cannabis craving during the placebo condition only and increased explicit cannabis avoidance during the active condition only. Explicit tobacco avoidance decreased during both conditions. Baseline measures did not predict use at 6-month follow-up. Conclusions: In light users, cannabis intoxication did not affect implicit and explicit tobacco or cocaine motivations. Tobacco avoidance decreased regardless of condition, indicating that the cannabis cue-rich setting-rather than tetrahydrocannabinol itself-may momentarily increase the likelihood to smoke tobacco. However, motivation at baseline did not predict use 6 months later, deeming any gateway-like function unlikely.

Attentional biases in abstinent patients with cocaine use disorder: rapid orienting or delayed disengagement?

Addiction-related attentional biases may play a central role in the development and maintenance of drug-seeking and drug-taking behaviors. However, evidence in cocaine dependence is limited and mixed. This study examined the time course and component processes of attentional biases for cocaine-related cues in a sample of 47 outpatients (38 men) with cocaine use disorder (CUD) with varying durations of current abstinence. Reaction times in a visual dot-probe task with two picture exposure durations -500 ms, to assess initial stages of attention, and 2,000 ms, to assess maintained attention- were recorded. We found faster responses to probes replacing cocaine-related vs. matched control pictures in the 500 ms but not in the 2,000 ms condition, indicative of early but not late attentional biases for cocaine cues in abstinent patients with CUD. Further comparisons with a neutral baseline revealed that it was not due to rapid orienting but to delayed disengagement from cocaine-related pictures, being this effect greater the longer the period of current abstinence. Consistent with the incentive-sensitization theory, these data suggest that cocaine-related stimuli maintain the capacity to hold spatial attention in abstinent patients with CUD, even after months of abstinence, highlighting the relevance of carrying out stimulus control to avoid relapses.

Trajectories of craving during medication-assisted treatment for opioid-use disorder: Subtyping for early identification of higher risk

AIMS

To examine evidence for subtypes of opioid craving trajectories during medication for opioid use disorder (MOUD), and to (a) test whether these subtypes differed on MOUD-related outcomes, and (b) determine whether nonresponders could be identified before treatment initiation.

DESIGN, SETTING, AND PARTICIPANTS

Outpatients (n = 211) being treated with buprenorphine or methadone for up to 16 weeks. Growth mixture modeling was used to identify unobserved craving-trajectory subtypes. Support Vector Machines (SVM) were trained to predict subtype membership from pretreatment data.

MEASUREMENTS

Self-reported opioid craving (Ecological Momentary Assessment - EMA - three random moments per day). Participant-initiated EMA reports of drug use or higher-than-usual stress. Addiction Severity Index (ASI) pretreatment.

FINDINGS

Four craving trajectories were identified: Low (73%); High and Increasing (HIC) (10.9%); Increasing and Decreasing (8.5%); and Rapidly Declining (7.6%). The HIC subgroup reported the highest use of heroin, any opiate, and cannabis during treatment. The Low Craving subgroup reported the lowest use of heroin or any opiate use, and the lowest levels of stress and drug-cue exposure during treatment. SVM models predicting HIC membership before treatment initiation had a sensitivity of 0.70, specificity of 0.78, and accuracy of 0.77. Including 3 weeks of EMA reports increased sensitivity to 0.78, specificity to 0.84, and accuracy to 0.85.

CONCLUSIONS

Subgroups of MOUD patients show distinct patterns of opioid craving during treatment. Subgroups differ on critical outcomes including drug-use lapse, stress, and exposure to drug cues. Data from enrollment and early in treatment may help focus clinical attention.

A Brief Introduction to Human Behavioral Pharmacology: Methods, Design Considerations and Ethics

Human behavioral pharmacology methods have been used to rigorously evaluate the effects of a range of centrally acting drugs in humans under controlled conditions for decades. Methods like drug self-administration and drug discrimination have been adapted from nonhuman laboratory animal models. Because humans have the capacity to communicate verbally, self-report methods are also commonly used to understand drug effects. This perspective article provides an overview of these traditional human behavioral pharmacology methods and introduces some novel methodologies that have more recently been adapted for use in the field. Design (e.g., using placebo controls, testing multiple doses) and ethical (e.g., avoiding enrollment of individuals seeking treatment, determining capacity to consent) considerations that must be addressed when conducting these types of studies are also described.

Alterations of Amphetamine Reward by Prior Nicotine and Alcohol Treatment: The Role of Age and Dopamine

Evidence suggests that nicotine and alcohol can each serve as a gateway drug. We determined whether prior nicotine and alcohol treatment would alter amphetamine reward. Also, we examined whether age and dopaminergic neurotransmission are important in this regard. Male and female adolescent and adult C57BL/6J mice were tested for baseline place preference. Mice then received six conditioning with saline/nicotine (0.25 mg/kg) twice daily, followed by six conditioning with saline/ethanol (2 g/kg). Control mice were conditioned with saline/saline throughout. Finally, mice were conditioned with amphetamine (3 mg/kg), once in the nicotine-alcohol-paired chamber, and tested for place preference 24 h later. The following day, mice were challenged with amphetamine (1 mg/kg) and tested for place preference under a drugged state. Mice were then immediately euthanized, their brain removed, and nucleus accumbens isolated and processed for the level of dopamine receptors and transporter and glutamate receptors. We observed a greater amphetamine-induced place preference in naïve adolescents than adult mice with no change in state-dependent place preference between the two age groups. In contrast, amphetamine induced a significant place preference in adult but not adolescent mice with prior nicotine-alcohol exposure under the drug-free state. The preference was significantly greater in adults than adolescents under the drugged state. The enhanced response was associated with higher dopamine-transporter and D₁ but reduced D₂ receptors’ expression in adult rather than adolescent mice, with no changes in glutamate receptors levels. These results suggest that prior nicotine and alcohol treatment differentially alters amphetamine reward in adult and adolescent mice. Alterations in dopaminergic neurotransmission may be involved in this phenotype.

Acute methylphenidate administration reduces cocaine-cue attentional bias

Mechanistic research on behavioral processes underlying substance use disorder might help identify novel targets for interventions development. Drug-related attentional bias and response inhibition deficits have received a great deal of consideration in substance use research, broadly, and cocaine use research, specifically. Studies investigating pharmacological mechanisms that may ameliorate, or further impair, these behaviors relevant to cocaine use are relatively lacking. This study evaluated the impact of acute administration of methylphenidate, a dopamine-favoring reuptake inhibitor, on both gaze-related cocaine-cue-attentional bias and cocaine-cue related disruptions in response inhibition among individuals with cocaine use disorder. Participants (N = 12; 33% female) completed a within-subject, outpatient, acute dosing study. Two sessions were completed in which methylphenidate (60 mg) or placebo were administered followed by completion of an attentional bias task using eye-tracking technology and neutral-cue and cocaine-cue response inhibition tasks. Subjective and physiological effects were also recorded. Significant cocaine cue attentional bias and response inhibition failures were observed during placebo administration. Acute methylphenidate administration reduced cocaine-cue attentional bias as measured by cocaine-cue gaze fixations (d_z = 1.04; Bayes Factor = 12.37). No statistically significant effects of methylphenidate were observed on response inhibition (Bayes Factors = 0.17-1.04). Methylphenidate produced prototypical subjective and physiological effects. Although the small sample should be considered, these findings indicate acute manipulation of dopaminergic activity reduced cue-related attentional allocation related to cocaine use disorder. Future research evaluating alternative dopaminergic agents and applications within a clinical setting are needed to determine the clinical significance of targeting this neurobehavioral mechanism.

A Literature Review of Attentional Biases amongst Individuals with Substance Dependency: Individual Differences and Modulating Factors

Introduction: Advances in experimental psychology have led to a better understanding of automatic, unconscious processes, referred to as attentional biases. Despite the growing evidence from meta-analytical studies, we still do not understand why some individuals have a greater magnitude of these biases, and why others have none. There has been little focus on elucidating individual differences and task parameters that affect the overall magnitude of the biases. In this opinion piece, we will attempt to identify these. We will then discuss both the research and clinical implications. Methods and Analysis: To identify the factors that modulated the magnitude of attentional biases across all the substance disorders (i.e., opioid use, cannabis use, and stimulant-use disorders), we performed a search using the bibliographic databases PubMed and MEDLINE. The search terminologies “attention bias” or “cognitive bias” or “approach bias” or “avoidance bias” were used when we looked for relevant articles. Results: It was evident from the published literature that several individual differences and factors modulated the magnitude of baseline biases. Across opioid, cannabis, and stimulant-use disorders, the most common individual differences identified were the severity of the dependence and the quantity of substance used. For both opioid and cannabis disorders the timing of stimulus presentation influenced the detection of attentional bias; it appeared that short stimulus timing was better able to detect attentional bias. Other identified individual differences included subjective craving and impulsiveness. The results highlight several research and clinical implications. Conclusions: The discovery of these individual differences and factors of the task paradigm that affect the magnitude of attentional biases will help in the future conceptualization of attention-bias-modification intervention.

Does Reducing Drinking in Patients with Unhealthy Alcohol Use Improve Pain Interference, Use of Other Substances, and Psychiatric Symptoms?

BACKGROUND

We aimed to investigate the impact of reducing drinking in patients with unhealthy alcohol use on improvement of chronic pain interference, substance use, and psychiatric symptoms.

METHODS

We analyzed longitudinal data from 2003 to 2015 in the Veterans Aging Cohort Study, a prospective, multisite observational study of US veterans, by emulating a hypothetical randomized trial (a target trial). Alcohol use was assessed using the Alcohol Use Disorders Identification Test (AUDIT) questionnaire, and outcome conditions were assessed via validated survey items. Individuals were followed from the first time their AUDIT score was ≥ 8 (baseline), a threshold consistent with unhealthy alcohol use. We compared individuals who reduced drinking (AUDIT < 8) at the next follow-up visit with individuals who did not (AUDIT ≥ 8). We fit separate logistic regression models to estimate odds ratios for improvement of each condition 2 years postbaseline among individuals who had that condition at baseline: moderate or severe pain interference symptoms, tobacco smoking, cannabis use, cocaine use, depressive symptoms, and anxiety symptoms. Inverse probability weighting was used to account for potential selection bias and confounding.

RESULTS

Adjusted 2-year odds ratios (95% confidence intervals) for associations between reducing drinking and improvement or resolution of each condition were as follows: 1.49 (0.91, 2.42) for pain interference symptoms, 1.57 (0.93, 2.63) for tobacco smoking, 1.65 (0.92, 2.95) for cannabis use, 1.83 (1.03, 3.27) for cocaine use, 1.11 (0.64, 1.92) for depressive symptoms, and 1.33 (0.80, 2.22) for anxiety symptoms.

CONCLUSIONS

We found some evidence for improvement of pain interference symptoms and substance use after reducing drinking among US veterans with unhealthy alcohol use, but confidence intervals were wide.

Association of Alcohol Screening Scores With Adverse Mental Health Conditions and Substance Use Among US Adults

IMPORTANCE

Alcohol screening may be associated with health outcomes that cluster with alcohol use (ie, alcohol-clustering conditions), including depression, anxiety, and use of tobacco, marijuana, and illicit drugs.

OBJECTIVE

To quantify the extent to which alcohol screening provides additional information regarding alcohol-clustering conditions and to compare 2 alcohol use screening tools commonly used for this purpose.

DESIGN, SETTING, AND PARTICIPANTS

This longitudinal cohort study used data from the Veterans Aging Cohort Study. Data were collected at 8 Veterans Health Administration facilities from 2003 through 2012. A total of 7510 participants were enrolled, completed a baseline survey, and were followed up. Veterans with HIV were matched with controls without HIV by age, race, sex, and site of care. Data were analyzed from January 2019 to December 2019.

EXPOSURES

The Alcohol Use Disorders Identification Test (AUDIT) and Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) were used to assess alcohol use, with 4 risk groups delineated for each test: score 0 to 7 (reference), score 8 to 15, score 16 to 19, and score 20 to 40 (maximum score) for the full AUDIT and score 0 to 3 (reference), score 4 to 5, score 6 to 7, and score 8 to 12 (maximum score) for the AUDIT-C.

MAIN OUTCOMES AND MEASURES

Alcohol-clustering conditions, including self-reported symptoms of depression and anxiety and use of tobacco, marijuana, cocaine, other stimulants, opioids, and injection drugs.

RESULTS

A total of 6431 US patients (6104 [95%] men; median age during survey years 2003-2004, 50 years [range, 28-86 years; interquartile range, 44-55 years]) receiving care in the Veterans Health Administration completed 1 or more follow-up surveys when the AUDIT was administered and were included in the present analyses. Of the male participants, 4271 (66%) were African American, 1498 (24%) were white, and 590 (9%) were Hispanic. The AUDIT and AUDIT-C scores were associated with each alcohol-clustering condition. In particular, an AUDIT score of 20 or higher (vs <8, the reference) was associated with symptoms of depression (odds ratio [OR], 8.37; 95% CI, 6.20-11.29) and anxiety (OR, 8.98; 95% CI, 6.39-12.60) and with self-reported use of tobacco (OR, 14.64; 95% CI, 8.94-23.98), marijuana (OR, 12.41; 95% CI, 8.61-17.90), crack or cocaine (OR, 39.47; 95% CI, 27.38-56.90), other stimulants (OR, 21.31; 95% CI, 12.73-35.67), and injection drugs (OR, 8.67; 95% CI, 5.32-14.13). An AUDIT score of 20 or higher yielded likelihood ratio (sensitivity / 1 - specificity) values greater than 3.5 for depression, anxiety, crack or cocaine use, and other stimulant use. Associations between AUDIT-C scores and alcohol-clustering conditions were more modest.

CONCLUSIONS AND RELEVANCE

Alcohol screening can inform decisions about further screening and diagnostic assessment for alcohol-clustering conditions, particularly for depression, anxiety, crack or cocaine use, and other stimulant use. Future studies using clinical diagnoses rather than screening tools to assess alcohol-clustering conditions may be warranted.

Cognitive Biases in Cannabis, Opioid, and Stimulant Disorders: A Systematic Review

Background: Opiates, cannabis, and stimulants are highly abused and are prevalent disorders. Psychological interventions are crucial given that they help individuals maintain abstinence following a lapse or relapse into substance use. The dual-process theory has posited that while the repeated use of a substance leads to increased automatic processing and increased automatic tendencies to approach substance-specific cues, in addition to the inhibition of other normal cognitive processes. Prior reviews are limited, as they failed to include trials involving participants with these prevalent addictive disorders or have not reviewed the published literature extensively. Objectives: The primary aim of this review is to synthesize the evidence for cognitive biases in opioid use, cannabis use, and stimulant use disorders. The secondary aim of the review is to determine if cognitive bias could be consistently detected using the different methods. Lastly, this review will narratively synthesize the evidence of possible associations between cognitive biases and other addiction-related outcomes. Methods: A search was conducted from November 2017 to January 2018 on PubMed, MEDLINE, Embase, PsycINFO, Science Direct, Cochrane Central, and Scopus. Articles were included if participants had a primary diagnosis of opioid use, cannabis use, or stimulant use disorder. The selection process of the articles was in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A qualitative synthesis was undertaken. Results: A total of 38 studies were identified. The main finding is the evidence that cognitive biases are present in the 38 studies identified, except for a single study on opioid use and stimulant use disorders. Cognitive biases were reported despite a variety of different methods being utilized. Synthesis of secondary outcome was not feasible, due to the varied outcomes reported. Conclusions: Cognitive biases have been consistently observed in opioid use, cannabis use, and stimulant use disorders, despite a range of assessment tools being utilized in the assessment for these biases.

Attentional bias toward alcohol stimuli as a predictor of treatment retention in cocaine dependence and alcohol user patients

BACKGROUND

Attentional bias towards substance-related stimuli has shown to be involved in the development and maintenance of cocaine dependence. The relationship between alcohol use and cocaine dependence shown in literature justify the need of study these two substances jointly.

METHODS

This paper analyzes patterns of attentional bias in 71 patients with cocaine dependence and compares these patterns according to whether occasional or problematic concurrent alcohol use is taken into account. It also analyzes whether attentional bias towards alcohol and cocaine-related stimuli predicts treatment retention. Attentional bias was evaluated with a visual probe task between 15 and 20days after admission to treatment. Treatment status was recorded at a three-month follow-up. Severity of dependence and cocaine and alcohol craving were also measured.

RESULTS

Results show that patients with cocaine dependence and problematic alcohol use show a pattern of approach towards alcohol stimuli (M=8.32, SD=27.01). In contrast, patients with cocaine dependence with occasional consumption of alcohol exhibit a pattern of avoidance of such stimuli (M=-7.23, SD=19.20) (t=2.79, p=0.007). Logistic regression indicates that alcohol attentional bias is the only variable with predictive capacity (OR=1.05, 95% CI=[1.01, 1.09]). It should also be noted that there is a pattern of avoidance of alcohol stimuli in patients who drop out of treatment.

CONCLUSION

The results of this study suggest the need to delve into whether therapeutic strategies involving deeper emotional processing or avoidance strategies are more suitable for preventing relapse.

Influence of Cocaine-Related Images and Alcohol Administration on Inhibitory Control in Cocaine Users

BACKGROUND

Alcohol use and impulsivity, including decreased inhibitory control, predict poor treatment outcomes for individuals with cocaine use disorders. This study sought to determine the effects of alcohol administration on inhibitory control following cocaine-related and neutral cues on the Attentional Bias-Behavioral Activation (ABBA) task in cocaine users. We hypothesized that the proportion of inhibitory failures would increase following cocaine, compared to neutral, cues. We further hypothesized that there would be an interaction between alcohol administration and task version, such that alcohol would impair inhibitory control following cocaine, but not neutral cues.

METHODS

Fifty current cocaine users completed this mixed-model, double-blind, placebo-controlled, crossover study over 2 experimental sessions. The ABBA task was completed following alcohol administration (0.0 and 0.65 g/kg). Subject-rated drug effect and physiological measures were collected prior to and after alcohol administration.

RESULTS

Proportion of inhibitory failures was increased following cocaine-related cues compared to neutral cues independent of alcohol dose. Alcohol administration also produced prototypical subject-rated drug effects.

CONCLUSIONS

A better understanding of the relationship between alcohol consumption and inhibitory control in cocaine users could direct the development of interventions to decrease the risk of relapse in individuals who drink and display impaired inhibitory control.

Effects of ethanol on cocaine self-administration in monkeys responding under a second-order schedule of reinforcement

BACKGROUND

Concurrent alcohol use among cocaine abusers is common but the behavioral variables that promote co-abuse are not well understood. The present study examined the effects of intragastric (i.g.) ethanol (EtOH) administration in monkeys responding under a schedule of cocaine reinforcement in which extensive drug seeking was maintained by conditioned stimuli.

METHODS

Four adult male cynomolgus monkeys (Macaca fascicularis) were trained to respond under a second-order fixed-interval (FI) 600s (fixed-ratio (FR) 30:S) schedule of cocaine (0.003-0.56mg/kg/injection) presentation. Sessions ended after 5 injections or 90min had elapsed. Different EtOH doses (0.5-2.0g/kg, i.g.) were administered 30min before the session, typically on Tuesdays and Fridays. Blood ethanol concentrations (BECs) were also assessed. Pattern of FI responding was assessed by determining quarter-life (QL) values.

RESULTS

Cocaine self-administration was characterized as an inverted U-shaped function of dose; QL values increased monotonically with dose. EtOH pretreatments dose-dependently decreased self-administration at several cocaine doses in 3 of 4 monkeys. In one animal, EtOH increased low-dose cocaine-maintained responding. For all monkeys, QL values were increased by EtOH when low- and high-cocaine doses were self-administered, suggesting additive effects of EtOH and cocaine. Furthermore, BECs were not altered following cocaine self-administration.

CONCLUSIONS

The reductions in cocaine self-administration and the increases in QL values following EtOH, suggest that EtOH was enhancing cocaine-related conditioned reinforcement. A better understanding of the behavioral mechanisms that mediate the co-abuse of alcohol and cocaine will lead to improved treatments for both drugs.