Contribution of cocaine-related cues to concurrent monetary choice in humans

A contextualized reinforcer pathology approach to addiction

Behavioural economic accounts of addiction conceptualize harmful drug use as an operant reinforcer pathology, emphasizing that a drug is consumed because of overvaluation of smaller immediate rewards relative to larger delayed rewards (delay discounting) and high drug reinforcing value (drug demand). These motivational processes are within-individual determinants of behaviour. A third element of learning theory posits that harmful drug use depends on the relative constraints on access to other available activities and commodities in the choice context (alternative reinforcers), reflecting the substantial influence of environmental factors. In this Perspective, we integrate alternative reinforcers into the contemporary behavioural economic account of harmful drug use - the contextualized reinforcer pathology model - and review empirical literature across the translational spectrum in support of this model. Furthermore, we consider how increases in drug-related mortality and health disparities in addiction can be understood and potentially ameliorated via a contextualized reinforcer pathology model in which lack of alternative reinforcement is a major risk factor for addiction.

Sexual discounting: A systematic review of discounting processes and sexual behavior

Behavioral processes underlying sexual behavior are important for understanding normal human functioning and risk behavior leading to sexually transmitted infections (STIs). This systematic review examines delay and probability discounting in human sexual behavior through synthesis of 50 peer-reviewed, original research articles. Sixteen studies focusing exclusively on monetary delay discounting found small effect size positive correlations with sexual risk behaviors. Eleven studies examined delay or probability discounting of sexual behavior itself using tasks that varied duration, frequency, or quality of sex to determine value. Results show delay and uncertainty of sex causes systematic decreases in value. These studies also show consistent medium effect size relationships between sexual discounting measures and sexual health and substance use, supporting utility above and beyond monetary discounting. Twenty-three studies have modeled clinically relevant decision-making, examining effects of delay until condom availability and STI contraction probability on condom use. Observational and experimental designs found condom-use discounting is elevated in high-risk substance use populations, is sensitive to context (e.g., partner desirability), and is more robustly related to sexual risk compared with monetary discounting or condom use decisions when no delay/uncertainty was involved. Administering cocaine, alcohol, and, for some participants, methamphetamine increased condom-use discounting with minimal effect on monetary discounting or condom use when no delay/uncertainty was involved. Reviewed studies robustly support that sexual behavior is highly dependent on delay and probability discounting, and that these processes strongly contribute to sexual risk. Future research should exploit these systematic relationships to design behavioral and pharmacological approaches to decrease sexual risk behavior. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cocaine abstinence modulates NMDA receptor subunit expression: An analysis of the GluN2B subunit in cocaine-seeking behavior

Cocaine use disorder develops in part due to the strong associations formed between drugs and the stimuli associated with drug use. Recently, treatment strategies including manipulations of drug-associated memories have been investigated, and the possibility of interfering with N-methyl-d-aspartate (NMDA)-mediated neurotransmission may represent an important option. The aim of this study was to examine the significance of the NMDA receptor subunit GluN2B at the molecular level (the expression of the GluN2B subunit, the Grin2B gene and the association of GluN2B with postsynaptic density protein 95 (PSD95)) in the brain structures of rats with a history of cocaine self-administration after i) cocaine abstinence with extinction training or ii) cocaine abstinence without instrumental tasks, as well as at the pharmacological level (peripheral or intracranial administration of CP 101,606, a GluN2B subunit antagonist during the cocaine- or cue-induced reinstatement). The GluN2B subunit levels and the GluN2B/PSD95 complex levels were either increased in the ventral hippocampus (vHIP) with higher levels of Grin2B gene expression in the HIP or decreased in the dorsal striatum (dSTR) after cocaine abstinence with extinction training. Moreover, CP 101,606, a GluN2B subunit antagonist, administered peripherally, attenuated the reinstatement of active lever presses induced by a priming dose of cocaine or by drug-associated conditioned stimuli, while injection into the vHIP reduced the cocaine- or cue with the subthreshold dose of cocaine-induced reinstatement. In cocaine abstinence without instrumental tasks, an increase in the GluN2B subunit levels and the level of the GluN2B/PSD95 complex in the dSTR was observed in rats that had previously self-administered cocaine. In conclusion, cocaine abstinence with extinction training seems to be associated with the up-regulation of the hippocampal GluN2B subunits, which seems to control cocaine-seeking behavior.

Cardiorespiratory Fitness Predicts Higher Inhibitory Control in Patients With Substance Use Disorder

Impaired inhibitory control has been shown in individuals with substance use disorder (SUD). Cardiorespiratory fitness has been described as a potential factor to improve inhibitory control; however, the benefits in individuals with SUD are unclear. The aim of this study was to investigate the relationship between cardiorespiratory fitness with general and drug-specific inhibitory control in individuals with SUD. Sixty-two male participants under treatment for SUD performed a general and drug-specific inhibitory control test (go/no-go) and a cardiorespiratory fitness test. Cardiorespiratory fitness, age, and years of drug use were inversely associated with reaction time for both general and drug-specific inhibitory control. In addition, the regression models showed that cardiorespiratory fitness predicts general and drug-specific inhibitory control adjusted for age and time of drug use. However, cardiorespiratory fitness predicts equally both general and drug-specific inhibitory control. These findings suggest that increasing cardiorespiratory fitness could provide benefits in the inhibitory function of individuals with SUD.

Associations between the Brief Assessment of Alcohol Demand (BAAD) questionnaire and alcohol use disorder severity in UK samples of student and community drinkers

Value based choice and compulsion theories of addiction offer distinct explanations for the persistence of alcohol use despite harms. Choice theory argues that problematic drinkers ascribe such high value to alcohol that costs are outweighed, whereas compulsion theory argues that problematic drinkers discount costs in decision making. The current study evaluated these predictions by testing whether alcohol use disorder (AUD) symptom severity (indexed by the AUDIT) was more strongly associated with the intensity item (maximum alcohol consumption if free, indexing alcohol value) compared to the breakpoint item (maximum expenditure on a single drink, indexing sensitivity to monetary costs) of the Brief Assessment of Alcohol Demand (BAAD) questionnaire, in student (n = 579) and community (n = 120) drinkers. The community sample showed greater AUD than the student sample (p = .004). In both samples, AUD severity correlated with intensity (students, r = 0.63; community, r = 0.47), but not with breakpoint (students, r = -0.01; community, r = 0.12). Similarly, multiple regression analyses indicated that AUD severity was independently associated with intensity (student, ΔR² < 0.20, p < .001; community, ΔR² = 0.09, p = .001) but not breakpoint (student, ΔR² = 0.003, p = .118; community ΔR² = 0.01, p = .294). There was no difference between samples in the strength of these associations. The value ascribed to alcohol may play a more important role in AUD severity than discounting of alcohol-associated costs (compulsivity), and there is no apparent difference between student and community drinkers in the contribution of these two mechanisms.

Profiles of patients with cocaine and alcohol use disorder based on cognitive domains and their relationship with relapse

BACKGROUND

Relapse in drug use constitutes a research topic on addiction that is relevant for understanding both the addictive process and its clinical implications. The objective of this study was to explore if it is possible to identify patient profiles according to their performance on cognitive tasks whilst examining the relationship between such profiles and relapse.

METHODS

The sample consisted of 222 patients with dependence on cocaine and / or alcohol, of which 86 % were men. Cognitive domains related to salience, decision- making, and emotional processing were measured.

RESULTS

Latent class analysis revealed three patient profiles that differ in terms of performance on cognitive tasks. Two of these profiles are clearly differentiated in terms of their execution of the impulsive decision-making task. The third patient profile, unlike the latter two, is composed of patients with severe alterations in the three domains evaluated. Analysis revealed that patients in Profile 3 are those with the highest rates of relapse in cocaine (Profile 1 = 40.3 %; Profile 2 = 35.6 %; Profile 3 = 69.2 %; Chi2 = 9.169; p < .05) and cocaine and alcohol use (Profile 1 = 55.1 %; Profile 2 = 54.1 %; Profile 3 = 80 %; Chi2 = 6.698; p < .05).

CONCLUSIONS

The results support the postulates of the I-RISA model. From a clinical perspective, these findings highlight the need for a comprehensive evaluation of the cognitive domains involved in addiction.

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.

Eye Tracking Studies Exploring Cognitive and Affective Processes among Alcohol Drinkers: a Systematic Review and Perspectives

Acute alcohol intoxication and alcohol use disorders are characterized by a wide range of psychological and cerebral impairments, which have been widely explored using neuropsychological and neuroscientific techniques. Eye tracking has recently emerged as an innovative tool to renew this exploration, as eye movements offer complementary information on the processes underlying perceptive, attentional, memory or executive abilities. Building on this, the present systematic and critical literature review provides a comprehensive overview of eye tracking studies exploring cognitive and affective processes among alcohol drinkers. Using PRISMA guidelines, 36 papers that measured eye movements among alcohol drinkers were extracted from three databases (PsycINFO, PubMed, Scopus). They were assessed for methodological quality using a standardized procedure, and categorized based on the main cognitive function measured, namely perceptive abilities, attentional bias, executive function, emotion and prevention/intervention. Eye tracking indexes showed that alcohol-related disorders are related to: (1) a stable pattern of basic eye movement impairments, particularly during alcohol intoxication; (2) a robust attentional bias, indexed by increased dwell times for alcohol-related stimuli; (3) a reduced inhibitory control on saccadic movements; (4) an increased pupillary reactivity to visual stimuli, regardless of their emotional content; (5) a limited visual attention to prevention messages. Perspectives for future research are proposed, notably encouraging the exploration of eye movements in severe alcohol use disorders and the establishment of methodological gold standards for eye tracking measures in this field.

Relative expected value of drugs versus competing rewards underpins vulnerability to and recovery from addiction

Behavioural economic theories of addiction contend that greater expected value of drug relative to alternative non-drug rewards is the core mechanism underpinning vulnerability to and recovery from addiction. To evaluate this claim, we exhaustively review studies with human drug users that have measured concurrent choice between drugs vs. alternative rewards, and explored individual differences. These studies show that drug choice can be modulated by drug cues, drug devaluation, imposition of costs/punishment and negative mood induction. Regarding individual differences, dependence severity was reliably associated with overall drug preference, and self-reported drug use to cope with negative affect was reliably associated with greater sensitivity to mood induced increases in drug choice. By contrast, there were no reliable individual differences in sensitivity to the effect of drug cues, drug devaluation or punishment on drug choice. These findings provide insight into the mechanisms that underpin vulnerability to dependence: vulnerability is conferred by greater relative value ascribed to drugs, and relative drug value is further augmented by negative affective states in those who report drug use coping motives. However, dependence does not appear to be characterised by abnormal cue-reactivity, habit learning or compulsion. We then briefly review emerging literature which demonstrates that therapeutic interventions and recovery from addiction might be attributed to changes in the expected relative value of drug versus alternative rewards. Finally, we outline a speculative computational account of the distortions in decision-making that precede action selection in addiction, and we explain how this account provides a blueprint for future research on the determinants of drug choice, and mechanisms of treatment and recovery from addiction. We conclude that a unified economic decision-making account of addiction has great promise in reconciling diverse addiction theories, and neuropsychological evaluation of the underlying decision mechanisms is a fruitful area for future research and treatment.

Contribution of alcohol- and cigarette-related cues to concurrent reinforcer choice in humans

Drug-related cues have been extensively studied for their contributions to decision-making processes involving drug consumption. Less studied is how drug-related stimuli may impact decisions involving outcomes not directly related to substance use. Studies using concurrent choice tasks have demonstrated that cocaine and cannabis cues result in robust and selective biases for monetary reinforcers contiguous with those cues. The purpose of this study was to provide a conceptual replication of these findings with alcohol and cigarettes. Participants recruited using crowdsourcing completed a cued concurrent choice task involving presentation of two cues (one drug and one neutral) followed by concurrent monetary offers below each image. Alcohol (Experiment 1; N = 103) and cigarette (Experiment 2; N = 256) visual cues were evaluated. Participants with hazardous alcohol use and current cigarette use showed greater-than-indifference selection for the alcohol- (p = .004) and cigarette-cued (p = .02) monetary choices, respectively. Qualitative responses indicated that the most popular rationale for responding was "image quality" despite images having no explicit impact on the reinforcer received. Low alcohol use (p = .03) and non-cigarette using controls (p < .001) showed an avoidance bias with lower-than-indifference selection for drug-cued choices. These findings replicate and extend observations that spatially contiguous drug-related cues can bias decisions involving concurrently presented non-drug reinforcers.

Contribution of cannabis-related cues to concurrent reinforcer choice in humans

BACKGROUND

Drug-related cues play a critical role in the development and persistence of substance use disorder. Few human laboratory studies have evaluated how these cues contribute to decisions between concurrently presented reinforcers, and none have examined the specific role of cannabis cues. This study evaluated the contribution of cannabis-related cues to concurrent monetary reinforcer choice in humans.

METHODS

Participants with a cannabis use history (i.e., use in the past two weeks and 50 or more lifetime uses; n = 71) and controls without this history (i.e., 5 or less lifetime uses; n = 79) were recruited using Amazon Mechanical Turk. A cued concurrent choice task was used in which cannabis trials presented two cues (one cannabis and one neutral) side-by-side followed by concurrent monetary offers below each image. The primary dependent measure was choice for cannabis-cued monetary reinforcers on equal value trials. Secondary analyses evaluated individual difference variables related to choice bias.

RESULTS

Participants in the cannabis group showed a significant bias for cannabis-cued choices (mean 76.0%) whereas participants in the control group showed a significant bias against cannabis-cued choices (mean 30.3%). Reaction times on cannabis trials were faster than neutral filler trials and did not differ by group. Cannabis-cued choice was significantly associated with more frequent cannabis use (r = .44), higher cannabis demand intensity (r = .28), and lower cannabis elasticity (r = -.30).

CONCLUSIONS

These findings suggest that cannabis-related cues can influence reinforcer choice and potentially promote disadvantageous decision-making related to non-drug reinforcers.