Appetitive and aversive cue reactivities differentiate neural subtypes of alcohol drinkers

Craving reflects the subjective urge to use drugs and can be triggered by both positive and negative emotional states. No studies have systematically investigated the relative roles of these mechanisms in the pathophysiology of substance misuse. Here, we performed meta-analyses of drug cue-elicited reactivity and win and loss processing in the monetary incentive delay task to identify distinct neural correlates of appetitive and aversive responses to drug cues. We then characterized the appetitive and aversive cue responses in seventy-six alcohol drinkers performing a cue craving task during fMRI. Imaging data were processed according to published routines. The appetitive circuit involved medial cortical regions and the ventral striatum, and the aversive circuit involved the insula, caudate and mid-cingulate cortex. We observed a significant correlation of cue-elicited activity (β estimates) of the appetitive and aversive circuit. However, individuals varied in appetitive and aversive cue responses. From the regression of appetitive (y) vs. aversive (x) β, we identified participants in the top 1/3 each of those with positive and negative residuals as "approach" (n = 15) and "avoidance" (n = 11) and the others as the "mixed" (n = 50) subtype. In clinical characteristics, the avoidance subtype showed higher sensitivity to punishment and, in contrast, the approach subtype showed higher levels of sensation seeking and alcohol expectancy for social and physical pressure. The findings highlighted distinct neural underpinnings of appetitive and aversive components of cue-elicited reactivity and provided evidence for potential subtypes of alcohol drinkers.

Brain responses to drug cues predict craving changes in abstinent heroin users: A preliminary study

BACKGROUND

Loss of control over drug intake occurring in drug addiction is believed to result from disruption of reward circuits, including reduced responsiveness to natural rewards (e.g., monetary, sex) and heightened responsiveness to drug reward. Yet few studies have assessed reward deficiency and related brain responses in abstinent heroin users with opioid use disorder, and less is known whether the brain responses can predict cue-induced craving changes following by prolonged abstinence.

METHOD

31 heroin users (age: 44.13±7.68 years, male: 18 (58%), duration of abstinence: 85.2 ± 52.5 days) were enrolled at a mandatory detoxification center. By employing a cue-reactivity paradigm including three types of cues (drug, sexual, neutral), brain regional activations and circuit-level functional coupling were extracted. Among the 31 heroin users, 15 were followed up longitudinally to assess cue induced craving changes in the ensuing 6 months.

RESULTS

One way analysis of variance results showed that heroin users have differential brain activations to the three cues (neutral, drug and sexual) in the left dorsolateral prefrontal cortex (DLPFC), insula, orbiotofrontal cortex (OFC) and the bilateral thalamus. Drug cue induced greater activations in left DLPFC, insula and OFC compared to sexual cue. The psychophysiological interactions (PPI) analysis revealed negative couplings of the left DLPFC and the left OFC, bilateral thalamus, putamen in heroin users during drug cue exposure. In the 6-month follow-up study, both drug cue induced activation of the left DLPFC and the functional coupling of the left DLPFC-bilateral thalamus at baseline was correlated with craving reductions, which were not found for sexual cues.

CONCLUSION

Our preliminary study provided novel evidence for the reward deficiency theory of opioid use disorder. Our findings also have clinical implications, as drug cue induced activation of the left DLPFC and functional coupling of left DLPFC-bilateral thalamus may be potential neuroimaging markers for craving changes during prolonged abstinence. Evidently, the findings in the current preliminary study should be confirmed by large sample size in the future.

Cue-elicited functional connectivity of the periaqueductal gray and tonic cocaine craving

BACKGROUND

Withdrawal from chronic cocaine use leads to anxiety and dysphoria that may perpetuate habitual drug use. The pain circuit is widely implicated in the processing and manifestations of negative emotions. Numerous studies have focused on characterizing reward circuit dysfunction but relatively little is known about the pain circuit response during cocaine withdrawal.

METHODS

Here we examined the activity and connectivity of the periaqueductal gray (PAG), a hub of the pain circuit, during cocaine cue exposure in 52 recently abstinent cocaine dependent participants (CD, 42 men). Imaging data were processed with published routines, and the results were evaluated at a corrected threshold.

RESULTS

CD showed higher activation of the PAG and connectivity of the PAG with the ventromedial prefrontal cortex (vmPFC) during cocaine as compared to neutral cue exposure. PAG-vmPFC connectivity was positively and negatively correlated with tonic cocaine craving, as assessed by the Cocaine Craving Questionnaire, in male and female CD, respectively, and the sex difference was confirmed by a slope test. Granger causality analyses showed that the PAG Granger caused vmPFC time series in men and the reverse was true in women, substantiating sex differences in the directional interactions of the PAG and vmPFC.

CONCLUSION

The findings provide the first evidence in humans implicating the PAG circuit in cocaine withdrawal and cocaine craving and advance our understanding of the role of the pain circuit and negative reinforcement in sustaining habitual drug use in cocaine addiction.

Methamphetamine and Opioid Cue Database (MOCD): Development and Validation

INTRODUCTION

Drug cue reactivity (DCR) is widely used in experimental settings for both assessment and intervention. There is no validated database of pictorial cues available for methamphetamine and opioids.

METHODS

360 images in three-groups (methamphetamine, opioid and neutral (control)) matched for their content (objects, hands, faces and actions) were selected in an initial development phase. 28 participants with a history of both methamphetamine and opioid use (37.71 ± 8.11 years old, 12 female) with over six months of abstinence were asked to rate images for craving, valence, arousal, typicality and relatedness.

RESULTS

All drug images were differentiated from neutral images. Drug related images received higher arousal and lower valence ratings compared to neutral images (craving (0-100) for neutral (11.5 ± 21.9), opioid (87.7 ± 18.5) and methamphetamine (88 ± 18), arousal (1-9) for neutral (2.4 ± 1.9), opioid (4.6 ± 2.7) and methamphetamine (4.6 ± 2.6), and valence (1-9) for neutral (4.8 ± 1.3), opioid (4.4 ± 1.9) and methamphetamine (4.4 ± 1.8)). There is no difference between methamphetamine and opioid images in craving, arousal and valence. There is a significant positive relationship between the amount of time that participants spent on drug-related images and the craving they reported for the image. Every 10 points of craving were associated with an increased response time of 383 ms. Three image sets were automatically selected for equivalent fMRI tasks (methamphetamine and opioids) from the database (tasks are available at github).

CONCLUSION

The methamphetamine and opioid cue database (MOCD) provides a resource of validated images/tasks for future DCR studies. Additionally, researchers can select several sets of unique but equivalent images based-on their psychological/physical characteristics for multiple assessments/interventions.

Improved low-cost, MR-compatible olfactometer to deliver tobacco smoke odor

We describe a low-cost, MRI-compatible olfactometer that delivers fresh cigarette smoke odor, a challenging odorant to present, as well as other odorants. This new olfactometer retains all of the advantages of an earlier design that was capable of only delivering volatile odors (Lowen & Lukas, Behavior Research Methods, 38, 307-313, 2006). The new system incorporates a novel switching mechanism that allows it to deliver fresh smoke generated from a burning cigarette during a stimulus presentation paradigm that might be employed in a cue-reactivity experiment. An evaluation study established that the olfactometer reliably delivered smoke to the participants and that tobacco smoke was discriminated from other odorants; there were no adverse reactions to the device.

Effects of progesterone stimulated allopregnanolone on craving and stress response in cocaine dependent men and women

OBJECTIVES

Fluctuations in progesterone levels during the menstrual cycle have been shown to affect physiological and subjective effects of cocaine. Furthermore, our laboratory has demonstrated that following drug-cue exposure, cocaine dependent women with high levels of circulating progesterone display lower diastolic and systolic blood pressure responses and report lower levels of anxiety and drug craving compared to cocaine dependent women with low levels of progesterone. In the current study we examined the role of the progesterone derived neuroactive steroid allopregnanolone (ALLO) on stress arousal, inhibitory control and drug craving in cocaine dependent subjects.

METHODS

Plasma levels of ALLO were measured using GC/MS in 46 treatment-seeking cocaine dependent men and women on day 5 of a 7-day treatment regimen of micronized progesterone (15M/8F) (400mg/day) or placebo (14M/9F) administered in a double blind, randomized manner. As a control, levels of the testosterone derived neurosteroid androstanediol (ADIOL) were also measured. All subjects participated in laboratory sessions on days 5-7 of progesterone/placebo administration in which they were exposed to a series of 5-min personalized guided imagery of either a stressful situation, cocaine use or of a neutral setting and dependent variables including subjective craving, mood, Stroop task as a measure of inhibitory control performance and plasma cortisol were assessed. Participants were grouped by high or low ALLO level and levels of dependent variables compared between ALLO groups.

RESULTS

Progesterone relative to placebo significantly increased ALLO levels with no sex differences. There were no effects of micronized progesterone on the testosterone derived ADIOL. Individuals in the high versus the low ALLO group showed decreased levels of cortisol at baseline, and a higher cortisol response to stress; higher positive mood scores at baseline and improved Stroop performance in the drug-cue and stress conditions, and reduced cocaine craving across all imagery conditions.

CONCLUSIONS

As expected, cocaine dependent individuals administered progesterone showed significantly higher ALLO plasma levels. High levels of ALLO appeared to normalize basal and stress response levels of cortisol, decrease cocaine craving and also contribute to improvements in positive emotion and Stroop performance in response to stress and drug-cue exposures. These findings suggest that the neuroactive steroid ALLO plays a significant role in mediating the positive effects of progesterone on stress arousal, cognitive performance and drug craving in cocaine dependence.

The effects of exogenous progesterone on drug craving and stress arousal in cocaine dependence: impact of gender and cue type

AIMS

Exogenous progesterone has been shown to attenuate the rewarding effects of cocaine. However, its effects on provoked drug craving, stress arousal and cognitive performance has not been systematically investigated in cocaine dependent men and women. Thus, we conducted a double-blind placebo-controlled study assessing the efficacy of progesterone in reducing provoked drug craving, stress system arousal and improving cognitive performance in cocaine dependent men and women.

METHODS

Forty-two early abstinent treatment-seeking cocaine dependent individuals were randomly assigned to either daily doses of placebo (12M/9F) or micronized progesterone (12M/9F) (400 mg/day), for 7 days. Under experimental conditions, all subjects were exposed to three 5-min personalized guided imagery conditions (stress, cocaine cue, relaxing), one per day, consecutively in a random, counterbalanced order. Subjective craving, mood, hypothalamic-pituitary-adrenal (HPA) and cardiovascular output, and a cognitive measure of inhibitory control (Stroop Color Word Task) were assessed pre- and post imagery.

RESULTS

Progesterone relative to placebo significantly decreased cue-induced craving and cortisol responses and increased cue-induced ACTH. In addition, women but not men receiving progesterone reported lower ratings of negative emotion and higher ratings of relaxed mood following stress exposure. Improved Stroop performance was observed in all participants receiving progesterone, across all conditions.

CONCLUSIONS

Progesterone was selectively effective in reducing cocaine cue-induced but not stress-related cocaine craving as well as specific measures of the provoked arousal state. Findings suggest that progesterone's effects on drug craving and arousal are moderated by both the type of environmental cue exposure and gender.