Substance use patterns, quantities, and associated risk factors in women with polysubstance misuse

Polysubstance use (PSU), the use of two or more substances proximally, is highly prevalent and has amplified the risk for morbidity and mortality. However, PSU patterns and associated risk factors are not well characterized. This may be especially relevant to women who are known to be vulnerable to stress/trauma, craving, pain, and anxious and depressive symptoms as associated risk factors for PSU. A cross-sectional observational study was conducted to characterize substance use patterns in women who regularly used cocaine, opioids, marijuana, alcohol, benzodiazepines and/or nicotine and were being assessed for a placebo-controlled study of guanfacine treatment (n = 94; ages 19-65). Data on stress/traumatic life events, drug cravings for each substance, pain ratings, and anxiety and depressive symptoms were also obtained using standardized well-validated surveys. High use per day of two or more drugs was observed (72.7% ± 33.3%) and opioid amounts were high relative to other drug amounts (p's < 0.001). Notably, higher stress/trauma events and higher cravings are each associated with cumulative PSU days, amounts and probability of an individual PSU day (p's < 0.02). This remained when PSU versus single substance use was compared. Pain, anxiety and depressive symptoms were not associated with PSU metrics. These findings characterize specific patterns of PSU in women and show that average drug craving and stress/trauma events are associated with PSU. Interventions that focus on stress/trauma and craving management could be of benefit in reducing PSU risk in women.

Cannabidiol as a Harm Reduction Strategy for People Who Use Drugs: A Rapid Review

OBJECTIVE

The drug poisoning crisis throughout North America necessitates novel harm reduction approaches. Emerging evidence suggests that cannabidiol (CBD) may have some utility as a harm reduction modality for those with problematic substance use. This rapid review aimed to synthesize available evidence on CBD as a potential harm reduction tool for people who use drugs while providing clinical and research insights.

METHOD

A systematic search in EMBASE, MEDLINE, CENTRAL, and CINAHL was completed in July 2022. For inclusion, studies had to meet the following criteria: (1) drawn from an adult population of people who use drugs; (2) investigates CBD as an intervention for problematic substance use or harm reduction-related outcomes; (3) be published after the year 2000 and in English; and (4) be primary research or a review article. A narrative synthesis was used to group outcomes relevant to harm reduction and provide clinical and research insights.

RESULTS

We screened 3,134 records, of which 27 studies (5 randomized trials) were included. The evidence remains limited, but available studies support the potential utility of CBD to reduce drug-induced craving and anxiety in opioid use disorder. There were low-quality studies suggesting that CBD may improve mood and general well-being of people who use drugs. Evidence suggests that CBD monotherapy may not be an adequate harm reduction strategy for problematic substance use but rather an adjunct to the standard of care.

CONCLUSION

Low-quality evidence suggests that CBD may reduce drug cravings and other addiction-related symptoms and that CBD may have utility as an adjunct harm reduction strategy for people who use drugs. However, there is a significant need for more research that accurately reflects CBD dosing and administration regimens used in a real-world context.

Efficacy of a Brief Mindfulness Intervention in Underserved Individuals Receiving Inpatient Treatment for Opioid Use Disorder: A Pilot Study

Introduction A mindfulness intervention is a mind-body complementary health approach that focuses on the relationships between mind, body, brain, and behavior. Mindfulness-Based Stress Reduction (MBSR) and similar mindfulness programs have been shown to decrease drug craving and relapse and improve emotional regulation, stress, pain, and anxiety. To our knowledge, a very limited number of studies have examined its efficacy in individuals from underserved populations. Underserved populations experience disparities in healthcare access, and as a result, see poorer addiction-related outcomes. The goal of this pilot study was to utilize an evidence-based, neuroscience-informed brief mindfulness intervention to improve mental health and decrease substance use behavior in a vulnerable, underserved population in New Jersey suffering from opioid use disorder (OUD). Methods We implemented a brief MBSR intervention in 15 underserved individuals undergoing inpatient medication-assisted treatment (MAT) for OUD. Individuals received weekly intervention sessions lasting one hour over six weeks. Furthermore, they practiced mindfulness for 10 minutes daily. Participants completed pre-and post-mindfulness intervention surveys to examine their mental well-being, drug craving, perceived stress, and emotional regulation. Results Within-subjects t-test results showed that compared to pre-intervention, participants showed significantly decreased perceived stress (t(14) =2.401, p=.015) and significantly decreased difficulty in emotional regulation (t(13) =3.426, p=.002 ) at post-intervention. They also showed significantly decreased drug craving post-intervention (t(14) =5.501, p=.<001). Anxiety decreased post-intervention but was not statistically significant (t(14) =1.582, p=.068). Conclusion This pilot study demonstrates that a brief mindfulness intervention can be effective for underserved individuals with OUD. Consistent with our hypothesis, results showed that a six-week mindfulness intervention could reduce everyday stress, drug craving, and difficulties in emotional regulation. In the future, a large-scale randomized control trial should be conducted with a control group to demonstrate the efficacy of this useful intervention.

Attention bias and alcohol craving: Differential effects via biological sex and mood

BACKGROUND

Attentional bias (AB) has been linked to alcohol use, mood, and alcohol craving, with key differences across different types of mood and biological sex. However, further exploration of the role of AB across these alcohol variables is needed. The current study examined the relationship between mood and AB as predictors of alcohol craving using ecological momentary assessment (EMA). Exploratory analysis examined these effects as a function of biological sex.

METHODS

Participants (n = 69) from a Midwestern University carried a mobile device for 15 days and provided ratings of momentary mood (positive mood, anxious mood, and sad mood), alcohol craving, and AB. Data were analyzed using a two-level multilevel regression model, with associations between craving, mood, and AB examined at both the momentary and between-subjects levels.

RESULTS

Across assessments, positive and negative moods were positively associated with momentary craving, with AB found to operate differently between men and women. At the within-subjects level, increases in positive mood among men strengthened the AB-craving association, while women showed stronger AB-craving associations when positive mood decreased. At the between-subjects level, trait-like sadness led to positive AB-craving associations for men, however, this was the opposite for women. Similarly, AB-craving associations were positive and robust for men with trait-like positive mood but again the opposite was observed for women.

CONCLUSIONS

The findings highlight the importance and nuances of biological sex in the context of mood, AB, and craving. Interventions targeting AB and/or emotion regulation may yield different outcomes for men and women.

Theta-Burst Stimulation Combined With Virtual-Reality Reconsolidation Intervention for Methamphetamine Use Disorder: Study Protocol for a Randomized-Controlled Trial

Background

Craving associated with drug-related memory is one of the key factors that induce the relapse of methamphetamine (MA). Disruption or modulation of the reconsolidation of drug-related memory may serve as an option for clinical treatment of MA addiction. This protocol proposes to use virtual reality (VR) to retrieve drug-associated memory and then use transcranial magnetic stimulation (TMS) at the neural circuit that encodes the reward value of drug cues to provide a non-invasive intervention during reconsolidation. We aim to evaluate the effectiveness of TMS treatment after VR retrieval on the reduction of cue reactivity and craving of MA.

Methods

This is a randomized, double-blind, sham-controlled, parallel group trial, targeting participants with MA use disorder aged from 18 to 45 years old. Forty-five eligible volunteers in Shanxi Drug Rehabilitation Center will be recruited and be randomly allocated into three parallel groups, receiving either 1) MA-related cues retrieval in VR combined with active TMS (MA VR scene + TBS) or 2) sham TMS (MA VR scene + sham TBS), or 3) neutral cues retrieval in VR combined with active TMS (neutral VR scene + TBS). Two sessions of post-VR-retrieval TBS will be scheduled on two separate days within 1 week. The primary outcome will detect the memory-related activity by the electroencephalography (EEG) reactivity to drug cues in VR scenes. Secondary outcomes are the self-reported MA craving in VR scene, the physiological parameter (cue-induced heart rate) and the scores of psychological questionnaires including anxiety, depression, and mood. All primary and secondary outcomes will be assessed at baseline, 1-week, and 1-month post-intervention. Assessments will be compared between the groups of 1) MA VR scene + TBS, 2) MA VR scene + sham TBS and 3) neutral VR scene + TBS.

Discussion

This will be the first study to examine whether the TMS modulation after VR retrieval can reduce self-reported craving and drug-related cue reactivity. It will promote the understanding of the neural circuit mechanism of the reconsolidation-based intervention and provide an effective treatment for MA use disorder patients.

Clinical Trial Registration

[Chinese Clinical Trial Registry], identifier [ChiCTR1900026902]. Registered on 26 October 2019.

The Relationship between Different Amounts of Physical Exercise, Internal Inhibition, and Drug Craving in Individuals with Substance-Use Disorders

Purpose: To explore the relationship between different amounts of physical exercise and drug craving in individuals with substance-use disorders (SUD), and to reveal the mediating role of internal inhibition between physical activity and drug craving. Method: This study adopted the Physical Activity Rating Scale, Internal Inhibition Scale, and Drug Craving Scale to assess 438 cases of SUD in a compulsory isolation detoxification center in southwest China. Results: (1) The amount of physical exercise individuals with SUD engaged in was positively correlated with internal inhibition and negatively correlated with drug craving, while the amount of physical exercise was negatively correlated with drug craving. (2) The amount of physical exercise was able to negatively predict drug craving in addicts, the amount of physical exercise and internal inhibition were able to jointly predict drug craving, and internal inhibition played a mediating role between the amount of physical exercise and drug craving (the mediating effect was 0.22). (3) There was a dose-effect relationship regarding different amounts of physical exercises and drug craving. Internal inhibition did not mediate between a low amount of physical exercise and drug craving, it played a partial mediating role between a moderate amount of physical exercise and drug craving (the mediating effect was −0.19), and it played a partial mediating role between a high amount of physical exercise and drug craving (the mediating effect was −0.15). Conclusions: Physical activity has a positive effect on reducing drug craving in individuals with SUD. Moreover, in the process of sports rehabilitation for SUD, medium or high amounts of physical activity were required in order to effectively reduce and alleviate drug cravings.

The cue-reactivity paradigm: An ensemble of networks driving attention and cognition when viewing drug and natural reward-related stimuli

The cue-reactivity paradigm is a widely adopted neuroimaging probe engendering brain activity linked with attentional, affective, and reward processes following presentation of appetitive stimuli. Given the multiple mental operations invoked, we sought to decompose cue-related brain activity into constituent components employing emergent meta-analytic techniques when considering drug and natural reward-related cues. We conducted coordinate-based meta-analyses delineating common and distinct brain activity convergence across cue-reactivity studies (N = 196 articles) involving drug (n = 133) or natural (n = 63) visual stimuli. Across all studies, convergence was observed in limbic, cingulate, insula, and fronto-parieto-occipital regions. Drug-distinct convergence was observed in posterior cingulate, dorsolateral prefrontal, and temporo-parietal regions, whereas distinct-natural convergence was observed in thalamic, insular, orbitofrontal, and occipital regions. We characterized connectivity profiles of identified regions by leveraging task-independent and task-dependent MRI datasets, grouped these profiles into subnetworks, and linked each with putative mental operations. Outcomes suggest multifaceted brain activity during cue-reactivity can be decomposed into elemental processes and indicate that while drugs of abuse usurp the brain's natural-reward-processing system, some regions appear distinct to drug cue-reactivity.

Anxiety, Loneliness, Drug Craving, and Depression Among Substance Abusers in Sichuan Province, China

Studies have reported that anxiety had a positive effect on depression among substance abusers in males. However, little is known about the mechanism underlying this relationship in substance abusers in males. The purpose of this study was to investigate the mediating effect of loneliness and drug craving between anxiety and depression in substance abusers in males. State-Trait Anxiety Inventory, The UCLA Loneliness Scale, Drug Craving Scale, and The Center for Epidemiologic Studies Depression Scale were employed into this study to investigate 585 substance abusers in males (age range of 20–58 years: M = 33.21, SD = 6.97). Structural equation modeling and the bootstrap approach were used to analyze the mediating effect of loneliness and drug craving on the relationship between anxiety and depression. The results indicated that: Loneliness had a significant positive correlation with anxiety (r = 0.37, p < 0.001) and depression (r = 0.49, p < 0.001); Drug craving had a significant positive correlation with anxiety (r = 0.28, p < 0.001) and depression (r = 0.39, p < 0.001). Loneliness and drug craving mediated the link between anxiety and depression. There was a significant positive correlation between substance abusers in male’s anxiety, loneliness, drug craving, and depression. Loneliness and drug craving had a significant mediating effect on the relationship between anxiety and depression. Therefore, it was suggested that substance abusers in male’s anxiety and depression might be improved and driven by decreasing loneliness and drug craving. Targeted interventions to decrease substance abusers in male’s loneliness and drug craving should be developed, implemented, and help them to recover.

The Effect of Physical Activity on Drug Cravings of Drug Addicts With AIDS: The Dual Mediating Effect of Internal Inhibition

Background

As a global infectious disease, Acquired Immune Deficiency Syndrome (AIDS) poses a serious threat to the safety and health of the society. In recent years, the proportion of drug addicts infected with HIV has been increased, and drug addicts became one of the main carriers of the spread of AIDS, which has attracted worldwide attention. It has been reported that physical activity has positive effects on improving the inhibitory function of drug addicts and reducing their drug craving, but the mechanism of the internal inhibition remains to be further explored.

Method

The drug addicts in an AIDS treatment center in Chongqing were investigated by means of a Physical Activity Rating Scale (PARS – 3), Internal Inhibition Scale and Drug Craving Scale, and a structural equation model was established.

Results

(1) There is no gender difference in the internal inhibition and drug craving of drug addicts with AIDS, and there are significant differences across the types and years of drug abuse. (2) The amount of physical activity in drug addicts with AIDS is positively correlated with the intrinsic inhibition, while the internal inhibition is negatively correlated with the drug craving, and the physical exercise amount is negatively correlated with the drug craving. The years of drug abuse were negatively correlated with internal inhibition and positively correlated with drug craving. (3) Internal inhibition plays a partly mediatory role between the physical activity amount and the craving for drugs, and internal inhibition plays a partly mediatory role between the number of years of drug abuse and the craving for drugs, which indicates that internal inhibition has a dual mediating effect.

Conclusion

Actively participate in physical activity, especially high-intensity physical activity, can effectively enhance the internal inhibition of drug addicts with AIDS and reduce their drug craving. Meanwhile, the difference in the drug-taking years among addicts should be paid attention to, and the physical activity prescription should be formulated according to the actual situation.

Effect of Physical Activity on Drug Craving of Women With Substance Use Disorder in Compulsory Isolation: Mediating Effect of Internal Inhibition

Background

Women with substance use disorder has attracted widespread attention as a prominent social issue. According to reports, physical exercise can improve the internal inhibition, effectively reduce the substance user's drug graving, and improve withdrawal symptoms, however, the specific mechanism of internal inhibition should be further considered. This study was designed to determine the critical role of internal inhibition in the path of physical exertion affecting the drug cravings of women drug users.

Methods

By means of Physical Activity Rating Scale (PARS-3), internal Inhibition Scale and Drug Craving Scale, this study investigated the individuals with substance use disorder under rehabilitation in the women compulsory isolation rehabilitation center in Chongqing, China.

Results

(1) Women with traditional drug users had the strongest internal inhibition and new drug use disorder had the highest drug craving. The longer the duration of drug abuse, the lower the internal inhibition and the higher the drug craving. Women with moderate-intensity activity had the strongest internal inhibition and the lowest drug craving. (2) The physical activity intensity was negatively correlated with drug craving, positively correlated with intrinsic inhibition, and negatively correlated with drug craving. (3) Internal inhibition played a partial mediating effect between physical activity intensity and drug craving.

Conclusion

Physical activity has a positive effect on inhibiting drug craving among drug addicts, while moderate-intensity activity seems to be more conducive to enhancing the internal inhibition of addicts, to improving their resistance to drugs, and thus more conducive to reducing drug craving.

Effects of a Theta/Sensorimotor Rhythm Neurofeedback Training Protocol on Measures of Impulsivity, Drug Craving, and Substance Abuse in Forensic Psychiatric Patients With Substance Abuse: Randomized Controlled Trial

BACKGROUND

Forensic psychiatric patients are often diagnosed with psychiatric disorders characterized by high levels of impulsivity as well as comorbid substance use disorders (SUD). The combination of psychiatric disorders and SUD increases the risk of future violence. Chronic substance abuse can lead to a structural state of disinhibition, resulting in more drug taking and eventually loss of control over drug intake. When treating SUD, it is crucial to address high levels of impulsivity and lack of inhibitory control.

OBJECTIVE

This study set out to investigate the effects of a theta/sensorimotor rhythm (SMR) neurofeedback training protocol on levels of impulsivity, levels of drug craving, and actual drug intake in a population of forensic psychiatric patients with a diagnosis of SUD.

METHODS

A total of 21 participants received 20 sessions of theta/SMR neurofeedback training in combination with treatment-as-usual (TAU). Results of the intervention were compared with results from 21 participants who received TAU only.

RESULTS

SMR magnitude showed a significant (P=.02) increase post training for patients in the neurofeedback training group, whereas theta magnitude did not change (P=.71). Levels of drug craving as well as scores on the motor subscale of the Barratt Impulsivity Scale-11 decreased equally for patients in the neurofeedback training group and the TAU group. Other measures of impulsivity as well as drug intake did not change posttreatment (P>.05). Therefore, neurofeedback+TAU was not more effective than TAU only.

CONCLUSIONS

This study demonstrated evidence that forensic psychiatric patients are able to increase SMR magnitude over the course of neurofeedback training. However, at the group level, the increase in SMR activity was not related to any of the included impulsivity or drug craving measures. Further research should focus on which patients will be able to benefit from neurofeedback training at an early stage of the employed training sessions.

TRIAL REGISTRATION

Dutch National Trial Register: NTR5386; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5386 (Archived by WebCite at http://www.webcitation.org/6nXLQuoLl).

Activin Signaling in the Pathogenesis and Therapy of Neuropsychiatric Diseases

Activins are members of the transforming growth factor β (TGFβ) family and serve as multifunctional regulatory proteins in many tissues and organs. In the brain, activin A, which is formed by two disulfide-linked βA subunits, is recognized as the predominant player in activin signaling. Over the last years, considerable progress has been made in elucidating novel and unexpected functions of activin in the normal and diseased brain and in deciphering the underlying molecular mechanisms. Initially identified as a neurotrophic and protective factor during development and in several forms of acute injury, the scope of effects of activin A in the adult central nervous system (CNS) has been considerably broadened by now. Here, we will highlight recent findings that bear significance for a better understanding of the pathogenesis of various neuropsychiatric diseases and might hold promise for novel therapeutic strategies. While the basal level of activin A in the adult brain is low, significant short-term up-regulation occurs in response to increased neuronal activity. In fact, brief exposure to an enriched environment (EE) is already sufficient to considerably strengthen activin signaling. Enhancement of this pathway tunes the performance of glutamatergic and GABAergic synapses in a fashion that impacts on cognitive functions and affective behavior, counteracts death-inducing signals through extrasynaptic NMDA receptors (NMDARs), and stimulates adult neurogenesis in the hippocampus. We will discuss how impaired activin signaling is involved in anxiety disorders, depression, drug dependence, and neurodegenerative diseases such as Alzheimer’s and Parkinson’s, and how reinforcement of activin signaling might be exploited for therapeutic interventions.

Psychopathic traits modulate brain responses to drug cues in incarcerated offenders

Recent neuroscientific evidence indicates that psychopathy is associated with abnormal function and structure in limbic and paralimbic areas. Psychopathy and substance use disorders are highly comorbid, but clinical experience suggests that psychopaths abuse drugs for different reasons than non-psychopaths, and that psychopaths do not typically experience withdrawal and craving upon becoming incarcerated. These neurobiological abnormalities may be related to psychopaths' different motivations for—and symptoms of—drug use. This study examined the modulatory effect of psychopathic traits on the neurobiological craving response to pictorial drug stimuli. Drug-related pictures and neutral pictures were presented and rated by participants while hemodynamic activity was monitored using functional magnetic resonance imaging. These data were collected at two correctional facilities in New Mexico using the Mind Research Network mobile magnetic resonance imaging system. The sample comprised 137 incarcerated adult males and females (93 females) with histories of substance dependence. The outcome of interest was the relation between psychopathy scores (using the Hare Psychopathy Checklist-Revised) and hemodynamic activity associated with viewing drug-related pictures vs. neutral pictures. There was a negative association between psychopathy scores and hemodynamic activity for viewing drug-related cues in the anterior cingulate, posterior cingulate, hippocampus, amygdala, caudate, globus pallidus, and parts of the prefrontal cortex. Psychopathic traits modulate the neurobiological craving response and suggest that individual differences are important for understanding and treating substance abuse.

Guanfacine effects on stress, drug craving and prefrontal activation in cocaine dependent individuals: preliminary findings

Cocaine dependence is associated with increased stress and drug cue-induced craving and physiological arousal but decreased prefrontal activity to emotional and cognitive challenge. As these changes are associated with relapse risk, we investigated the effects of α2 receptor agonist guanfacine on these processes. Twenty-nine early abstinent treatment-seeking cocaine dependent individuals were randomly assigned to either daily placebo or guanfacine (up to 3 mg) for four weeks. In a laboratory experiment, all patients were exposed to three 10-min guided imagery conditions (stress/stress, drug cue/drug cue, stress/drug cue), one per day, consecutively in a random, counterbalanced order. Subjective craving, anxiety and arousal as well as cardiovascular output were assessed repeatedly. Brain response to stress, drug cue and relaxing imagery was also assessed during a functional magnetic resonance (fMRI) imaging session. In the current study, guanfacine was found to be safe and well-tolerated. Lower basal heart rate and blood pressure was observed in the guanfacine versus placebo group. Guanfacine lowered stress and cue-induced nicotine craving and cue-induced cocaine craving, anxiety and arousal. The guanfacine group also showed increased medial and lateral prefrontal activity following stress and drug cue exposure compared with placebo. Data suggest further exploration of guanfacine is warranted in terms of its potential for reducing stress-induced and cue-induced drug craving and arousal.

New findings on biological factors predicting addiction relapse vulnerability

Relapse is a highly prevalent phenomenon in addiction. This paper examines the new research on identifying biological factors that contribute to addiction relapse risk. Prospective studies examining relapse risk are reviewed, and clinical, biological, and neural factors that predict relapse risk are identified. Clinical factors, patient-related factors, and subjective and behavioral measures such as depressive symptoms, stress, and drug craving all predict future relapse risk. Among biological measures, endocrine measures such as cortisol and cortisol/corticotropin (ACTH) ratio as a measure of adrenal sensitivity and serum brain-derived neurotrophic factor were also predictive of future relapse risk. Among neural measures, brain atrophy in the medial frontal regions and hyperreactivity of the anterior cingulate during withdrawal were identified as important in drug withdrawal and relapse risk. Caveats pertaining to specific drug abuse type and phase of addiction are discussed. Finally, significant implications of these findings for clinical practice are presented, with a specific focus on determining biological markers of relapse risk that may be used to identify those individuals who are most at risk of relapse in the clinic. Such markers may then be used to assess treatment response and develop specific treatments that will normalize these neural and biological sequelae so as to significantly improve relapse outcomes.

Glutamate receptors in extinction and extinction-based therapies for psychiatric illness

Some psychiatric illnesses involve a learned component. For example, in posttraumatic stress disorder, memories triggered by trauma-associated cues trigger fear and anxiety, and in addiction, drug-associated cues elicit drug craving and withdrawal. Clinical interventions to reduce the impact of conditioned cues in eliciting these maladaptive conditioned responses are likely to be beneficial. Extinction is a method of lessening conditioned responses and involves repeated exposures to a cue in the absence of the event it once predicted. We believe that an improved understanding of the behavioral and neurobiological mechanisms of extinction will allow extinction-like procedures in the clinic to become more effective. Research on the role of glutamate-the major excitatory neurotransmitter in the mammalian brain-in extinction has led to the development of pharmacotherapeutics to enhance the efficacy of extinction-based protocols in clinical populations. In this review, we describe what has been learned about glutamate actions at its three major receptor types (N-methyl-D-aspartate (NMDA) receptors, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and metabotropic glutamate receptors) in the extinction of conditioned fear, drug craving, and withdrawal. We then discuss how these findings have been applied in clinical research.

Community-dwelling cocaine-dependent men and women respond differently to social stressors versus cocaine cues

There are likely to be gender differences in determinants of relapse to drug use following abstinence in cocaine-dependent individuals. Cocaine-dependent women are more likely to attribute relapse to negative emotional states and interpersonal conflict. Cocaine dependence has also been linked to dysregulation of stress response and the hypothalamic pituitary adrenal (HPA) axis which may differ between genders. Subjective and HPA-axis responses to a social evaluative stressor, the Trier Social Stress Test (TRIER), and in vivo cocaine-related cues were examined in the present study.

RESULTS

There were no gender differences in magnitude of craving responses to the TRIER or the CUE. Both genders had a greater craving response to the CUE than to the TRIER, but the magnitude of the difference was greater for men than women (p=0.04). Cocaine-dependent subjects, compared to the control group, had significantly higher response throughout the TRIER (p<0.0001) and CUE (p<0.0001) testing sessions. There were no gender differences and no gender by cocaine interaction for ACTH responses to the TRIER, although women had lower baseline ACTH (p=0.049). On the CUE task, in contrast, female cocaine-dependent subjects had a more blunted ACTH response than did the other three groups (p=0.02). Female cocaine-dependent subjects also had a lower odds of a positive cortisol response to the TRIER as compared to the other three groups (OR=0.84, 95% CI=[0.02, 1.01]). During the CUE task, cocaine-dependent subjects had overall higher mean cortisol levels (p=0.0001), and higher odds of demonstrating a positive cortisol response to the CUE (OR=2.61, 95% CI=[1.11, 6.11]). No gender differences were found in ACTH responses to the CUE. The results are reviewed in the context of the existing literature on gender differences in cocaine dependence and potential implications for treatment are discussed.

Self-reports of interoceptive responses during stress and drug cue-related experiences in cocaine- and alcohol-dependent individuals

Cocaine dependence is associated with neuroadaptations in stress and reward pathways that could alter stress and drug-related experiences and associated interoceptive sensations and result in enhanced craving states. Subjective interoceptive emotional and physiological responses experienced in stressful and drug cue situations were examined in abstinent cocaine-dependent individuals. Fifty-six treatment engaged cocaine-dependent patients with comorbid alcohol abuse or dependence were interviewed to identify personal stressful, drug cue, and neutral situations using a scene construction questionnaire (SCQ) that includes an emotional and physiological response checklist. Using this checklist, subjects identified emotional and bodily sensations that they recently experienced in the stress- and drug-related scenarios. Kappa coefficients indicated fair to moderate but significant degree of concordance in heart (p < .01), perspiration (p < .05), stomach (p < .05), and blood flow (p < .01) sensations for both stress and drug cue scenarios, while the McNemar change test indicated differential endorsement of interoceptive responses in stress and drug cue situations for breathing (p < .05), stomach (p < .05), tension (p < .05), and chest (p < .05) sensations, and for sad (p < .01), anger (p < .01), and excitement (p < .01) responses. Increased heartbeat and tension, tears, and anger urges were most commonly endorsed in the stress scenarios (between 50% and 79%), whereas butterflies in stomach, increased heartbeat and tension, jittery, restless, and warm excitement (53%-73%) were the most frequently endorsed sensations in the drug cue-related experiences. These self-reported sensations comprise both general arousal and specific interoceptive responses pertaining to stress or drug cue-related experiences in cocaine dependence, with potential value in guiding treatments targeting craving reduction.

Modeling stress and drug craving in the laboratory: implications for addiction treatment development

Addition is a chronic relapsing illness affected by multiple social, individual and biological factors that significantly impact course and recovery of the illness. Stress interacts with these factors and increases addiction vulnerability and relapse risk, thereby playing a significant role in the course of the illness. This paper reviews our efforts in developing and validating laboratory models of stress and drug cue-related provocation to assess stress responses and stress-related adaptation in addicted individuals compared with healthy controls. Empirical findings from human laboratory and brain imaging studies are presented to show the specific stress-related dysregulation that accompanies the drug-craving state in addicted individuals. In order to adequately validate our laboratory model, we have also carefully examined relapse susceptibility in the addicted individuals and these data are reviewed. The overarching goal of these efforts is to develop a valid laboratory model to identify the stress-related pathophysiology in addiction with specific regard to persistent craving and compulsive seeking. Finally, the significant implications of these findings for the development of novel treatment interventions that target stress processes and drug craving to improve addiction relapse outcomes are discussed.

Region-specific involvement of AMPA/Kainate receptors in Fos protein expression induced by cocaine-conditioned cues

This study investigated the effects of the AMPA/Kainate receptor antagonist, NBQX, on cue-elicited cocaine-seeking behavior and concomitant changes in Fos protein expression. After cocaine self-administration training, rats underwent 24 days of abstinence during which they were exposed daily either to the self-administration environment with response-contingent cues previously paired with cocaine infusions available (Extinction group) or to an alternate environment (No Extinction group). Subsequently, rats were tested for cocaine-seeking behavior (i.e., operant responses without cocaine reinforcement) elicited by the cocaine-associated cues after pretreatment with either vehicle or NBQX (10 mg/kg, IP). NBQX markedly attenuated cue-elicited cocaine-seeking behavior relative to vehicle pretreatment in the No Extinction group and also decreased cue-elicited Fos protein expression in a region-specific manner in the anterior cingulate and orbitofrontal cortices, basolateral amygdala, nucleus accumbens core, and dorsal caudate-putamen, suggesting involvement of AMPA glutamate systems in specific subregions of the neuronal circuitry activated by cocaine cues.

Upregulation of Arc mRNA expression in the prefrontal cortex following cue-induced reinstatement of extinguished cocaine-seeking behavior

Cocaine-associated cues acquire incentive motivational effects that manifest as cue-elicited craving in humans and cocaine-seeking behavior in rats. Here we examine the hypothesis that neuronal processes associated with incentive motivational effects of cocaine cues involve increased expression of the plasticity-associated gene, Arc. Rats trained to self-administer cocaine subsequently underwent extinction training, during which cocaine-seeking behavior (i.e., responses without cocaine reinforcement) progressively decreased. Rats were then tested for cocaine-seeking behavior either with or without response-contingent presentations of light/tone cues that had been previously paired with cocaine infusions during self-administration training. Cues elicited reinstatement of cocaine-seeking behavior and were accompanied by increased Arc mRNA levels in the orbitofrontal, prelimbic, and anterior cingulate cortices, suggesting Arc involvement in conditioned plasticity associated with incentive motivational effects of cocaine cues. Additionally, rats with a history of cocaine self-administration and extinction exhibited upregulation of Arc expression in several limbic and cortical regions relative to saline-yoked controls regardless of cue exposure condition, suggesting persistent neuroadaptations involving Arc within these regions.

Involvement of cAMP-dependent protein kinase in the nucleus accumbens in cocaine self-administration and relapse of cocaine-seeking behavior

cAMP-dependent protein kinase (PKA) in the nucleus accumbens (NAc) has been implicated in cocaine addiction because (1) cocaine reinforcement is mediated by dopamine receptors that modulate cAMP formation, and (2) repeated exposure to cocaine upregulates the cAMP system in NAc neurons. This study tested PKA involvement in cocaine self-administration and relapse of cocaine-seeking behavior by infusing cAMP analogs that activate or inhibit PKA into the NAc of rats. Bilateral intra-NAc infusions of the PKA inhibitor Rp-cAMPS reduced baseline cocaine self-administration, shifted the dose-response curve for cocaine self-administration to the left, and induced relapse of cocaine-seeking behavior after extinction from cocaine self-administration, consistent with an enhancement of cocaine effects in each paradigm. In contrast, pretreatment with intra-NAc infusions of a PKA activator, Sp-cAMPS or dibutyryl cAMP, increased baseline cocaine self-administration during the second hour of testing and shifted the dose-response curve to the right, consistent with an antagonist-like action. After extinction from cocaine self-administration, similar infusions of Sp-cAMPS induced generalized responding at both drug-paired and inactive levers. As an index of PKA activity in vivo, NAc infusions of Rp-cAMPS reduced basal levels of dopamine-regulated phosphoprotein-32 phosphorylation and blocked amphetamine-induced increases in cAMP response element-binding protein (CREB) phosphorylation. Conversely, NAc infusions of Sp-cAMPS increased phosphorylation of CREB. Together, these results suggest that sustained upregulation of the cAMP system in the NAc after repeated cocaine exposure could underlie tolerance to cocaine reinforcement, whereas acute inhibition of this system may contribute to drug craving and relapse in addicted subjects.