How does stress increase risk of drug abuse and relapse?

Pregnenolone Reduces Stress-Induced Craving, Anxiety, and Autonomic Arousal in Individuals with Cocaine Use Disorder

Chronic cocaine use leads to adaptations in stress biology and in neuroactive steroid system. These adaptations are associated with high cocaine craving and increased relapse risk. This study tested whether potentiation of the neuroactive steroid system with the precursor pregnenolone (PREG) affects stress- and cue-induced cocaine craving, anxiety and autonomic response in individuals with cocaine use disorder (CUD). Thirty treatment-seeking individuals (21 Male, 9 Female) with CUD were randomized to placebo (PBO) or supraphysiologic PREG doses of 300 mg or 500 mg per day for 8 weeks. After 2 weeks of treatment, participants were exposed to 5-min personalized guided imagery provocation of stress, cocaine, or neutral/relaxing cues in a 3-day experiment, one condition per day on separate days, in a random, counterbalanced order. Repeated assessment of cocaine craving, anxiety, heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP) were assessed on each day. PREG significantly increased pregnenolone levels compared to PBO. Both PREG doses decreased stress- and cocaine cue-induced craving and reduced both stress- and cue-induced anxiety only in the 500 mg/day group. The 500 mg/day PREG group also displayed decreased stress-induced HR, SBP and DBP. Findings indicate that pregnenolone decreases stress- and cocaine cue-provoked craving and anxiety and reduces stress-induced autonomic arousal in individuals with CUD.

Alcohol’s Negative Emotional Side: The Role of Stress Neurobiology in Alcohol Use Disorder

This article is part of a Festschrift commemorating the 50th anniversary of the National Institute on Alcohol Abuse and Alcoholism (NIAAA). Established in 1970, first as part of the National Institute of Mental Health and later as an independent institute of the National Institutes of Health, NIAAA today is the world’s largest funding agency for alcohol research. In addition to its own intramural research program, NIAAA supports the entire spectrum of innovative basic, translational, and clinical research to advance the diagnosis, prevention, and treatment of alcohol use disorder and alcohol-related problems. To celebrate the anniversary, NIAAA hosted a 2-day symposium, “Alcohol Across the Lifespan: 50 Years of Evidence-Based Diagnosis, Prevention, and Treatment Research,” devoted to key topics within the field of alcohol research. This article is based on Dr. Sinha’s presentation at the event. NIAAA Director George F. Koob, Ph.D., serves as editor of the Festschrift.

Cue-induced cocaine craving enhances psychosocial stress and vice versa in chronic cocaine users

Stress and craving, it has been found, contribute to the development and maintenance of and relapse in cocaine use disorder. Chronic cocaine users (CU), previous research has shown, display altered physiological responses to psychosocial stress and increased vegetative responding to substance-related cues. However, how psychosocial stress and cue-induced craving interact in relation to the CU's physiological responses remains largely unknown. We thus investigated the interaction between acute psychosocial stress and cocaine-cue-related reactivity in 47 CU and 38 controls. In a crossed and balanced design, the participants were randomly exposed to a video-based cocaine-cue paradigm and the Trier Social Stress Test (TSST) or vice versa to investigate possible mutually augmenting effects of both stressors on physiological stress responses. Over the course of the experimental procedure, plasma cortisol, ACTH, noradrenaline, subjective stress, and craving were assessed repeatedly. To estimate the responses during the cocaine-cue paradigm and TSST, growth models and discontinuous growth models were used. Overall, though both groups did not differ in their endocrinological responses to the TSST, CU displayed lower ACTH levels at baseline. The TSST did not elevate craving in CU, but when the cocaine-cue video was shown first, CU displayed an enhanced cortisol response to the subsequent TSST. In CU, cocaine-cues robustly evoked craving but no physiological stress response, while cue-induced craving was intensified after the TSST. Taken together, though CU did not show an altered acute stress response during the TSST, stress and craving together seemed to have mutually augmenting effects on their stress response.

Excessive alcohol consumption after exposure to two types of chronic social stress: intermittent episodes vs. continuous exposure in C57BL/6J mice with a history of drinking

RATIONALE

The attraction to alcohol can be greatly increased when it is consumed in a social context. While pro-social interactions can potentiate voluntary alcohol drinking under some conditions, aversive social experience (i.e., social stress) can similarly intensify alcohol consumption.

OBJECTIVE

We sought to determine how exposure to different types of chronic social stress (i.e., intermittent episodes of social defeat or continuous social stress) influences alcohol consumption and the reinforcing effects of alcohol in mice with a history of drinking.

METHODS

Separate cohorts of male C57BL/6J mice were exposed to either 10 days of continuous or intermittent social defeat stress. In experiment 1, mice were assigned to 20% w/v alcohol consumption in a two-bottle choice protocol both prior to and after exposure to social defeat stress. In a second experiment, mice engaged in an operant response sequence to gain access to alcohol wherein completion of a fixed interval (FI; 5 min) schedule was reinforced with continuous access to alcohol (fixed ratio; FR1) for up to 1.8 g/kg. Alcohol-reinforced responding and subsequent alcohol consumption were assessed daily for 4 weeks prior to the 10-day social stress exposure and for 6-week post-stress. Machine learning was implemented to standardize the analysis of defeat behaviors exhibited by the intruder mouse during confrontation with an attacking resident.

RESULTS

In mice with a prior history of alcohol drinking, intermittent episodes of social defeat stress produced a significant increase in 20% EtOH consumption in preference over concurrently available water. This increased intake persisted for at least 6 weeks after the final social stress experience. Intermittently stressed mice also accelerated their anticipatory responding during the fixed interval component of the operant response chain that was reinforced by alcohol. Neither unstressed controls nor mice exposed to continuous social stress exhibited significant increases in alcohol consumption and alcohol reinforcement.

DISCUSSION

Episodic social defeat stress promotes the seeking and consumption of alcohol, extending earlier work to alcohol-experienced mice. We hypothesize that intermittent access to alcohol and intermittent episodes of social stress are additive and share common sensitizing neural mechanisms that engender excessive alcohol consumption.

Atypical working hours are associated with tobacco, cannabis and alcohol use: longitudinal analyses from the CONSTANCES cohort

BACKGROUND

This study examined prospective associations between atypical working hours with subsequent tobacco, cannabis and alcohol use as well as sugar and fat consumption.

METHODS

In the French population-based CONSTANCES cohort, 47,288 men and 53,324 women currently employed included between 2012 and 2017 were annually followed for tobacco and cannabis use. Among them, 35,647 men and 39,767 women included between 2012 and 2016 were also followed for alcohol and sugar and fat consumption. Three indicators of atypical working hours were self-reported at baseline: working at night, weekend work and non-fixed working hours. Generalized linear models computed odds of substance use and sugar and fat consumption at follow-up according to atypical working hours at baseline while adjusting for sociodemographic factors, depression and baseline substance use when appropriate.

RESULTS

Working at night was associated with decreased smoking cessation and increased relapse in women [odds ratios (ORs) of 0.81 and 1.25], increased cannabis use in men [ORs from 1.46 to 1.54] and increased alcohol use [ORs from 1.12 to 1.14] in both men and women. Weekend work was associated with decreased smoking cessation in women [ORs from 0.89 to 0.90] and increased alcohol use in both men and women [ORs from 1.09 to 1.14]. Non-fixed hours were associated with decreased smoking cessation in women and increased relapse in men [ORs of 0.89 and 1.13] and increased alcohol use in both men and women [ORs from 1.12 to 1.19]. Overall, atypical working hours were associated with decreased sugar and fat consumption.

CONCLUSIONS

The potential role of atypical working hours on substance use should be considered by public health policy makers and clinicians in information and prevention strategies.

Role of Orbitofrontal Cortex and Differential Effects of Acute and Chronic Stress on Motor Impulsivity Measured With 1-Choice Serial Reaction Time Test in Male Rats

BACKGROUND

Deficits in motor impulsivity, that is, the inability to inhibit a prepotent response, are frequently observed in psychiatric conditions. Several studies suggest that stress often correlates with higher impulsivity. Among the brain areas affected by stress, the orbitofrontal cortex (OFC) is notable because of its role in impulse control. OFC subregions with unique afferent and efferent circuitry play distinct roles in impulse control, yet it is not clear what OFC subregions are engaged during motor impulsivity tasks.

METHODS

In this study we used a rodent test of motor impulsivity, the 1-choice serial reaction time test, to explore activation of OFC subregions either during a well-learned motor impulsivity task or in a challenge task with a longer wait time that increases premature responding. We also examined the effects of acute inescapable stress, chronic intermittent cold stress and chronic unpredictable stress on motor impulsivity.

RESULTS

Fos expression increased in the lateral OFC and agranular insular cortex during performance in both the mastered and challenge conditions. In the ventral OFC, Fos expression increased only during challenge, and within the medial OFC, Fos was not induced in either condition. Inescapable stress produced a transient effect on premature responses in the mastered task, whereas chronic intermittent cold stress and chronic unpredictable stress altered premature responses in both conditions in ways specific to each stressor.

CONCLUSIONS

These results suggest that different OFC subregions have different roles in motor impulse control, and the effects of stress vary depending on the nature and duration of the stressor.

Transcutaneous cervical vagus nerve stimulation reduces behavioral and physiological manifestations of withdrawal in patients with opioid use disorder: A double-blind, randomized, sham-controlled pilot study

BACKGROUND

Opioid Use Disorder (OUD) is a serious public health problem, and the behavioral and physiological effects of opioid withdrawal can be a major impediment to recovery. Medication for OUD is currently the mainstay of treatment; however, it has limitations and alternative approaches are needed.

OBJECTIVE

The purpose of this study was to assess the effects of transcutaneous cervical vagus nerve stimulation (tcVNS) on behavioral and physiological manifestations of acute opioid withdrawal.

METHODS

Patients with OUD undergoing acute opioid withdrawal were randomly assigned to receive double blind active tcVNS (N = 10) or sham stimulation (N = 11) while watching neutral and opioid cue videos. Subjective opioid withdrawal, opioid craving, and anxiety were measured using a Visual Analogue Scale (VAS). Distress was measured using the Subjective Units of Distress Scale (SUDS), and pain was measured using the Numerical Rating Scale (NRS) for pain. Electrocardiogram signals were measured to compute heart rate. The primary outcomes of this initial phase of the clinical trial (ClinicalTrials.gov NCT04556552) were heart rate and craving.

RESULTS

tcVNS compared to sham resulted in statistically significant reductions in subjective opioid withdrawal (p = .047), pain (p = .045), and distress (p = .004). In addition, tcVNS was associated with lower heart rate compared to sham (p = .026). Craving did not significantly differ between groups (p = .11).

CONCLUSIONS

tcVNS reduces behavioral and physiological manifestations of opioid withdrawal, and should be evaluated in future studies as a possible non-pharmacologic, easily implemented approach for adjunctive OUD treatment.

High-Risk Drinkers Engage Distinct Stress-Predictive Brain Networks

BACKGROUND

Excessive alcohol intake is a major public health problem and can be triggered by stress. Heavy drinking in patients with alcohol use disorder also alters neural, physiological, and emotional stress responses. However, it is unclear whether adaptations in stress-predictive brain networks can be an early marker of risky drinking behavior.

METHODS

Risky social drinkers (regular bingers; n = 53) and light drinker control subjects (n = 51) aged 18 to 53 years completed a functional magnetic resonance imaging-based sustained stress protocol with repeated measures of subjective stress state, during which whole-brain functional connectivity was computed. This was followed by prospective daily ecological momentary assessment for 30 days. We used brain computational predictive modeling with cross-validation to identify unique brain connectivity predictors of stress in risky drinkers and determine the prospective utility of stress-brain networks for subsequent loss of control over drinking.

RESULTS

Risky drinkers had anatomically and functionally distinct stress-predictive brain networks (showing stronger predictions from visual and motor networks) compared with light drinkers (default mode and frontoparietal networks). Stress-predictive brain networks defined for risky drinkers selectively predicted future real-world stress levels for risky drinkers and successfully predicted prospective future real-world loss of control over drinking across all participants.

CONCLUSIONS

These results indicate adaptations in computationally derived stress-related brain circuitry among high-risk drinkers, suggesting potential targets for early preventive intervention and revealing the malleability of the neural processes that govern stress responses.

The association between cortisol-AA coordination in response to stress, negative urgency, and antisocial behavior in an urban adult sample

Prior study has found that the interplay of the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS) influences behavior problems in youth. Yet, little is known regarding this relationship in adults and traits related to the coordination of the stress systems. This study aims to extend the findings of a youth sample that the coordination between HPA and ANS, measured as cortisol and alpha-amylase (AA) respectively, was associated with antisocial behavior in adults. Additionally, this study tests whether cortisol-AA coordination was associated with a conceptually relevant trait, negative urgency. A heterogeneous sample of 124 adults (college students, active offenders, and demographically matched controls) was recruited from a southern city. Participants filled out instruments for negative urgency and antisocial behavior, completed a modified Trier Social Stress Test (mTSST), and provided four saliva samples before and after mTSST to assay for cortisol and AA. Results showed that cortisol-AA stress coordination was stronger among offenders than other groups. Cortisol-AA stress coordination was also positively associated with antisocial behavior and with negative urgency. This study found support for the interpretation that cortisol-AA stress coordination may indicate an overshooting ANS response at high emotional distress, and highlight the importance of the multisystem approach in gaining new insights into behavior research.

One-year into COVID-19 pandemic: Decision-making and mental-health outcomes and their risk factors

BACKGROUND

The COVID-19 pandemic represents an unprecedented worldwide crisis with serious socioeconomic, physical and mental health consequences. However, its long-lasting effects on both mental health and decision-making difficulties remain unexplored. This study aimed to determine the prevalence and severity of psychological disorders in Italy's populace one-year after the outbreak; further, we investigated potential risks impacting mental health and decision-making.

METHODS

In March 2021, 586 individuals (18-73 years) completed an online-survey plus a computerized delay discounting task for hypothetical money rewards.

RESULTS

Psychological symptoms prevalence exceeded the Italy's lockdown rates, with about one-third reporting moderate-to-extremely severe depression, another third anxiety, and the rest stress; mirrored by an increase of symptoms at clinically significant severity levels. One year into the pandemic, half of our sample presented at least one psychological problem, and one-third was at risk of developing a more clinically severe psychological outcome. Fear of job loss, loneliness and intolerance of uncertainty were among the major risk factors to mental health. Plus, social-relationships and financial uncertainty were key determinants of depression, while fear of COVID-19 infection predicted anxiety symptoms. For decision-making tendencies, elevated delay discounting rates, implying less future-oriented behaviors, were mostly predicted by increased job loss fear and older age (>35 years).

LIMITATIONS

This study provides cross-sectional evidence.

CONCLUSIONS

Depression, anxiety and stress levels were still alarming one-year into COVID-19. Individuals experiencing financial insecurity, loneliness and intolerance of uncertainty perhaps benefit most from early interventions. Governments need to implement timely recovery plans to reduce financial insecurity, given its significant mental health impact and decision-making outcomes.

Subjective stress and alcohol use among young adult and adult drinkers: Systematic review of studies using Intensive Longitudinal Designs

Background: Understanding how stress dynamically associates with alcohol use could provide a finer-grain resolution of drinking behavior, facilitating development of more effective and personalized interventions. The primary aim of this systematic review was to examine research using Intensive Longitudinal Designs (ILDs) to determine if greater naturalistic reports of subjective stress (e.g., those assessed moment-to-moment, day-to-day) in alcohol-drinkers associated with a) greater frequency of subsequent drinking, b) greater quantity of subsequent drinking, and c) whether between-/within-person variables moderate or mediate any relationships between stress and alcohol use. Methods: Using PRISMA guidelines, we searched EMBASE, PubMed, PsycINFO, and Web of Science databases in December 2020, ultimately identifying 18 eligible articles, representing 14 distinct studies, from a potential pool of 2,065 studies. Results: Results suggested subjective stress equivocally predicted subsequent alcohol use; in contrast, alcohol use consistently demonstrated an inverse relationship with subsequent subjective stress. These findings remained across ILD sampling strategy and most study characteristics, except for sample type (treatment-seeking vs. community/collegiate). Conclusions: Results appear to emphasize the stress-dampening effects of alcohol on subsequent stress levels and reactivity. Classic tension-reduction models may instead be most applicable to heavier-drinking samples and appear nuanced in lighter-drinking populations, and may depend on specific moderators/mediators (e.g., race/ethnicity, sex, relative coping-strategy use). Notably, a preponderance of studies utilized once-daily, concurrent assessments of subjective stress and alcohol use. Future studies may find greater consistency by implementing ILDs that integrate multiple within-day signal-based assessments, theoretically-relevant event-contingent prompts (e.g., stressor-occurrence, consumption initiation/cessation), and ecological context (e.g., weekday, alcohol availability).

Individual cortisol response to acute stress influences neural processing of sexual cues

BACKGROUND AND AIMS

Problematic pornography use can be conceptualized as an impulse control disorder or alternatively as a behavioral addiction. Stress is an important trigger in addiction, but less is known about the neural effect of stress in problematic pornography use. Therefore, we aimed at investigating the effect of stress during the anticipation and viewing of sexually explicit material while considering person characteristics related to potentially being at risk for developing problematic pornography use.

METHODS

In an fMRI study (n = 157 men, age: mean = 25.46, SD = 4.11) we used a sexual incentive delay task. A social stress test was used to induce stress in half of the participants. Salivary cortisol was repeatedly measured and person characteristics were considered moderating the effects of cortisol response.

RESULTS

We found no group differences in the neural responses during the anticipation phase, but a higher reactivity to sexual stimuli in the dACC in the stress group. Acute stress activated a pronounced cortisol response, which positively correlated with neural activations in the reward system (NAcc, dACC) to sexual cues. Further, the individual time spent on pornography use moderated the effect of cortisol in some regions of the reward system (dACC, mOFC).

DISCUSSION AND CONCLUSIONS

Our results suggest that acute stress related increases in cortisol can enhance the incentive value of cues announcing sexual stimuli. This might explain why acute stress is considered a trigger of pornography use and relapse and why individual stress response might be a risk factor for developing a problematic pornography use.

Understanding the role of urban social and physical environment in opioid overdose events using found geospatial data

Opioid use disorder is a serious public health crisis in the United States. Manifestations such as opioid overdose events (OOEs) vary within and across communities and there is growing evidence that this variation is partially rooted in community-level social and economic conditions. The lack of high spatial resolution, timely data has hampered research into the associations between OOEs and social and physical environments. We explore the use of non-traditional, "found" geospatial data collected for other purposes as indicators of urban social-environmental conditions and their relationships with OOEs at the neighborhood level. We evaluate the use of Google Street View images and non-emergency "311" service requests, along with US Census data as indicators of social and physical conditions in community neighborhoods. We estimate negative binomial regression models with OOE data from first responders in Columbus, Ohio, USA between January 1, 2016, and December 31, 2017. Higher numbers of OOEs were positively associated with service request indicators of neighborhood physical and social disorder and street view imagery rated as boring or depressing based on a pre-trained random forest regression model. Perceived safety, wealth, and liveliness measures from the street view imagery were negatively associated with risk of an OOE. Age group 50-64 was positively associated with risk of an OOE but age 35-49 was negative. White population, percentage of individuals living in poverty, and percentage of vacant housing units were also found significantly positive however, median income and percentage of people with a bachelor's degree or higher were found negative. Our result shows neighborhood social and physical environment characteristics are associated with likelihood of OOEs. Our study adds to the scientific evidence that the opioid epidemic crisis is partially rooted in social inequality, distress and underinvestment. It also shows the previously underutilized data sources hold promise for providing insights into this complex problem to help inform the development of population-level interventions and harm reduction policies.

Magnitude of Substance Use and Its Associated Factors Among the Medical Students in India and Implications for Medical Education: A Narrative Review

BACKGROUND

Medical students are at an increased risk of developing substance use and related problems (SURP) because of the inherent stress associated with the professional medical course apart from the developmental risk factors. However, this is under-researched. Moreover, a comprehensive review on the prevalence of SURP among the medical undergraduates (UGs) and associated factors is lacking from India. To fill this gap, the current research work is aimed to review the existing literature on the magnitude of the SURP among UGs of India and its determinants.

METHODS

PubMed, Medline, and Google Scholar databases were searched for the original articles studying the prevalence of SURP among medical UGs of India, published from inception till date. Non-original articles, studies on behavioral addictions, and those not directly assessing the prevalence of SURP among the medical UGs were excluded.

RESULTS

A total of 39 studies were found eligible for the review. Alcohol (current use: 3.2%-43.8%), followed by tobacco (3.7%-28.8%) and cannabis (1.6%-15%), were the common substances used by the medical students. Among the females, an increasing trend of substance use, particularly of nonprescription sedatives (even higher than males), alcohol, and smoking, was seen. Family history, peer pressure, transition from school to college life, and progression in the medical course were important associated factors.

CONCLUSION

Sensitizing medical students and college authorities, increasing the duration of training on SURP in medical curricula, and providing psychological support for the students with SURP could address this issue.

Neurodevelopmental origins of substance use disorders: Evidence from animal models of early-life adversity and addiction

Addiction is a chronic relapsing disorder with devastating personal, societal, and economic consequences. In humans, early-life adversity (ELA) such as trauma, neglect, and resource scarcity are linked with increased risk of later-life addiction, but the brain mechanisms underlying this link are still poorly understood. Here, we focus on data from rodent models of ELA and addiction, in which causal effects of ELA on later-life responses to drugs and the neurodevelopmental mechanisms by which ELA increases vulnerability to addiction can be determined. We first summarize evidence for a link between ELA and addiction in humans, then describe how ELA is commonly modeled in rodents. Since addiction is a heterogeneous disease with many individually varying behavioral aspects that may be impacted by ELA, we next discuss common rodent assays of addiction-like behaviors. We then summarize the specific addiction-relevant behavioral phenotypes caused by ELA in male and female rodents and discuss some of the underlying changes in brain reward and stress circuits that are likely responsible. By better understanding the behavioral and neural mechanisms by which ELA promotes addiction vulnerability, we hope to facilitate development of new approaches for preventing or treating addiction in those with a history of ELA.

No Significant Changes in Addictive and Problematic Behaviors During the COVID-19 Pandemic and Related Lockdowns: A Three-Wave Longitudinal Study

Introduction

The COVID-19 outbreak and related lockdowns brought substantial changes in people's lives and led to concerns about possible increases of addictive behaviors at the initial stages of the pandemic. To examine these concerns, the aim of the present study was to assess longitudinal changes in addictive and problematic behaviors (i.e., problematic social media use, Internet gaming disorder, gambling disorder, problematic pornography use, and compulsive sexual behavior disorder) over time during the COVID-19 pandemic.

Methods

Three waves of data collection took place in different stages of the COVID-19 outbreak in Hungary in a general population, from the first wave of lockdowns to the second and third waves of restrictions (May, 2020; N T1 = 1747; June-August, 2020; N T2 = 656; January, 2021; N T3 = 411). Latent growth curve models were calculated to assess the potential changes in addictive and problematic behaviors over time.

Results

Latent growth curve models showed that the sample varied in their initial scores, but there were no significant changes over time in any of the examined behaviors, except for compulsive sexual behavior disorder, which demonstrated a small but significant increase (i.e., positive and significant slope factor). However, the rate of this change was negligible. Overall, there were no noteworthy changes over time regarding any of the examined addictive and problematic behaviors.

Conclusion

Contrary to initial concerns, no substantial changes over time were observed regarding the examined addictive behaviors during the COVID-19 pandemic and related lockdowns. These findings indicate that those who had no previous problem with these addictive behaviors, might have not developed a problem, and those who had problem with either of the behaviors previously, might have not experienced a significant increase in their symptoms.

Prevention of relapse to methamphetamine self-administration by environmental enrichment: involvement of glucocorticoid receptors

RATIONALE

In rodents, environmental enrichment (EE) produces both preventive and curative effects on drug addiction, and this effect is believed to depend at least in part on EE's actions on the stress system.

OBJECTIVES

This study investigated whether exposure to EE during abstinence reduces methamphetamine seeking after extended self-administration. In addition, we investigated whether these effects are associated with alterations in the levels of glucocorticoid receptors (GR) in the brain and whether administration of GR antagonists blocks methamphetamine relapse.

METHODS

We allowed rats to self-administer methamphetamine for twenty 14-h sessions. After 3 weeks of abstinence either in standard (SE) or EE conditions, we measured methamphetamine seeking in a single 3-h session. Then, we used western blot techniques to measure GR levels in several brain areas. Finally, in an independent group of rats, after methamphetamine self-administration and abstinence in SE, we administered the GR antagonist mifepristone, and we investigated methamphetamine seeking.

RESULTS

Exposure to EE reduced methamphetamine seeking and reversed methamphetamine-induced increases in GR levels in the ventral and dorsal hippocampus. In addition, EE decreased GR levels in the amygdala in drug-naive animals, but this effect was prevented by previous exposure to methamphetamine. Administration of mifepristone significantly decreased methamphetamine seeking.

CONCLUSIONS

The anti-craving effects of EE are paralleled by restoration of methamphetamine-induced dysregulation of GR in the hippocampus. These results provide support for the hypothesis that the effect of EE on methamphetamine relapse is at least in part mediated by EE's action on the brain stress system.

Does Traumatic Brain Injury Cause Risky Substance Use or Substance Use Disorder?

There is a high co-occurrence of risky substance use among adults with traumatic brain injury (TBI), although it is unknown if the neurologic sequelae of TBI can promote this behavior. We propose that to conclude that TBI can cause risky substance use, it must be determined that TBI precedes risky substance use, that confounders with the potential to increase the likelihood of both TBI and risky substance use must be ruled out, and that there must be a plausible mechanism of action. In this review, we address these factors by providing an overview of key clinical and preclinical studies and list plausible mechanisms by which TBI could increase risky substance use. Human and animal studies have identified an association between TBI and risky substance use, although the strength of this association varies. Factors that may limit detection of this relationship include differential variability due to substance, sex, age of injury, and confounders that may influence the likelihood of both TBI and risky substance use. We propose possible mechanisms by which TBI could increase substance use that include damage-associated neuroplasticity, chronic changes in neuroimmune signaling, and TBI-associated alterations in brain networks.

Friend of the Devil: Negative Social Influences Driving Substance Use Disorders

Substance use disorders in humans have significant social influences, both positive and negative. While prosocial behaviors promote group cooperation and are naturally rewarding, distressing social encounters, such as aggression exhibited by a conspecific, are aversive and can enhance the sensitivity to rewarding substances, promote the acquisition of drug-taking, and reinstate drug-seeking. On the other hand, withdrawal and prolonged abstinence from drugs of abuse can promote social avoidance and suppress social motivation, accentuating drug cravings and facilitating relapse. Understanding how complex social states and experiences modulate drug-seeking behaviors as well as the underlying circuit dynamics, such as those interacting with mesolimbic reward systems, will greatly facilitate progress on understanding triggers of drug use, drug relapse and the chronicity of substance use disorders. Here we discuss some of the common circuit mechanisms underlying social and addictive behaviors that may underlie their antagonistic functions. We also highlight key neurochemicals involved in social influences over addiction that are frequently identified in comorbid psychiatric conditions. Finally, we integrate these data with recent findings on (±)3,4-methylenedioxymethamphetamine (MDMA) that suggest functional segregation and convergence of social and reward circuits that may be relevant to substance use disorder treatment through the competitive nature of these two types of reward. More studies focused on the relationship between social behavior and addictive behavior we hope will spur the development of treatment strategies aimed at breaking vicious addiction cycles.

Too Much Information? Excessive Media Use, Maladaptive Coping, and Increases in Problematic Cannabis Use during the COVID-19 Pandemic

During a health crisis like the COVID-19 pandemic, the public depends on the media for accurate and up-to-date information. However, frequent use of media for COVID-19-related information may be associated with maladaptive coping, and with increased prevalence of substance use. This study examined indirect associations between the frequency of media use for information about COVID-19 and increases in cannabis use behaviors through maladaptive coping strategies. We use data from an online survey of Israeli adult cannabis users (N = 440), conducted in May of 2020, to test associations between media use frequency for COVID-19 information and three problematic cannabis use behaviors: increased cannabis use, increased use alone, and increased use before midday. Among all respondents, 41% agreed that their cannabis use had increased since the onset of the pandemic. Analyses showed that higher frequency of media use was positively associated with all three indicators of problematic cannabis use, and that associations were partly mediated by maladaptive coping strategies. Higher frequency of media use for information about COVID-19 may be an indicator of difficulty with coping and of increased risk of escalation of cannabis use. These results have implications for assessing and mitigating the risk of coping-motivated cannabis use during a crisis.

Early life stress and substance use disorders: The critical role of adolescent substance use

Early life stress (ELS) is a well-established risk factor for many psychiatric and medical disorders, including substance use disorders (SUDs). The relationship between ELS and SUDs is complex and there are likely multiple pathways from ELS to adverse substance use outcomes. The association between ELS and substance use emerges in adolescence. Adolescence is a critical period in development during which substance exposure markedly increases risk for SUDs. Therefore, this review focuses on the literature supporting the hypothesis that ELS increases risk for the development of SUDs through its influence on adolescent substance use. We discuss studies substantiating the role of ELS in adolescent substance use and explore how internalizing and externalizing psychopathology may be antecedents of substance use in adolescence. We examine clinical work suggesting ELS sculpts the Hypothalamic-Pituitary-Adrenal (HPA) Axis and developing brain-particularly subcortical brain regions that underlie stress response, mesocorticolimbic brain systems associated with reward sensitivity, and prefrontal regions that underlie executive control-in a way that increases risk for adolescent substance use and SUDs. We further explore how substance use during adolescence alters structure and function of these same systems, and how brain changes following ELS and adolescent substance use may independently, additively, or interactively contribute to risk for addiction. We conclude by discussing how the current literature can inform interventions aimed at reducing risk for SUDs in individuals with a history of ELS.

Alcohol craving and withdrawal at treatment entry prospectively predict alcohol use outcomes during outpatient treatment

OBJECTIVE

Chronic alcohol use increases risk of alcohol craving and withdrawal symptoms (AW) as well as abstinence-related distress symptoms, in those entering alcohol use disorder (AUD) treatment. Here, we examined whether AW and alcohol craving in AUD patients entering outpatient treatment prospectively predicts future heavy drinking days/week (HDD) and additional alcohol use outcomes during 8-weeks of outpatient treatment, and their relationship to abstinence symptoms of depression, anxiety and sleep difficulties.

METHODS

Participants were 80 treatment-seeking adults with current DSM-5 AUD (39% female; 43% White; 20-60 years) who completed assessments of AW and alcohol craving and also alcohol abstinence symptoms of depression, anxiety, and sleep quality at treatment intake. Participants were prospectively followed using daily diaries for alcohol intake during 8-week of standardized weekly relapse prevention counseling to support recovery.

RESULTS

After accounting for demographic and pre-treatment alcohol use, greater alcohol craving at treatment entry predicted higher HDD (p < .013) as well as greater drinking days (DD: p < .004), average drinks per drinking day/week (AvgD: p < .001) and relapse to heavy drinking (p < .05), while higher levels of pretreatment AW symptoms interacted with treatment week to predict greater HDD (p < .018). Abstinence symptoms of depression, anxiety, and sleep difficulties were associated with craving and AW but did not predict any drinking-related outcomes.

CONCLUSIONS

These results provide evidence that increased alcohol craving and AW may serve as prognostic indicators of greater risk of heavy drinking in outpatient treatment. Findings suggest the need to evaluate craving and AW at outpatient treatment entry and develop targeted treatments to specifically address the effects of craving and AW on drinking outcomes in outpatient AUD treatment.

Intermittent social stress produces different short- and long-term effects on effort-based reward-seeking behavior

Previous studies show that intermittent social defeat (ISD) stress increases self-administration of psychostimulants, which suggests that ISD promotes reward-seeking behavior and, ultimately, increases vulnerability to develop drug abuse. The present study investigates whether ISD alters cost/benefit evaluations to promote reward-seeking behavior and whether these alterations are time-dependent. Male rats performed two different tasks that assessed their motivation to seek and consume food rewards. An effort-discounting task in which rats chose between less and more effortful options (i.e., 1 lever-press versus 2, 5, 10 or 20 lever-presses) associated with low- and high-reward (i.e., 1 sugar pellet versus 3 sugar pellets), respectively; and a progressive ratio task in which rats had to increase their effort (more lever presses) to obtain a sugar pellet. ISD consisted of exposing animals to social defeat once every three days for ten days (4 stress episodes). Rats were tested 24-48 h after stress episodes, and 1 week and 6 weeks after the last stress episode. In the effort-discounting task, stressed animals showed a decrease in their preference for high rewards associated with more effort (i.e., 10 and 20 lever-presses). These effects were transient and not maintained one week after stress. In the progressive ratio task, stressed animals showed an increase in the number of lever presses to obtain rewards that emerged six weeks after the last stress episode. These results suggest different short- and long-term effects on the motivation for rewards after ISD and indicate temporal dynamic adaptations in the function of the brain reward system.

Physical exertion at work and addictive behaviors: tobacco, cannabis, alcohol, sugar and fat consumption: longitudinal analyses in the CONSTANCES cohort

We examined the prospective association of physical exertion at work with subsequent tobacco, cannabis, alcohol use, and sugar and fat consumption. Volunteers of the French population-based CONSTANCES cohort currently employed were included from 2012 to 2017 for tobacco and cannabis outcomes (n = 100,612), and from 2012 to 2016 for alcohol and sugar and fat outcomes (n = 75,414). High level of physical exertion at work was defined as a score ≥ 12 at the Rating Perceived Exertion Borg scale. Substance use was self-reported and diet rich in sugar and fat was obtained from principal component analysis and analyzed as quartiles. Generalized linear models computed odds of substance use and sugar and fat consumption at follow-up according to baseline physical exertion at work, while adjusting for sociodemographic factors, depressive symptoms and baseline level of consumption. High physical exertion was associated with tobacco use with dose-dependent relationships. It was also associated with increased odds of cannabis use at least once per month compared to no use in the past and with increased odds of diet rich in sugar and fat. Hence, the role of physical exertion at work on tobacco and cannabis use and diet rich in sugar and fat should be tackled for information and prevention strategies.

Student-, Study- and COVID-19-Related Predictors of Students' Smoking, Binge Drinking and Cannabis Use before and during the Initial COVID-19 Lockdown in The Netherlands

Tobacco, alcohol and cannabis are commonly used among university students. However, student lives and their substance use have changed dramatically since the start of the COVID-19 pandemic. This study investigated the impact of COVID-19 on (trends in) weekly smoking, weekly binge drinking and weekly cannabis use in Dutch university students and investigated associated student-, study- and COVID-19-related characteristics. Between April and June 2020, several Dutch higher educational institutes invited their students to participate in an online survey. Data of 9967 students (M_age = 22.0 (SD = 2.6); N_female = 7008 (70.3%)) were available for analyses. Overall, weekly smoking remained stable (±11.5%), weekly binge drinking decreased (from 27.8% to 13.9%) and weekly cannabis use increased (from 6.7% to 8.6%). Male gender, not living with parents, being a bachelor student, having less financial resources and less adherence to the COVID-19 measures were found to increase the risk of substance use (before/during the first COVID-19 lockdown). Additionally, male gender, not living with parents, being a bachelor student, not being born in the Netherlands and having a student loan contributed to the likelihood of increased substance use during COVID-19. Patterns of characteristics contributing to the likelihood of decreased weekly substance use during COVID-19 were less clear. The risk factors male gender, not living with parents and being a bachelor student do not only contribute to the likelihood of using substances but also contribute to the likelihood of increased use during a lockdown. Prevention and intervention programs should especially target these risk groups.

Prevention of glutamate excitotoxicity in lateral habenula alleviates ethanol withdrawal-induced somatic and behavioral effects in ethanol dependent mice

Ethanol withdrawal commonly leads to anxiety-related disorder, a central factor toward negative reinforcement leading to relapse. The lateral habenula (LHb), an epithalamic nucleus, has emerged to be critical for both reward and aversion processing. Recent studies have also implicated the hyperactivity of LHb, adding to the emergence of negative emotional states during withdrawal from addictive drugs. Herein, we have studied the effects of glutamate transporter inhibitor (PDC), GluN2B-containing NMDAR antagonist (Ro25-6981), and intracellular calcium chelator (BAPTA-AM) injection in LHb on ethanol withdrawal symptoms. We found that ethanol 4 g/kg 20 % w/v intragastric (i.g.) for 10 days followed by 24 h of withdrawal showed a significant increase in somatic signs characterized by vocalization, shaking, and scratching. It also increased locomotor activity and anxiety-like behavior, collectively showing expression of ethanol withdrawal symptoms. The intra-LHb administration of PDC (0.5 ng) worsened the effect of ethanol withdrawal, whereas Ro25-6981 (2 and 4 ng) and BAPTA-AM (6.5 and 13 ng) significantly reversed ethanol withdrawal-induced behavior evident by a decrease in somatic signs, locomotor activity, and anxiety-like behavior. Further, pretreatment of Ro25-6981 and BAPTA-AM reduced the neuronal loss, whereas PDC increased it compared to the vehicle-treated group, as evidenced by NeuN staining. Altogether, our results suggest that increased glutamate, GluN2B activation, and likely calcium increase indicative of glutamate excitotoxicity-induced neuronal loss in LHb possibly endorse the emergence of ethanol withdrawal symptoms, while their inhibition might help in alleviating the ethanol withdrawal symptoms.

Establishment of a biomarker of peripheral stress in opioid addicts based on the hypothalamic-pituitary-adrenal axis-The improvement effect of exercise

PURPOSE

This study aims to investigate the relationship between peripheral blood oxytocin (OT), vasopressin (AVP), and subjectively perceived stress and cortisol in male opioid addicts based on the hypothalamic-pituitary-adrenal (HPA) axis. We also investigate the impact of exercise on reducing subjectively perceived stress, craving level, negative reinforcement, anxiety, sleep quality, plasma OT, AVP, and cortisol levels.

METHODS

Participants were divided into 28 subjects in the low-stress control group (LSC group), 29 subjects in the medium-high stress control group (MTHSC group), and 28 subjects in the moderate-high-stress exercise group (MTHSE group), based on their subjectively perceived stress levels. Subjects in the MTHSE group performed 12 weeks of combined aerobic resistance training (60 min per day, 5 days per week). Plasma OT, AVP, and cortisol concentrations were analyzed via Elisa. PSQI was used to assess the subjective perceived stress, craving, negative reinforcement, anxiety, and sleep quality level, respectively. Mixed-effects ANOVA and Pearson correlation analysis were employed to explore the impact and correlation between different parameters.

RESULT

Plasma OT levels significantly increased (95% CI: -7.48, -2.26), while plasma AVP (95% CI: 2.90, 4.10), and cortisol (95% CI: 19.76, 28.17) levels significantly decreased in the MTHSE group after exercise. The PSS (95% CI: 1.756, 4.815), "Desire and Intention" (95% CI: 1.60, 2.71), and "Negative reinforcement" (95% CI: 0.85, 1.90) (DDQ), SAS (95% CI: 17.51, 26.06), and PSQI (95% CI: 1.18, 3.25) scores of the MTHSE group were significantly decreased after exercise. Plasma OT, plasma cortisol, craving, negative reinforcement and anxiety were negatively correlated. Plasma AVP was positively correlated with craving.

CONCLUSION

As an auxiliary treatment, exercise improves the plasma OT, AVP, and cortisol levels of opioid addicts, and reduces their subjective perceived stress level, desire, negative reinforcement level, anxiety level, and sleep quality. In addition, peripheral plasma OT, AVP, and cortisol may play a role as potential peripheral biomarkers to predict stress in male opioid addicts.

Inflammatory Markers in Substance Use and Mood Disorders: A Neuroimaging Perspective

Chronic exposure to addictive drugs in substance use disorders and stressors in mood disorders render the brain more vulnerable to inflammation. Inflammation in the brain, or neuroinflammation, is characterized by gliosis, microglial activation, and sustained release of cytokines, chemokines, and pro-inflammatory factors compromising the permeability of the blood-brain barrier. There is increased curiosity in understanding how substance misuse and/or repeated stress exposure affect inflammation and contribute to abnormal neuronal activity, altered neuroplasticity, and impaired cognitive control, which eventually promote compulsive drug-use behaviors and worsen mood disorders. This review will emphasize human imaging studies to explore the link between brain function and peripheral markers of inflammation in substance use disorders and mood disorders.

COVID-19 Pandemic and Stress: Coping with the New Normal

COVID-19 is the new face of pandemic. Since the discovery of COVID-19 in December 2019 in Wuhan, China, it has spread all over the world and the numbers are increasing day by day. Anyone can be susceptible to this infection but children, older adults, pregnant women, and people with comorbidity are more vulnerable. The spread of coronavirus resulted in closures of schools, businesses, and public spaces worldwide and forced many communities to enact stay at home orders, causing stress to all irrespective of their age, gender, or socioeconomic status. The sudden and unexpected changes caused by the outbreak of coronavirus are overwhelming for both adults and children, causing stress and evoking negative emotions like fear, anxiety, and depression, among different populations. The aim of the paper is to ascertain how stress during this pandemic inculcates various psychological health issues like depression anxiety, OCD, panic behavior, and so on. Further, the paper is an attempt to identify different general as well as population specific coping strategies to reduce the stress level among individuals and prevent various stress-induced psychological disorders with reference to different theories and research articles.

Cell-Type-Specific Adaptions in Striatal Medium-Sized Spiny Neurons and Their Roles in Behavioral Responses to Drugs of Abuse

Drug addiction is defined as a compulsive pattern of drug-seeking- and taking- behavior, with recurrent episodes of abstinence and relapse, and a loss of control despite negative consequences. Addictive drugs promote reinforcement by increasing dopamine in the mesocorticolimbic system, which alters excitatory glutamate transmission within the reward circuitry, thereby hijacking reward processing. Within the reward circuitry, the striatum is a key target structure of drugs of abuse since it is at the crossroad of converging glutamate inputs from limbic, thalamic and cortical regions, encoding components of drug-associated stimuli and environment, and dopamine that mediates reward prediction error and incentive values. These signals are integrated by medium-sized spiny neurons (MSN), which receive glutamate and dopamine axons converging onto their dendritic spines. MSN primarily form two mostly distinct populations based on the expression of either DA-D1 (D1R) or DA-D2 (D2R) receptors. While a classical view is that the two MSN populations act in parallel, playing antagonistic functional roles, the picture seems much more complex. Herein, we review recent studies, based on the use of cell-type-specific manipulations, demonstrating that dopamine differentially modulates dendritic spine density and synapse formation, as well as glutamate transmission, at specific inputs projecting onto D1R-MSN and D2R-MSN to shape persistent pathological behavioral in response to drugs of abuse. We also discuss the identification of distinct molecular events underlying the detrimental interplay between dopamine and glutamate signaling in D1R-MSN and D2R-MSN and highlight the relevance of such cell-type-specific molecular studies for the development of innovative strategies with potential therapeutic value for addiction. Because drug addiction is highly prevalent in patients with other psychiatric disorders when compared to the general population, we last discuss the hypothesis that shared cellular and molecular adaptations within common circuits could explain the co-occurrence of addiction and depression. We will therefore conclude this review by examining how the nucleus accumbens (NAc) could constitute a key interface between addiction and depression.

Neurobiological Bases of Alcohol Consumption After Social Stress

The urge to seek and consume excessive alcohol is intensified by prior experiences with social stress, and this cascade can be modeled under systematically controlled laboratory conditions in rodents and non-human primates. Adaptive coping with intermittent episodes of social defeat stress often transitions to maladaptive responses to traumatic continuous stress, and alcohol consumption may become part of coping responses. At the circuit level, the neural pathways subserving stress coping intersect with those for alcohol consumption. Increasingly discrete regions and connections within the prefrontal cortex, the ventral and dorsal striatum, thalamic and hypothalamic nuclei, tegmental areas as well as brain stem structures begin to be identified as critical for reacting to and coping with social stress while seeking and consuming alcohol. Several candidate molecules that modulate signals within these neural connections have been targeted in order to reduce excessive drinking and relapse. In spite of some early clinical failures, neuropeptides such as CRF, opioids, or oxytocin continue to be examined for their role in attenuating stress-escalated drinking. Recent work has focused on neural sites of action for peptides and steroids, most likely in neuroinflammatory processes as a result of interactive effects of episodic social stress and excessive alcohol seeking and drinking.

Neural Underpinnings of Social Stress in Substance Use Disorders

BACKGROUND

Drug addiction is a complex brain disorder that is characterized by craving, withdrawal, and relapse, which can be perpetuated by social stress. Stemming from an acute life event, chronic stress, or trauma in a social context, social stress has a major role in the initiation and trajectory of substance use. Preclinical literature shows that early life stress exposure and social isolation facilitate and enhance drug self-administration. Epidemiological evidence links childhood adversity to increased risk for drug use and demonstrates that cumulative stress experiences are predictive of substance use severity in a dose-dependent manner. Stress and drug use induce overlapping brain alterations leading to downregulation or deficits in brain reward circuitry, thereby resulting in greater sensitization to the rewarding properties of drugs. Though stress in the context of addiction has been studied at the neural level, a gap in our understanding of the neural underpinnings of social stress in humans remains.

METHODS

We conducted a systematic review of in vivo structural and functional neuroimaging studies to evaluate the neural processes associated with social stress in individuals with substance use disorder. Results were considered in relation to participants' history of social stress and with regard to the effects of social stress induced during the neuroimaging paradigm.

RESULTS

An exhaustive search yielded 21 studies that matched inclusion criteria. Social stress induces broad structural and functional neural effects in individuals with substance use disorder throughout their lifespan and across drug classes. A few patterns emerged across studies: (1) many of the brain regions altered in individuals who were exposed to chronic social stress and during acute stress induction have been implicated in addiction networks (including the prefrontal cortex, insula, hippocampus, and amygdala); (2) individuals with childhood maltreatment and substance use history had decreased gray matter or activation in regions of executive functioning (including the medial prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex), the hippocampal complex, and the supplementary motor area; and (3) during stress-induction paradigms, activation in the anterior cingulate cortex, caudate, and amygdala was most commonly observed.

CONCLUSIONS/IMPLICATIONS

A distinct overlap is shown between social stress-related circuitry and addiction circuitry, particularly in brain regions implicated in drug-seeking, craving, and relapse. Given the few studies that have thoroughly investigated social stress, the evidence accumulated to date needs to be replicated and extended, particularly using research designs and methods that disentangle the effects of substance use from social stress. Future clinical studies can leverage this information to evaluate the impact of exposure to trauma or adverse life events within substance use research. Expanding knowledge in this emerging field could help clarify neural mechanisms underlying addiction risk and progression to guide causal-experimental inquiry and novel prevention and treatment strategies.

Is There an Association Between Salivary Cortisol and Dropping Out of Inpatient Substance Addiction Treatments? A Prospective Repeated Measures Study

Several studies have found an association between salivary cortisol levels and dropping out of inpatient substance addiction treatment programs. The results are mixed due to variations in the study design and the lack of standardized routines for cortisol assessment. The aim of this study was to investigate whether there was (1) an association between salivary cortisol levels and dropping out from inpatient substance addiction treatments; (2) higher predictive validity for dropout in one of the cortisol indexes: Area Under the Curve with respect to ground (AUC_G) or Daily Cortisol Slope (DCS); (3) an interaction effect with time for each cortisol index; and (4) different dropout rates for sex and patients in short-term versus long-term treatment programs. This was a prospective, repeated-measures observational study. Patients (n = 173) were recruited from 2 inpatient facilities in the central region of Norway between 2018 and 2021. Salivary cortisol was measured 4 times during the treatment period, with 8 samples collected over 2 consecutive days at each time point. Cortisol levels were calculated using the cortisol indices AUC_G and DCS. Dropout was used as the outcome measure at each time point. Associations were calculated using a logistic linear regression. The results suggest a main effect of AUC_G, whereby higher levels reduce dropout risk (OR = 0.92, P = .047). An interaction with time in treatment also revealed a higher dropout risk (OR = 1.09, P = .044) during week 4 of the treatment, depending on the AUC_G. These results support using AUC_G as the recommended index when assessing cortisol, and that the relationship between cortisol levels and length of treatment should be further investigated.

The histone methyltransferase G9a mediates stress-regulated alcohol drinking

The epigenetic enzyme G9a is a histone methyltransferase that dimethylates lysine 9 on histone H3 (H3K9me2), and in the adult nucleus accumbens (NAc), G9a regulates multiple behaviors associated with substance use disorder. We show here that chronic intermittent ethanol (CIE) exposure in male mice reduced both G9a and H3K9me2 levels in the adult NAc, but not dorsal striatum. Viral-mediated reduction of G9a in the NAc had no effects on baseline volitional ethanol drinking or escalated alcohol drinking produced by CIE exposure; however, NAc G9a was required for stress-regulated changes in ethanol drinking, including potentiated alcohol drinking produced by activation of the kappa-opioid receptor. In addition, we observed that chronic systemic administration of a G9a inhibitor, UNC0642, also blocked stress-potentiated alcohol drinking. Together, our findings suggest that chronic alcohol use, similar to other abused substances, produces a NAc-selective reduction in G9a levels that serves to limit stress-regulated alcohol drinking. Moreover, our findings suggest that pharmacological inhibition of G9a might provide a novel therapeutic approach to treat stress-induced alcohol drinking, which is a major trigger of relapse in individuals suffering from AUD.

Reviewing the role of the orexinergic system and stressors in modulating mood and reward-related behaviors

In this review study, we aimed to introduce the orexinergic system as an important signaling pathway involved in a variety of cognitive functions such as memory, motivation, and reward-related behaviors. This study focused on the role of orexinergic system in modulating reward-related behavior, with or without the presence of stressors. Cross-talk between the reward system and orexinergic signaling was also investigated, especially orexinergic signaling in the ventral tegmental area (VTA), the nucleus accumbens (NAc), and the hippocampus. Furthermore, we discussed the role of the orexinergic system in modulating mood states and mental illnesses such as depression, anxiety, panic, and posttraumatic stress disorder (PTSD). Here, we narrowed down our focus on the orexinergic signaling in three brain regions: the VTA, NAc, and the hippocampus (CA1 region and dentate gyrus) for their prominent role in reward-related behaviors and memory. It was concluded that the orexinergic system is critically involved in reward-related behavior and significantly alters stress responses and stress-related psychiatric and mood disorders.

Maternal Separation Stress Affects Voluntary Ethanol Intake in a Sex Dependent Manner

Maternal separation (MS) stress is a predictive animal model for evaluating the effects of early stress exposure on alcohol use disorders (AUD). The extended amygdala (AMY) is a complex circuit involved in both stress- and ethanol-related responses. We hypothesized that MS stress may increase ethanol consumption in adulthood, as well as augment neuronal activity in extended AMY, in a sex-dependent manner. We aimed to investigate the influence of MS stress on the ethanol consumption of male and female mice, and the involvement of extended amygdala sub-nuclei in this process. The C57BL/6J pups were subjected to 180min of MS, from postnatal day (PND) 1 to 14. The control group was left undisturbed. On PND 45, mice (n=28) in cages were exposed to a bottle containing 20% ethanol (w/v) for 4h during the dark period of the light-dark cycle, for 3weeks. Afterward, mice underwent ethanol self-administration training in operant chambers under fixed ratio (FR) schedule. Then, subjects were tested under 2h sessions of a progressive-ratio (PR) schedule of reinforcement (the last ratio achieved was considered the breaking point), and at the end, a 4h session of FR schedule (binge-intake). An immunohistochemistry assay for Fos protein was performed in Nucleus Accumbens (NAcc), Bed Nucleus of Stria Terminalis (BNST), and AMY. Our results showed that in the third week of training, the female MS group consumed more ethanol than the respective control group. The MS group presented increased breakpoint parameters. Female control group and male MS group were more resistant to bitter quinine taste. Increased Fos-immunoreactive neurons (Fos-IR) were observed in the central nucleus of AMY, but not in NAcc nor BNST in male maternal-separated mice. Maternal separation stress may influence ethanol intake in adulthood, and it is dependent on the sex and reinforcement protocol.

Alcohol Abuse and Insomnia Disorder: Focus on a Group of Night and Day Workers

The sleep-wake cycle plays a fundamental role in maintaining the physiological balance of our body. Its alteration favours the genesis of several organic alterations and diseases including sleep disorders and the consumption of several substances of abuse. It has been reported that the work activity, especially that carried out during the night, is able to influence the sleep-wake cycle, promoting the development of insomnia, which, in turn, would subject the worker to a stressful condition such as to encourage adverse behaviour such as the use/abuse of psychotropic substances. Based on the above premises, the aim of our research was to evaluate, in night workers: (i) the pattern of consumption of alcoholic beverages; (ii) the presence of insomnia; and (iii) the possible correlation between alcohol consumption and insomnia disorder. We used the AUDIT-C test (the abbreviated version of the Alcohol Use Disorders Identification Test) and the Insomnia Severity Index to assess alcohol consumption and insomnia disorder, respectively. All questionnaires were completed by workers of both sexes belonging to different types of work activities, exclusively day or night. The results of our research show a higher propensity of night workers to consume alcoholic beverages than those who work during daytime hours, often in binge-drinking mode. In addition, an increase in the amount of alcohol consumed was found to be related to insomnia disorder, especially in night workers. This study provides further awareness of the importance of the negative impact of alcohol consumption on sleep quality in night workers.

Dopaminergic and noradrenergic modulation of stress-induced alterations in brain activation associated with goal-directed behaviour

BACKGROUND

Acute stress is thought to reduce goal-directed behaviour, an effect purportedly associated with stress-induced release of catecholamines. In contrast, experimentally increased systemic catecholamine levels have been shown to increase goal-directed behaviour. Whether experimentally increased catecholamine function can modulate stress-induced reductions in goal-directed behaviour and its neural substrates, is currently unknown.

AIM

To assess whether and how experimentally induced increases in dopamine and noradrenaline contribute to the acute stress effects on goal-directed behaviour and associated brain activation.

METHODS

One hundred participants underwent a stress induction protocol (Maastricht acute stress test; MAST) or a control procedure and received methylphenidate (MPH) (40 mg, oral) or placebo according to a 2 × 2 between-subjects design. In a well-established instrumental learning paradigm, participants learnt stimulus-response-outcome associations, after which rewards were selectively devalued. Participants' brain activation and associated goal-directed behaviour were assessed in a magnetic resonance imaging scanner at peak cortisol/MPH concentrations.

RESULTS

The MAST and MPH increased physiological measures of stress (salivary cortisol and blood pressure), but only MAST increased subjective measures of stress. MPH modulated stress effects on activation of brain areas associated with goal-directed behaviour, including insula, putamen, amygdala, medial prefrontal cortex, frontal pole and orbitofrontal cortex. However, MPH did not modulate the tendency of stress to induce a reduction in goal-directed behaviour.

CONCLUSION

Our neuroimaging data suggest that MPH-induced increases in dopamine and noradrenaline reverse stress-induced changes in key brain regions associated with goal-directed behaviour, while behavioural effects were absent. These effects may be relevant for preventing stress-induced maladaptive behaviour like in addiction or binge eating disorder.

Factors modulating the incubation of drug and non-drug craving and their clinical implications

It was suggested in 1986 that cue-induced cocaine craving increases progressively during early abstinence and remains high during extended periods of time. Clinical evidence now supports this hypothesis and that this increase is not specific to cocaine but rather generalize across several drugs of abuse. Investigators have identified an analogous incubation phenomenon in rodents, in which time-dependent increases in cue-induced drug seeking are observed after abstinence from intravenous drug or palatable food self-administration. Incubation of craving is susceptible to variation in magnitude as a function of biological and/or the environmental circumstances surrounding the individual. During the last decade, the neurobiological correlates of the modulatory role of biological (sex, age, genetic factors) and environmental factors (environmental enrichment and physical exercise, sleep architecture, acute and chronic stress, abstinence reinforcement procedures) on incubation of drug craving has been investigated. In this review, we summarized the behavioral procedures adopted, the key underlying neurobiological correlates and clinical implications of these studies.

Psychological and biological resilience modulates the effects of stress on epigenetic aging

Our society is experiencing more stress than ever before, leading to both negative psychiatric and physical outcomes. Chronic stress is linked to negative long-term health consequences, raising the possibility that stress is related to accelerated aging. In this study, we examine whether resilience factors affect stress-associated biological age acceleration. Recently developed "epigenetic clocks" such as GrimAge have shown utility in predicting biological age and mortality. Here, we assessed the impact of cumulative stress, stress physiology, and resilience on accelerated aging in a community sample (N = 444). Cumulative stress was associated with accelerated GrimAge (P = 0.0388) and stress-related physiologic measures of adrenal sensitivity (Cortisol/ACTH ratio) and insulin resistance (HOMA). After controlling for demographic and behavioral factors, HOMA correlated with accelerated GrimAge (P = 0.0186). Remarkably, psychological resilience factors of emotion regulation and self-control moderated these relationships. Emotion regulation moderated the association between stress and aging (P = 8.82e-4) such that with worse emotion regulation, there was greater stress-related age acceleration, while stronger emotion regulation prevented any significant effect of stress on GrimAge. Self-control moderated the relationship between stress and insulin resistance (P = 0.00732), with high self-control blunting this relationship. In the final model, in those with poor emotion regulation, cumulative stress continued to predict additional GrimAge Acceleration even while accounting for demographic, physiologic, and behavioral covariates. These results demonstrate that cumulative stress is associated with epigenetic aging in a healthy population, and these associations are modified by biobehavioral resilience factors.

Psychosocial Factors Predict the Level of Substance Craving of People with Drug Addiction: A Machine Learning Approach

This study aimed to explore which factors had a greater impact on substance craving in people with substance use and the direction of the impact. A total of 895 male substance users completed questionnaires regarding substance craving, psychological security, positive psychological capital, interpersonal trust, alexithymia, impulsivity, parental conflict, aggression behavior, life events, family intimacy, and deviant peers. Calculating the factor importance by gradient boosting method (GBM), found that the psychosocial factors that had a greater impact on substance craving were, in order, life events, aggression behavior, positive psychological capital, interpersonal trust, psychological security, impulsivity, alexithymia, family intimacy, parental conflict, and deviant peers. Correlation analysis showed that life events, positive psychological capital, interpersonal trust, psychological security, and family intimacy negatively predicted substance craving, while aggression behavior, impulsivity, alexithymia, parental conflict, and deviant peers positively predicted substance cravings. These findings have important implications for the prevention and intervention of substance craving behavior among substance users.

Putting Together Pieces of the Lateral Septum: Multifaceted Functions and Its Neural Pathways

The lateral septum (LS) is implicated as a hub that regulates a variety of affects, such as reward, feeding, anxiety, fear, sociability, and memory. However, it remains unclear how the LS, previously treated as a structure of homogeneity, exhibits such multifaceted functions. Emerging evidence suggests that different functions of the LS are mediated largely by its diverse input and output connections. It has also become clear that the LS is a heterogeneous region, where its dorsal and ventral poles play dissociable and often opposing roles. This functional heterogeneity can often be explained by distinct dorsal and ventral hippocampal inputs along the LS dorsoventral axis, as well as antagonizing connections between LS subregions. Similarly, outputs from LS subregions to respective downstream targets, such as hypothalamic, preoptic, and tegmental areas, also account for this functional heterogeneity. In this review, we provide an updated perspective on LS subregion classification, connectivity, and functions. We also identify key questions that have yet to be addressed in the field.

Social Support Effects on Neural Stress and Alcohol Reward Responses

Social support (SS), or having people to depend on during times of stress, may offer an emotional and neurological buffer to problem drinking. Specifically, SS may modulate reward and stress-related brain responses to mitigate perceptions of alcohol reward and stress. There is limited evidence, however, on this topic and specifically on brain networks that may modulate SS effects on stress and alcohol reward. Here we present a review of the current literature on this topic as well as data from a large community sample of 115 social drinkers. Findings from a novel fMRI task viewing alcohol cue, stress, and neutral images, in separate blocks, while providing ratings on subjective feelings of alcohol craving, stress, and arousal are included. Lower SS significantly predicted greater alcohol craving during alcohol cue and stress conditions, higher baseline levels of stress, and greater arousal in the alcohol cue, relative to neutral condition. Remarkably, individuals with low SS showed greater reward activation (ventral medial prefrontal cortex (VmPFC) and ventral striatum) during alcohol cue exposure, while those with high SS showed no such activation (p < 0.001, family wise error corrected at 0.05). Furthermore, individuals with lower SS showed greater stress circuit (VmPFC, dorsal striatum, and periaqueductal gray) activation not observed in the high SS groups. Both groups showed increased amygdala activation under stress condition. The findings support the notion that SS is a powerful modulator of stress response and reward motivation. High SS buffers neural and subjective stress responses, while low SS potentiates greater reward seeking with higher alcohol craving and greater brain activation during alcohol cue exposure. Previous research and current results suggest the need to further explore the role of SS in those at risk of developing alcohol use disorder and assess novel prevention strategies to boost SS in at-risk drinkers.

Differential effects of recent versus past traumas on mood, social support, binge drinking, emotional eating and BMI, and on neural responses to acute stress

Traumatic stress is associated with risk of psychiatric and physical illnesses. However, the differential and separable effects of past versus recent traumas on maladaptive coping and neural responses are not known. We conducted two studies to assess separate and combined effects of cumulative recent and past trauma on health outcomes (study 1) and on neural responses to acute stress exposure in a subsample of individuals (study 2). Study 1 assessed a large cohort of 677 community adults cross-sectionally, and findings indicated that both high recent (within the last 12 months) and past trauma (prior to the last twelve months) were associated with more physical and psychological symptoms, including increased depression (all p's < .05). However, recent trauma alone was associated with higher problematic alcohol use, a greater maximum number of alcohol drinks consumed, greater emotional eating scores, higher state and trait anxiety scores, and poorer lifestyle habits (all p's < .05). Past trauma alone was associated with higher BMI, decreased social support, and a lower average cortisol relative to ACTH ratio (all p's < .02). Study 2 involving a functional brain scan on a subsample (N = 75) indicated greater recent trauma was associated with a hyperactive response in the ventromedial prefrontal cortex (VmPFC) to neutral-relaxed exposure, but blunted VmPFC response to acute stress exposure (p < .05: whole brain corrected-WBC). By contrast, high past trauma was associated with a hyper-sensitized neural response to stress in the cortico-limbic-striatal regions (p < .05, WBC) critical for reward and emotion processing. Together, these findings suggest differential neurobehavioral and health effects of cumulative past versus recent trauma exposure.

Attenuated beta-adrenergic response to stress and increased anticipation and perception of social threat in women high on perceived criticism

A large amount of literature has demonstrated that Perceived Criticism (PC)-that is, how critical a person believes a given relative is of him or her-is associated with negative clinical outcomes in a broad range of psychiatric disorders (e.g., relapse or recurrence of symptoms). A possible mechanism behind the predictive value of PC might be its association with the stress regulation process. This is the first study to investigate differences in the psychophysiological response to a social stress task in young women (mean age = 21.66, SD = 4.33) with high (n = 40) and low (n = 39) PC. The physiological response was investigated by measuring two markers of sympathetic activity mediated by acetylcholine (skin conductance levels; SCL) and adrenaline (pre-ejection period; PEP) levels, respectively, and one marker of the vagally-mediated parasympathetic system (heart rate variability; HRV). Moreover, we investigated the anticipation and perception of social threat, in the form of criticism, during the stressor. No differences in HRV and SCL were observed. However, individuals high in PC mobilized fewer cardiovascular resources to deal with the stressor, reflected in an attenuated beta-adrenergic response (i.e., lower PEP response). Women high in PC also expected and perceived more criticism during the stress task. Together, our results indicate that women high in PC make heightened social threat anticipation and interpretations, and they tend to engage in less active coping when exposed to socially evaluated stressful events. Our findings indicate that PC is associated with underlying stress-related psychobiological vulnerabilities that may contribute to its association with negative clinical outcomes.

Stress-induced vulnerability to develop cocaine addiction depends on cofilin modulation

Actin dynamics in dendritic spines can be associated with the neurobiological mechanisms supporting the comorbidity between stress exposure and cocaine increase rewards. The actin cytoskeleton remodeling in the nucleus accumbens (NA) has been implicated in the expression of stress-induced cross-sensitization with cocaine. The present study evaluates the involvement of cofilin, a direct regulator of actin dynamics, in the impact of stress on vulnerability to cocaine addiction. We assess whether the neurobiological mechanisms that modulate repeated-cocaine administration also occur in a chronic restraint stress-induced cocaine self-administration model. We also determine if chronic stress induces alterations in dendritic spines through dysregulation of cofilin activity in the NA core. Here, we show that the inhibition of cofilin expression in the NA core using viral short-hairpin RNA is sufficient to prevent the cocaine sensitization induced by chronic stress. The reduced cofilin levels also impede a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor surface expression enhancement and promote the reduction of head diameter in animals pre-exposed to stress after a cocaine challenge in the NA core. Moreover, downregulation of cofilin expression prevents facilitation of the acquisition of cocaine self-administration (SA) in male rats pre-exposed to chronic stress without modifying performance in sucrose SA. These findings reveal a novel, crucial role for cofilin in the neurobiological mechanisms underpinning the comorbidity between stress exposure and addiction-related disorders.