The role of stress in drug addiction. An integrative review

Comparison of psychological reactions, fear of negative evaluation and mood-emotional alexithymia in successful and unsuccessful people in addiction recovery: a survey of Baluchestan in Iran

The aim of this study was to examine psychological responses, fear of negative evaluation, and mood-related alexithymia in individuals in addiction recovery who have succeeded versus those who have not. This study employed a causal-comparative design. The research focused on all individuals who sought treatment for addiction at clinics within a specific district in Zahedan city, Iran. Out of the group, 100 individuals were chosen (50 who successfully stopped their addiction and 50 who were unsuccessful in their attempts to quit) through convenience sampling. Data were gathered using the depression, Anxiety, and Stress Scale (DASS-21), Lori's fear of negative evaluation scale, and Toronto's mood-emotional alexithymia scale. Data were examined through both descriptive statistics and multivariate analysis of variance. Based on the results, successful and unsuccessful individuals in addiction recovery showed varying levels of depression, stress, fear of negative evaluation, and having no fear of negative evaluation (p < .01). In simpler terms, unsuccessful individuals in addiction recovery scored higher in depression, stress, fear of negative evaluation, inability feeling emotions, inability to express feelings compared to successful individuals. But successful individuals in addiction recovery obtained higher mean scores than unsuccessful individuals in addiction recovery on having no fear of negative evaluation. According to the findings psychological reactions, fear of negative evaluation and mood-emotional alexithymia play a significant role in addiction treatment and can be helpful in addiction recovery in unsuccessful people in addiction recovery. It is feasible to enhance the effectiveness of addiction recovery by implementing interventions that target the reduction of depression, stress, fear of negative evaluation, and alexithymia.

Coping Mechanisms Utilized by Individuals With Drug Addiction in Overcoming Challenges During the Recovery Process: A Qualitative Meta-synthesis

OBJECTIVES

Recovery from drug addiction often poses challenges for the recovering person. The coping mechanisms employed by these individuals to resist temptations and manage stress play a key role in the healing process. This study was conducted to explore the coping strategies or techniques that individuals with addiction use to handle stress and temptation while undergoing treatment.

METHODS

A qualitative meta-synthesis approach was utilized to critically evaluate relevant qualitative research. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines were used for article selection, with these standards applied to 4 academic databases: Scopus, PubMed, ProQuest, and CINAHL. The present review included studies published between 2014 and 2023, selected based on pre-established inclusion criteria. The quality of the studies was assessed using the Critical Appraisal Skills Programme Qualitative Studies Checklist. This review was registered with the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD42024497789.

RESULTS

The analysis of 13 qualifying qualitative articles revealed 5 major themes illustrating the coping mechanisms employed in the pursuit of recovery by individuals who use drugs. These themes include seeking social support, as well as psychological coping strategies, spiritual experiences, professional interventions, and the enhancement of awareness.

CONCLUSIONS

Among individuals with drug addiction, coping mechanisms are crucial for resisting stress and temptations throughout the recovery process. Healthcare professionals, as medical specialists, can establish more thorough and effective plans to support these patients on their path to recovery.

Age moderates the association of optimism on craving during substance use disorder treatment

BACKGROUND

Optimism, characterized by a positive expectancy toward future outcomes, has garnered attention for its potential role in influencing well-being and may be a protective factor in substance use disorder (SUD) treatment. This study evaluated the relationship of optimism and craving among those in substance use disorder SUD treatment.

METHODS

Drawing from a cohort of 4201 individuals in residential SUD treatment programs, this study used both cross-sectional and longitudinal assessment to examine tonic (steady-state) and cue-induced (phasic) cravings across individuals primarily using eight classes of substances. Previous research established that optimism increases during adulthood and peaks during an individual's 50s. This study sought to establish if the association between optimism and craving is moderated by age during the first week of treatment and if that relationship changes over the course of treatment both within and between-person.

RESULTS

This study found a negative correlation between optimism and craving intensity. Elevated optimism scores correlated with substantially reduced levels of both tonic (β = -0.31, p < 0.001) and cue-induced (β = -0.29, p < 0.001) cravings. Age was a significant moderator of the relationship between optimism and craving such that as individuals age, the potency of optimism in mitigating cravings gradually attenuates (interaction for tonic craving: β = 0.06, p < 0.001; interaction for cue-induced craving: β = 0.05, p < 0.001). Reflected in the fact that in older individuals' cravings tended to converge toward lower or moderate levels, regardless of their optimism scores.

CONCLUSIONS

By delineating the contemporaneous association between high optimism and lower cravings, the study suggests that interventions aimed at fostering optimism may represent an avenue to improve the effectiveness of SUD treatment, especially in emerging adults.

Emerging Theories of Allostatic-Interoceptive Overload in Neurodegeneration

Recent integrative multilevel models offer novel insights into the etiology and course of neurodegenerative conditions. The predictive coding of allostatic-interoception theory posits that the brain adapts to environmental demands by modulating internal bodily signals through the allostatic-interoceptive system. Specifically, a domain-general allostatic-interoceptive network exerts adaptive physiological control by fine-tuning initial top-down predictions and bottom-up peripheral signaling. In this context, adequate adaptation implies the minimization of prediction errors thereby optimizing energy expenditure. Abnormalities in top-down interoceptive predictions or peripheral signaling can trigger allostatic overload states, ultimately leading to dysregulated interoceptive and bodily systems (endocrine, immunological, circulatory, etc.). In this context, environmental stress, social determinants of health, and harmful exposomes (i.e., the cumulative life-course exposition to different environmental stressors) may interact with physiological and genetic factors, dysregulating allostatic interoception and precipitating neurodegenerative processes. We review the allostatic-interoceptive overload framework across different neurodegenerative diseases, particularly in the behavioral variant frontotemporal dementia (bvFTD). We describe how concepts of allostasis and interoception could be integrated with principles of predictive coding to explain how the brain optimizes adaptive responses, while maintaining physiological stability through feedback loops with multiple organismic systems. Then, we introduce the model of allostatic-interoceptive overload of bvFTD and discuss its implications for the understanding of pathophysiological and neurocognitive abnormalities in multiple neurodegenerative conditions.

Behavioural traits related with resilience or vulnerability to the development of cocaine-induced conditioned place preference after exposure of female mice to vicarious social defeat

Exposure to stress induced by intermittent repeated social defeat (IRSD) increases vulnerability to the development of cocaine-induced conditioned place preference (CPP) among male mice; however, some defeated mice are resilient to these effects of stress. In the present study we evaluated the effects of vicarious IRSD (VIRSD) in female mice and explored behavioural traits that are potentially predictive of resilience. C57BL/6 female mice (n = 28) were exposed to VIRSD, which consisted of the animals witnessing a short experience of social defeat by a male mouse on postnatal day (PND) 47, 50, 53 and 56. The control group (n = 10) was not exposed to stress. Blood samples were collected on PND 47 and 56 for corticosterone and interleukin-6 determinations. On PND 57-58, female mice performed several behavioural tests (elevated plus maze, hole-board, object recognition, social interaction, TST and splash tests). Three weeks later, the effects of cocaine (1.5 mg/kg) on the CPP paradigm were assessed. VIRSD decreased corticosterone levels (on PND 56), increased interleukin-6 levels, enhanced novelty-seeking, improved recognition memory and induced anxiety- and depression-like symptoms. Control and VIRSD female mice did not acquire CPP, although some stressed individuals with certain behavioural traits - including a high novelty-seeking profile or the development of depression-like behaviour in the splash test shortly after VIRSD - acquired cocaine CPP. Our results confirm that some behavioural traits of female mice are associated with vulnerability or resilience to the long-term effects of social stress on cocaine reward, as previously observed in males.

The perception of Mandarin speech conveying communicative functions in Chinese heroin addicts

Drug addiction can cause severe damage to the human brain, leading to significant problems in cognitive processing, such as irritability, speech distortions, and exaggeration of negative stimuli. Speech plays a fundamental role in social interaction, including both the production and perception. The ability to perceive communicative functions conveyed through speech is crucial for successful interpersonal communication and the maintaining good social relationships. However, due to the limited number of previous studies, it remains unclear whether the cognitive disorder caused by drug addiction affects the perception of communicative function conveyed in Mandarin speech. To address this question, we conducted a perception experiment involving sixty male participants, including 25 heroin addicts and 35 healthy controls. The experiment aimed to examine the perception of three communicative functions (i.e., statement, interrogative, and imperative) under three background noise conditions (i.e., no noise, SNR [Signal to Noise Ratio] = 10, and SNR = 0). Eight target sentences were first recorded by two native Mandarin speakers for each of the three communicative functions. Each half was then combined with Gaussian White Noise under two background noise conditions (i.e., SNR = 10 and SNR = 0). Finally, 48 speech stimuli were included in the experiment with four options provided for perceptual judgment. The results showed that, under the three noise conditions, the average perceptual accuracies of the three communicative functions were 80.66% and 38% for the control group and the heroin addicts, respectively. Significant differences were found in the perception of the three communicative functions between the control group and the heroin addicts under the three noise conditions, except for the recognition of imperative under strong noise condition (i.e., SNR = 0). Moreover, heroin addicts showed good accuracy (around 50%) in recognizing imperative and poor accuracy (i.e., lower than the chance level) in recognizing interrogative. This paper not only fills the research gap in the perception of communicative functions in Mandarin speech among drug addicts but also enhances the understanding of the effects of drugs on speech perception and provides a foundation for the speech rehabilitation of drug addicts.

Connectome-based predictive modeling of Internet addiction symptomatology

Internet addiction symptomatology (IAS) is characterized by persistent and involuntary patterns of compulsive Internet use, leading to significant impairments in both physical and mental well-being. Here, a connectome-based predictive modeling approach was applied to decode IAS from whole-brain resting-state functional connectivity in healthy population. The findings showed that IAS could be predicted by the functional connectivity between prefrontal cortex with the cerebellum and limbic lobe and connections of the occipital lobe with the limbic lobe and insula lobe. The identified edges associated with IAS exhibit generalizability in predicting IAS within an independent sample. Furthermore, we found that the unique contributing network, which predicted IAS in contrast to the prediction networks of alcohol use disorder symptomatology (the range of symptoms and behaviors associated with alcohol use disorder), prominently comprised connections involving the occipital lobe and other lobes. The current data-driven approach provides the first evidence of the predictive brain features of IAS based on the organization of intrinsic brain networks, thus advancing our understanding of the neurobiological basis of Internet addiction disorder (IAD) susceptibility, and may have implications for the timely intervention of people potentially at risk of IAD.

Proposing an integrative, dynamic and transdiagnostic model for addictions: dysregulation phenomena of the three main modes of the predostatic mind

Several theories have been proposed to explain the complex diagnostic aspects related to addiction disorders and their development. Recent frameworks tend to focus on dimensional perspectives of symptoms rather than categorical systems, since substance use disorders are frequently comorbid with other psychiatric and especially personality disorders. However, useful transdiagnostic models that could integrate clinical evaluation derived from neuroscientific theories are lacking. In the present manuscript, the authors propose a model based on a new paradigm, in an attempt to better explain this complex, multifaceted phenomenon. The new paradigm presupposes that emotions and behavior are a response to risk prediction. Individuals make choices and engage in actions to manage potential risks/rewards in order to seek or maintain homeostasis in their internal and external environments - a mechanism that the authors call predostatic (predictive mechanism with homeostatic purpose). The model considers three main modes of the predostatic mind: (1) Alarm Mode, activated by high and/or imminent risk prediction; (2) Seek Mode, activated by long-term risk or reward prediction; and (3) Balance Mode, a self-regulating state of mind related to low risk prediction, a soothing system and a calm state. Addiction is seen as a chronic dysregulation of organism systems leading to internalizing or externalizing phenomena mainly related to the Seek and Alarm Modes, which are persistently activated by reward and risk prediction, respectively, thus hindering Balance. Addiction neuroscience research has shown that chronic drug use or engagement in addictive behaviors can lead to neuroadaptations in the brain reward circuitry, disrupting normal balance and the regulation of reward processes. This dysregulation can contribute to persistent drug-seeking/addictive behaviors despite negative consequences. This newly proposed dynamic and integrative model, named dysregulation based on externalizing and internalizing phenomena of the three main modes of the predostatic mind (DREXI3), proposes six dysregulation dimensions with basic emotional and behavioral symptoms, such as neurophysiological alterations, impulsivity, compulsion, cognitive impairment/psychosis, mood, and anxiety/anger. In this paper, the authors explain the rationale behind DREXI3 and present some hypothetical clinical examples to better illustrate the use of the model in clinical practice. The development of this innovative model could possibly guide tailored treatment interventions in the addiction field.

Organic cation transporters in psychiatric and substance use disorders

Psychiatric and substance use disorders inflict major public health burdens worldwide. Their widespread burden is compounded by a dearth of effective treatments, underscoring a dire need to uncover novel therapeutic targets. In this review, we summarize the literature implicating organic cation transporters (OCTs), including three subtypes of OCTs (OCT1, OCT2, and OCT3) and the plasma membrane monoamine transporter (PMAT), in the neurobiology of psychiatric and substance use disorders with an emphasis on mood and anxiety disorders, alcohol use disorder, and psychostimulant use disorder. OCTs transport monoamines with a low affinity but high capacity, situating them to play a central role in regulating monoamine homeostasis. Preclinical evidence discussed here suggests that OCTs may serve as promising targets for treatment of psychiatric and substance use disorders and encourage future research into their therapeutic potential.

Protective and risk factors associated with substance use coping among healthcare workers during the COVID-19 pandemic

Background

Healthcare workers (HCWs) experienced high levels of stress and mental health consequences associated with the COVID-19 pandemic, which may have contributed to unhealthy coping behaviors, such as substance use coping (SUC). This study aimed to understand the extent of and predictors of SUC.

Methods

The sample consisted of 263 HCWs in North Central Florida. Univariable and multivariable logistic regression analyses investigated whether moral injury and other work risk factors, protective factors, and clinically relevant symptoms (i.e., work exhaustion, interpersonal disengagement, depression, anxiety, and/or PTSD) were associated with likelihood of SUC.

Results

Clinically relevant levels of interpersonal disengagement and anxiety increased the likelihood of SUC. Mediational analyses found that interpersonal disengagement and anxiety explained 54.3% of the relationship between Self Moral Injury and SUC and explained 80.4% of the relationship between professional fulfillment and SUC.

Conclusion

Healthcare supervisors should be aware that providers who are experiencing moral injury and less professional fulfillment may be experiencing significant interpersonal disengagement and anxiety, which could lead to SUC. Future studies should examine the effects of implementing targeted prevention and treatment interventions, along with longitudinal outcomes related to SUC behaviors.

Higher perceived stress during admission is associated with shorter retention in short-term residential substance use disorder treatment

Introduction

Over one million people in the U.S. received residential treatment for a substance use disorder (SUD) in 2020. Longer treatment retention is associated with better outcomes (e.g., reduced substance use). Entering treatment with higher stress may be associated with shorter retention. This paper examines the impact of perceived stress at admission on SUD treatment retention in short-term residential treatment.

Methods

A sample of 271 treatment episodes with admissions between October 2019 and February 2020 were collected from de-identified records of an urban mid-Atlantic adult 28-day short-term residential SUD treatment facility. Treatment completion involved finishing 28 days. Sociodemographic, substance use, perceived stress, and treatment discharge variables were analyzed. Bivariate analyses examined differences between treatment completion and early discharge, and Cox regression investigated the effect of perceived stress on treatment retention with covariates.

Results

The sample was primarily male (73.8%) and non-Hispanic Black (71.6%). A majority used heroin as their primary substance (54.6%) and reported polysubstance use (72.3%). About half (51.3%) completed treatment, and completed an average of 18.7 (SD = 10.7) days. Those who prematurely discharged from treatment stayed an average of 8.9 (SD = 7.0) days. The Cox regression model found that higher perceived stress (adjusted hazard ratio (AHR) = 1.028; 95% CI = [1.005, 1.053], p =.019) and a race/ethnicity other than non-Hispanic Black (AHR = 1.546, 95% CI = [1.037, 2.305], p =.033) predicted premature discharge.

Conclusions

Perceived stress at admission is associated with shorter treatment retention. Early stress management interventions may help increase treatment retention.

Experiencing stress impact on adolescent repetitive nonsuicidal self-injury: The Mediating role of emotion dysregulation and maladaptive cognitive schemas

BACKGROUND

Repetitive nonsuicidal self-injury (R-NSSI) is a growing concern in adolescents and is associated with various mental health problems. However, little is known about the potential psychology and addiction mechanisms of R-NSSI in adolescents. This study aimed to examine the mediating effects of emotion dysregulation and maladaptive cognitive schemas based on the Interaction of Person-Affect-Cognition-Execution (I-PACE) model and the integrated model of NSSI among adolescents who repeatedly engage in NSSI.

METHODS

This longitudinal study was conducted in two waves with 6-month lags. A total of 3925 adolescents (Mage = 13.22 ± 0.86 years, 42 % female) were recruited from three middle schools. Relevant questionnaires were used to evaluate stressful life events, emotion dysregulation, maladaptive cognitive schemas, NSSI, and NSSI addictive features. The structural equation modeling approach was conducted separately for adolescents who engaged in occasional NSSI (O-NSSI) and those who engaged in R-NSSI.

RESULTS

Results showed that emotion dysregulation played a significant mediating role in the associations between stressful life events and NSSI frequency, and both maladaptive cognitive schemas and emotion dysregulation played a significant mediating role in the associations between stressful life events and NSSI addictive features in adolescents who engaged in R-NSSI but not in those who engaged in O-NSSI.

LIMITATIONS

The main limiting factor is self-reported data.

CONCLUSIONS

These findings contribute to the understanding of the psychological and addictive mechanisms involved in R-NSSI. Both emotion dysregulation and maladaptive cognitive schemas could be a suitable therapeutic target to reduce R-NSSI in the context of stress during adolescence.

Critical appraisal and systematic review of genes linked with cocaine addiction, depression and anxiety

Recent lifestyle changes have resulted in tremendous peer pressure and mental stress, and increased the incidences of chronic psychological disorders; like addiction, depression and anxiety (ADA). In this context, the stress-tolerance levels vary amongst individuals and genetic factors play prominent roles. Vulnerable individuals may often be drawn towards drug-addiction to combat stress. This systematic review critically appraises the relationship of various genetic factors linked with the incidences of ADA development. For coherence, we focused solely on cocaine as a substance of abuse in this study. Online scholarly databases were used to screen pertinent literature using apt keywords; and the final retrieval included 42 primary-research articles. The major conclusion drawn from this systematic analysis states that there are 51 genes linked with the development of ADA; and 3 (BDNF, PERIOD2 and SLC6A4) of them are common to all the three aspects of ADA. Further, inter-connectivity analyses of the 51 genes further endorsed the central presence of BDNF and SLC6A4 genes in the development of ADA disorders. The conclusions derived from this systematic study pave the way for future studies for the identification of diagnostic biomarkers and drug targets; and for the development of novel and effective therapeutic regimens against ADA.

Mediated and moderated associations between cumulative lifetime stressor exposure, emotional dysregulation, impulsivity, and lifetime alcohol use: A cross-sectional scoping study of UK drinkers

Stress, trait impulsivity, and emotional dysregulation are independent predictors of alcohol use and misuse, but little is known about the potential mechanisms that link these risk factors together. To address this issue, we carried out an exploratory cross-sectional study, on UK-based participants. Our preregistered, hypothesised theoretical framework was that emotional dysregulation mediates the association between cumulative lifetime stressor exposure and lifetime alcohol use. We also hypothesised that heightened impulsivity would strengthen these relations. As hypothesised, emotional dysregulation fully mediated the relation between cumulative lifetime stressor exposure and lifetime alcohol use. Several facets of impulsivity moderated these associations. For example, as levels of negative urgency increased, the associations between cumulative lifetime stressor exposure and emotional dysregulation, emotional dysregulation and lifetime alcohol use, and lifetime stress exposure and lifetime alcohol use, via emotional dysregulation, strengthened. These preliminary findings propose a theoretically framed model which integrates several prominent risk-factors for alcohol misuse, extending prior research and generating interesting and novel lines of enquiry for longitudinal and cross-cultural analyses. The findings also highlight the potential clinical utility of screening for lifetime stress exposure while tailoring personalised treatment interventions.

Effects of Acute Exercise on Affect, Anxiety, and Self-Esteem in Poly-Substance Dependent Inpatients

INTRODUCTION

Negative affect and anxiety frequently precede the onset of drug use in those with substance use disorder (SUD). Low self-esteem may increase the risk of relapse. We examined the short-term effects of exercise on affect, anxiety, and self-esteem in inpatients with poly-SUD.

METHODS

This is a multicenter randomized control trial (RCT) with a crossover design. Thirty-eight inpatients (37.3 ± 6.4 years; 84% male) from three clinics participated in 45 min of soccer, circuit training, and control condition (psychoeducation) in a random order. Positive and negative affect (PANAS), state anxiety (single item), and self-esteem (Rosenberg SE-scale) were measured immediately before, immediately after, 1-h, 2-h, and 4-h post-exercise. Heart rate and ratings of perceived exertion were taken. Effects were assessed using linear mixed effects models.

RESULTS

Compared to the control condition, there were significant post-exercise improvements in positive affect (β = 2.99, CI = 0.39: 5.58), self-esteem (β = 1.84, CI = 0.49: 3.20), and anxiety (β = -0.69, CI = -1.34: -0.04) after circuit training (shown) and soccer. Effects persisted 4-h post-exercise. Reductions in negative affect were observed 2-h (circuit training: β = -3.39, CI = -6.35: -1.51) and 4-h (soccer: β = -3.71, CI = -6.03: -1.39) post-exercise, respectively.

CONCLUSION

Moderately strenuous exercise undertaken in naturalistic settings may improve mental health symptoms in poly-SUD inpatients for up to 4-h post-exercise.

Congruence couple therapy for alcohol use and gambling disorders with comorbidities (part II): Targeted areas and mechanisms of change

Study of change mechanisms is important to advance theory development and to reveal the active components that make a critical difference in treatment. Improved outcomes in a randomized controlled trial that favored Congruence Couple Therapy (CCT) vs individual-based Treatment-as-Usual (TAU) were correlated within each group. Partial correlations were used to test for mediation effects. The aggregate correlation coefficient of improved variables in addiction and mental health, couple adjustment, emotion regulation (ER) and life stress was moderate for CCT and weak for TAU. CCT showed greater number of mediating effects among improved variables than TAU. The prominence of the process mechanism of improved ER with its mediating effects for addiction and psychiatric symptoms evidenced in both groups is noteworthy, but ER improvement was significantly associated with improved couple adjustment only in CCT. Reduction in life stress in CCT was associated with a broader range of improvements in CCT compared to TAU. Correlation patterns were substantiated by CCT participants' endorsement of treatment targets emphasizing relationship, communication, emotion, problem solving, addiction and intergenerational issues of trauma. TAU participants reported significantly lower endorsements for these treatment targets. The correlation of ER and couple adjustment suggested as a key process mechanism should be further elucidated in future studies to differentiate relationship-based vs individual-based models and their respective outcomes for primary clients and partners. These findings are considered preliminary, requiring larger samples and advanced modelling among variables to provide a more profound mechanism analysis.

Short- and long-term effects of chronic toluene exposure on spatial memory in adolescent and adult male Wistar rats

Addiction to toluene-containing volatile inhalants is of significant medical and social concern, particularly among youth. These concerns are underscored by the fact that the majority of adult abusers of toluene started as teenagers. Surprisingly, however, the lasting effects of chronic toluene exposure, especially in various age groups, have not been well investigated. Recently, we reported that adolescent and adult male Wistar rats show differential responses to chronic toluene exposure in recognition memory tasks. Since different cognitive functions may be differentially affected by drugs of abuse, we used the same model to evaluate the short- and long-term effects of chronic toluene on spatial learning and memory using Morris water maze. Daily exposure to toluene (2000 ppm) for 40 days (5 min/day) resulted in age-dependent behavioral changes. For example, only adolescent animals showed a decrease in time and distance travelled to find the hidden platform 24 h after the last toluene exposure. In contrast, only adult rats exhibited a decrease in acquisition time and distance travelled at 90 days' post toluene exposure. Our data provide further support for the contention that age-dependent responses should be taken into consideration in interventional attempts to overcome specific detrimental consequences of chronic toluene exposure.

Measuring attentional bias in smokers during and after psychosocial stress induction with a Trier Social Stress Test in virtual reality via eye tracking

Introduction

Attentional bias (AB) is considered an important factor not only in the etiology of addiction, but also with respect to relapse. However, evidence for the predictive ability of AB for relapse is not robust. One reason for this might be fluctuations of AB due to stress. Therefore, the current study investigated whether AB was present during and after stress induction and whether AB was enhanced by stress induction.

Methods

A Virtual Reality (VR) adaptation of the Trier Social Stress Test (VR-TSST) was used to induce psychosocial stress in smokers (n = 34) and non-smokers (n = 37) followed by a novel free-viewing task in VR. Eye tracking data was recorded to examine gaze behavior to smoking-related and neutral stimuli presented in the VR-TSST and the free-viewing task.

Results

Stress ratings increased significantly from baseline to post VR-TSST in smokers and non-smokers. During the VR-TSST we observed, more frequent, longer, and earlier fixations on smoke-related compared with neutral stimuli without significant group differences. However, in the free-viewing task following the stress induction, a specific AB of smokers in terms of earlier and longer fixations on smoke stimuli was found.

Conclusion

Results indicate that AB is not a persistent trait in smokers, but is context dependent. It is suggested that emotional learning processes such as smoking in the context of relief after stress may contribute to changes of AB both in terms of increased initial attention and deeper stimulus processing. Additionally, the potential of the VR-TSST to induce psychosocial stress could be replicated.

Preventing incubation of drug craving to treat drug relapse: from bench to bedside

In 1986, Gawin and Kleber reported a progressive increase in cue-induced drug craving in individuals with cocaine use disorders during prolonged abstinence. After years of controversy, as of 2001, this phenomenon was confirmed in rodent studies using self-administration model, and defined as the incubation of drug craving. The intensification of cue-induced drug craving after withdrawal exposes abstinent individuals to a high risk of relapse, which urged us to develop effective interventions to prevent incubated craving. Substantial achievements have been made in deciphering the neural mechanisms, with potential implications for reducing drug craving and preventing the relapse. The present review discusses promising drug targets that have been well investigated in animal studies, including some neurotransmitters, neuropeptides, neurotrophic factors, and epigenetic markers. We also discuss translational exploitation and challenges in the field of the incubation of drug craving, providing insights into future investigations and highlighting the potential of pharmacological interventions, environment-based interventions, and neuromodulation techniques.

Associations Between Self-reported Inhibitory Control, Stress, and Alcohol (Mis)use During the First Wave of the COVID-19 Pandemic in the UK: a National Cross-sectional Study Utilising Data From Four Birth Cohorts

We explored (1) self-reported changes in alcohol use during the pandemic in the UK and (2) the extent to which self-reported inhibitory control and/or stress were associated with any change in drinking behaviour. We used a UK-based cross-sectional online survey administered to four nationally representative birth cohorts (N = 13,453). A significant minority of 30- (29.08%) and 50-year-olds (26.67%) reported drinking more, and between 32.23 and 45.02% of respondents reported feeling more stressed depending on the cohort. Stress was associated with hazardous drinking among 30-year-olds (OR = 3.77, 95% CI 1.15 to 12.28). Impatience was associated with both increased alcohol use (1.14, 95% CI 1.06, 1.24) and hazardous drinking (1.20, 95% CI 1.05, 1.38) among 19-year-olds. Risk-taking was associated with hazardous drinking for 30-year-olds (OR = 1.18, 95% CI 1.05, 1.32). These data highlight concerns for those at risk of alcohol misuse and alcohol-related harm during COVID-19 lockdowns.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11469-021-00599-8.

Time course of plasticity-related alterations following the first exposure to amphetamine in juvenile rats

In vulnerable consumers, the first drug exposure induces various neurobehavioral adaptations that may represent the starting point toward addiction. Elucidating the neuroplastic mechanisms underlying that first rewarding experience would contribute to understanding the transition from recreational to compulsive drug use. In a preclinical model with juvenile rats, we analyzed the time-dependent fluctuations in the expression of neuroplasticity-related genes like the brain-derived neurotrophic factor (BDNF), its tropomyosin receptor kinase B (TrkB), the cAMP response element-binding protein (CREB), the microRNA-132, the Rho GTPase-activating protein 32 (p250GAP), the corticotropin-releasing factor (CRF), and the neurotransmitters contents in the nucleus accumbens (NAc) and the dorsal striatum (DS) 45, 90, and 180 min after an amphetamine (AMPH) injection. As expected, AMPH altered the concentration of norepinephrine, dopamine, DOPAC, and serotonin in a region- and time-dependent manner. Regarding gene expression, AMPH at 45 min upregulated BDNF and primiR-132 expression in NAc and downregulated TrkB expression in DS. At 90 min, AMPH upregulated TrkB, CREB, p250GAP, and primiR-132 expression in NAc and BDNF, primiR-132, and CRF in DS. At 180 min, only BNDF in NAc continued to be upregulated by AMPH. Based on the levels of AMPH-induced hyperactivity, we classified the rats as low and high AMPH responders. High AMPH responders characterized by overexpressing BDNF, CREB, p250GAP, and CRF in NAc and by showing lower levels of dopamine and serotonin metabolites and turnovers in both regions. Our findings demonstrated that a single AMPH administration is enough to induce neuroplastic adaptations, especially in the NAc of prone rats.

A predictive coding framework of allostatic-interoceptive overload in frontotemporal dementia

Recent allostatic-interoceptive explanations using predictive coding models propose that efficient regulation of the body's internal milieu is necessary to correctly anticipate environmental needs. We review this framework applied to understanding behavioral variant frontotemporal dementia (bvFTD) considering both allostatic overload and interoceptive deficits. First, we show how this framework could explain divergent deficits in bvFTD (cognitive impairments, behavioral maladjustment, brain atrophy, fronto-insular-temporal network atypicality, aberrant interoceptive electrophysiological activity, and autonomic disbalance). We develop a set of theory-driven predictions based on levels of allostatic interoception associated with bvFTD phenomenology and related physiopathological mechanisms. This approach may help further understand the disparate behavioral and physiopathological dysregulations of bvFTD, suggesting targeted interventions and strengthening clinical models of neurological and psychiatric disorders.

Child maltreatment and substances use throughout adolescence and adulthood: Data from a Brazilian Birth Cohort

BACKGROUND

Child maltreatment has been associated with substance use later in life, but few studies have used repeated measures.

OBJECTIVE

To assess the association between child maltreatment and use of psychoactive substances from adolescence to early adulthood, and whether this differs by sex.

PARTICIPANTS AND SETTING

3641 participants from the 1993 Pelotas Birth Cohort, Brazil.

METHODS

Child maltreatment (psychological, physical and sexual abuse, and physical neglect) was assessed up to age 15 and use of psychoactive substances (smoking, harmful use of alcohol and use of illicit drugs) was assessed at ages 15, 18, and 22 years. Associations between child maltreatment and use of substances at each time point were analyzed using logistic regression, adjusted for confounders.

RESULTS

Overall, child maltreatment was associated with substance use, and the strength of the associations decreased over time. E.g., the association between psychological abuse and harmful use of alcohol was OR 2.17 (95%CI 1.80, 2.62; p-value < 0.001) at 15 years, OR 1.61 (95%CI 1.31, 1.97; p-value < 0.001) at 18 years, and OR1.55 (95%CI 1.22, 1.96; p-value < 0.001) at 22 years. When sex differences were evident, stronger associations were observed among females. E.g., the association between physical abuse and smoking at 15 years was OR 3.49 (95%CI 2.17, 5.62) in females and OR 0.87 (95%CI 0.30, 2.52) in males (p-value for sex interaction = 0.041).

CONCLUSIONS

Child maltreatment was associated with psychoactive substance in adolescence and early adulthood. Strategies to prevent use of substances could benefit those who suffered maltreatment in childhood.

Comparison of Neural Correlates of Reactive Inhibition in Cocaine, Heroin, and Polydrug Users through a Contextual Go/No-Go Task Using Event-Related Potentials

Simple Summary

Witnessing the current increase in the use of substances in society and considering the associated pervasive relapse rate, the management of addictions remains a significant challenge. The identification of biomarkers that are linked to specific profiles of consumption would allow a more targeted, and therefore, more effective care. In this view, the present study evaluates and compares the cognitive performance usually associated with substance use disorder—inhibitory control, attentional bias, and error detection—of heroin, cocaine, and polydrug users to matched healthy controls. Simultaneously, the addition of measurement of the modulation of brain activity during the task (event-related potentials technique) offers a reliable representation of the neuronal mechanisms underlying cognitive functioning. The results reveal substance-specific neural patterns of response, notably a more deleterious impact on polydrug use, and, despite nonsignificant results, suggest a more drastically affected cognitive functioning in cocaine users. Such evidence refines our knowledge of the specific mode of action of each substance. Ultimately, knowing their neural signature will lead to the implementation of more targeted interventions, thereby allowing specific needs to be addressed.

Abstract

Recent global data indicates a worldwide increase in polydrug use associated with a shift from recreational to productive habits of consumption. Such non-responsible abuse of substances (alcohol, cocaine, heroin, etc.) is likely to lead to addictive disorders that are characterized by various neuropsychopharmacological effects. A main cognitive function involved in the onset and long-term maintenance of addiction is reactive inhibition, i.e., the ability to withhold a prepotent motor dominant response. In the present study, 63 (poly)drug user patients who were undergoing a detoxification program, in addition to 19 healthy controls matched for gender, age, and education, were subjected to a “contextual Go/No-Go task” with concomitant electroencephalography. Stimuli were superimposed on three contextual backgrounds: control (black screen), drug-unrelated (neutral pictures), or drug-related (pictures related to drug consumption). Of these patients, 23 were cocaine users (CU), 21 were heroin users (HU), and 19 were polydrug users (PDU). The main results showed that (1) at the behavioral level, more commission errors occurred with the PDU patients compared to the healthy controls; (2) at the neurophysiological level, specific alterations were found on classical event-related potentials that index reactive inhibition. Indeed, the higher rate of errors in the PDU group was subtended by both reduced amplitude and latency on the ∆N2 component and increased ∆P3 latency compared to controls. These data clearly suggest a more deleterious impact of polydrug use on inhibitory functions. In addition, our results provide evidence of reduced ERN amplitude in cocaine users, suggesting that impaired performance monitoring and error-processing may support impaired awareness, thereby preventing these patients from changing their behaviors.

Allostatic-Interoceptive Overload in Frontotemporal Dementia

BACKGROUND

The predictive coding theory of allostatic-interoceptive load states that brain networks mediating autonomic regulation and interoceptive-exteroceptive balance regulate the internal milieu to anticipate future needs and environmental demands. These functions seem to be distinctly compromised in behavioral variant frontotemporal dementia (bvFTD), including alterations of the allostatic-interoceptive network (AIN). Here, we hypothesize that bvFTD is typified by an allostatic-interoceptive overload.

METHODS

We assessed resting-state heartbeat evoked potential (rsHEP) modulation as well as its behavioral and multimodal neuroimaging correlates in patients with bvFTD relative to healthy control subjects and patients with Alzheimer's disease (N = 94). We measured 1) resting-state electroencephalography (to assess the rsHEP, prompted by visceral inputs and modulated by internal body sensing), 2) associations between rsHEP and its neural generators (source location), 3) cognitive disturbances (cognitive state, executive functions, facial emotion recognition), 4) brain atrophy, and 5) resting-state functional magnetic resonance imaging functional connectivity (AIN vs. control networks).

RESULTS

Relative to healthy control subjects and patients with Alzheimer's disease, patients with bvFTD presented more negative rsHEP amplitudes with sources in critical hubs of the AIN (insula, amygdala, somatosensory cortex, hippocampus, anterior cingulate cortex). This exacerbated rsHEP modulation selectively predicted the patients' cognitive profile (including cognitive decline, executive dysfunction, and emotional impairments). In addition, increased rsHEP modulation in bvFTD was associated with decreased brain volume and connectivity of the AIN. Machine learning results confirmed AIN specificity in predicting the bvFTD group.

CONCLUSIONS

Altogether, these results suggest that bvFTD may be characterized by an allostatic-interoceptive overload manifested in ongoing electrophysiological markers, brain atrophy, functional networks, and cognition.

Neurological and Psychological Characteristics of Young Nitrous Oxide Abusers and Its Underlying Causes During the COVID-19 Lockdown

Background

The COVID-19 pandemic has a serious impact on the mental health of the public due to its economic and social impact. And psychological effects have led to drug and alcohol abuse. After the city lifted the lockdown, we consecutively encountered several young nitrous oxide abusers admitted to hospital for neurological treatment.

Purpose

To inform physician decisions and social intervention, this observational study aimed at investigating the neurological and psychological characteristics of nitrous oxide abusers and its underlying causes during the COVID-19 lockdown.

Methods

The nitrous oxide abusers who sought neurological treatment at our hospital between May 2020 and June 2020 were enrolled. Clinical data including socio-demographic, physical examination, laboratory examination, electromyography and neuroimaging were collected. Their motivations for inhaling nitrous oxide, knowledge about the nitrous oxide abuse and the accompanying of family were investigated face to face. Psychological status was assessed by the Symptom Checklist 90 (SCL-90) psychological evaluation.

Results

Six nitrous oxide abusers were enrolled and the age was 22 ± 4.3. Clinical presentations included varying degrees of limb numbness and an ataxic gait. Laboratory examination revealed that all the patients did not have pernicious anemia, 4 patients had decreased vitamin B12 while 3 patients exhibited elevated homocysteine levels. MR of the spinal cord revealed that 4 patients had abnormal signals in the cervical spinal cord of high symmetry with splayed or inverted V sign after T2WI. Electromyogram (EMG) test showed 5 patients had peripheral nerve damage. The SCL-90 psychological evaluation results indicated that all patients had severe anxiety, depression and psychosis and they had severer psychological problems than ordinary citizens. Their motives for inhaling nitrous oxide are to relieve boredom, curiosity and buddy pressure. Their family spent <1 day per week to stay with them during city lockdown.

Conclusion

The enrolled patients caused by abuse of nitrous oxide presented with symptoms of subacute combined with spinal degeneration. They had more serious psychological problems related to the COVID-19 pandemic. These cases make us value the psychological problems of young people under the outbreak and take multi-layered measures from families, schools (companies), hospitals, and governments to address it.

Momentary associations between stress and alcohol craving in the naturalistic environment: differential associations for Black and White young adults

BACKGROUND AND AIMS

Black drinkers compared with White drinkers experience more alcohol-related problems. Examination of social determinants of inequities in alcohol problems is needed. The current study measured (1) associations between acute stress and alcohol craving in the naturalistic environment for self-identified Black and White individuals who drink alcohol and (2) whether a history of attention deficit hyperactivity disorder (ADHD) moderated these associations.

DESIGN AND SETTING

Observational study using ecological momentary assessment (EMA) to collect data from participants at six semi-random time-points throughout the day during a 10-day period. A series of three-level multi-level models examined between- and within-person associations for stress and alcohol and tested if these associations differed for Black and White adults.

PARTICIPANTS

Participants were 229 adult drinkers (aged 21-35 years) who completed a larger study examining alcohol response for Black and White adults with and without a history of childhood ADHD.

MEASUREMENTS

Momentary stress and alcohol craving, ADHD history and socio-demographic characteristics (i.e. racial identity, sex, age, current education level, household income) were assessed. Participants were required to self-identify as either 'African American or Black' or 'European American or White'.

FINDINGS

Significant racial identity × stress interactions indicated that associations between stress and craving were stronger for Black compared with White adults across the 10-day period (between-person: B = 0.14, P = 0.007), concurrently within a given EMA time-point (within-person: B = 0.04, P = 0.001) and prospectively from time-point to time-point (within-person: B = 0.05, P = 0.001). Results remained while accounting for income × stress interactions.

CONCLUSIONS

Acute stress appears to be more strongly related to alcohol craving in self-identified Black compared with self-identified White individuals. This provides support for policy changes to eliminate structural inequities that increase stress exposure and the development of just-in-time culturally responsive interventions focused on coping with acute stress for Black individuals.

The Kynurenine Pathway and Mediating Role of Stress in Addictive Disorders: A Focus on Alcohol Use Disorder and Internet Gaming Disorder

Stress plays an important role in the pathophysiology of addictive disorders. The kynurenine (KYN) pathway involved in neuroimmune and cognitive functions is activated under stress. However, the neuroimmunological–neurocognitive mechanisms in the role of stress in addictive disorders are unclear still now. Ninety-nine young adults aged 18–35 years [alcohol use disorder (AUD), N = 30; Internet gaming disorder (IGD), N = 34; healthy controls (HCs), N = 35] participated in this study. Stress levels, resilience, addiction severity, and neurocognitive functions were evaluated, and serum levels of tryptophan (TRP), 5-hydroxytryptamine (5-HT), KYN, and kynurenine acid (KYNA) were determined using liquid chromatography coupled with tandem mass spectrometry through blood samples. Both addictive disorder groups showed higher levels of stress, lower resilience, and impaired executive functions compared to the HC group. Importantly, the AUD group revealed significantly increased KYN levels and KYN/TRP ratios, as well as decreased KYNA levels and KYNA/KYN ratios compared to HCs (p < 0.001, p < 0.001, p = 0.033, and p < 0.001, respectively). The IGD group showed KYN levels and KYNA/KYN ratios intermediate between those of the AUD group and HCs. Furthermore, in the AUD group, the mediating effect of AUD on KYN through stress level was moderated by resilience [index of moderated mediation = −0.557, boot S.E = 0.331, BCa CI (−1.349, −0.081)]. Stress may induce an imbalance in downstream of KYN pathway metabolites, and the KYN/TRP ratio may play as a neuromediator between stress and behavioral changes in both addictive disorders. This study suggests that regulation of the KYN pathway is critical in the pathophysiology of addictive disorders and it may serve as an important target for future treatment modalities.

Sex differences in the rodent hippocampal opioid system following stress and oxycodone associated learning processes

Over the past two decades, opioid abuse has risen especially among women. In both sexes hippocampal neural circuits involved in associative memory formation and encoding of motivational incentives are critically important in the transition from initial drug use to drug abuse/dependence. Opioid circuits, particularly the mossy fiber pathway, are crucial for associative memory processes important for addiction. Our anatomical studies, especially those utilizing electron microscopic immunocytochemistry, have provided unique insight into sex differences in the distribution of opioid peptides and receptors in specific hippocampal circuits and how these distributions are altered following stress and oxycodone-associative learning processes. Here we review the hippocampal opioid system in rodents with respect to ovarian hormones effects and baseline sex differences then sex differences following acute and chronic stress. Next, we review sex differences in the hippocampal opioid system in unstressed and chronically stressed rats following oxycodone conditioned place preference. We show that opioid peptides and receptors are distributed within hippocampal circuits in females with elevated estrogen states in a manner that would enhance sensitivity to endogenous and exogenous opioids. Moreover, chronic stress primes the opioid system in females in a manner that would promote opioid-associative learning processes. In contrast, chronic stress has limited effects on the opioid system in males and reduces its capacity to support opioid-mediated learning processes. Interestingly, acute stress appears to prime males for opioid associative learning. On a broader scale the findings highlighted in this review have important implications in understanding sex differences in opioid drug use and abuse.

Associations between relationship quality and treatment-related stress among couples receiving methadone for opioid use disorder

BACKGROUND

Social relationships may buffer or exacerbate stress among patients receiving methadone treatment for opioid use disorder (OUD). Little is known, however, about how relationship quality is linked to treatment-related stress among couples in which both partners receive methadone. We considered the links between relationship quality and treatment-related stress among couples in methadone treatment for OUD.

METHODS

Participants for this cross-sectional observational study included 60 heterosexual married or cohabiting couples aged 18 and older drawn from two opioid treatment programs in Rhode Island and Massachusetts. Both partners completed a self-administered survey which assessed their sociodemographic information, relationship and treatment characteristics, and perceived treatment-related stress. We estimated actor-partner interdependence models to evaluate the links between each partner's perceptions of relationship quality (with their partner and their closest family member or friend) and treatment-related stress.

RESULTS

When their partners reported a more positive partner relationship, women had lower treatment-related stress. When women reported a more positive relationship with their own closest family member or friend, both women and their partners had lower treatment-related stress. When men perceived a more positive relationship with their closest family member or friend, their partners reported greater treatment-related stress. Negative relationship quality was not significantly linked to treatment-related stress.

CONCLUSIONS

This study highlights the importance of considering how social relationship quality might impact the experiences of couples receiving methadone for OUD. In particular, women's close relationships may help to mitigate treatment-related stress.

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.

Mindfulness buffers the influence of stress on cue-induced craving for Internet among Chinese colleges with problematic Internet use

BACKGROUND AND AIMS

Stress is a common experience among college students with problematic Internet use, and it may exacerbate their cue-induced Internet craving. This study aimed to examine the influence of stress on cue-induced craving for the Internet among subjects with problematic Internet use and the buffering effect of mindfulness.

METHODS

Sixty-eight college students with problematic Internet use were assigned to groups with a 2 (stress vs. no-stress) × 2 (high vs. low mindfulness) between-subject design.

RESULTS

It was deduced that stress could significantly enhance cue-induced craving for the Internet, and mindfulness could buffer this effect. Specifically, the effect of stress on cue-induced craving for the Internet was weaker among subjects with high mindfulness as compared to subjects with low mindfulness.

DISCUSSION AND CONCLUSIONS

These findings contribute to understanding of the factors influencing problematic Internet use and how such factors interact. It also provides recommendations on how to prevent the progression of problematic Internet use and suggests possible interventions.

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.

The SEEKING Drive and Its Fixation: A Neuro-Psycho-Evolutionary Approach to the Pathology of Addiction

Neuro-ethological studies conducted by Panksepp and his colleagues have provided an understanding of how the activity of the mesolimbic dopaminergic (ML DA) system leads to the emotional disposition to SEEK/Explore, which is involved in all appetitive motivated behavior and mental activity. In pathological addiction phenomena, this emotional disposition “fixes” itself on certain obsessive-compulsive habits, losing its versatility and its natural predisposition to spontaneous and unconditioned activation. Overall, the result is a consistent disinterest in everything that is not the object of addiction. From a neuro-psycho-evolutionary point of view, the predisposition to develop addictive behavior can be attributed to a loss of “functional autonomy” of the SEEKING/Explorative disposition. Indeed, as shown by animal and human studies, the tendency to be conditioned by situations and contexts that provide an immediate reward can be closely related to a deficit in the tonic endogenous activity of the ML DA-SEEKING system.

The influence of perceived stress and self-control on efficacy of repeated transcranial direct current stimulation in non-treatment-seeking smokers

INTRODUCTION

Transcranial direct current stimulation (tDCS) has recently been raising interest in its therapeutic impact on tobacco use disorder. This study investigates the effects of repeated frontal tDCS (anode: F3, cathode: F4) on cigarette consumption, craving and executive functions.

MATERIAL AND METHODS

In a randomized sham-controlled trial, 24 individuals received active (2.0 mA) and 20 individuals received sham stimulation (0.3 mA) for 20 min on five consecutive days. The participants indicated their tobacco cravings, answered questionnaires and completed neuropsychological tasks at various time points throughout the study. Carbon monoxide (CO) levels and the daily numbers of consumed cigarettes were recorded.

RESULTS

Both intervention groups experienced a significant decrease in the daily number of smoked cigarettes, CO levels, and craving after the stimulation, however, there were no improvements in executive functions. These results did not differ significantly between both intervention groups. Additionally, in the active group, a higher level of perceived stress and a lower level of self-control were linked to a lower cigarette consumption, respectively a higher reduction of the level of CO.

CONCLUSION

This study does not support the hypotheses that tDCS reduces cigarette consumption, attenuates substance craving, or improves executive functions beyond the placebo effect. Our subgroup analysis suggests that high levels of perceived stress and low self-control may be predictors for a successful reduction in cigarette consumption. Furthermore, the placebo effect might be rather high for light smokers, whereas heavy smokers seem to benefit more from the specific effects of tDCS.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03691805.

Decreased kynurenine pathway potentiate resilience to social defeat effect on cocaine reward

The kynurenine (KYN) pathway of tryptophan (TRP) degradation is activated by stress and inflammatory factors. It is now well established that social stress induces the activation of the immune system, with central inflammation and KYN metabolism being two of the main factors linking stress with depression. The aim of the present study was to evaluate the long-lasting changes in the KYN pathway induced by social defeat (SD) associated with the resilience or susceptibility to an increase in the conditioned rewarding effects of cocaine. Mice were exposed to repeated SD and 3 weeks later, a conditioned place preference (CPP) induced by a subthreshold dose of cocaine (1.5 mg/kg) was developed. KYN levels in plasma, cerebellum, hippocampus, striatum and limbic forebrain were studied at the end of the CPP procedure. Changes in the KYN pathway after exposure to pharmacological (oxytocin and indomethacin) and environmental interventions (environmental enrichment) were also evaluated. Our results showed that defeated susceptible (SD-S) mice had higher conditioning scores than resilient mice (SD-R). In addition, although KYN concentration was elevated in all defeated mice, SD-R mice showed smaller increases in KYN concentration in the cerebellum than SD-S mice. Oxytocin or Indomethacin treatment before SD normalized cocaine-induced CPP, although the increase in the KYN pathway was maintained. However, environmental enrichment before SD normalized cocaine-induced CPP and prevented the increase in the KYN pathway. The present study highlights the role of the KYN pathway and anti-inflammatory drugs acting on TRP metabolism as pharmacological targets to potentiate resilience to social stress effects.

Regional gray matter volume associated with exercise dependence: A voxel-based morphometry study

Although regular physical exercise has multiple positive benefits for the general population, excessive exercise may lead to exercise dependence (EXD), which is harmful to one's physical and mental health. Increasing evidence suggests that stress is a potential risk factor for the onset and development of EXD. However, little is known about the neural substrates of EXD and the underlying neuropsychological mechanism by which stress affects EXD. Herein, we investigate these issues in 86 individuals who exercise regularly by estimating their cortical gray matter volume (GMV) utilizing a voxel‐based morphometry method based on structural magnetic resonance imaging. Whole‐brain correlation analyses and prediction analyses showed negative relationships between EXD and GMV of the right orbitofrontal cortex (OFC), left subgenual cingulate gyrus (sgCG), and left inferior parietal lobe (IPL). Furthermore, mediation analyses found that the GMV of the right OFC was an important mediator between stress and EXD. Importantly, these results remained significant even when adjusting for sex, age, body mass index, family socioeconomic status, general intelligence and total intracranial volume, as well as depression and anxiety. Collectively, the results of the present study provide crucial evidence of the neuroanatomical basis of EXD and reveal a potential neuropsychological pathway in predicting EXD in which GMV mediates the relationship between stress and EXD.

Sexual dysfunction and drug use in women: A reciprocal etiologic relationship

Objetivo:

Realizar una reflexión sobre la relación etiológica recíproca entre la disfunción sexual femenina y la drogodependencia, y sus implicaciones prácticas e investigativas.

Materiales y métodos:

Se presenta una descripción de los efectos y las consecuencias a corto y a largo plazo del uso de drogas en mujeres y se analiza si el uso de drogas es la causa de la disfunción sexual o si, por el contrario, la disfunción sexual conduce al uso de drogas. Asimismo, se discute la necesidad de ahondar en la investigación que relaciona estas dos variables y sus implicaciones clínicas.

Conclusión:

El consumo de drogas afecta la función sexual femenina, por lo que es pertinente un diagnóstico inicial y la rehabilitación sexual tras el uso crónico de sustancias psicoactivas; asimismo, se hace indispensable implementar medidas profilácticas para disminuir el uso de drogas en la actividad sexual y sus consecuencias asociadas, y ampliar la investigación de esta área del conocimiento médico y psicológico.

Persistently Elevated mTOR Complex 1-S6 Kinase 1 Disrupts DARPP-32-Dependent D1 Dopamine Receptor Signaling and Behaviors

BACKGROUND

The serine-threonine kinase mTORC1 (mechanistic target of rapamycin complex 1) is essential for normal cell function but is aberrantly activated in the brain in both genetic-developmental and sporadic diseases and is associated with a spectrum of neuropsychiatric symptoms. The underlying molecular mechanisms of cognitive and neuropsychiatric symptoms remain controversial.

METHODS

The present study examines behaviors in transgenic models that express Rheb, the most proximal known activator of mTORC1, and profiles striatal phosphoproteomics in a model with persistently elevated mTORC1 signaling. Biochemistry, immunohistochemistry, electrophysiology, and behavior approaches are used to examine the impact of persistently elevated mTORC1 on D₁ dopamine receptor (D1R) signaling. The effect of persistently elevated mTORC1 was confirmed using D1-Cre to elevate mTORC1 activity in D1R neurons.

RESULTS

We report that persistently elevated mTORC1 signaling blocks canonical D1R signaling that is dependent on DARPP-32 (dopamine- and cAMP-regulated neuronal phosphoprotein). The immediate downstream effector of mTORC1, ribosomal S6 kinase 1 (S6K1), phosphorylates and activates DARPP-32. Persistent elevation of mTORC1-S6K1 occludes dynamic D1R signaling downstream of DARPP-32 and blocks multiple D1R responses, including dynamic gene expression, D1R-dependent corticostriatal plasticity, and D1R behavioral responses including sociability. Candidate biomarkers of mTORC1-DARPP-32 occlusion are increased in the brain of human disease subjects in association with elevated mTORC1-S6K1, supporting a role for this mechanism in cognitive disease.

CONCLUSIONS

The mTORC1-S6K1 intersection with D1R signaling provides a molecular framework to understand the effects of pathological mTORC1 activation on behavioral symptoms in neuropsychiatric disease.

Circuit selectivity in drug versus natural reward seeking behaviors

Substance use disorder (SUD) is characterized, in part by behavior biased toward drug use and away from natural sources of reward (e.g., social interaction, food, sex). The neurobiological underpinnings of SUDs reveal distinct brain regions where neuronal activity is necessary for the manifestation of SUD-characteristic behaviors. Studies that specifically examine how these regions are involved in behaviors motivated by drug versus natural reward allow determinations of which regions are necessary for regulating seeking of both reward types, and appraisals of novel SUD therapies for off-target effects on behaviors motivated by natural reward. Here, we evaluate studies directly comparing regulatory roles for specific brain regions in drug versus natural reward. While it is clear that many regions drive behaviors motivated by all reward types, based on the literature reviewed we propose a set of interconnected regions that become necessary for behaviors motivated by drug, but not natural rewards. The circuitry is selectively necessary for drug seeking includes an Action/Reward subcircuit, comprising nucleus accumbens, ventral pallidum, and ventral tegmental area, a Prefrontal subcircuit comprising prelimbic, infralimbic, and insular cortices, a Stress subcircuit comprising the central nucleus of the amygdala and the bed nucleus of the stria terminalis, and a Diencephalon circuit including lateral hypothalamus. Evidence was mixed for nucleus accumbens shell, insular cortex, and ventral pallidum. Studies for all other brain nuclei reviewed supported a necessary role in regulating both drug and natural reward seeking. Finally, we discuss emerging strategies to further disambiguate the necessity of brain regions in drug- versus natural reward-associated behaviors.

Neuroinflammatory and behavioral susceptibility profile of mice exposed to social stress towards cocaine effects

Using the social defeat (SD) model, numerous studies have shown that stressed mice display an enhanced response to the motivational effects of cocaine in the self-administration (SA) and conditioned-place preference (CPP) paradigms. However, not all subjects exposed to stress express its harmful effects. Some are particularly susceptible to the deleterious effects of repeated SD, while resilient mice successfully cope with stressful experiences and display adjusted psychological functioning after stress. Vulnerability to develop stress-related disorders, such as depression, has been linked to coping strategies and more recently to individual differences in the immune system. However, no studies have evaluated if coping strategies and immune system reactivity to social stress experiences can also predict susceptibility to stress-induced enhancement of the cocaine response. We evaluated cocaine response in socially defeated mice in the CPP and SA paradigms. To evaluate neuroimmune reactivity to stress the pro-inflammatory cytokine IL-6 and the chemokine CX3CL1 were measured in the striatum and hippocampus. Behavioral phenotype during and after SD episodes was also evaluated. Our results showed that susceptible mice to the depressive-like behaviors effects of stress showed increased conditioned rewarding effects of cocaine in the CPP. In addition, susceptible mice displayed passive-reactive coping behavior during social stress episodes and more pronounced changes in neuroinflammatory markers after the last SD episode, which lasted for one month. Although the complex mechanisms underlying susceptibility or resilience to social stress are still unclear, our results point to multiple adaptive stress responses expressed at different phenotypic levels.

Anger and substance abuse: a systematic review and meta-analysis

Objective:

Conduct a systematic review and meta-analysis to evaluate levels of anger among substance users compared to non-user controls and to analyze the possible association between anger and psychoactive substance use (PSU).

Methods:

The procedures of this review followed the Meta-Analyzes of Observational Studies in Epidemiology (MOOSE) and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Four electronic databases (MEDLINE, EMBASE, BIREME, PsycINFO) were searched.

Results:

Twelve studies were included in the meta-analysis; 10 used the State-Trait Anger Expression Inventory (STAXI) anger trait subscale and two used the Buss-Perry-Aggression Questionnaire (BPAQ) anger subscale. The sample included 2,294 users of psychoactive substances and 2,143 non-users, all male. The mean difference in anger scale scores between users and non-users was 2.151 (95%CI 1.166-3.134, p ≤ 0.00, inconsistency index [I²] = 98.83) standard deviations. Age and abstinence duration did not moderate the difference in anger between substance users and non-users.

Conclusion:

Users of psychoactive substances had elevated anger scores compared to non-users, which represents a high risk of relapse. It is suggested that PSU treatment programs include intensive anger management modules, focusing on factors such as dealing with daily stressors, family conflicts, frustrations, and problems.

Effect of Coronavirus Disease 2019 on the Psychology and Behavior of Patients on Methadone Maintenance Treatment in Wuhan, China: A Clinical Observational Study

Methadone maintenance treatment (MMT) is a national strategy adopted for the treatment of heroin dependency in China. The sudden outbreak of coronavirus disease 2019 (COVID-19) and the resultant social isolation in Wuhan have also had a significant negative impact on local patients undertaking MMT. In this study, 76 patients on MMT from the Wuhan First Health Clinic were selected as the research objects to investigate the effect of COVID-19 on the levels of stress, anxiety, and depression, as well as the withdrawal symptoms and craving and substance use. Our results revealed that, during the outbreak, the Perceived Stress Scale (PSS) score, HAMA score, HAMD score, and craving in the included patients was significantly higher than that at the baseline and post-epidemic (p < 0.01, p < 0.01, p < 0.01, p < 0.01, respectively); the positive rate of morphine and methamphetamine urine test was significantly lower than that the post-epidemic (p = 0.01, p < 0.01, respectively); the amount of tobacco used during the outbreak and the post-epidemic period was significantly higher than that at the baseline (p < 0.01, p < 0.01, respectively), while the amount of alcohol consumed at the outbreak was significantly higher than at the baseline and the post-epidemic (p < 0.01, p < 0.01, respectively). The negative emotions aroused by the COVID-19 outbreak and the accompanying social isolation to patients on MMT are an important factor of negative reinforcement that adversely affected the patients' craving for drugs and the consumption of legal substances. This finding suggests the need to strengthen the psychological counseling for patients on MMT during severe epidemic, actively alleviating the negative emotions, reducing the risk of substance abuse, and strengthening drug management after the epidemic to prevent the rise of substance (legal or illegal) abuse.

The effect of smoking on depressive symptoms

BACKGROUND

People who smoke tend to report higher levels of psychological distress than those who do not smoke. However, studies suggest that smoking reduces many sub-dimensions of distress, including depressive symptoms. A negative (i.e. depression reducing) effect of smoking on depressive symptoms might be observed in survey panel data only after adjustment for the effect of depressive symptoms on smoking. Results from analyses that make that adjustment are presented within groups jointly defined by race and gender, and for all respondents in a representative sample of the U.S.

POPULATION

METHOD

Reciprocal effects of smoking and depressive symptoms (DSx) are estimated with dynamic panel models. Data are from the Americans' Changing Lives study which assessed smoking and depressive symptoms five times over 25 years. Additional analyses provide estimates of effect of continuing to smoke versus quitting.

RESULTS

The estimated effect of smoking on DSx after adjustment for the simultaneous effect of DSx on smoking and unobserved confounders is negative among women. The estimated effect among men is not statistically significant, and no race difference is observed.

CONCLUSIONS

The tendency for smoking to reduce depressive symptoms among American women is masked in analyses that fail to account for the reciprocal effect of depressive symptoms on smoking.

Oxytocin reverses ethanol consumption and neuroinflammation induced by social defeat in male mice

Oxytocin (OXT) modulates social interactions, attenuates stressful responses and can decrease drug-seeking and taking behaviors. In previous studies, we observed that social defeat (SD) induced a long-lasting increase in ethanol intake and neuroinflammation in male mice. We also know that OXT blocks the increase in cocaine reward induced by SD. Therefore, in the present study we aimed to evaluate the effect of 1 mg/kg of OXT administered 30 min before each episode of SD on ethanol consumption and the neuroinflammatory response in adult male mice. Three weeks after the last SD, mice underwent oral ethanol self-administration (SA) procedure, and striatal levels of the two chemokines CX3CL1 and CXCL12 were measured after the last SD and at the end of the ethanol SA. OXT administration blocked the increase in voluntary ethanol consumption observed in defeated mice, although it did not affect motivation for ethanol. An increase in the striatal levels of CX3CL1 and CXCL12 was observed in defeated animals immediately after the last defeat and after the ethanol SA. However, defeated mice treated with OXT did not show this increase in the neuroinflammatory response. In conclusion, OXT treatment can be a powerful therapeutic target to reduce the negative effects of social stress on ethanol consumption and the neuroinflammatory process.

The Impact of Co-occurring Post-traumatic Stress Disorder and Substance Use Disorders on Craving: A Systematic Review of the Literature

The frequent co-occurrence of post-traumatic stress disorder (PTSD) and substance use disorders (SUDs) leads to manifestations of both conditions that are more severe and more resistance to treatment than single disorders. One hypothesis to explain this synergy is the impact of intrusive memories on craving which, in turn, increases the risk of relapse among patients with substance use disorders. The aim of this systematic review is to examine this possibility by assessing the impact of PTSD and its symptoms on craving among dual disorder patients. Using PRISMA criteria, four databases were comprehensively searched up to June, 2021, in order to identify all candidate studies based on broad key words. Resulting studies were then selected if they examined the impact of PTSD or PTSD symptoms on craving, and if they used standardized assessments of PTSD, SUD, and craving. Twenty-seven articles matched the selection criteria and were included in this review. PTSD was found to be significantly associated with increased craving levels among patients with alcohol, cannabis, cocaine, tobacco, and other substance use disorders. Exposition to traumatic cues among dual disorder patients was also shown to trigger craving, with an additive effect on craving intensity when exposure to substance-related cues occurred. In addition, certain studies observed a correlation between PTSD symptom severity and craving intensity. Concerning mechanisms underlying these associations, some findings suggest that negative emotional states or emotion dysregulation may play a role in eliciting craving after traumatic exposure. Moreover, these studies suggest that PTSD symptoms may, independently of emotions, act as powerful cues that trigger craving. These findings argue for the need of dual disorder treatment programs that integrate PTSD-focused approaches and emotion regulation strategies, in addition to more traditional interventions for craving management.

Voluntary wheel running protects against the increase in ethanol consumption induced by social stress in mice

Previous studies have shown that exposure to social defeat (SD), a model of social stress, produces a long-term increase in the consumption of ethanol, most likely through an increase in the neuroinflammation response. The aim of the present study was to evaluate whether exposure to physical activity in the form of voluntary wheel running (VWR) could block the increase in ethanol consumption and the neuroinflammatory response induced by social stress. Mice were exposed to either 4 sessions of repeated social defeat (RSD) or a non-stressful experience. During the whole procedure, half of the mice were exposed to controlled physical activity, being allowed 1 h access to a low-profile running wheel three times a week. Three weeks after the last RSD, animals started the oral self-administration (SA) of ethanol (6% EtOH) procedure. Biological samples were taken 4 h after the first and the fourth RSD, 3 weeks after the last RSD, and after the SA procedure. Brain tissue (striatum) was used to determine protein levels of the chemokines fractalkine (CX3CL1) and SDF-1 (CXCL12). RSD induced an increase in ethanol consumption and caused greater motivation to obtain ethanol. The striatal levels of CX3CL1 and CXCL12 were also increased after the last RSD. VWR was able to reverse the increase in ethanol intake induced by social stress and the neuroinflammatory response. In conclusion, our results suggest that VWR could be a promising tool to prevent and reduce the detrimental effects induced by social stress.