Stress psychobiology in the context of addiction medicine: from drugs of abuse to behavioral addictions

The influence of childhood aspirations on the risk of developing psychotic disorders, substance use disorders, and dual diagnosis in adulthood based on the Metropolit 1953 Danish Male Birth Cohort

The study aims to investigate the association of aspiration for future occupation, socioeconomic position, and intellectual abilities with risk of dual diagnosis, psychosis, substance use disorder (SUD) in later life, and to explore if social and intellectual disadvantage modify any effect of childhood aspirations on outcomes. The study included 7177 Danish boys born in 1953. We investigated childhood aspirations (preference regarding future occupation), socioeconomic position (paternal social group), and intellectual abilities (Härnquist intelligence score) on outcomes with dual diagnosis, psychotic disorder, or SUD in Danish registers. Combinations of variables were used for a two-way and three-way analysis (high and low levels of exposure variables). Cox regression with age as the underlying time scale was used for analysis. The separate analysis showed no associations between childhood aspirations and outcomes. Boys with low intelligence scores had an increased risk of developing psychotic disorders (aHR 1.5, 95% CI 1.1-2.1) and SUD (aHR 1.8, 95% CI 1.5-2.1) compared to high intelligence scores. The interaction analyses showed that individuals with a combination of low intelligence score, high aspirations, and/or high paternal social group might have an increased risk of developing dual diagnosis, psychotic disorders, or SUD in later life. This result should be interpreted with caution as interaction variables were not overall significant with the outcome of dual diagnosis or psychotic disorder. The findings suggest that childhood abilities and social position could be associated with the development of psychotic disorders and SUD in later life, however, further studies are needed to address the temporality of the association to gain an understanding of the underlying mechanism of the association.

Gender-related differences in involvement of addiction brain networks in internet gaming disorder: Relationships with craving and emotional regulation

BACKGROUND

Abnormal interactions among addiction brain networks associated with intoxication, negative affect, and anticipation may have relevance for internet gaming disorder (IGD). Despite prior studies having identified gender-related differences in the neural correlates of IGD, gender-related differences in the involvement of brain networks remain unclear.

METHODS

One-hundred-and-nine individuals with IGD (54 males) and 111 with recreational game use (RGU; 58 males) provided resting-state fMRI data. We examined gender-related differences in involvement of addiction brain networks in IGD versus RGU subjects. We further compared the strength between and within addiction brain networks and explored possible relationships between the strength of functional connectivities within and between addiction brain networks and several relevant behavioral measures.

RESULTS

The addiction brain networks showed high correct classification rates in distinguishing IGD and RGU subjects in men and women. Male subjects with versus without IGD showed stronger functional connectivities between and within addiction brain networks. Moreover, the strength of the connectivity within the anticipation network in male IGD subjects was positively related to subjective craving. However, female subjects with versus without IGD showed decreased functional connections between and within addiction brain networks. The strength of connectivity between the anticipation and negative-affect brain networks in female IGD subjects was negatively related to maladaptive cognitive emotion-regulation strategies.

CONCLUSIONS

Addiction brain networks have potential for distinguishing IGD and RGU individuals. Importantly, this study identified novel gender-related differences in brain-behavior relationships in IGD. These results help advance current neuroscientific theories of IGD and may inform gender-informed treatment strategies.

Clinical Considerations in Internet and Video Game Addiction Treatment

In order to address etiologic, clinical, and treatment strategies applicable to Internet and video game addiction (IVGA), a working definition of addiction is presented and unique aspects of Internet and screen use disorders and addictive patterns are discussed. Addictions share common neurobiological mechanisms, cause, triggers, and behavioral sequelae-often presenting with similar symptomatology-although severity and impairment vary widely. This article reviews etiologic and neurobiological antecedents to Internet and video game addiction.

Childhood maltreatment, psychiatric symptoms, and suicidal thoughts among adolescents receiving substance use treatment services

INTRODUCTION

Childhood maltreatment experiences are associated with future suicidal thoughts and suicide attempts, yet the roles of specific psychiatric symptoms mediating this relation remain to be clarified. To clarify these relations, we tested a model incorporating multiple forms of childhood maltreatment (sexual abuse, physical punishment, emotional neglect), past year psychiatric disorder symptoms during adolescence (anxiety, mood, and conduct disorders) and recent suicidal thoughts.

METHODS

We administered structured interviews to 394 adolescents receiving outpatient substance use treatment services in the Southeastern United States (280 males; Mage = 16.33; SDage = 1.15). Structural equation models (SEMs) were used to evaluate the degree to which relations between childhood maltreatment and suicidal thoughts were mediated by specific past-year psychiatric symptoms.

RESULTS

Mood disorder symptoms significantly mediated the relation between neglect/negative home environment and suicidal thoughts. This path of influence did not vary by gender.

CONCLUSIONS

Childhood maltreatment and subsequent psychopathology influence suicidal thoughts among adolescents receiving substance use treatment services. The findings of the present study have implications for the adaptation and delivery of substance use treatment services to adolescents to enhance treatment engagement and outcomes.

Global Changes and Factors of Increase in Caloric/Salty Food Intake, Screen Use, and Substance Use During the Early COVID-19 Containment Phase in the General Population in France: Survey Study

BACKGROUND

The international outbreak of coronavirus disease (COVID-19) has led many countries to enforce drastic containment measures. It has been suggested that this abrupt lockdown of populations will foster addiction-related habits such as caloric/salty food intake, screen use, and substance use.

OBJECTIVE

Our aim was to assess the global changes and factors of increase in addiction-related habits during the early COVID-19 containment phase in France.

METHODS

A web-based survey was provided from day 8 to day 13 of the containment and was completed by 11,391 participants. The questions explored sociodemographic features, psychiatric/addiction history, material conditions of lockdown, general stress, mental well-being, and reported changes in several addiction-related behaviors. Global changes were described and factors of increase were explored using population-weighted and adjusted logistic regression models, providing adjusted odds ratios (aORs) and their 95% confidence intervals.

RESULTS

Overall, the respondents reported more increases in addiction-related habits than decreases, specifically 28.4% (caloric/salty food intake), 64.6% (screen use), 35.6% (tobacco use), 24.8% (alcohol use), and 31.2% (cannabis use). Reduced well-being scores and increased stress scores were general factors of increase in addiction-related habits (P<.001 for all habits). Factors of increase in caloric/salty food intake (n=10,771) were female gender (aOR 1.62, 95% CI 1.48-1.77), age less than 29 years (P<.001), having a partner (aOR 1.19, 95% CI 1.06-1.35), being locked down in a more confined space (per 1 square meter/person decrease: aOR 1.02, 95% CI 1.01-1.03), being locked down alone (aOR 1.29, 95% CI 1.11-1.49), and reporting current (aOR 1.94, 95% CI 1.62-2.31) or past (aOR 1.27, 95% CI 1.09-1.47) psychiatric treatment. Factors of increase in screen use (n=11,267) were female gender (aOR 1.31, 95% CI 1.21-1.43), age less than 29 years (P<.001), having no partner (aOR 1.18, 95% CI 1.06-1.32), being employed (P<.001), intermediate/high education level (P<.001), being locked down with no access to an outdoor space (aOR 1.16, 95% CI 1.05-1.29), being locked down alone (aOR 1.15, 95% CI 1.01-1.32), living in an urban environment (P<.01), and not working (P<.001). Factors of increase in tobacco use (n=2787) were female gender (aOR 1.31, 95% CI 1.11-1.55), having no partner (aOR 1.30, 95% CI 1.06-1.59), intermediate/low education level (P<.01), and still working in the workplace (aOR 1.47, 95% CI 1.17-1.86). Factors of increase in alcohol use (n=7108) were age 30-49 years (P<.05), a high level of education (P<.001), and current psychiatric treatment (aOR 1.44, 95% CI 1.10-1.88). The only significant factor of increase in cannabis use (n=620) was intermediate/low level of education (P<.001).

CONCLUSIONS

The early phase of COVID-19 containment in France led to widespread increases in addiction-related habits in the general population. Reduced well-being and increased stress were universal factors of increase. More specific factors were associated with increases in each of the explored habits.

Heightened Negative Affects Associated With Neurotic Personality in Behavioral Addiction

Although studies have demonstrated that negative affects are critical attributes of drug addiction, this has remained less clear in behavioral addiction. In this preliminary study with a relatively small number of samples, we investigated negative affects in patients diagnosed with behavioral addiction, particularly paraphilia and kleptomania. Negative affects were examined using self-rating questionnaire and further evaluated by objective assessments in behavioral addicts and normal subjects. Explicit, self-referential negative affects, such as anxiety, stress, and depression, were higher in behavioral addicts than control subjects. Such self-referential negative affects were, although not entirely, consistent with objective evaluations by others and blood stress hormone concentrations. Further investigation of personality traits in behavioral addicts unveiled that heightened negative affects were associated with stronger neurotic personality in behavioral addicts than normal subjects. These results suggest that behavioral addiction, such as paraphilia and kleptomania, may be characterized by heightened negative affects attributable to stronger neurotic personality.

Stress and opioid use disorder: A systematic review

Medication assisted treatment (MAT) is highly effective in reducing illicit opioid use and preventing overdose in individuals with opioid use disorder (OUD); however, treatment retention of patients engaged in MAT is a significant clinical concern. The experience of stress may contribute to a decision to drop out of treatment. The current study is a systematic review conducted across multiple databases of empirical studies on primary appraisal of stress and its relationship to opioid craving, opioid use, and OUD treatment outcomes. Primary appraisal of stress is defined as an explicit inquiry into individual perception of feeling stressed using a self-report measure administered in laboratory, clinical, or naturalistic environment. A total of 21 included studies were organized into three categories: observed stress, experimentally-induced stress, and stress-focused interventions. Appraised stress was generally associated with greater craving, but associations with opioid use and treatment retention were mixed. All but one study included MAT samples and every study sample included some form of drug counseling. These findings suggest that individuals experience considerable stress in spite of receiving standard treatment for OUD. Psychopharmacological interventions targeting stress were promising, but no behavioral interventions specific to stress management were found. The preliminary results with clonidine and lofexidine targeting stress in individuals with OUD warrant further studies. To better understand the impact of stress in OUD, future research should consider using repeated assessment of stress in the context of daily life. Utilization of behavioral treatments specifically targeting stress could have benefits in improving OUD outcomes.

Circulating orexin changes during withdrawal are associated with nicotine craving and risk for smoking relapse

We examined the extent to which orexin measured during smoking and the early phase of abstinence was related to craving, withdrawal, stress hormones, and risk for smoking relapse in men and women. Considering its role in modulating nicotine-related reward, we predicted that a reduction in circulating orexin during withdrawal would be associated with increased craving and risk for smoking relapse. Two hundred and eighty five participants provided biological samples and self-report information to identify predictors of smoking relapse. All participants attended two laboratory sessions, which were before and after a period of required abstinence from smoking. After quitting, participants also attended four weekly sessions to track smoking relapse. Only smokers who relapsed within the follow-up period exhibited reduced orexin levels during the initial withdrawal period; ACTH, but not craving nor cortisol, increased across the abstinence period for successful abstainers but not for relapsers. Sex differences in orexin and craving or withdrawal associations also emerged. Adding sex, HPA hormones, and self-reported measures of craving and withdrawal as potential mediators had minimal effects on the above abstinence and orexin effects. These results provide the first evidence that circulating orexin may be a useful marker of risk for relapse; and sex, adrenal hormones, and self-reported craving and withdrawal were not mediators of this effect. The results point to a promising pathway to investigate objective biological markers for craving and smoking relapse and highlight the complexity of the neurobiology of relapse.

Stress System Response and Decision Making in Heavy Episodic Users of Alcohol and Online Video Games

Objective: Few empirical studies have addressed stress system response and subsequent decision making in problematic online video game players who also consume alcohol. Method: Participants were randomly assigned to either receive a psychosocial stressor, including evaluated public speaking and mental arithmetic, or control condition. Salivary cortisol, cardiovascular and subjective responses were collected. Following, decision making was assessed using the Iowa Gambling Task. Results: In this sample of moderate internet gamers (N = 71; 45 male, 16.9% meeting suggested DSM-5 criteria for internet gaming disorder), 53.52% met gender-specific cut-points for heavy episodic drinking. Overall, participants in the TSST condition demonstrated elevated systolic and diastolic blood pressure, self-reported anxiety, and negative affect (ps < .05). However, response to the TSST was varied, particularly in individuals reporting binge internet gaming (6 h or more consecutive use in the last 30 d) who did not display the expected decline in positive affect in response to the TSST (p = .02). Differences in greater advantageous decision making between heavy episodic internet gaming participants in the stress condition, versus those reading a travel magazine, were also noted. These differences were not significant in participants reporting an absence of heavy episodic gaming behavior. Conclusions: These findings support the continued study of individuals who engage in problematic internet gaming behavior, particularly those who engage in heavy episodic use of alcohol.

Review: brain neurobiology of gambling disorder based on rodent models

Different literature reviews of gambling disorder (GD) neurobiology have been focused on human studies, others have focused on rodents, and others combined human and rodent studies. The main question of this review was: which are the main neurotransmitters systems and brain structures relevant for GD based on recent rodent studies? This work aims to review the experimental findings regarding the rodent´s neurobiology of GD. A search in the Pub Med database was set (October 2012-October 2017) and 162 references were obtained. After screening, 121 references were excluded, and only 41 references remained from the initial output. More, other 25 references were added to complement (introduction section, neuroanatomical descriptions) the principal part of the work. At the end, a total of 66 references remained for the review. The main conclusions are: 1) according to studies that used noninvasive methods for drug administration, some of the neurotransmitters and receptors involved in behaviors related to GD are: muscarinic, N-methyl-D-aspartate (NMDA), cannabinoid receptor 1 (CB₁), cannabinoid receptor 2 (CB₂), dopamine 2 receptor (D₂), dopamine 3 receptor (D₃), and dopamine 4 receptor (D₄); 2) moreover, there are other neurotransmitters and receptors involved in GD based on studies that use invasive methods of drug administration (eg, brain microinjection); example of these are: serotonin 1A receptor (5-HT_1A), noradrenaline receptors, gamma-aminobutyric acid receptor A (GABA_A), and gamma-aminobutyric acid receptor B (GABA_B); 3) different brain structures are relevant to behaviors linked to GD, like: amygdala (including basolateral amygdala (BLA)), anterior cingulate cortex (ACC), hippocampus, infralimbic area, insular cortex (anterior and rostral agranular), nucleus accumbens (NAc), olfactory tubercle (island of Calleja), orbitofrontal cortex (OFC), medial prefrontal cortex (mPFC), prefrontal cortex (PFC) - subcortical network, striatum (ventral) and the subthalamic nucleus (STN); and 4) the search for GD treatments should consider this diversity of receptor/neurotransmitter systems and brain areas.

Plasma corticosterone, epinephrine, and norepinephrine levels increase during administration of nitrous oxide in rats

Nitrous oxide (N2O) is a gaseous drug with abuse potential. Despite its common clinical use, little is known about whether N2O administration activates the HPA axis and/or the sympathetic adrenomedullary system. The goal of this study was to determine whether 60% N2O alters plasma concentrations of corticosterone (CORT), epinephrine (EPI), and norepinephrine (NE) in male Long-Evans rats. A gas-tight swivel assembly in the lid of a gas administration chamber allowed the remote collection of blood samples from an indwelling jugular vein catheter at four time-points: baseline and at 30, 60, and 120 min during a two-hour administration of 60% N2O. Relative to baseline, plasma CORT (n = 9) was significantly elevated at all three time-points during N2O inhalation (mixed model analysis, p = .001) and plasma EPI and NE levels were each significantly elevated (n = 8, p ≤ .001) at the 30 min assessment. EPI then declined and did not differ from baseline at the 60 and 120 min assessments (p > .05) whereas NE remained elevated (120 min, p = .001). Administration of 60% N2O increases circulating CORT, EPI, and NE, supporting N2O as a physiological stressor. An N2O-induced increase in CORT is consistent with the observation that addictive drugs typically activate the HPA axis causing increased plasma levels of glucocorticoids. Allostatic models of drug addiction typically involve stress systems and the possible role of stress hormones in N2O-induced allostatic dysregulation is discussed.

Differential effects of acute versus chronic stress on ethanol sensitivity: Evidence for interactions on both behavioral and neuroimmune outcomes

Acute alcohol intoxication induces significant alterations in brain cytokines. Since stress challenges also profoundly impact central cytokine expression, these experiments examined the influence of acute and chronic stress on ethanol-induced brain cytokine responses. In Experiment 1, adult male rats were exposed to acute footshock. After a post-stress recovery interval of 0, 2, 4, or 24 h, rats were administered ethanol (4 g/kg; intragastric), with trunk blood and brains collected 3 h later. In non-stressed controls, acute ethanol increased expression of Il-6 and IκBα in the hippocampus. In contrast, rats exposed to footshock 24 h prior to ethanol demonstrated potentiation of hippocampal Il-6 and IκBα expression relative to ethanol-exposed non-stressed controls. Experiment 2 subsequently examined the effects of chronic stress on ethanol-related cytokine expression. Following a novel chronic escalating stress procedure, rats were intubated with ethanol. As expected, acute ethanol increased Il-6 expression in all structures examined, yet the Il-6 response was attenuated exclusively in the hippocampus in chronically stressed rats. Later experiments determined that neither acute nor chronic stress affected ethanol pharmacokinetics. When ethanol hypnosis was examined, however, rats exposed to chronic stress awoke at significantly lower blood ethanol levels compared to acutely stressed rats, despite similar durations of ethanol-induced sedation. These data indicate that chronic stress may increase sensitivity to ethanol hypnosis. Together, these experiments demonstrate an intriguing interaction between recent stress history and ethanol-induced increases in hippocampal Il-6, and may provide insight into novel pharmacotherapeutic targets for prevention and treatment of alcohol-related health outcomes based on stress susceptibility.

Treatment Considerations in Internet and Video Game Addiction: A Qualitative Discussion

Internet and video game addiction has been a steadily developing consequence of modern living. Behavioral and process addictions and particularly Internet and video game addiction require specialized treatment protocols and techniques. Recent advances in addiction medicine have improved our understanding of the neurobiology of substance and behavioral addictions. Novel research has expanded the ways we understand and apply well-established addiction treatments as well as newer therapies specific to Internet and video game addiction. This article reviews the etiology, psychology, and neurobiology of Internet and video game addiction and presents treatment strategies and protocols for addressing this growing problem.

Neuroscience-informed psychoeducation for addiction medicine: A neurocognitive perspective

Psychoeducation (PE) is defined as an intervention with systematic, structured, and didactic knowledge transfer for an illness and its treatment, integrating emotional and motivational aspects to enable patients to cope with the illness and to improve its treatment adherence and efficacy. PE is considered an important component of treatment in both medical and psychiatric disorders, especially for mental health disorders associated with lack of insight, such as alcohol and substance use disorders (ASUDs). New advancements in neuroscience have shed light on how various aspects of ASUDs may relate to neural processes. However, the actual impact of neuroscience in the real-life clinical practice of addiction medicine is minimal. In this chapter, we provide a perspective on how PE in addiction medicine can be informed by neuroscience in two dimensions: content (knowledge we transfer in PE) and structure (methods we use to deliver PE). The content of conventional PE targets knowledge about etiology of illness, treatment process, adverse effects of prescribed medications, coping strategies, family education, and life skill training. Adding neuroscience evidence to the content of PE could be helpful in communicating not only the impact of drug use but also the beneficial impact of various treatments (i.e., on brain function), thus enhancing motivation for compliance and further destigmatizing their symptoms. PE can also be optimized in its "structure" by implicitly and explicitly engaging different neurocognitive processes, including salience/attention, memory, and self-awareness. There are many interactions between these two dimensions, structure and content, in the delivery of neuroscience-informed psychoeducation (NIPE). We explore these interactions in the development of a cartoon-based NIPE to promote brain recovery during addiction treatment as a part of the brain awareness for addiction recovery initiative.

Sex differences in physiological response to the combination of stress and smoking

Stressful situations are among the most commonly cited smoking triggers. Smoking and stress exposure each individually increase cardiovascular and hypothalamic-pituitary-adrenal measures with larger increases occurring when stress and smoking are combined. In this analysis, sex differences in the physiological response to the combination of stress and smoking are examined. Smokers (36 males; 34 females) completed a laboratory session in which systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), plasma epinephrine (Epi), norepinephrine and cortisol concentrations were measured at rest, while smoking a cigarette, during a speech task occurring immediately after smoking and at several time-points following the stressor. Significant period by sex effects were observed for HR, SBP, DBP and Epi but not for cortisol or norepinephrine concentrations. For SBP (p=0.002), the increase between resting and speech were larger in men than in women, primarily due to a larger increase between smoking and speech occurring in men. A similar pattern was observed for DBP and Epi with a significantly larger Epi increase from smoking to speech observed in men than in women (p=0.016). A different pattern emerged for HR - the total increase was larger in women (p<0.001), due to a larger rest to smoking increase (p<0.001). In most measures therefore, overall increases were greater in men than women, primarily due to larger smoking to speech increases. Additional research is needed to determine the clinical implications of these results as they apply to sex difference in smoking cessation success rates and in the cardiovascular risks of smoking.

Neurobiology of addiction: a neurocircuitry analysis

Drug addiction represents a dramatic dysregulation of motivational circuits that is caused by a combination of exaggerated incentive salience and habit formation, reward deficits and stress surfeits, and compromised executive function in three stages. The rewarding effects of drugs of abuse, development of incentive salience, and development of drug-seeking habits in the binge/intoxication stage involve changes in dopamine and opioid peptides in the basal ganglia. The increases in negative emotional states and dysphoric and stress-like responses in the withdrawal/negative affect stage involve decreases in the function of the dopamine component of the reward system and recruitment of brain stress neurotransmitters, such as corticotropin-releasing factor and dynorphin, in the neurocircuitry of the extended amygdala. The craving and deficits in executive function in the so-called preoccupation/anticipation stage involve the dysregulation of key afferent projections from the prefrontal cortex and insula, including glutamate, to the basal ganglia and extended amygdala. Molecular genetic studies have identified transduction and transcription factors that act in neurocircuitry associated with the development and maintenance of addiction that might mediate initial vulnerability, maintenance, and relapse associated with addiction.