How bad could it be? Alcohol dampens stress responses to threat of uncertain intensity

Altered Effective Connectivity During Threat Anticipation in Individuals With Alcohol Use Disorder

BACKGROUND

A developing theory and recent research suggest that heightened reactivity to uncertain stressors or threats may be an important individual difference factor that facilitates excessive drinking as a means of avoidance-based coping and characterizes individuals with current and past alcohol use disorder (AUD). Neuroimaging studies of unpredictable threat processing have repeatedly demonstrated activation of the anterior insula, anteromedial thalamus, and dorsal anterior cingulate cortex. In the current study, we aimed to understand how these 3 regions function as a network during anticipation of unpredictable threat (and predictable threat).

METHODS

Participants were 43 adults (ages 21-30) with AUD and 26 healthy control participants. Functional magnetic resonance imaging and dynamic causal modeling were used to study interregional effective connectivities and predictable and unpredictable threat-related modulations thereof within this network. Parametric empirical Bayesian modeling was used to conduct between-group comparisons in effective connectivities.

RESULTS

During unpredictable threat trials, the increased projection from the right anteromedial thalamus to the right anterior insula was significantly present only in the AUD group. This directional influence was stronger among individuals who consumed more drinks per week on average. As expected, we found no group differences in modulatory changes to effective connectivities during predictable threat trials.

CONCLUSIONS

To our knowledge, this is the first study to examine directional interactions between key frontolimbic regions during anticipation of unpredictable and predictable threat and demonstrate the importance of bottom-up thalamic-insular projections during unpredictable threat processing in AUD. Prospective studies are warranted to determine whether this association is causal.

Sleep quality impacts the link between reactivity to uncertain threat and anxiety and alcohol use in youth

Individual differences in reactivity to unpredictable threat (U-threat) have repeatedly been linked to symptoms of anxiety and drinking behavior. An emerging theory is that individuals who are hyper-reactive to U-threat experience chronic anticipatory anxiety, hyperarousal, and are vulnerable to excessive alcohol use via negative reinforcement processes. Notably, anxiety and alcohol use commonly relate to disruptions in sleep behavior and recent findings suggest that sleep quality may impact the link between reactivity to U-threat and psychiatric symptoms and behaviors. The aim of the current study was to examine the unique and interactive effects of reactivity to U-threat and sleep quality on anxiety symptoms and drinking behavior in a cohort of youth, ages 16-19 years. Participants (N = 112) completed a well-validated threat-of-shock task designed to probe individual differences in reactivity to U-threat and predictable threat (P-threat). Startle eyeblink potentiation was recorded during the task as an index of aversive reactivity. Participants also completed well-validated self-report measures of anxiety and depression symptoms, lifetime alcohol use, and current sleep quality. Results revealed significant startle reactivity to U-threat by sleep quality interactions on anxiety symptoms and lifetime drinking behavior. At high levels of sleep disturbance (only), greater reactivity to U-threat was associated with greater anxiety symptoms and total number of lifetime alcoholic beverages. These results suggest that sensitivity to uncertainty and chronic hyperarousal increases anxiety symptoms and alcohol use behavior, particularly in the context of poor sleep quality.

Alcohol use and the pain system

The World Health Organization's epidemiological data from 2016 revealed that while 57% of the global population aged 15 years or older had abstained from drinking alcohol in the previous year, more than half of the population in the Americas, Europe, and Western Pacific consumed alcohol. The spectrum of alcohol use behavior is broad: low-risk use (sensible and in moderation), at-risk use (e.g., binge drinking), harmful use (misuse) and dependence (alcoholism; addiction; alcohol use disorder). The at-risk use and misuse of alcohol is associated with the transition to dependence, as well as many damaging health outcomes and preventable causes of premature death. Recent conceptualizations of alcohol dependence posit that the subjective experience of pain may be a significant contributing factor in the transition across the spectrum of alcohol use behavior. This narrative review summarizes the effects of alcohol at all levels of the pain system. The pain system includes nociceptors as sensory indicators of potentially dangerous stimuli and tissue damage (nociception), spinal circuits mediating defensive reflexes, and most importantly, the supraspinal circuits mediating nocifensive behaviors and the perception of pain. Although the functional importance of pain is to protect from injury and further or future damage, chronic pain may emerge despite the recovery from, and absence of, biological damage (i.e., in the absence of nociception). Like other biological perceptual systems, pain is a construction contingent on sensory information and a history of individual experiences (i.e., learning and memory). Neuroadaptations and brain plasticity underlying learning and memory and other basic physiological functions can also result in pathological conditions such as chronic pain and addiction. Moreover, the negative affective/emotional aspect of pain perception provides embodied and motivational components that may play a substantial role in the transition from alcohol use to dependence.

Sociability Alcohol Expectancies Shape Predictions of Drinking Behavior and Anxiety in a Novel Affective Forecasting Task

Background: Existing work proposes that people with higher social anxiety symptoms and sociability alcohol expectancies believe alcohol can lower their anxiety. However, studies have primarily analyzed retrospective reports, not anticipatory motives. Since predictions of future emotion (i.e., affective forecasts) strongly influence behavior, it is critical to understand how people predict alcohol will influence their anxiety. Additionally, intolerance of uncertainty (IU) is related to the use of alcohol as a coping tool, but there is a dearth of work testing whether IU influences alcohol-related forecasts. Objectives: Utilizing a novel affective forecasting task, we tested the prediction that social anxiety symptoms, sociability alcohol expectancies, and IU would relate to predictions about alcohol use. In an initial study and preregistered replication, participants imagined themselves in stressful social scenarios and forecasted how anxious they would feel when drinking and when sober. In the replication, participants also forecasted whether they would drink in the imagined scenarios. Results: Contrary to hypotheses, social anxiety symptoms and IU did not significantly predict higher forecasted anxiety across studies, nor did they predict forecasted drinking. Exploratory analyses showed that participants with higher sociability alcohol expectancies forecasted being more likely to drink, and forecasted feeling less anxious when drinking (versus being sober). Even after statistically controlling for social anxiety, the effect of sociability expectancies remained significant in predicting forecasted anxiety and forecasted drinking. Conclusions: Clinicians could consider specifically targeting sociability expectancies for alcohol use difficulties, and future research should continue utilizing affective forecasting paradigms to test links between social anxiety, alcohol expectancies, and alcohol-use problems.

The interactive effects of different facets of threat uncertainty and cognitive load in shaping fear and anxiety responses

A large body of research indicates that exaggerated response to uncertainty of a future threat is at the core of anxiety and related disorders, underscoring the need for a better understanding of the underlying mechanisms. Although behavioral and neuroimaging studies have suggested a close relationship between uncertainty responses and cognitive control, little is known about what elements of uncertainty are more or less vulnerable to cognitive modulation in shaping aversive responses. Leveraging a novel paradigm, an n-back working memory task embedded within a modified threat-of-shock paradigm, we examined how the influences of different facets of uncertainty (i.e., occurrence and timing) on psychophysiological responses were modulated by cognitive load. Psychophysiological responses were assessed using the acoustic startle reflex. Replicating prior work, the effects of cognitive load and temporal unpredictability of threat on startle responses were evident. The effect of occurrence unpredictability appears to depend on other factors. Under low cognitive load, startle response was potentiated when both the occurrence and the timing of threat were predictable. Under high cognitive load, startle response was significantly reduced, especially when a threat context involves uncertainty in both temporal and probability domains. These observations provide a framework for refining the model of fear and anxiety and for understanding the etiology of psychological disorders characterized by maladaptive uncertainty responses.

Behavioral and brain reactivity to uncertain stress prospectively predicts binge drinking in youth

Prior studies show that individuals with alcohol use disorder exhibit exaggerated behavioral and brain reactivity to uncertain threats (U-threat). It is posited this brain-based factor emerges early in life and contributes to the onset and escalation of alcohol problems. However, no study to date has tested this theory using a longitudinal within-subjects design. Ninety-five young adults, ages 17-19, with minimal alcohol exposure and established risk factors for alcohol use disorder participated in this multi-session study with a 1-year tracking period. Startle eyeblink potentiation and brain activation were collected at separate baseline sessions during the well-validated No-Predictable-Unpredictable (NPU) threat-of-shock task designed to probe reactivity to U-threat and predictable threat (P-threat). Participants self-reported their drinking behavior over the past 90 days at baseline and one-year later. We fit a series of multilevel hurdle models to model the binary outcome of whether binge drinking occurred and the continuous outcome of number of binge drinking episodes. Zero-inflated binary submodels revealed that greater baseline startle reactivity, bilateral anterior insula (AIC) reactivity, and dorsal anterior cingulate cortex (dACC) reactivity to U-threat were associated with increased probability of binge drinking. There were no other associations between reactivity to U- and P-threat and probability of binge drinking and number of binging episodes. These results demonstrate that exaggerated reactivity to U-threat is a brain-based individual difference factor that connotes risk for problem drinking. These findings also add to a growing literature implicating AIC and dACC dysfunction in the pathophysiology of alcohol use disorder.

Intolerance of Uncertainty, Negative Reinforcement Alcohol Use Motives, and Hazardous Drinking in College Students with Clinically Elevated Worry

Background: Hazardous drinking has remained high for college students in recent years, and individuals who endorse drinking to cope with emotional distress or to conform socially report higher levels of alcohol use. Intolerance of uncertainty, a core process underlying generalized anxiety disorder, has been linked to negative reinforcement drinking motives; however, no research, to date, has examined the role of intolerance of uncertainty in terms of alcohol use motives and hazardous drinking among individuals with generalized anxiety disorder. Objective: The current study was designed to examine the relationships between intolerance of uncertainty, coping and conformity alcohol use motives, and hazardous drinking in an analogue generalized anxiety disorder sample. Methods: Participants were 323 college students (M_age = 19.25, SD = 2.23, Range = 18-40) who endorsed past-year alcohol use and clinically elevated levels of worry. Self-report measures were completed online for course credit. Results: Partially consistent with our hypotheses, uncertainty paralysis predicted greater levels of coping motives, but not conformity motives. Desire for predictability did not predict either drinking motive. Mediation analyses revealed that there was a significant indirect effect of uncertainty paralysis on more hazardous drinking through greater coping motives. Conclusion: Overall, these findings highlight the potential utility of targeting behavioral inhibition due to uncertainty to reduce unhealthy coping via alcohol use and subsequent hazardous alcohol use.

College students' momentary stress and prescription drug misuse in daily life: Testing direct links and the moderating roles of global stress and coping

Prior survey-based research has documented associations between greater levels of stress and increased prescription drug misuse behaviour. These studies uniformly rely on assessments of both the stress experiences and the substance behaviour after they occurred (commonly spanning 6-12 month retrospective timeframes). Less is known about the extent to which variations in momentary stress predict the actual occurrence of prescription misuse in daily life among college students with elevated risk for engaging in the behaviour. In this study, 297 participants (69% females; Mage  = 19.5 years, SDage  = 0.71) completed a 28-day ecological momentary assessment procedure that collected self-reported stress and other contextual experiences in moments preceding prescription drug misuse. Analyses tested the within-person association between momentary stress and prescription drug misuse and examined the extent to which the relation between stress and misuse was moderated by participants' assigned sex or global stress and coping levels. Results from hierarchical generalised linear modelling indicated a significant within-person association between momentary stress (i.e., higher than usual relative to one's own mean) and greater likelihood of prescription misuse in daily life, accounting for the number of stressors and timing covariates. No significant moderation by participant sex was found, and moderation effects by global stress and coping levels were not in the expected directions. Direct results highlight the role of momentary stress experiences on health-relevant substance behaviours and provide future directions for research and applied efforts.

Threat effects on attention networks in individuals with a history of externalizing behaviors

Research identifying the biobehavioral processes that link threat exposure to cognitive alterations can inform treatments designed to reduce perpetration of stress-induced aggression. The present study attempted to specify the effects of relatively predictable versus unpredictable threat on two attention networks, attentional alerting and executive control. In a sample of adults (n = 74, 35 % identifying as women, Mage = 32.85) with high rates of externalizing behaviors (e.g., substance use, criminal/legal system involvement, aggressivity), we measured event-related brain activity during an attention network test that manipulated cognitive systems activation under relatively unpredictable and predictable threat conditions. Results showed that threat exposure alters attentional alerting and executive control. The predictable threat condition, relative to unpredictable threat, increased visual alerting (N1 amplitude to alert vs. no alert cue conditions) and decreased attention to the task (P3 amplitude to subsequent task-relevant flankers, but these effects did not survive adjusting for multiple tests. In contrast, overall threat and unpredictable threat conditions were associated with faster response time to alert cue (versus no cue) and poorer conflict processing, operationalized as flanker N2 reductions and slower response time to incongruent (versus congruent) flanker trials. These results expand what is known about threat-related modulation of cognition in a sample of individuals with histories of externalizing behaviors.

A social contextual review of the effects of alcohol on emotion

Drinking and drinking problems are complex phenomena. Understanding the etiology of alcohol use disorder requires consideration of biological, psychological, and social processes. It is our view that the last of these dimensions is just beginning to receive adequate scrutiny. In this selective review, we discuss the concept of a biopsychosocial analysis of the effects of alcohol. After briefly addressing biological and psychological research on alcohol's emotional effects, we bid to make a case for the vital role that social processes play in understanding why people drink. The bulk of the paper describes research illustrating the contributions that a social psychological perspective can make to advance understanding of the rewarding effects of alcohol. Overall, studies incorporating social contexts have revealed reliable evidence that alcohol enhances emotional experience in many social environments and have identified socio-contextual variables that moderate responses to alcohol. Further, these studies have broadened the scope of constructs thought to be socially rewarding, including social bonding, relationship functioning, and humor enjoyment. Our analysis concludes by identifying research areas we believe would profit from additional research.

Alcohol's effects during uncertain and uncontrollable stressors in the laboratory

Alcohol's effects on reactivity to stressors depends on the nature of the stressor and the reactivity being assessed. Research identifying characteristics of stressors that modulate reactivity and clarifies the neurobehavioral, cognitive, and affective components of this reactivity may help prevent, reduce or treat the negative impacts of acute and chronic alcohol use with implications for other psychopathology involving maladaptive reactivity to stressors. We used a novel, multi-measure, cued electric shock stressor paradigm in a greater university community sample of adult recreational drinkers to test how alcohol (N=64), compared to No-alcohol (N=64), effects reactivity to stressors that vary in both their perceived certainty and controllability. Preregistered analyses suggested alcohol significantly dampened subjective anxiety (self-report) and defensive reactivity (startle potentiation) more during uncertain than during certain stressors regardless of controllability, suggesting that stressor uncertainty -but not uncontrollability- may be sufficient to enhance alcohol's stress reactivity dampening and thus negative reinforcement potential.

Childhood Adversity and the Association Between Stress Sensitivity and Problematic Alcohol Use in Adults

Early life adversity (ELA) increases the risk of problematic alcohol use and alcohol use disorder (AUD). However, it is unclear why some but not all ELA-exposed individuals develop problematic alcohol use. Research is needed to determine how this environmental risk factor interacts with underlying neurobehavioral vulnerabilities to problem alcohol use. Hypersensitivity to uncertain threats (U-threat) has been posited as an endophenotype for AUD that might aid in the refinement of mechanistic models of problematic alcohol use. Therefore, U-threat hypersensitivity requires examination as a possible individual difference factor that facilitates problematic alcohol use among ELA-exposed individuals. We examined the unique and interactive effects of ELA and U-threat reactivity on problem drinking and depressive and anxiety symptom severity. Participants (N = 131) completed a well-validated threat-of-shock task, and startle eyeblink potentiation was recorded to index aversive responding. Individuals also completed self-report measures of alcohol use, anxiety, and depressive symptoms. Results demonstrated a positive association between ELA and higher levels of problematic alcohol use at high levels of U-threat reactivity, β = .75, t = 3.93, p < .001. Conversely, at low levels of U-threat reactivity, ELA exposure was negatively associated with problematic alcohol use, β = -.49, t = -2.30, p = .023. There was no significant ELA x U-Threat reactivity interaction on anxiety or depression. U-threat response strongly interacts with ELA exposure, affecting the direction of the association between ELA and problem drinking. U-threat reactivity may be a promising target for the prevention and treatment of problematic drinking among ELA-exposed individuals.

Binge Drinking Among Public Sector Food Service Workers in Brazil: Physical and Psychosocial Demands on Focus

OBJECTIVE

To investigate occupational risk factors associated with binge drinking (BD) among public sector food service workers in a Brazilian capital.

METHODS

All workers from the Government-backed Economy Restaurant Program (GbERP) in Belo Horizonte city were evaluated. BD was defined as consumption of five or more doses (male) or four or more doses (female) of alcoholic beverages on a single occasion within 30 days. Occupational psychosocial and physical stressors were the main exposure variables; sociodemographic, health, and lifestyle variables were inserted as potential confounding factors. We performed logistic regression.

RESULTS

A total of 214 people participated in the study and 30.7% reported BD. Psychosocial (violence and high demands) and ergonomic aspects were associated with the outcome.

CONCLUSION

There was a high prevalence of BD among GbERP workers. Actions are necessary to reduce violence and high strain and consequently BD.

Binge ethanol consumption-associated behavioral impairments in male mice using a gelatin-based drinking-in-the dark model

BACKGROUND

Acute intoxication caused by binge ethanol drinking is linked to widespread impairments in brain functions. Various alcohol administration paradigms have been used in animals to model the heterogeneous clinical manifestation of intoxication in people. It is challenging to model a procedure that produces "visible intoxication" in rodents; however, manipulation of variables such as route of alcohol administration, time of availability, frequency, and duration and amount of ethanol exposure has achieved some success. In the current study, we employed a modified drinking-in-the-dark model to assess the validity of this model in producing "post-ethanol consumption intoxication" impairments following prolonged repeated daily voluntary "binge" ethanol consumption.

METHODS

Adult male C57BL/6J mice were allowed a daily 3-h access to non-alcoholic plain or ethanol-containing gel during the dark cycle for a total of 83 days. After the initial 2-month daily DID, ethanol intake patterns were intensely characterized during the next 3 weeks. Immediately following the last DID session (day 83), plain and ethanol gel-consuming mice were then subjected to behavioral tests of locomotor ability and/or anxiety (cylinder, wire grip, open field) followed by blood ethanol concentration measurement.

RESULT

Mice exhibited a relatively consistent ethanol consumption pattern during and across daily access periods. Ethanol intake of individual mice positively correlated with blood ethanol concentration that averaged 61.64 ± 2.84 mg/dL (n = 12). Compared to the plain gel-consuming control mice, ethanol gel mice exhibited significant locomotor impairment as well as anxiety-like behavior, with the magnitude of impairments of key indices well correlated with blood ethanol levels.

CONCLUSION

The gelatin vehicle-based voluntary ethanol drinking-in-the-dark model reliably produced post consumption acute movement impairments as well as anxiety-like behaviors even after 2 months of daily binge ethanol consumption in male mice. Taken together, this mouse binge ethanol model should facilitate the investigation of mechanisms of binge drinking in subjects chronically abusing ethanol and the search for effective novel treatment strategies.

Shared and unique neural circuitry underlying temporally unpredictable threat and reward processing

Temporally unpredictable stimuli influence behavior across species, as previously demonstrated for sequences of simple threats and rewards with fixed or variable onset. Neuroimaging studies have identified a specific frontolimbic circuit that may become engaged during the anticipation of temporally unpredictable threat (U-threat). However, the neural mechanisms underlying processing of temporally unpredictable reward (U-reward) are incompletely understood. It is also unclear whether these processes are mediated by overlapping or distinct neural systems. These knowledge gaps are noteworthy given that disruptions within these neural systems may lead to maladaptive response to uncertainty. Here, using functional magnetic resonance imaging data from a sample of 159 young adults, we showed that anticipation of both U-threat and U-reward elicited activation in the right anterior insula, right ventral anterior nucleus of the thalamus and right inferior frontal gyrus. U-threat also activated the right posterior insula and dorsal anterior cingulate cortex, relative to U-reward. In contrast, U-reward elicited activation in the right fusiform and left middle occipital gyrus, relative to U-threat. Although there is some overlap in the neural circuitry underlying anticipation of U-threat and U-reward, these processes appear to be largely mediated by distinct circuits. Future studies are needed to corroborate and extend these preliminary findings.

Ambulatory Assessment Methods to Examine Momentary State-Based Predictors of Opioid Use Behaviors

PURPOSE OF REVIEW

Addiction scientists have begun using ambulatory assessment methods-including ecological momentary assessment (EMA), experience sampling, and daily diaries-to collect real-time or near-real-time reports of participants' internal states in their natural environments. The goal of this short review is to synthesize EMA findings from our research group, which has studied several hundred outpatients during treatment for opioid-use disorder (OUD). (We cite pertinent findings from other groups, but have not tried to be comprehensive.) One of our main goals in using EMA is to examine momentary changes in internal states that proximally predict, or concurrently mark, events such as lapses to opioid use.

RECENT FINDINGS

We summarize findings evaluating several classes of momentary markers or predictors (craving, stress, negative and positive moods, and physical pain/discomfort) of lapses and other states/behaviors. Craving and some negatively valenced mood states are concurrently and prospectively associated with lapses to opioid use during treatment. Craving is also concurrently and prospectively associated with momentary changes in stress and mood. Convincing evidence has not yet emerged for stress as a robust redictor of lapse to opioid use; it appears to be contributory, but neither necessary nor sufficient.

SUMMARY

Ambulatory assessment can capture changes in internal states and drug-related behaviors in situ and at high temporal resolution. We recommend research strategies that may increase the clinical and prognostic utility of ambulatory assessment, including denser sampling (i.e., more assessments per day) and more attention to heterogeneity across people and across populations.

Acute effects of alcohol on error-elicited negative affect during a cognitive control task

RATIONALE

Alcohol intoxication can dampen negative affective reactions to stressors. Recently, it has been proposed that these acute anxiolytic effects of alcohol may extend to dampening of negative affective reactions to error commission during cognitive control tasks. Nonetheless, empirical verification of this claim is lacking.

OBJECTIVES

Test the acute effect of alcohol on negative affective reactions to errors during an effort-demanding cognitive control task.

METHODS

Healthy, young adult social drinkers (N = 96 [49 women], 21-36 years old) were randomly assigned to consume alcohol (0.80 g/kg; n = 33 [15 female]), active placebo (0.04 g/kg; n = 33 [18 women]), or a non-alcoholic control beverage (n = 30 [16 women]) before completing the Eriksen flanker task. Corrugator supercilii (Corr) activation, a psychophysiological index of negative affect, was tracked across the task. Two neurophysiological reactions to errors, the error-related negativity (ERN) and the error positivity (Pe), were also measured.

RESULTS

Erroneous actions increased Corr activation in the control and (to a lesser extent) placebo groups, but not in the alcohol group. Error-induced Corr activation was coupled to ERN and Pe in the control, but not in the alcohol and placebo groups. Error-induced Corr activation was not coupled to post-error performance adjustments in any group.

CONCLUSIONS

The ability of alcohol to dampen error-related negative affect was verified. It was also shown that placebo alone can disrupt coupling of affective and (neuro)cognitive reactions to errors. Although its behavioral relevance remains to be demonstrated, more attention should be paid to the role of affect in action monitoring and cognitive control processes.

Stress Allostasis in Substance Use Disorders: Promise, Progress, and Emerging Priorities in Clinical Research

Clinicians and researchers alike have long believed that stressors play a pivotal etiologic role in risk, maintenance, and/or relapse of alcohol and other substance use disorders (SUDs). Numerous seminal and contemporary theories on SUD etiology posit that stressors may motivate drug use and that individuals who use drugs chronically may display altered responses to stressors. We use foundational basic stress biology research as a lens through which to evaluate critically the available evidence to support these key stress-SUD theses in humans. Additionally, we examine the field's success to date in targeting stressors and stress allostasis in treatments for SUDs. We conclude with our recommendations for how best to advance our understanding of the relationship between stressors and drug use, and we discuss clinical implications for treatment development.

Behavioral and neural sensitivity to uncertain threat in individuals with alcohol use disorder: Associations with drinking behaviors and motives

A developing theory is that individuals with alcohol use disorder (AUD) display exaggerated reactivity to threats that are uncertain (U-threat), which facilitates excessive drinking as a means of avoidance-based coping. There is a promising initial behavioral evidence supporting this theory; however, the neural bases of reactivity to U-threat in individuals with AUD have not been examined. The extent to which biomarkers of U-threat reactivity map onto drinking behaviors and coping motives for alcohol use is also unknown. The current study therefore examined group differences in behavioral and neural reactivity to U-threat in adults with and without AUD. The study also tested whether behavior and brain responses to U-threat correlate with problematic drinking and coping motivated drinking. Volunteers (n = 65) with and without a history of AUD (38 AUD, 27 controls) were included and completed a well-validated threat-of-shock task to probe responses to U-threat and predictable threat (P-threat) while startle eyeblink potentiation was collected. Individuals also completed a newly designed, analogous version of the task during functional magnetic resonance imaging (fMRI). Results indicated that individuals with AUD displayed greater startle magnitude during U-threat, but not P-threat, and greater right insula and dorsal anterior cingulate cortex (dACC) activation during both forms of threat compared with controls. Startle magnitude and insula activation during U-threat positively correlated with self-reported problem drinking and coping motives for alcohol use. Findings demonstrate that individuals with AUD display exaggerated sensitivity to U-threat at the behavioral and neural level and that these multimethod biomarkers tap into negative reinforcement processes of alcohol abuse.

To Infuse or Ingest in Human Laboratory Alcohol Research

Human alcohol laboratory studies use two routes of alcohol administration: ingestion and infusion. The goal of this paper was to compare and contrast these alcohol administration methods. The work summarized in this report was the basis of a 2019 Research Society on Alcoholism Roundtable, "To Ingest or Infuse: A Comparison of Oral and Intravenous Alcohol Administration Methods for Human Alcohol Laboratory Designs." We review the methodological approaches of each and highlight strengths and weaknesses pertaining to different research questions. We summarize methodological considerations to aid researchers in choosing the most appropriate method for their inquiry, considering exposure variability, alcohol expectancy effects, safety, bandwidth, technical skills, documentation of alcohol exposure, experimental variety, ecological validity, and cost. Ingestion of alcohol remains a common and often a preferable, methodological practice in alcohol research. Nonetheless, the main problem with ingestion is that even the most careful calculation of dose and control of dosing procedures yields substantial and uncontrollable variability in the participants' brain exposures to alcohol. Infusion methodologies provide precise exposure control but are technically complex and may be limited in ecological validity. We suggest that alcohol ingestion research may not be the same thing as alcohol exposure research; investigators should be aware of the advantages and disadvantages that the choice between ingestion and infusion of alcohol invokes.

Human Plasma BDNF Is Associated With Amygdala-Prefrontal Cortex Functional Connectivity and Problem Drinking Behaviors

BACKGROUND

Preclinical studies suggest that decreased levels of brain-derived neurotrophic factor in the amygdala play a role in anxiety and alcohol use disorder. The association between brain-derived neurotrophic factor levels and amygdala function in humans with alcohol use disorder is still unclear, although neuroimaging studies have also implicated the amygdala in alcohol use disorder and suggest that alcohol use disorder is associated with disrupted functional connectivity between the amygdala and prefrontal cortex during aversive states.

METHODS

The current study investigated whether plasma brain-derived neurotrophic factor levels in individuals with and without alcohol use disorder (n = 57) were associated with individual differences in amygdala reactivity and amygdala-prefrontal cortex functional connectivity during 2 forms of aversive responding captured via functional magnetic resonance imaging: anxiety elicited by unpredictable threat of shock and fear elicited by predictable threat of shock. We also examined whether brain-derived neurotrophic factor and brain function were associated with binge drinking episodes and alcohol use disorder age of onset.

RESULTS

During anxiety, but not fear, lower levels of plasma brain-derived neurotrophic factor were associated with less connectivity between the left amygdala and the medial prefrontal cortex and the inferior frontal gyrus. In addition, within individuals with alcohol use disorder (only), lower levels of brain-derived neurotrophic factor and amygdala-medial prefrontal cortex functional connectivity during anxiety were associated with more binge episodes within the past 60 days and a lower age of alcohol use disorder onset. There were no associations between brain-derived neurotrophic factor levels and focal amygdala task reactivity.

CONCLUSIONS

Together, the results indicate that plasma brain-derived neurotrophic factor levels are related to amygdala circuit functioning in humans, particularly during anxiety, and these individual differences may relate to drinking behaviors.

Interpersonal trauma exposure and startle reactivity to uncertain threat in individuals with alcohol use disorder

BACKGROUND

Exposure to interpersonal trauma is highly prevalent within individuals with alcohol use disorder (AUD); however, the mechanisms underlying the pathway between trauma exposure and AUD are unclear. Preliminary evidence suggests that heightened reactivity to threats that are uncertain (U-threat) may characterize individuals with AUD and interpersonal trauma exposure and contribute to alcohol abuse within this subgroup of individuals; however, this hypothesis has yet to be tested.

METHOD

The aim of the study was to examine whether heightened reactivity to U-threat characterizes individuals with AUD and a history of interpersonal trauma. Specifically, the study compared defensive reactivity to U-threat (and predictable threat [P-threat]) in those with: 1) AUD and a history of interpersonal trauma (AUD + Trauma); 2) AUD and no history of interpersonal trauma (AUD-Trauma); and 3) matched controls. Participants (N = 77) completed a well-validated threat-of-shock task and startle eyeblink potentiation was collected as an index of aversive responding.

RESULTS

Results revealed a group by threat condition interaction (F[4, 142] = 3.17, p = 0.03; ηG2 = 0.08) such that individuals with AUD + Trauma exhibited greater startle reactivity to U-threat, but not P-threat, compared with individuals with AUD-Trauma and controls (who did not differ from each other). The findings were significant even when controlling for current anxiety and depression symptoms.

CONCLUSIONS

Within individuals with AUD, those with a history of interpersonal trauma exposure may be a neurobiologically unique subtype characterized by exaggerated U-threat reactivity and high levels of anticipatory anxiety. Reactivity to U-threat may be a promising alcohol use prevention and intervention target for trauma-exposed individuals.

Modeling anxiety in healthy humans: a key intermediate bridge between basic and clinical sciences

Animal models of anxiety disorders are important for elucidating neurobiological defense mechanisms. However, animal models are limited when it comes to understanding the more complex processes of anxiety that are unique to humans (e.g., worry) and to screen new treatments. In this review, we outline how the Experimental Psychopathology approach, based on experimental models of anxiety in healthy subjects, can mitigate these limitations and complement research in animals. Experimental psychopathology can bridge basic research in animals and clinical studies, as well as guide and constrain hypotheses about the nature of psychopathology, treatment mechanisms, and treatment targets. This review begins with a brief review of the strengths and limitations of animal models before discussing the need for human models of anxiety, which are especially necessary to probe higher-order cognitive processes. This can be accomplished by combining anxiety-induction procedures with tasks that probe clinically relevant processes to identify neurocircuits that are potentially altered by anxiety. The review then discusses the validity of experimental psychopathology and introduces a methodological approach consisting of five steps: (1) select anxiety-relevant cognitive or behavioral operations and associated tasks, (2) identify the underlying neurocircuits supporting these operations in healthy controls, 3) examine the impact of experimental anxiety on the targeted operations in healthy controls, (4) utilize findings from step 3 to generate hypotheses about neurocircuit dysfunction in anxious patients, and 5) evaluate treatment mechanisms and screen novel treatments. This is followed by two concrete illustrations of this approach and suggestions for future studies.

Acute prazosin administration does not reduce stressor reactivity in healthy adults

RATIONALE

Norepinephrine plays a critical role in the stress response. Clarifying the psychopharmacological effects of norepinephrine manipulation on stress reactivity in humans has important implications for basic neuroscience and treatment of stress-related psychiatric disorders, such as posttraumatic stress disorder and alcohol use disorders. Preclinical research implicates the norepinephrine alpha-1 receptor in responses to stressors. The No Shock, Predictable Shock, Unpredictable Shock (NPU) task is a human laboratory paradigm that is well positioned to test cross-species neurobiological stress mechanisms and advance experimental therapeutic approaches to clinical trials testing novel treatments for psychiatric disorders.

OBJECTIVES

We hypothesized that acute administration of prazosin, a noradrenergic alpha-1 antagonist, would have a larger effect on reducing stress reactivity during unpredictable, compared to predictable, stressors in the NPU task.

METHODS

We conducted a double-blind, placebo-controlled, crossover randomized controlled trial in which 64 healthy adults (32 female) completed the NPU task at two visits (2 mg prazosin vs. placebo).

RESULTS

A single acute dose of 2 mg prazosin did not reduce stress reactivity in a healthy adult sample. Neither NPU startle potentiation nor self-reported anxiety was reduced by prazosin (vs. placebo) during unpredictable (vs. predictable) stressors.

CONCLUSIONS

Further research is needed to determine whether this failure to translate preclinical neuroscience to human laboratory models is due to methodological factors (e.g., acute vs. chronic drug administration, brain penetration, study population) and/or suggests limited clinical utility of noradrenergic alpha-1 antagonists for treating stress-related psychiatric disorders.

Attention and anticipation in response to varying levels of uncertain threat: An ERP study

Individual differences in responding to uncertainty have been proposed as a key mechanism of how anxiety disorders develop and are maintained. However, most empirical work has compared responding to uncertain versus certain threat dichotomously. This is a significant limitation because uncertainty in daily life occurs along a continuum of probability, ranging from very low to high chances of negative outcomes. The current study investigated (1) how varying levels of uncertainty impact attention and anticipatory emotion, and (2) how these effects are moderated by individual differences in risk factors for anxiety disorders, particularly intolerance of uncertainty (IU) and worry. Participants (n = 65) completed a card task in which the probability of shock varied across trials. Two event-related potential components were examined: the P2, an index of attention, and the stimulus-preceding negativity (SPN), an index of anticipation. The P2 tracked the level of uncertainty and was smaller for more uncertain outcomes. Participants higher in IU exhibited greater differences in the P2 across levels of uncertainty. The SPN did not track specific levels of uncertainty but was largest for uncertain threat compared with certain threat and safety. Greater worry was associated with blunting of the SPN in anticipation of all outcomes. Thus, attention appears to be sensitive to variations in uncertainty, whereas anticipation seems sensitive to uncertainty globally. The two processes appear to be distinctly related to anxiety risk factors. These results highlight the value of examining multiple aspects of anticipatory responding to varying levels of uncertainty for understanding risk for anxiety disorders.

Cued for risk: Evidence for an incentive sensitization framework to explain the interplay between stress and anxiety, substance abuse, and reward uncertainty in disordered gambling behavior

Gambling disorder is an impairing condition confounded by psychiatric co-morbidity, particularly with substance use and anxiety disorders. Yet, our knowledge of the mechanisms that cause these disorders to coalesce remains limited. The Incentive Sensitization Theory suggests that sensitization of neural "wanting" pathways, which attribute incentive salience to rewards and their cues, is responsible for the excessive desire for drugs and cue-triggered craving. The resulting hyper-reactivity of the "wanting' system is believed to heavily influence compulsive drug use and relapse. Notably, evidence for sensitization of the mesolimbic dopamine pathway has been seen across gambling and substance use, as well as anxiety and stress-related pathology, with stress playing a major role in relapse. Together, this evidence highlights a phenomenon known as cross-sensitization, whereby sensitization to stress, drugs, or gambling behaviors enhance the sensitivity and dopaminergic response to any of those stimuli. Here, we review the literature on how cue attraction and reward uncertainty may underlie gambling pathology, and examine how this framework may advance our understanding of co-mordidity with substance-use disorders (e.g., alcohol, nicotine) and anxiety disorders. We argue that reward uncertainty, as seen in slot machines and games of chance, increases dopaminergic activity in the mesolimbic pathway and enhances the incentive value of reward cues. We propose that incentive sensitization by reward uncertainty may interact with and predispose individuals to drug abuse and stress, creating a mechanism through which co-mordidity of these disorders may emerge.

The central extended amygdala in fear and anxiety: Closing the gap between mechanistic and neuroimaging research

Anxiety disorders impose a staggering burden on public health, underscoring the need to develop a deeper understanding of the distributed neural circuits underlying extreme fear and anxiety. Recent work highlights the importance of the central extended amygdala, including the central nucleus of the amygdala (Ce) and neighboring bed nucleus of the stria terminalis (BST). Anatomical data indicate that the Ce and BST form a tightly interconnected unit, where different kinds of threat-relevant information can be integrated to assemble states of fear and anxiety. Neuroimaging studies show that the Ce and BST are engaged by a broad spectrum of potentially threat-relevant cues. Mechanistic work demonstrates that the Ce and BST are critically involved in organizing defensive responses to a wide range of threats. Studies in rodents have begun to reveal the specific molecules, cells, and microcircuits within the central extended amygdala that underlie signs of fear and anxiety, but the relevance of these tantalizing discoveries to human experience and disease remains unclear. Using a combination of focal perturbations and whole-brain imaging, a new generation of nonhuman primate studies is beginning to close this gap. This work opens the door to discovering the mechanisms underlying neuroimaging measures linked to pathological fear and anxiety, to understanding how the Ce and BST interact with one another and with distal brain regions to govern defensive responses to threat, and to developing improved intervention strategies.

Heavy marijuana use but not deprivation is associated with increased stressor reactivity

Although stressors appear to motivate marijuana use, and marijuana use, in turn, is believed to induce stress system neuroadaptations, relatively little empirical work has explicitly tested for stress neuroadaptations associated with heavy marijuana use. We examined stressor reactivity to threat of unpredictable electric shock via startle potentiation among heavy marijuana users and a control group that reported minimal history of marijuana use. Heavy marijuana users were randomly assigned to 3 days of marijuana deprivation or no deprivation. This design allowed us to test contrasts for heavy (vs. minimal) use and deprivation (vs. no deprivation) on stressor reactivity. Heavy marijuana users (both deprived and nondeprived) displayed increased startle potentiation during threat of unpredictable electric shock relative to minimal use controls. In contrast, marijuana deprivation had no effect on startle potentiation. Startle potentiation was also increased among users who reported greater stress-coping motives for their marijuana use and users with cannabis use disorder diagnoses. To our knowledge, this is the 1st study to demonstrate increased reactivity to unpredictable stressors among heavy marijuana users. However, comparable increased unpredictable stressor reactivity among patients with alcohol and other substance use disorders has been previously documented. This relationship to heavy marijuana use is consistent with predictions from rodent addiction models regarding stress neuroadaptations following heavy, chronic drug use but could also represent an etiologically relevant premorbid risk characteristic. Finally, the clinical import of unpredictable stressor reactivity is reinforced by its relationships with stress-coping motives and cannabis use disorder status. (PsycINFO Database Record

Acute alcohol administration dampens central extended amygdala reactivity

Alcohol use is common, imposes a staggering burden on public health, and often resists treatment. The central extended amygdala (EAc)—including the bed nucleus of the stria terminalis (BST) and the central nucleus of the amygdala (Ce)—plays a key role in prominent neuroscientific models of alcohol drinking, but the relevance of these regions to acute alcohol consumption in humans remains poorly understood. Using a single-blind, randomized-groups design, multiband fMRI data were acquired from 49 social drinkers while they performed a well-established emotional faces paradigm after consuming either alcohol or placebo. Relative to placebo, alcohol significantly dampened reactivity to emotional faces in the BST. To rigorously assess potential regional differences in activation, data were extracted from unbiased, anatomically predefined regions of interest. Analyses revealed similar levels of dampening in the BST and Ce. In short, alcohol transiently reduces reactivity to emotional faces and it does so similarly across the two major divisions of the human EAc. These observations reinforce the translational relevance of addiction models derived from preclinical work in rodents and provide new insights into the neural systems most relevant to the consumption of alcohol and to the initial development of alcohol abuse in humans.

Exercise decreases defensive responses to unpredictable, but not predictable, threat

BACKGROUND

Research supports the anxiolytic effect of exercise, but the mechanism underlying this effect is unclear. This study examines the influence of exercise in healthy controls on two distinct defensive states implicated in anxiety disorders: fear, a phasic response to a predictable threat, and anxiety, a sustained response to an unpredictable threat.

METHODS

Thirty-four healthy volunteers (17 male, age M = 26.18, SD = 5.6) participated in sessions of exercise (biking at 60-70% of heart rate reserve) and control (biking at 10-20% of heart rate reserve) activity for 30 min, separated by 1 week. Threat responses were measured by eyeblink startle and assessed with the "Neutral-Predictable-Unpredictable threat test," which includes a neutral (N) and two threat conditions, one with predictable (P) and one with unpredictable (U) shock.

RESULTS

Results show that exercise versus control activity reduces startle potentiation during unpredictable threat (P = .031), but has no effect on startle potentiation during predictable threat (P = .609).

CONCLUSIONS

These results suggest that exercise reduces defensive response to unpredictable, but not predictable, threat, a dissociation that may help inform clinical indications for this behavioral intervention, as well as provide clues to its underlying neurobehavioral mechanisms.

The effects of alcohol on positive emotion during a comedy routine: A facial coding analysis

There is considerable interest in understanding the emotional effects of alcohol. While a great deal of experimental research has focused on alcohol's ability to relieve negative emotions, there has been far less focus on the effects of alcohol on positive emotions. Further, the available research on positive emotion tends to test alcohol while participants are alone. Yet alcohol is often consumed in social settings, and enhancing social pleasure is consistently identified as being a primary motive for drinking. We aimed to address this gap in the literature by investigating the impact of alcohol on positive emotional experience in a social setting. We used the Facial Action Coding System (FACS) to examine in a large sample the effects of alcohol on response to comedy in a group setting. Five hundred thirteen social drinkers (51.9% female) were assembled into groups of three unacquainted persons and administered either a moderate dose of alcohol, a placebo, or a nonalcohol control beverage. Following beverage consumption, groups listened to a roughly 5-min comedy clip while their facial expressions were video recorded. More than 5 million frames of video were then FACS-coded. Alcohol consumption enhanced enjoyment (Duchenne) smiles-but not nonenjoyment social smiles-and elevated mood ratings. Results provide multimodal evidence supporting the ability of alcohol to enhance positive emotional experience during a comedy routine delivered in a social context. More broadly, this research illustrates the value of studying emotion in a social context using both self-report and behavior-expressive approaches. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Considering the context: social factors in responses to drugs in humans

BACKGROUND

Drugs are typically used in social settings. Here, we consider two factors that may contribute to this observation: (i) the presence of other people may enhance the positive mood effects of a drug, and conversely, (ii) drugs may enhance the value of social stimuli.

METHODS

We review evidence from controlled laboratory studies with human volunteers, which investigated either of these interactions between social factors and responses to drugs. We examine the bidirectional effects of social stimuli and single doses of alcohol, stimulants, opioids, and cannabis.

RESULTS

All four classes of drugs interact with social contexts, but the nature of these interactions varies across drugs, and depends on whether the context is positive or negative.

CONCLUSIONS

Alcohol and stimulant drugs enhance the attractiveness of social stimuli and the desire to socialize, and social contexts, in turn, enhance these drugs' effects. In contrast, opioids and cannabis have subtler effects on social interactions and their effects are less influenced by the presence of others. Overall, there is stronger evidence that drugs enhance positive social contexts than that they dampen the negativity of unpleasant social settings. Controlled research is needed to understand the interactions between drugs of abuse and social contexts, to model and understand the determinants of drug use outside the laboratory.

Probing for Neuroadaptations to Unpredictable Stressors in Addiction: Translational Methods and Emerging Evidence

Stressors clearly contribute to addiction etiology and relapse in humans, but our understanding of specific mechanisms remains limited. Rodent models of addiction offer the power, flexibility, and precision necessary to delineate the causal role and specific mechanisms through which stressors influence alcohol and other drug use. This review describes a program of research using startle potentiation to unpredictable stressors that is well positioned to translate between animal models and clinical research with humans on stress neuroadaptations in addiction. This research rests on a solid foundation provided by three separate pillars of evidence from (a) rodent behavioral neuroscience on stress neuroadaptations in addiction, (b) rodent affective neuroscience on startle potentiation, and (c) human addiction and affective science with startle potentiation. Rodent stress neuroadaptation models implicate adaptations in corticotropin-releasing factor and norepinephrine circuits within the central extended amygdala following chronic alcohol and other drug use that mediate anxious behaviors and stress-induced reinstatement among drug-dependent rodents. Basic affective neuroscience indicates that these same neural mechanisms are involved in startle potentiation to unpredictable stressors in particular (vs. predictable stressors). We believe that synthesis of these evidence bases should focus us on the role of unpredictable stressors in addiction etiology and relapse. Startle potentiation in unpredictable stressor tasks is proposed to provide an attractive and flexible test bed to encourage tight translation and reverse translation between animal models and human clinical research on stress neuroadaptations. Experimental therapeutics approaches focused on unpredictable stressors hold high promise to identify, repurpose, or refine pharmacological and psychosocial interventions for addiction.

Preliminary evidence that reactivity to uncertain threat is an endophenotype for alcohol use disorder

BACKGROUND

Having an exaggerated reactivity to threats that are uncertain (U-threat) may facilitate the initiation and maintenance of excessive alcohol use in some individuals. This abnormality may not just be a concomitant for alcohol use disorder (AUD), but also an endophenotype for AUD.

METHOD

The aim of the current study was therefore to provide a preliminary test of whether U-threat is an endophenotype for AUD using several of the endophenotype criteria outlined by Gottesman and Gould (2003). Specifically, the study examined whether heightened U-threat reactivity is evidenced in those with: 1) current AUD; 2) remitted AUD (early and sustained remission examined separately); and 3) at-risk for AUD by virtue of having a positive family history of AUD. Participants (N = 147) completed a well-validated threat-of-shock task and startle eyeblink potentiation was collected as an index of aversive responding. Individuals and all available first-degree family members were diagnosed using structured clinical interviews.

RESULTS

Individuals at-risk for AUD, with current AUD, and AUD in remission (both early and sustained) all displayed exaggerated reactivity to U-threat, but not predictable threat, compared with non-AUD controls. Moreover, there were no significant differences between the at-risk and any of the AUD groups indicating that exaggerated reactivity to U-threat is relatively state-independent and present regardless of current AUD disease status.

CONCLUSIONS

The findings together highlight that exaggerated reactivity to U-threat may be a promising endophenotype for AUD that can aid in the refinement of mechanistic AUD disease models.

Alcohol's effects on emotionally motivated attention, defensive reactivity and subjective anxiety during uncertain threats

Developing a better understanding of how and under what circumstances alcohol affects the emotions, cognitions and neural functions that precede and contribute to dangerous behaviors during intoxication may help to reduce their occurrence. Alcohol intoxication has recently been shown to reduce defensive reactivity and anxiety more during uncertain vs certain threat. However, alcohol's effects on emotionally motivated attention to these threats are unknown. Alcohol may disrupt both affective response to and attentional processing of uncertain threats making intoxicated individuals less able to avoid dangerous and costly behaviors. To test this possibility, we examined the effects of a broad range of blood alcohol concentrations on 96 participants' sub-cortically mediated defensive reactivity (startle potentiation), retrospective subjective anxiety (self-report) and cortically assessed emotionally motivated attention (probe P3 event related potential) while they experienced visually cued uncertain and certain location electric shock threat. As predicted, alcohol decreased defensive reactivity and subjective anxiety more during uncertain vs certain threat. In a novel finding, alcohol dampened emotionally motivated attention during uncertain but not certain threat. This effect appeared independent of alcohol's effects on defensive reactivity and subjective anxiety. These results suggest that alcohol intoxication dampens processing of uncertain threats while leaving processing of certain threats intact.

Impact of anxiety symptoms and problematic alcohol use on error-related brain activity

Anxiety disorders are associated with enhanced defensive reactivity to errors, measured via the error-related negativity (ERN). There is some evidence to suggest that problematic alcohol use is also associated with an enhanced ERN; although prior studies have been almost exclusively in men and have yet to examine the potential interactive effects of anxiety and alcohol abuse symptoms. The aim of the current study was to address the gaps in this literature by examining the unique and interactive effects of anxiety symptoms and problematic alcohol use on the ERN in a sample of 79 heterogeneous internalizing disorder patients. All participants completed a flanker task designed to robustly elicit the ERN and questionnaires assessing current internalizing symptoms and problematic alcohol use. As expected, results revealed that greater anxiety symptoms, but not depressive symptoms, were associated with a more enhanced ERN. There was no main effect of problematic alcohol use but there was a significant anxiety by problematic alcohol use interaction. At high anxiety symptoms, greater problematic alcohol use was associated with a more enhanced ERN; at low anxiety symptoms, alcohol use was unrelated to the ERN. There was no depression by alcohol abuse interaction. The findings suggest that within anxious individuals, heightened reactivity to errors/threat may be related to risk for alcohol abuse. The findings also converge with a broader literature suggesting that heightened reactivity to threat may be a shared vulnerability factor for anxiety and alcohol abuse and a novel prevention and intervention target for anxiety-alcohol abuse comorbidity.

Increased startle potentiation to unpredictable stressors in alcohol dependence: Possible stress neuroadaptation in humans

Stress plays a key role in addiction etiology and relapse. Rodent models posit that following repeated periods of alcohol and other drug intoxication, compensatory allostatic changes occur in the central nervous system (CNS) circuits involved in behavioral and emotional response to stressors. We examine a predicted manifestation of this neuroadaptation in recently abstinent alcohol-dependent humans. Participants completed a translational laboratory task that uses startle potentiation to unpredictable (vs. predictable) stressors implicated in the putative CNS mechanisms that mediate this neuroadaptation. Alcohol-dependent participants displayed significantly greater startle potentiation to unpredictable than predictable stressors relative to nonalcoholic controls. The size of this effect covaried with alcohol-related problems and degree of withdrawal syndrome. This supports the rodent model thesis of a sensitized stress response in abstinent alcoholics. However, this effect could also represent premorbid risk or mark more severe and/or comorbid psychopathology. Regardless, pharmacotherapy and psychological interventions may target unpredictable stressor response to reduce stress-induced relapse. (PsycINFO Database Record

Impact of alcohol use motives and internalizing symptoms on mood changes in response to drinking: An ecological momentary assessment investigation

BACKGROUND

Theory implies that individuals who use alcohol to cope with negative emotions experience the acute mood-altering effects they desire. However, no study to date has directly tested whether alcohol coping motives map onto alcohol-induced changes in mood in real-time or how co-occurring internalizing symptoms (i.e., depression and anxiety) impact the relation between coping motives and alcohol-induced changes in mood.

METHOD

The current study tested the unique and interactive effects of alcohol coping motives and internalizing symptoms on mood changes during drinking using ecological momentary assessment (EMA) in a sample of young adults (n=257). Participants completed a battery of questionnaires and a 7-day EMA assessment protocol.

RESULTS

In general, alcohol use was associated with greater positive mood and reduced negative mood while drinking. However, individuals who reported that they use alcohol to cope with anxiety, but not depression, experienced less mood benefits from alcohol relative to those without mood coping motives. In contrast, individuals with high internalizing symptoms experienced greater mood benefits while drinking relative to those with low levels of internalizing symptoms; and at high levels of anxiety, alcohol consumption was reinforcing for everyone regardless of coping motives. Only at low levels of anxiety symptoms, did coping with anxiety motives attenuate alcohol's acute reinforcing effects.

CONCLUSIONS

These results together confirm that alcohol has a robust impact on real-time mood in young adults and sheds light on the processes that may contribute to repeated alcohol use within individuals who do, and do not, use alcohol as a means of coping.

Defensive motivation and attention in anticipation of different types of predictable and unpredictable threat: A startle and event-related potential investigation

Predictability is an important characteristic of threat that impacts defensive motivation and attentional engagement. Supporting research has primarily focused on actual threat (e.g., shocks), and it is unclear whether the predictability of less intense threat (e.g., unpleasant pictures) similarly affects motivation and attention. The present study utilized a within-subject design and examined defensive motivation (startle reflex and self-reported anxiety) and attention (probe N100 and P300) in anticipation of shocks and unpleasant pictures during a no, predictable, and unpredictable threat task. This study also examined the impact of predictability on the P300 to shocks and late positive potential (LPP) to unpleasant pictures. The startle reflex and self-reported anxiety were increased in anticipation of both types of threat relative to no threat. Furthermore, startle potentiation in anticipation of unpredictable threat was greater for shocks compared to unpleasant pictures, but there was no difference for predictable threat. The probe N100 was enhanced in anticipation of unpredictable threat relative to predictable threat and no threat, and the probe P300 was suppressed in anticipation of predictable and unpredictable threat relative to no threat. These effects did not differ between the shock and unpleasant picture trials. Finally, the P300 and early LPP component were increased in response to unpredictable relative to predictable shocks and unpleasant pictures, respectively. The present study suggests that the unpredictability of unpleasant pictures increases defensive motivation, but to a lesser degree relative to actual threat. Moreover, unpredictability enhances attentional engagement in anticipation of, and in reaction to, both types of threat.

Altered subjective reward valuation among female heavy marijuana users

Maladaptive decision-making is a cardinal feature of drug use, contributing to ongoing use, and reflecting alterations in how drug users assess uncertain reward value. Accumulating evidence indicates the consequences of heavy marijuana use are worse for female versus male animals and humans, but research assessing sex differences in reward-related decision-making among marijuana users remains scarce. We examined sex differences in the subjective valuation of certain and uncertain rewards among heavy marijuana users (52; 26 male and 26 female) and controls (52; 26 male and 26 female). We offered male and female heavy marijuana users and controls monetary rewards of certain and uncertain (probabilistic) values. We measured how preferences for uncertain rewards varied by the objective value of those rewards, moderators of reward uncertainty, Marijuana Group and Sex. Men were more sensitive to changes in the objective value of uncertain rewards than women. However, this effect of Sex differed by Marijuana Group. Female heavy marijuana users were more sensitive to changes in uncertain reward value, particularly when the "stakes" were high (i.e., greater difference between potential uncertain rewards), than female controls. Female heavy marijuana users' sensitivity to changes in the value of high stakes uncertain rewards was comparable to male marijuana users and controls. In contrast, male marijuana users' sensitivity to changes in the value of high stakes uncertain rewards did not differ from male controls. These results suggest sex differences in sensitivity to high risk rewards may be one pathway contributing to severer consequences of heavy marijuana use among women. (PsycINFO Database Record

The effects of alcohol on emotion in social drinkers

Understanding why people drink alcohol and in some cases develop drinking problems has long puzzled researchers, clinicians, and patients alike. In the mid-1940s and early 1950s, experimental research began to systematically investigate alcohol's hedonic properties. Presumably, alcohol consumption would prove reinforcing as a consequence of its capacity either to relieve stress or to brighten positive emotional experiences. This article reviews experimental research through the years examining the impact of alcohol on both the relief of negative affect and the enhancement of positive affect. It covers initial accounts that emphasized direct pharmacological effects of ethanol on the central nervous system. These early studies offered surprisingly tepid support for the premise that alcohol improved emotional states. Next, studies conducted in the 1970s are considered. Informed by social learning theory and employing advances derived from experimental psychology, this research sought to better understand the complex effects of alcohol on emotion. Coverage of this work is followed by discussion of current formulations, which integrate biological and behavioral approaches with the study of cognitive, affective, and social processes. These current perspectives provide insight into the particular conditions under which alcohol can boost emotional experiences. Finally, future research directions and clinical implications are considered.

Reactivity to uncertain threat as a familial vulnerability factor for alcohol use disorder

BACKGROUND

When sober, problematic drinkers display exaggerated reactivity to threats that are uncertain (U-threat). Since this aversive affective state can be alleviated via acute alcohol intoxication, it has been posited that individuals who exhibit heightened reactivity to U-threat at baseline are motivated to use alcohol as a means of avoidance-based coping, setting the stage for excessive drinking. To date, however, no study has attempted to characterize the dispositional nature of exaggerated reactivity to U-threat and test whether it is a vulnerability factor or exclusively a disease marker of problematic alcohol use.

METHOD

The current investigation utilized a family study design to address these gaps by examining whether (1) reactivity to U-threat is associated with risk for problematic alcohol use, defined by family history of alcohol use disorder (AUD) and (2) reactivity to U-threat is correlated amongst adult biological siblings. A total of 157 families, and 458 individuals, participated in the study and two biological siblings completed a threat-of-shock task designed to probe reactivity to U-threat and predictable threat (P-threat). Startle potentiation was collected as an index of aversive responding.

RESULTS

Within biological siblings, startle potentiation to U-threat [intraclass correlation (ICC) = 0.35] and P-threat (ICC = 0.63) was significantly correlated. In addition, independent of an individuals' own AUD status, startle potentiation to U-threat, but not P-threat, was positively associated with risk for AUD (i.e. AUD family history).

CONCLUSION

This suggests that heightened reactivity to U-threat may be a familial vulnerability factor for problematic drinking and a novel prevention target for AUD.

Dispositional negativity: An integrative psychological and neurobiological perspective

Dispositional negativity-the propensity to experience and express more frequent, intense, or enduring negative affect-is a fundamental dimension of childhood temperament and adult personality. Elevated levels of dispositional negativity can have profound consequences for health, wealth, and happiness, drawing the attention of clinicians, researchers, and policymakers. Here, we highlight recent advances in our understanding of the psychological and neurobiological processes linking stable individual differences in dispositional negativity to momentary emotional states. Self-report data suggest that 3 key pathways-increased stressor reactivity, tonic increases in negative affect, and increased stressor exposure-explain most of the heightened negative affect that characterizes individuals with a more negative disposition. Of these 3 pathways, tonically elevated, indiscriminate negative affect appears to be most central to daily life and most relevant to the development of psychopathology. New behavioral and biological data provide insights into the neural systems underlying these 3 pathways and motivate the hypothesis that seemingly "tonic" increases in negative affect may actually reflect increased reactivity to stressors that are remote, uncertain, or diffuse. Research focused on humans, monkeys, and rodents suggests that this indiscriminate negative affect reflects trait-like variation in the activity and connectivity of several key brain regions, including the central extended amygdala and parts of the prefrontal cortex. Collectively, these observations provide an integrative psychobiological framework for understanding the dynamic cascade of processes that bind emotional traits to emotional states and, ultimately, to emotional disorders and other kinds of adverse outcomes. (PsycINFO Database Record

Contributions of the Central Extended Amygdala to Fear and Anxiety

It is widely thought that phasic and sustained responses to threat reflect dissociable circuits centered on the central nucleus of the amygdala (Ce) and the bed nucleus of the stria terminalis (BST), the two major subdivisions of the central extended amygdala. Early versions of this hypothesis remain highly influential and have been incorporated into the National Institute of Mental Health Research Research Domain Criteria framework. However, new observations encourage a different perspective. Anatomical studies show that the Ce and BST form a tightly interconnected unit, where different kinds of threat-relevant information can be integrated and used to assemble states of fear and anxiety. Imaging studies in humans and monkeys show that the Ce and BST exhibit similar functional profiles. Both regions are sensitive to a range of aversive challenges, including uncertain or temporally remote threat; both covary with concurrent signs and symptoms of fear and anxiety; both show phasic responses to short-lived threat; and both show heightened activity during sustained exposure to diffusely threatening contexts. Mechanistic studies demonstrate that both regions can control the expression of fear and anxiety during sustained exposure to diffuse threat. These observations compel a reconsideration of the central extended amygdala's contributions to fear and anxiety and its role in neuropsychiatric disease.

Association between problematic alcohol use and reactivity to uncertain threat in two independent samples

BACKGROUND

Recent laboratory studies have shown that acute alcohol intoxication selectively and effectively dampens aversive responding to uncertain threat. An emerging hypothesis is that individuals who exhibit heightened reactivity to uncertain threat may be especially motivated to use alcohol to dampen their distress, setting the stage for negative reinforcement processes to drive excessive alcohol use. However, no study to date has directly examined whether current problematic drinkers exhibit heightened reactivity to uncertain threat as would be expected.

METHODS

The present study was therefore designed to examine the association between current problematic alcohol use and reactivity to uncertain threat during sobriety in two, independent samples. In Study 1 (n=221) and Study 2 (n=74), adult participants completed the same well-validated threat-of-shock task which separately probes responses to temporally predictable and unpredictable threat. Startle potentiation was measured as an index of aversive responding. Problematic alcohol use was defined as number of binge episodes within the past 30days in Study 1 and total scores on a self-report measure of hazardous drinking in Study 2.

RESULTS

As hypothesized, across both studies greater levels of problematic drinking were associated with greater startle potentiation to unpredictable threat. In Study 2, hazardous drinking scores were also positively associated with startle potentiation to predictable threat.

CONCLUSIONS

The findings are notably consistent with the notion that heightened reactivity to uncertain threat is an important individual difference factor associated with the onset and/or maintenance of problematic drinking behaviors and may therefore be a novel prevention and intervention target.