Anxiety sensitivity and CO2 challenge reactivity as unique and interactive prospective predictors of anxiety pathology

CO2 challenge-evoked hormonal changes predicting TSST changes in cortisol and subjective distress

The importance of stressor response in relation to the development of psychopathology has been recognized for decades, yet the relationship is not fully understood. The Trier Social Stress Test (TSST) is an established conditioned stressor and frequently used to assess cortisol response to acute stress in different psychopathologies. The 35 % CO2 Challenge is a biological stressor and has mostly been utilized to assess subjective responses in anxiety related disorders. In the current study (N=189), we assessed the hormonal effects (cortisol, testosterone) and subjective distress (stress, anxiety, and fear) of the 35 % CO2 Challenge, and several days later, assessed the hormonal and subjective distress effects of the TSST in a mixed-sex, college-aged sample, to test for predictive effects of the 35 % CO2 Challenge on TSST-evoked outcomes. No testosterone by cortisol interaction effects were found in females. In males, the 35 % CO2 Challenge-evoked interaction of testosterone and cortisol predicted TSST-evoked subjective stress, anxiety, and fear, with higher concentrations of testosterone predicting subjective distress, but only at (relatively) low concentrations of cortisol (one standard deviation below mean concentrations). This result - in line with the dual-hormone hypothesis - suggests the 35 % CO2 Challenge could be utilized in a wider array of laboratory stress response research.

Anxiety Sensitivity Social Concerns Predicts Electrodermal Activity during the Niacin Biological Challenge Paradigm

Anxiety sensitivity social concerns (ASSC), or the fear of observable anxiety symptoms, is a risk factor for social anxiety. ASSC predicts anxiety following the niacin biological challenge, a paradigm in which niacin is used to manipulate facial flushing during a speech task. However, it remains unclear if ASSC predicts physiological arousal during this task. The current study was designed to examine the effects of ASSC on self-reported distress and electrodermal activity (EDA) during the niacin biological challenge in a sample of undergraduates (N = 36; M age = 18.9, SD = 0.84; 69.4% female). Participants were randomly assigned to one of four conditions in a 2 (100 mg niacin vs. 100 mg sugar) × 2 (instructional set) design. Participants completed a speech task in a virtual reality environment. Participants rated their distress halfway through the speech and EDA was averaged over four intervals. There was a main effect for ASSC on subjective distress. There was a significant ASSC by condition interaction predicting EDA, in that ASSC was related to EDA only in the niacin condition. ASSC also was more strongly related to EDA anticipating the speech. These findings highlight the role of ASSC in predicting anxiety and physiological arousal.

Real-world outcomes of an innovative digital therapeutic for treatment of panic disorder and PTSD: A 1,500 patient effectiveness study

Objective

Prior clinical trials have shown consistent clinical benefit for Capnometry Guided Respiratory Intervention (CGRI), a prescription digital therapeutic for the treatment of panic disorder (PD) and post-traumatic stress disorder (PTSD). The purpose of this study is to report real-world outcomes in a series of patients treated with the intervention in clinical practice.

Design

This paper reports pre- and post-treatment self-reported symptom reduction, measures of respiratory rate and end-tidal carbon dioxide levels, drop-out and adherence rates drawn from an automatic data repository in a large real-world series of patients receiving CGRI for panic disorder and PTSD.

Setting

Patients used the intervention in their homes, supported by telehealth coaching.

Participants

Patients meeting symptom criteria for panic disorder (n = 1,395) or posttraumatic stress disorder (n = 174) were treated following assessment by a healthcare professional.

Intervention

Capnometry Guided Respiratory Intervention is a 28-day home-based treatment that provides breath-to-breath feedback of respiratory rate and exhaled carbon dioxide levels, aimed at normalizing respiratory style and increasing patients' mastery for coping with symptoms of stress, anxiety, and panic. Health coaches provide initial training with weekly follow up during the treatment episode. Remote data upload and monitoring facilitates individualized coaching and aggregate outcomes analysis.

Main outcome measures

Self-reported Panic Disorder Severity Scale (PDSS) and the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5) scores were obtained at pre-treatment and post-treatment.

Results

Panic disorder (PD) patients showed a mean pre-to-post-treatment reduction in total PDSS scores of 50.2% (P < 0.001, d = 1.31). Treatment response rates for PD (defined as a 40% or greater reduction in PDSS total scores) were observed in 65.3% of the PD patients. PTSD patients showed a pre-to-post-treatment reduction in total PCL-5 scores of 41.1% (P < 0.001, d = 1.16). The treatment response rate for PTSD (defined as a ≥10-point reduction in PCL-5 scores) was 72.4%. In an additional analysis of response at the individual level, 55.7% of panic disorder patients and 53.5% of PTSD patients were classified as treatment responders using the Reliable Change Index. Patients with both normal and below-normal baseline exhaled CO2 levels experienced comparable benefit. Across the 28-day treatment period, mean adherence rates of 74.8% (PD) and 74.9% (PTSD) were recorded during the 28-day treatment. Dropout rates were 10% (PD) and 11% (PTSD) respectively.

Conclusions

The results from this cohort of 1,569 patients treated with the CGRI intervention demonstrate significant rates of symptom reduction and adherence consistent with prior published clinical trials. The brief duration of treatment, high adherence rates, and clinical benefit suggests that CGRI provides an important addition to treatment options for panic disorder and PTSD.

Impact of cannabidiol-rich hemp extract oil on reconsolidation disruption of naturalistic interoceptive aversive memory in humans: Protocol for a randomized clinical trial

BACKGROUND

Preclinical experiments with rodents demonstrate that cannabidiol (CBD), the non-psychotomimetic constituent of the Cannabis sativa plant, disrupts reconsolidation of aversive memories conditioned in the laboratory when administered within the memory reconsolidation window (< 6 h. post-retrieval) by indirectly activating cannabinoid type-1 (CB₁) receptors in the dorsal anterior cingulate cortex (dACC). Based on these findings, we aim to test whether administration of 300 mg CBD-rich hemp extract oil following fear reactivation of an aversive interoceptive threat memory can disrupt reconsolidation of naturalistic aversive memories in humans. More specifically, naturalistic interoceptive aversive memories, a form of transdiagnostic fear memory that contributes to the pathogenesis of fear-related disorders such as panic disorder, posttraumatic stress disorder (PTSD), and illness anxiety disorder.

METHODS

For this proof-of-concept, placebo-controlled double-blind trial, volunteers (n = 99) reporting elevated fears of somatic sensations will be stratified on biological sex and randomized to one of three intervention arms: (a). CBD-rich oil administered within the reconsolidation window, (b) Placebo oil administered within the reconsolidation window; or (c) CBD-rich oil administered outside of the reconsolidation window. Change in emotional reactivity to a 35% CO₂ challenge from baseline to two-week follow-up will serve as our primary outcome.

CONCLUSION

Study findings may contribute towards the development of a novel brief transdiagnostic intervention guided by reconsolidation theory for individuals prone to fear-related psychiatric disorders.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04726475.

Baroreflex sensitivity derived from the Valsalva manoeuvre: A physiological protective factor for anxiety induced by breathing CO2-enriched air

This study aimed to determine the capacity of baroreflex sensitivity, derived from the Valsalva manoeuvre (BRS_v), to predict state anxiety induced by a biological stressor (CO₂ inhalation). Healthy adults (n = 50) breathed 7.5 % CO₂-enriched air for 8 min, preceded and followed by breathing medical air for 5 min. State anxiety was evaluated with a visual analogue scale. Anxiety sensitivity (Anxiety Sensitivity Index-3; ASI-3) and trait anxiety (Trait form of the State-Trait Anxiety Inventory; STAI_T) served as cognitive-affective predictors. BRS_v was adopted as a physiological predictor. Multiple regression analysis revealed that BRS_v predicted lower anxiety during CO₂ exposure, and attenuated the effect of ASI-3 in increasing anxiety. No significant effects were found for STAI_T. This is the first study to identify baroreflex sensitivity as a strong protective physiological factor for anxiety beyond the effect of anxiety sensitivity.

Evaluating the Role of Anxiety Sensitivity on Behavioral Health Outcomes among Latinx Persons

Background

Mexican Americans represent the largest subpopulation among Latinx persons and experience numerous health inequalities for psychological symptoms and behavioral health problems. First generation Mexican Americans are particularly vulnerable to such disparities and past work suggests that the experience of acculturative stress may play a vital role in terms of mental and physical health problems among this population. The current study sought to bridge past work on acculturative stress among first-generation Mexican Americans by exploring the role of anxiety sensitivity (AS; fear of the negative consequences of internal sensations) as a potential mediational factor in terms of psychological and behavioral health problems among this group.

Methods

The current study consisted of 369 first generation Mexican American persons (86.2% female, 40.1 years of age (SD = 11.1) years in the U.S. attending a Federally Qualified Healthcare Center located in an urban southwestern community. We explored whether AS served as a mediator between acculturative stress and some of the most common and disabling clinical problems among this group, including social anxiety, anxious arousal, general depression, insomnia and pain intensity and disability.

Result

Consistent with prediction, there was a statistically significant indirect effect of acculturative stress via AS across all criterion variables apart from pain intensity (depression [ab = - 0.17, SE = 0.05, 95% CI [0.08, 0.26]], insomnia [ab = 0.07, SE = 0.02, 95% CI [0.03, 0.10]], social anxiety [ab 0.05, SE = 0.02, 95% CI [0.02, 0.08]], anxious arousal [ab = 0.08, SE = 0.03, 95% CI [0.03, 0.12]], pain disability [ab = 0.05, SE = 0.02, 95% CI [0.02, 0.09]]). Comparative models were run to evaluate the specificity of hypothesized statistically significant models. For all models except anxious arousal and general depression, the alternative model was rejected, adding support to the hypothesized pathway.

Conclusion

Overall, this work provides initial support for the role of AS in terms of the relation between acculturative stress and numerous psychological and behavioral health problems among Mexican American adults in a clinical setting.

Psychological Distress and Physical Health Symptoms in the Latinx Population During the COVID-19 Pandemic: Exploring the Role of Anxiety Sensitivity

Objective

The outbreak of the novel 2019 SARS2-Coronavirus disease (COVID-19) has led to substantial physical and mental health consequences. Rates of mortality and hospitalization are highest among those of racial and ethnic minority persons, including Latinx persons. Further, Latinx persons have been experiencing elevated mental health problems in response to the pandemic compared to non-Latinx Whites. The current study examined whether individual differences in anxiety sensitivity (AS) related to more severe emotional distress associated with social distancing, financial strain, fear of COVID-19, and physical health symptoms stemming from the COVID-19 pandemic among Latinx adults.

Methods

Participants included 188 Latinx persons (31.4% female, M_age = 34.1 years, SD = 8.16) recruited via an online survey panel program.

Results

Results indicated that AS significantly contributed to increased severity of the emotional stress response associated with social distancing (ΔR² = 0.15, p < 0.001), financial strain (ΔR² = 0.15, p < 0.001), physical health symptoms (ΔR² = 0.03, p = 0.006), and fear of COVID-19 (ΔR² = 0.15, p < 0.001). These effects were evident over and above the variance accounted for by gender, years living in the United States, education, and work and home life COVID-19-related stress.

Conclusions

These cross-sectional findings suggest AS may be an important individual difference factor for better understanding mental health among Latinx persons in the context of the COVID-19 pandemic.

Development and Initial Validation of the Relaxation Sensitivity Index

Relaxation sensitivity indexes the fear of relaxation-related events. The purpose of this study was to develop and provide initial validation of a self-report measure of relaxation sensitivity, the Relaxation Sensitivity Index (RSI). Three independent samples of undergraduate students (n=300 unselected, n=349 non-clinical, and n=197 clinical analogs with elevated anxiety/depression symptoms) completed self-report measures to examine the factor structure, reliability, and validity of the RSI. Results of exploratory and confirmatory factor analyses supported a three-factor structure (correlated Physical, Cognitive, and Social Concerns). The RSI demonstrated good internal consistency and construct validity as evidenced by expected correlations with measures of anxiety and depression symptoms. The RSI showed good predictive validity in terms of a history of fearful responding to relaxation. RSI scores were significantly higher in the symptomatic compared to non-clinical sample. Results suggest the RSI is a valid and reliable measure that may be useful in clinical and research settings.

Anxiety Sensitivity and Arousal Symptom Implicit Association Task Performance: An Event-Related Potential Study of Cognitive Processing of Anxiety-Relevant Stimuli

BACKGROUND

Anxiety sensitivity (AS), or the fear of anxious arousal, is a transdiagnostic risk factor. Despite the proliferation of self-report research showing AS is related to anxiety, cognitive processes underlying AS are poorly understood. Specifically, AS may reflect processes related to early attentional orientation and response monitoring (reflecting automatic processes), or later engagement and assigning emotional salience towards stimuli (reflecting conscious processes).

METHODS

To elucidate cognitive processes underlying AS, event-related potential (ERP) components were elicited in the current study during a novel implicit association task (IAT) in which participants paired self (versus other) words with anxious arousal (versus calm) words. Analyses were then conducted in a sample of community adults (N = 67; M age 39.43, SD = 15.33, 61.2% female) to investigate the association between AS and ERP markers indicative of cognitive processing derived during the IAT.

RESULTS

AS was not related to performance on the arousal-IAT and that ERP components did not differ by IAT condition. AS predicted overall late positive potential (LPP) amplitude, particularly in the me/anxiety condition. Elevated IAT scores (reflecting greater ease pairing self-words with anxiety-words) predicted greater P300 amplitude in the me/anxiety condition.

LIMITATIONS

The sample was relatively small, and bottom-up processes were not assessed.

CONCLUSIONS

These findings are inconsistent with the claim that AS is related to top-down cognitive processes driving self-arousal automatic associations. Instead, AS may relate to cognitive processes regulating emotional engagement with stimuli. Further investigations of cognitive processes underlying AS are needed to inform novel interventions targeting AS.

The Impact of the Menstrual Cycle and Underlying Hormones in Anxiety and PTSD: What Do We Know and Where Do We Go From Here?

PURPOSE OF REVIEW

This paper reviews the recent literature on menstrual cycle phase effects on outcomes relevant to anxiety and PTSD, discusses potential neurobiological mechanisms underlying these effects, and highlights methodological limitations impeding scientific advancement.

RECENT FINDINGS

The menstrual cycle and its underlying hormones impact symptom expression among women with anxiety and PTSD, as well as psychophysiological and biological processes relevant to anxiety and PTSD. The most consistent findings are retrospective self-report of premenstrual exacerbation of anxiety symptoms and the protective effect of estradiol on recall of extinction learning among healthy women. Lack of rigorous methodology for assessing menstrual cycle phase and inconsistent menstrual cycle phase definitions likely contribute to other conflicting results. Further investigations that address these limitations and integrate complex interactions between menstrual cycle phase-related hormones, genetics, and psychological vulnerabilities are needed to inform personalized prevention and intervention efforts for women.

A computerized anxiety sensitivity intervention for opioid use disorders: A pilot investigation among veterans

The opioid epidemic is having a disproportionate impact on veterans. Indeed, veterans are twice as likely to die from an accidental overdose than members of the general population, even after accounting for gender and age distribution. Although many veterans seek treatment, a large proportion drop out prematurely and/or relapse highlighting the need to identify malleable factors that may contribute to the recovery process. One such variable is anxiety sensitivity (AS; i.e., fear of anxious arousal). AS is elevated in opioid use populations and is a predictor of treatment dropout among opioid users. Importantly, research suggests that AS is highly malleable; although, no studies have systematically examined such protocols among opioid users. To this end, the purpose of the proposed study was to test the acceptability, feasibility, and utility of a brief, one-session Computerized Anxiety Sensitivity Treatment (termed CAST) delivered to veterans seeking services for an opioid use disorder (OUD). Veterans (n = 16) were assessed at baseline and also at one-week and one-month following CAST. All veterans completed the protocol and reported being interested and engaged during the intervention. Further, small to medium reductions in psychopathology and substance use outcomes were found. Although more work is needed, the current study provides preliminary support for the effectiveness of a brief AS-focused intervention among veterans seeking treatment for an OUD.

Assessing vulnerability to panic: a systematic review of psychological and physiological responses to biological challenges as prospective predictors of panic attacks and panic disorder

Background

Cognitive–behavioural theories of panic disorder posit that panic attacks arise from a positive feedback loop between arousal-related bodily sensations and perceived threat. In a recently developed computational model formalising these theories of panic attacks, it was observed that the response to a simulated perturbation to arousal provided a strong indicator of vulnerability to panic attacks and panic disorder. In this review, we evaluate whether this observation is borne out in the empirical literature that has examined responses to biological challenge (eg, CO₂ inhalation) and their relation to subsequent panic attacks and panic disorder.

Method

We searched PubMed, Web of Science and PsycINFO using keywords denoting provocation agents (eg, sodium lactate) and procedures (eg, infusion) combined with keywords relevant to panic disorder (eg, panic). Articles were eligible if they used response to a biological challenge paradigm to prospectively predict panic attacks or panic disorder.

Results

We identified four eligible studies. Pooled effect sizes suggest that there is biological challenge response has a moderate prospective association with subsequent panic attacks, but no prospective relationship with panic disorder.

Conclusions

These findings provide support for the prediction derived from cognitive–behavioural theories and some preliminary evidence that response to a biological challenge may have clinical utility as a marker of vulnerability to panic attacks pending further research and development.

Trial registration number

135908.

Niacin biological challenge: A paradigm to evaluate social concerns

BACKGROUND AND OBJECTIVES

Anxiety sensitivity (AS) social concerns, the fear of observable anxiety symptoms is posited as a risk factor for social anxiety by increasing fear reactivity in social situations when observable anxiety symptoms are present. Experimental evaluation of AS social concerns is limited. The current study utilized several manipulations designed to be relevant to AS social concerns or fear of negative evaluation (FNE), a distinct social anxiety risk factor. The effects of these manipulations on fear reactivity to a speech were examined.

METHODS

Participants (N = 124 students; M age = 19.44, SD = 2.45; 64.5% female) were randomized to one of four conditions in a 2 (100 mg niacin vs 100 mg sugar pill) X 2 (instructional set) design. For the instructional set manipulation, participants were told their speech performance would be evaluated by a judge based on their performance (i.e., FNE-relevant) or their observable anxiety symptoms (i.e., AS social concerns-relevant).

RESULTS

There was a main effect for vitamin condition with participants in the niacin condition reporting higher panic symptoms post-speech relative to those in the placebo condition. There was no main effect for speech instructions. As hypothesized, these effects were qualified by an interaction indicating that AS social concerns significantly predicted panic symptoms for those receiving niacin.

LIMITATIONS

Limitations include the reliance on self-reports of outcome variables and the use of an undergraduate student sample.

CONCLUSIONS

These findings highlight a distinct role of AS social concerns in fear responding to socially evaluative situations in the context of physically observable arousal.

The state of boredom: Frustrating or depressing?

Boredom is a prevalent emotion with potential negative consequences. Previous research has associated boredom with outcomes indicating both high and low levels of arousal and activation. In the present study we propose that the situational context is an important factor that may determine whether boredom relates to high versus low arousal/activation reactions. In a correlational (N = 443) and an experimental study (N = 120) we focused on the situational factor (perceived) task autonomy, and examined whether it explains when boredom is associated with high versus low arousal affective reactions (i.e., frustration versus depressed affect). Results of both studies indicate that when task autonomy is low, state boredom relates to more frustration than when task autonomy is high. In contrast, some support (i.e., Study 1 only) was found suggesting that when task autonomy is high, state boredom relates to more depressed affect than when task autonomy is low. These findings imply that careful attention is needed for tasks that are relatively boring. In order to reduce frustration caused by such tasks, substantial autonomy should be provided, while monitoring that this does not result in increased depressed affect.

Effects of Aerobic Exercise on Anxiety Symptoms and Cortical Activity in Patients with Panic Disorder: A Pilot Study

BACKGROUND

The effects of the aerobic exercise on anxiety symptoms in patients with Panic Disorder (PD) remain unclear. Thus, the investigation of possible changes in EEG frontal asymmetry could contribute to understand the relationship among exercise, brain and anxiety.

OBJECTIVE

To investigate the acute effects of aerobic exercise on the symptoms of anxiety and the chronic effects of aerobic exercise on severity and symptoms related to PD, besides the changes in EEG frontal asymmetry.

METHODS

Ten PD patients were divided into two groups, Exercise Group (EG; n=5) and Control Group (CG; n=5), in a randomized allocation. At baseline and post-intervention, they submitted the psychological evaluation through Panic Disorder Severity Scale (PDSS), Beck Anxiety Inventory (BAI), Beck Depression Inventory-II (BDI-II), EEG frontal asymmetry, and maximal oxygen consumption (VO2max). On the second visit, the patients of EG being submitted to the aerobic exercise (treadmill, 25 minutes, and 50-55% of heart rate reserve) and the CG remained seated for the same period of time. Both groups submitted a psychological evaluation with Subjective Units of Distress Scale (SUDS) at baseline, immediately after (Post-0), and after 10 minutes of the rest pause (Post-10). The patients performed 12 sessions of aerobic exercise with 48-72 hours of interval between sessions.

RESULTS

In EG, SUDS increased immediately after exercise practice and showed chronic decrease in BAI and BDI-II as well as increased in VO2max (Post-intervention).

CONCLUSION

Aerobic exercise can promote increase in anxiety acutely and regular aerobic exercise promotes reduction in anxiety levels.

Dual-hormone stress reactivity predicts downstream war-zone stress-evoked PTSD

BACKGROUND

The crucial role of the hypothalamic-pituitary-adrenal axis (HPA) in stress-related homeostasis suggests dysregulated HPA involvement in the pathogenesis of post-traumatic stress disorder (PTSD), yet most studies examining linkages between HPA axis measures and PTSD have yielded null findings. One untested explanation for this inconsistency is a failure to account for simultaneous adrenal and gonadal influence. Here we tested the singular and interactive effects of cortisol (C_R) and testosterone (T_R) reactivity as moderators of war-zone stress evoked PTSD emergence in the war-zone.

METHODS

U.S. soldiers (N=120) scheduled for deployment to Iraq completed pre-deployment measures of C_R and T_R stress reactivity to a CO₂ inhalation challenge. Once deployed, monthly assessments of exposure to traumatic war-zone stressors and PTSD symptoms were collected via a web-based assessment system.

RESULTS

Cortisol hypo-reactivity potentiated the pathogenic impact of war-zone stressors only in soldiers for whom the CO₂ challenge did not elevate testosterone, suggesting that the dual hormone stress reactivity profile of blunted cortisol and testosterone may confer increased risk for PTSD emergence by potentiating the pathogenic effects of war-zone stressors.

CONCLUSIONS

Findings underscore the utility of assessing both HPA and HPG stress reactivity when assessing PTSD vulnerability and may help inform efforts for enhanced soldier screening and inoculation to war-zone stressors.

Is computerized psychoeducation sufficient to reduce anxiety sensitivity in an at-risk sample?: A randomized trial

BACKGROUND

Anxiety sensitivity (AS), or a fear of anxiety-related sensations, has become one of the most well researched risk factors for the development of psychopathology and comprises three subfactors: physical, cognitive, and social concerns. Fortunately, research has demonstrated brief protocols can successfully reduce AS, and in turn improve psychopathological symptoms. Computerized AS reduction protocols have combined psychoeducation with interoceptive exposure (IE), but they have not been dismantled to evaluate the effects of psychoeducation alone.

METHOD

The current study sought to determine the efficacy of a brief single-session psychoeducation intervention for AS, compared to a control intervention, in a sample of at-risk individuals (N=54) with elevated AS cognitive concerns.

RESULTS

Individuals in the active condition displayed greater reductions in self-reported AS (β=.198, 95% CI [.065, .331]) and less fear reactivity (β=.278, 95% CI [.069, .487]) to the induction of AS cognitive-relevant sensations through a behavioral challenge compared to those in the control condition. Further, fear reactivity to the challenge was mediated by reductions in self-reported AS cognitive concerns.

LIMITATIONS

Study limitations include use of an at-risk nonclinical student sample, lack of a long-term follow-up assessment, and inability to discern whether AS reductions due to CAST psychoeducation prevent future, or improve current, psychological symptoms.

CONCLUSIONS

These results suggest that psychoeducation alone can produce significant AS reduction.

Transdiagnostic processes linking anxiety symptoms and substance use problems among adolescents

Numerous anxiety syndromes co-occur with substance use problems in adolescents, though the mechanisms underlying these comorbidities are not well understood. There are 3 transdiagnostic processes-anxiety sensitivity (fear of anxiety-related sensations), distress tolerance (capacity to withstand emotional distress), and negative urgency (propensity to respond impulsively to negative emotion)-that have been implicated in various anxiety and substance use problems. To examine whether anxiety sensitivity, distress tolerance, and negative urgency statistically mediated relations between symptoms of 3 different anxiety disorders (social anxiety, generalized anxiety, and panic disorders) and alcohol and cannabis use problems, cross-sectional analysis of high school students in Los Angeles (N = 3002) was assessed via paper and pencil questionnaires. When mediators were entered simultaneously, negative urgency accounted for a significant 33 to 85% of the covariance between anxiety symptomatology and substance use problems over and above the other trandiagnostic processes. This pattern was consistent across all 3 anxiety syndromes and both alcohol and cannabis problems. Anxiety sensitivity and distress tolerance did not account for positive associations between anxiety symptoms and substance use problems. Negative urgency may be an important mechanism underlying the relationship between various types of anxiety and substance use problems in adolescence, and thus represents a possible target for preventive interventions targeting adolescent anxiety and substance use.

Relationships among depression, anxiety, anxiety sensitivity, and perceived social support in adolescents with conversion disorder

OBJECTIVE

This study aimed to assess the relationships of depression, anxiety, anxiety sensitivity, and perceived social support with conversion symptoms in adolescents with conversion disorder (CD).

METHODS

Fifty outpatients, aged 8-18 years, who had been diagnosed with CD and members of a control group were assessed using the psychological questionnaires.

RESULTS

Compared with controls, adolescents with CD scored higher on the Child Depression Inventory (CDI), Screen for Child Anxiety-related Emotional Disorders (SCARED), Childhood Anxiety Sensitivity Index (CASI) total, CASI physical and cognitive subscales, and Multidimensional Scale of Perceived Social Support family subscale. Multiple regression analysis showed that CDI, CASI total, and CASI cognitive scores predicted the Somatoform Dissociation Questionnaire (SDQ) scores and that CDI and CASI total scores predicted the Children's Somatization Inventory (CSI) scores of subjects.

CONCLUSIONS

This study suggest that adolescents with CD had poor psychosocial well-being, and depression, global anxiety sensitivity and anxiety sensitivity cognitive concerns are related to conversion symptoms.

Examining the latent class structure of CO2 hypersensitivity using time course trajectories of panic response systems

BACKGROUND AND OBJECTIVES

Carbon dioxide (CO2) hypersensitivity is hypothesized to be a robust endophenotypic marker of panic spectrum vulnerability. The goal of the current study was to explore the latent class trajectories of three primary response systems theoretically associated with CO2 hypersensitivity: subjective anxiety, panic symptoms, and respiratory rate (fR).

METHODS

Participants (n = 376; 56% female) underwent a maintained 7.5% CO2 breathing task that included three phases: baseline, CO2 air breathing, and recovery. Growth mixture modeling was used to compare response classes (1…n) to identify the best-fit model for each marker. Panic correlates also were examined to determine class differences in panic vulnerability.

RESULTS

For subjective anxiety ratings, a three-class model was selected, with individuals in one class reporting an acute increase in anxiety during 7.5% CO2 breathing and a return to pre-CO2 levels during recovery. A second, smaller latent class was distinguished by elevated anxiety across all three phases. The third class reported low anxiety reported during room air, a mild increase in anxiety during 7.5% CO2 breathing, and a return to baseline during recovery. Latent class trajectories for fR yielded one class whereas panic symptom response yielded two classes.

LIMITATIONS

This study examined CO2 hypersensitivity in one of the largest samples to date, but did not ascertain a general population sample thereby limiting generalizability. Moreover, a true resting baseline measure of fR was not measured.

CONCLUSIONS

Two classes potentially representing different risk pathways were observed. Implications of results will be discussed in the context of panic risk research.

Validation of candidate anxiety disorder genes using a carbon dioxide challenge task

Few replicable genetic variants have been identified in the etiology of heritable anxiety disorders such as panic disorder. Endophenotypic measures that have reduced heterogeneity may provide more powerful targets for gene identification. We assessed hypersensitivity to carbon dioxide (a reliable endophenotype of panic and anxiety) in 174 Caucasian college students, who were genotyped on 26 polymorphic markers from 11 genes previously associated with panic/anxiety. Individual trajectories of respiratory and subjective anxiety response to carbon dioxide were measured and tested for association with these genetic markers. One marker in the acid-sensing ion channel 1 (ASIC1) gene, rs1108923, had a significant association with respiratory rate. No genes had a significant association with subjective anxiety response. Our findings support previously reported associations between ASIC1 and panic/anxiety, but not other genes previously associated with anxiety disorders. The use of endophenotypic markers is a promising avenue for gene identification in anxiety and other complex disorders.

Effects of a Single Bout of Aerobic Exercise Versus Resistance Training on Cognitive Vulnerabilities for Anxiety Disorders

The purpose of this study was to compare the relative effects of a single bout of aerobic exercise versus resistance training on cognitive vulnerabilities for anxiety disorders. Seventy-seven participants (60% female; 84% Caucasian) were randomized to complete 20 min of moderate-intensity aerobic exercise, resistance training, or rest, followed by a 35% CO2/65% O2 inhalation challenge task. Results indicated that aerobic exercise and resistance training were significantly and equally effective in reducing anxiety sensitivity (AS) compared with rest ((η(2)(p ) = 52), though only aerobic exercise significantly attenuated reactivity to the CO2 challenge task. Neither form of exercise generated observable effects on distress tolerance, discomfort intolerance, or state anxiety (all ps >.10). The results of this study are discussed with regard to their implications for the use of exercise interventions for anxiety and related forms of psychopathology, and potential directions for future research are discussed.

Etiology, triggers and neurochemical circuits associated with unexpected, expected, and laboratory-induced panic attacks

Panic disorder (PD) is a severe anxiety disorder that is characterized by recurrent panic attacks (PA), which can be unexpected (uPA, i.e., no clear identifiable trigger) or expected (ePA). Panic typically involves an abrupt feeling of catastrophic fear or distress accompanied by physiological symptoms such as palpitations, racing heart, thermal sensations, and sweating. Recurrent uPA and ePA can also lead to agoraphobia, where subjects with PD avoid situations that were associated with PA. Here we will review recent developments in our understanding of PD, which includes discussions on: symptoms and signs associated with uPA and ePAs; Diagnosis of PD and the new DSM-V; biological etiology such as heritability and gene×environment and gene×hormonal development interactions; comparisons between laboratory and naturally occurring uPAs and ePAs; neurochemical systems that are associated with clinical PAs (e.g. gene associations; targets for triggering or treating PAs), adaptive fear and panic response concepts in the context of new NIH RDoc approach; and finally strengths and weaknesses of translational animal models of adaptive and pathological panic states.

Predictors of trait dissociation and peritraumatic dissociation induced via cold pressor

Understanding which factors predict individual dissociative response during stressful situations is important to clarify the nature of dissociation and the mechanisms associated to its use as a coping strategy. The present study examined (1) whether experiential avoidance (EA), anxiety sensitivity (AS), depressive symptoms, and state anxiety concurrently predicted trait dissociation (TD)-absorption, amnesia, depersonalization, and total TD scores-and laboratory induced dissociation (LID); and (2) whether TD and catastrophizing predicted LID. We also examined whether catastrophizing mediated the relationships between both AS and depressive symptoms and LID. A total of 101 female undergraduate students participated in a cold pressor task, which significantly induced dissociation. Results of hierarchical regression analyses showed that AS at Time 1 (9 months before the experimental session), as well as depressive symptoms and catastrophizing at the time of the experiment (Time 2), predicted LID at Time 2. Depressive symptoms at Time 2 predicted total TD, absorption, and amnesia scores. AS at Time 1 and depressive symptoms at Time 2 predicted depersonalization. AS, depressive symptoms, and catastrophizing seem to facilitate the use of dissociative strategies by healthy individuals, even in response to non-traumatic but discomforting stress.

Changes in neuroactive steroid secretion associated with CO2-induced panic attacks in normal individuals

Neuroactive steroids modulate anxiety in experimental animals and possibly in humans. The secretion of these compounds has been found to be altered in panic disorder (PD), with such alterations having been suggested to be a possible cause or effect of panic symptomatology. Panic-like attacks can be induced in healthy individuals by administration of panicogenic agents or by physical procedures, and we have now measured the plasma concentrations of neuroactive steroids in such individuals before, during, and after panicogenic inhalation of CO2 in order to investigate whether abnormalities of neuroactive steroid secretion might contribute to the pathogenesis of PD. Fifty-nine psychologically and physically healthy subjects, including 42 women (11 in the follicular phase of the menstrual cycle, 14 in the luteal phase, and 17 taking contraceptive pills) and 17 men, who experienced a panic-like attack on previous exposure to 7% CO2 were again administered 7% CO2 for 20min. Thirty-three of these individuals (responders) again experienced a panic-like attack, whereas the remaining 26 subjects did not (nonresponders). All subjects were examined with the VAS-A and PSL-III-R scales for anxiety and panic symptomatology before and after CO2 inhalation. The plasma concentrations of progesterone, 3α,5α-tetrahydroprogesterone (3α,5α-THPROG=allopregnanolone), 3α,5α-tetrahydrodesoxycorticosterone (3α,5α-THDOC), dehydroepiandrosterone (DHEA), and cortisol were measured 15min and immediately before the onset of CO2 administration as well as immediately, 10, 30, and 50min after the end of CO2 inhalation. Neuroactive steroids were measured in the laboratory of Prof. Biggio in Cagliari, Sardinia, Italy. Neurosteroid levels did not change significantly in both responders and nonresponders before, during, or after CO2 inhalation. These data suggest that neuroactive steroid concentrations before, during, or after CO2 inhalation do not seem to correlate with panic symptomatology during panic-like attacks in subjects not affected by PD, and they therefore do not support the notion that abnormalities in neuroactive steroid secretion are either a cause or an effect of such attacks.

Hypersensitivity to 35% carbon dioxide in patients with adult separation anxiety disorder

BACKGROUND

Adults with panic disorder (PD) and children with separation anxiety disorder (CSAD) show higher reactivity to CO(2). Our hypothesis was patients with adult separation anxiety disorder (ASAD) would show similar hypersensitivity to CO(2). In the present study, we determined whether sensitivity to CO(2) was enhanced in adult patients with separation anxiety disorder with no history of panic attacks.

METHODS

Patients with PD (n=38), adult separation anxiety disorder (ASAD) patients with no history of panic attacks (n=31), and healthy subjects (n=40) underwent a 35% CO(2) inhalation challenge procedure. Baseline and post-inhalation anxiety were assessed with the Acute Panic Inventory, Visual Analog Scale, and Anxiety Sensitivity Index-3 (ASI-3).

RESULTS

As hypothesized the rate of CO(2)-induced panic attacks was significantly greater in PD and ASAD patient groups (55.3% and 51.6% respectively) than healthy comparison group (17.5%). Nine (69.2%) of 13 patients in PD group who have ASAD concurrent with PD had a CO(2)-induced panic attack. ASI-3 total scores were not different between PD and ASAD groups and both were significantly higher than controls. However, anxiety sensitivity did not predict the occurrence of panic attacks.

LIMITATIONS

The researchers were not blind to the diagnosis and there was no placebo arm for comparison. Besides, parameters of respiratory physiology were not evaluated.

CONCLUSION

ASAD was associated with CO(2) hypersensitivity quite similar to PD. This finding partly unfolds the complex relationship of 'CSAD, PD, and CO(2) hypersensitivity' and indicates that CO(2) hypersensitivity and separation anxiety extend together beyond childhood.

Prospective evaluation of the effects of anxiety sensitivity and state anxiety in predicting acute nicotine withdrawal symptoms during smoking cessation

The current investigation explored the main and interactive effects of anxiety sensitivity (AS) and state anxiety in predicting acute nicotine withdrawal symptoms experienced during the initial 14 days of smoking cessation. Participants included 123 adult daily smokers (84 women; Mage = 45.93 years, SD = 10.34) undergoing psychosocial-pharmacological cessation treatment. Results indicated that after controlling for the effects of participant sex and nicotine dependence, state anxiety but not AS significantly predicted initial levels of nicotine withdrawal symptoms. Results also demonstrated that both state anxiety and AS were significantly related to the change in nicotine withdrawal symptoms over time. Finally, our results revealed a significant interaction between AS and state anxiety. Specifically, higher levels of AS were associated with a stronger relation between state anxiety and nicotine withdrawal symptoms experienced during the cessation attempt. Results suggest that among high AS persons, state anxiety may be more relevant, compared to those low in AS, in regard to experiencing withdrawal symptoms as more intense during the early phases of quitting.

Attentional control moderates fearful responding to a 35% CO(2) challenge

Attentional control (AC) is an individual difference variable indexing the ability to voluntarily focus attention and shift attention when desired. AC is thought to impact the experience of fear by facilitating the disengagement of attention from threat and promoting the deployment of attentional resources toward regulatory or coping strategies. Whereas previous research has focused on visual threat cues, in the current study we examined whether this model also applies to interoceptive threat by evaluating the extent to which individual differences in AC moderated the relationship between trait anxiety and self-reported fear in response to a single vital capacity inhalation of a 35% CO(2), 65% balanced O(2) gas mixture. The sample comprised a large nonclinical group of young adults (N=128). Results indicated that AC moderated the relationship between trait anxiety and fearful responding to the challenge. Findings suggest that AC plays a significant and clinically important role in modulating self-reported fear.

Panic attack history and anxiety sensitivity in relation to cognitive-based smoking processes among treatment-seeking daily smokers

INTRODUCTION

Empirical research has found that panic attacks are related to increased risk of more severe nicotine withdrawal and poor cessation outcome. Anxiety sensitivity (AS; fear of anxiety and related sensations) has similarly been found to be related to an increased risk of acute nicotine withdrawal and poorer cessation outcome. However, research has yet to examine the relative contributions of panic attacks and AS in terms of cognitive-based smoking processes (e.g., negative reinforcement smoking expectancies, addictive and negative affect-based reduction smoking motives, barriers to cessation, problem symptoms experienced while quitting).

METHOD

Participants (n = 242; 57.4% male; M (age) = 38.1) were daily smokers recruited as a part of a larger randomized control trial for smoking cessation. It was hypothesized that both panic attacks and AS would uniquely and independently predict the studied cognitive-based smoking processes.

RESULTS

As hypothesized, AS was uniquely and positively associated with all smoking processes after controlling for average number of cigarettes smoked per day, current Axis I diagnosis, and participant sex. However, panic attack history was only significantly related to problem symptoms experienced while quitting smoking.

CONCLUSIONS

Although past research has demonstrated significant associations between panic attacks and certain aspects of cigarette smoking (e.g., severity of nicotine withdrawal; lower abstinence rates, and negative affect reduction motives), the present findings suggest that AS may be more relevant to understanding beliefs about and motives for smoking behavior as well as perceptions of cessation-related difficulties.

Sex differences in panic-relevant responding to a 10% carbon dioxide-enriched air biological challenge

The current study examined sex differences in psychological (i.e., self-reported anxiety, panic symptoms, and avoidance) and physiological (i.e., heart rate and skin conductance level) response to, and recovery from, a laboratory biological challenge. Participants were a community-recruited sample of 128 adults (63.3% women; M(age)=23.2 years, SD=8.9) who underwent a 4-min 10% CO(2)-enriched air biological challenge. As predicted, women reported more severe physical panic symptoms and avoidance (i.e., less willingness to participate in another challenge) and demonstrated increased heart rate as compared to men above and beyond the variance accounted for by other theoretically relevant variables (recent panic attack history, neuroticism, and anxiety sensitivity). Additionally, women demonstrated a faster rate of recovery with respect to heart rate compared to men. These results are in line with literature documenting sex-specific differences in panic psychopathology, and results are discussed in the context of possible mechanisms underlying sex differences in panic vulnerability.

An examination of the relation between traumatic event exposure and panic-relevant biological challenge responding among adolescents

The current study uniquely extended research that has linked traumatic event exposure to panic-spectrum problems among adolescents. It was hypothesized that among 127 adolescents (age range: 10 to 17 years; M = 14.63, SD = 2.24), those who endorsed a history of traumatic event exposure would evidence significantly greater anxious and fearful reactivity to a well-established 3-min voluntary hyperventilation procedure compared to nonexposed individuals. Results were consistent with hypotheses, suggesting traumatic event exposure is associated with anxious and fearful reactivity to abrupt increases in bodily arousal among adolescents. Moreover, consistent with hypotheses, anxiety sensitivity significantly mediated the relations between traumatic event exposure and both self-reported panic symptoms and panic symptoms elicited by the challenge. Future prospective research is now needed to better understand temporal relations between traumatic event exposure and indices of panic and related vulnerability.

Avoidant coping in panic disorder: a yohimbine biological challenge study

Few studies have addressed whether the use of avoidance-oriented coping strategies is related to the development of panic in patients with panic disorder(PD). Self-report, clinician-rated, and physiological data were collected from 42 individuals who participated in a yohimbine biological challenge study, performed under double-blind, placebo-controlled conditions. Participants included 20 healthy controls and 22 currently symptomatic patients who met DSM-IV-TR diagnostic criteria for PD. Consistent with prediction, patients with PD who had higher perceived efficacy of avoidance-oriented strategies in reducing anxiety-related thoughts reported increased severity in panic symptoms during the yohimbine challenge condition as compared to the placebo. Further, patients with PD who had more fear of cognitive dyscontrol, cardiovascular symptoms, and publicly observable anxiety also reported increased severity in panic symptoms during the challenge. Healthy controls who had more fear of cardiovascular symptoms similarly reported increased severity in panic symptoms during the challenge. No effects were found for heart rate response to the challenge agent. These results provide support for the role of avoidance-oriented coping strategies and fear of anxiety-related symptoms as risk and maintenance factors in the development of panic symptoms, particularly within a biological challenge model.

Anxiety sensitivity, the menstrual cycle, and panic disorder: a putative neuroendocrine and psychological interaction

The 2:1 female-to-male sex difference in the prevalence of panic disorder (PD) suggests that there is a sex-specific vulnerability involved in the etiology and/or maintenance of this disorder. The purpose of this paper is to present a new conceptual model, which emphasizes the interaction between a cognitive vulnerability for PD, anxiety sensitivity, and the effects of progesterone and its metabolite, allopregnanolone, on behavioral and physiological responses to stress during the premenstrual phase. This interaction is proposed to be a potential sex-specific pathway that may initiate and/or maintain panic and anxiety symptoms in women. This review paper presents preliminary evidence from both the human and animal literatures to support this new model. Specific topics reviewed include: psychopathology related to the menstrual cycle, anxiety sensitivity and its relationship to the menstrual cycle, PMS, and PMDD, anxiety-modulating effects of progesterone and its neuroactive metabolite, allopregnanolone, and how results from the neuroendocrine literature relate to psychopathology or symptoms associated with the menstrual cycle.

The interplay between physical activity and anxiety sensitivity in fearful responding to carbon dioxide challenge

OBJECTIVE

Physical activity may confer protective effects in the development of anxiety and its disorders. These effects may be particularly strong among individuals who have elevated levels of anxiety sensitivity (AS; i.e., the fear of somatic arousal), an established cognitive-based risk factor for anxiety and its disorders. The present study performed a laboratory test of the interplay between physical activity and AS.

METHODS

The participants were adults free of Axis I psychopathology (n = 145) who completed measures of physical activity and AS before undergoing a recurrent 20% carbon dioxide-enriched air (CO(2)) challenge.

RESULTS

Consistent with the hypothesis, physical activity was significantly related to CO(2) challenge reactivity among persons with elevated levels of AS, at high levels of physical activity (p < .001) but not at low levels of physical activity (p = .90). Also consistent with hypothesis, irrespective of the level of physical activity, physical activity did not relate significantly to CO(2) challenge reactivity among persons with normative levels of AS (p = .28).

CONCLUSIONS

These findings provide novel empirical insight into the role that physical activity may play in terms of resiliency for the development of anxiety disorders. Specifically, the protective effects of physical activity may only be evident at higher doses and among persons who are at increased risk of developing anxiety disorders because they have elevated AS.

Neural correlates of anxiety sensitivity during masked presentation of affective faces

BACKGROUND

Anxiety Sensitivity (AS), the tendency to fear the thoughts, symptoms, and social consequences associated with the experience of anxiety, is associated with increased risk for developing anxiety disorders. Some evidence suggests that higher scores on the Anxiety Sensitivity Index (ASI), a measure of the AS construct, are associated with activation of the anterior insular cortex during overt emotion perception. Although the ASI provides subscale scores measuring Physical, Mental Incapacitation, and Social Concerns of AS, no study has examined the relationship between these factors and regional brain activation during affect processing. We hypothesized that insular responses to fear-related stimuli would be primarily related to the Physical Concerns subscale of the ASI, particularly for a sample of subjects with specific phobias.

METHODS

Adult healthy controls (HC; n = 22) and individuals with specific phobia, small animal subtype (SAP; n = 17), completed the ASI and underwent functional magnetic resonance imaging while engaged in a backward-masked affect perception task that presents emotional facial stimuli below the threshold of conscious perception.

RESULTS

Groups did not differ in ASI, state or trait anxiety scores, or insula activation. Total ASI scores were positively correlated with activation in the right middle/anterior insula for the combined sample and for the HC and SAP groups separately. Multiple regression analysis revealed that the relationship between AS and insular activation was primarily accounted for by Physical Concerns only.

CONCLUSIONS

Findings support the hypothesized role of the right anterior insula in the visceral/interoceptive aspects of AS, even in response to masked affective stimuli.

Induction of c-Fos in 'panic/defence'-related brain circuits following brief hypercarbic gas exposure

Inspiration of air containing high concentrations of carbon dioxide (CO(2); hypercarbic gas exposure) mobilizes respiratory, sympathetic and hypothalamic-pituitary-adrenal axis responses and increases anxiety-like behaviour in rats and humans. Meanwhile the same stimulus induces panic attacks in the majority of panic disorder patients. However, little is known about the neural circuits that regulate these acute effects. In order to determine the effects of acute hypercarbic gas exposure on forebrain and brainstem circuits, conscious adult male rats were placed in flow cages and exposed to either atmospheric air or increasing environmental CO(2) concentrations (from baseline concentrations up to 20% CO(2)) during a 5 min period. The presence of immunoreactivity for the protein product of the immediate-early gene c-fos was used as a measure of functional cellular responses. Exposing rats to hypercarbic gas increased anxiety-related behaviour and increased numbers of c-Fos-immunoreactive cells in subcortical regions of the brain involved in: (1) the initiation of fear- or anxiety-associated behavioural responses (i.e. the dorsomedial hypothalamus, perifornical nucleus and dorsolateral and ventrolateral periaqueductal gray); (2) mobilization of the hypothalamic-pituitary-adrenal axis (i.e. the dorsomedial hypothalamus, perifornical nucleus and paraventricular hypothalamic nucleus); and (3) initiation of stress-related sympathetic responses (i.e. the dorsomedial hypothalamus, dorsolateral periaqueductal grey and rostroventrolateral medulla). These findings have implications for understanding how the brain senses changes in environmental CO(2) concentrations and the neural mechanisms underlying the subsequent adaptive changes in stress-related physiology and behaviour.

Gene-environment interactions in panic disorder and CO₂ sensitivity: Effects of events occurring early in life

Heterogeneous life events (LE) precede the onset of-and potentially increase the susceptibility to-panic disorder (PD). It remains unknown whether LE can act as moderators in the context of gene-by-environment interactions (G×E) that alter the susceptibility to PD and the related trait of CO₂ sensitivity, nor it is known whether such moderation may depend on occurrence of events at different epochs in life. In 712 general population twins we analyzed by Maximum Likelihood analyses of ordinal data whether life (major- and stressful) events moderate the genetic risk for PD and CO₂ sensitivity, as indexed by the 35% CO₂ /65% O₂ challenge. For CO₂ sensitivity, best-fitting models encompassed both additive and interactional effects that increased linearly with the cumulative number and severity (SEV) of events in lifetime. By analyzing the moderation effect of cumulative SEV separately for events that had occurred in adulthood (between age 18 and 37) or during childhood-adolescence (before the 18th birthday), we found evidence of G×E only within the childhood-adolescence window of risk, although twins had rated the childhood-adolescence events as significantly (P = 0.001) less severe than those having occurred during adulthood. For PD, all interactional terms could be dropped without significant worsening of the models' fit. Consistently with a diathesis-stress model, LE appear to act as moderators of the genetic variance for CO₂ sensitivity. Childhood-adolescence appears to constitute a sensitive period to the action of events that concur to alter the susceptibility to this panic-related trait.

Effects of threat context and cardiac sensitivity on fear responding to a 35% CO2 challenge: a test of the context-sensitivity panic vulnerability model

The present study tested several predictions of a context-sensitivity panic vulnerability model emphasizing the interaction between threat context and threat sensitivities. Participants without a history of panic (N=47) completed both global and domain-specific panic relevant sensitivity measures and were then randomized to undergo a 35% CO2 inhalation challenge in the presence or absence of a cardiac defibrillator (threat context). As predicted by the model, cardiac sensitivity (but not trait anxiety or anxiety sensitivity) potentiated the effects of the presence of the defibrillator on CO2 fear responding. Moreover, as predicted by the model, the observed potentiation effects of cardiac sensitivity on CO2 fear responding were mediated by participants' threat appraisals connected to the presence of the defibrillator. Theoretical and clinical implications are discussed.

Premenstrual distress predicts panic-relevant responding to a CO2 challenge among young adult females

The current study examined the incremental validity of self-reported premenstrual distress in predicting panic responsivity (self-reported panic symptoms and skin conductance response frequency; SCR) following inhalation of 10% CO(2)-enriched air. A community sample of young adult women (n=46) completed questionnaires assessing substance use patterns, premenstrual symptoms and distress, and anxiety sensitivity and underwent a laboratory biological challenge procedure (4-min 10% CO(2)-enriched air inhalation). As hypothesized, higher premenstrual distress scores significantly predicted greater self-reported panic symptoms following the CO(2) challenge above and beyond other theoretically relevant variables (anxiety sensitivity, cigarette use, and alcohol consumption). In predicting SCR, premenstrual distress exhibited only a trend towards statistical significance. These findings provide preliminary evidence that premenstrual symptoms may serve as a potential risk factor to experience more intense panic symptoms in response to perturbations in bodily sensations.

Temporal and structural dynamics of anxiety sensitivity in predicting fearful responding to a 35% CO2 challenge

The current study assessed the incremental prediction of anxiety sensitivity (AS) in both taxonic (categorical) and dimensional representations at various time points before and after a single vital capacity inhalation of a 35% CO(2), 65% balanced O(2) gas mixture. Participants were 128 young adults screened for a history of panic attacks. By controlling for traitwise factors including state anxiety and testing both categorical and continuous conceptualizations of the AS construct at various timepoints, the present report was able to evaluate the temporal and structural dynamics of AS in relation to fearful responding to the challenge. Relevant variables were evaluated in a hierarchical linear regression framework, and it was found that a continuous conceptualization of AS provided incremental predictive validity above and beyond trait anxiety immediately post-challenge, while a categorical representation of AS was equivalent to a continuous model of AS at post-challenge but outperformed a continuous model at follow-up. These data provide basic but important evidence suggesting that AS is uniquely associated with anxious responding to a 35% CO(2) challenge, and that categorical representations of AS should be considered in biological challenge studies.

Panic disorder: a review of DSM-IV panic disorder and proposals for DSM-V

This review covers the literature since the publication of DSM-IV on the diagnostic criteria for panic attacks (PAs) and panic disorder (PD). Specific recommendations are made based on the evidence available. In particular, slight changes are proposed for the wording of the diagnostic criteria for PAs to ease the differentiation between panic and surrounding anxiety; simplification and clarification of the operationalization of types of PAs (expected vs. unexpected) is proposed; and consideration is given to the value of PAs as a specifier for all DSM diagnoses and to the cultural validity of certain symptom profiles. In addition, slight changes are proposed for the wording of the diagnostic criteria to increase clarity and parsimony of the criteria. Finally, based on the available evidence, no changes are proposed with regard to the developmental expression of PAs or PD. This review presents a number of options and preliminary recommendations to be considered for DSM-V.

Evaluating emotional sensitivity and tolerance factors in the prediction of panic-relevant responding to a biological challenge

The current study investigated anxiety sensitivity, distress tolerance (Simons & Gaher, 2005), and discomfort intolerance (Schmidt, Richey, Cromer, & Buckner, 2007) in relation to panic-relevant responding (i.e., panic attack symptoms and panic-relevant cognitions) to a 10% carbon dioxide enriched air challenge. Participants were 216 adults (52.6% female; M(age)=22.4, SD=9.0). A series of hierarchical multiple regressions was conducted with covariates of negative affectivity and past year panic attack history in step one of the model, and anxiety sensitivity, discomfort intolerance, and distress tolerance entered simultaneously into step two. Results indicated that anxiety sensitivity, but not distress tolerance or discomfort intolerance, was significantly incrementally predictive of physical panic attack symptoms and cognitive panic attack symptoms. Additionally, anxiety sensitivity was significantly predictive of variance in panic attack status during the challenge. These findings emphasize the important, unique role of anxiety sensitivity in predicting risk for panic psychopathology, even when considered in the context of other theoretically relevant emotion vulnerability variables.

Attributional style and anxiety sensitivity as maintenance factors of posttraumatic stress symptoms: A prospective examination of a diathesis-stress model

Diathesis-stress models of posttraumatic stress disorder (PTSD) assert that traumatic events function as stressors that interact with vulnerabilities to influence the development of PTSD. The present study prospectively examined negative attributional style (NAS) and anxiety sensitivity (AS) as maintenance factors for PTSD in female adult sexual assault victims. A diathesis-stress model was tested by examining interactions between the vulnerabilities and negative life events. The present study included both the traditional three-factor model of PTSD (re-experiencing, avoidance and emotional numbing, and arousal) and the dysphoria four-factor model of PTSD (re-experiencing, avoidance, arousal, and dysphoria). Robust regression analyses revealed that negative life events at Time 2 significantly predicted increases in all clusters of the three-factor model (i.e., re-experiencing, avoidance and numbing, and arousal) and the re-experiencing, arousal, and dysphoria clusters of the four-factor model (but not avoidance). Neither NAS nor AS significantly independently predicted any of the symptom clusters for either model. Both NAS and AS interacted with negative life events to predict increases in the avoidance and numbing symptoms. However, examination of the dysphoria four-factor model of PTSD revealed that the NAS and AS interactions with negative life events only predicted dysphoria symptoms.

An experimental investigation of the effects of acute sleep deprivation on panic-relevant biological challenge responding

Prospective research indicates sleep deprivation potentiates anxiety development, yet relatively little research has examined the effects of sleep deprivation in terms of specific types of anxiety. The current study tested the association between acute sleep deprivation and panic-relevant biological challenge responding among nonclinical participants. One hundred and two participants were randomly assigned to either an experimental (acute sleep deprivation) or control (no sleep deprivation) group. The day prior to and following the experimental (sleep) manipulation, participants completed a 5-minute 10% carbon dioxide-enriched air laboratory-based biological challenge. As predicted, sleep deprivation increased anxious and fearful responding to the challenge. Findings suggest sleep deprivation may be an important factor to consider in models of panic development. There are several areas in this general domain that warrant additional investigation.

Anxiety sensitivity and CO2 challenge anxiety during recovery: differential correspondence of arousal and perceived control

The relations between changes in arousal and perceived control with changes in anxiety-related distress during a 10-min recovery period after exposure to 10% CO(2)-enriched air was examined among community participants (N=47) high (n=23) and low (n=24) in anxiety sensitivity (AS). Rate of decline in arousal was significantly positively associated with rate of decline in anxiety among high and low AS participants when controlling for valence. Rate of increase in perceived control was significantly negatively related to rate of decline in anxiety in the high AS group but not in the low AS group when controlling for valence. These findings suggest that associations between arousal, perceived control, and anxiety-related recovery from a panic-relevant episode of abrupt increases in bodily arousal differ as a function of pre-existing fears of anxiety-related symptoms (i.e., AS). Implications of these findings for disorders associated with elevated AS are discussed.