Subtypes of panic attacks: a critical review of the empirical literature

Biological and cognitive theories explaining panic disorder: A narrative review

The current narrative review summarizes and examines several theories of panic disorder (PD) including biological theories, encompassing neurochemical factors, metabolic and genetic theories, respiratory and hyperventilation theories and cognitive theory. Biological theories have informed the development of psychopharmacological treatments; however, they may be limited in their utility given the efficacy of psychological treatments. In particular, behavioral and, more recently, cognitive models have garnered support due to the efficacy of cognitive-behavior therapy (CBT) in treating PD. The role of combination treatments has been found to be superior in the treatment of PD in particular cases, lending support for the need for an integrated approach and model for PD given that the etiology of PD is complex and multifactorial.

The clinical characterization of the adult patient with an anxiety or related disorder aimed at personalization of management

The clinical construct of "anxiety neurosis" was broad and poorly defined, so that the delineation of specific anxiety disorders in the DSM-III was an important advance. However, anxiety and related disorders are not only frequently comorbid, but each is also quite heterogeneous; thus diagnostic manuals provide only a first step towards formulating a management plan, and the development of additional decision support tools for the treatment of anxiety conditions is needed. This paper aims to describe systematically important domains that are relevant to the personalization of management of anxiety and related disorders in adults. For each domain, we summarize the available research evidence and review the relevant assessment instruments, paying special attention to their suitability for use in routine clinical practice. We emphasize areas where the available evidence allows the clinician to personalize the management of anxiety conditions, and we point out key unmet needs. Overall, the evidence suggests that we are becoming able to move from simply recommending that anxiety and related disorders be treated with selective serotonin reuptake inhibitors, cognitive-behavioral therapy, or their combination, to a more complex approach which emphasizes that the clinician has a broadening array of management modalities available, and that the treatment of anxiety and related disorders can already be personalized in a number of important respects.

The role of cognitive factors in differentiating individuals with somatoform disorders with and without depression

The present study, based on a cross-sectional design, was conducted in the primary care setting with patients presenting somatic symptoms suggestive of somatoform disorders (SFD). The main aim of the study was to determine whether cognitive variables could differentiate between patients with SFD alone and those who also present depressive symptoms suggestive of depression (SFD + depression). All participants (N = 796) completed validated self-report measures to assess somatic, depressive, and/or anxiety symptoms, as well as functional impairment, quality of life (QoL), and cognitive variables (worry, rumination, metacognition, cognitive distortions, and emotion regulation). Univariate and multivariate analyses (controlled for potential sociodemographic and clinical confounders) were performed. On the univariate analysis, significant differences between the SFD and SFD + depression groups were found in sociodemographic and clinical variables, functional impairment, QoL, and cognitive variables. On the multivariate analysis, the only significative variables associated with comorbid SFD + depression were anxiety (β = 0.27; p < 0.001), physical and psychological QoL (β = -0.10; p = 0.01; and β = -0.21; p < 0.001, respectively), and marital status (β = -65; p < 0.05). Cognitive variables were not significantly related to depressive symptoms in patients with SFD. These findings suggest that patients with SFD - with or without comorbid depression - share common cognitive processes and thus both groups could benefit from transdiagnostic cognitive therapy.

Factors differentiating panic disorder with and without comorbid symptoms of depression

The aim of this study was to examine the sociodemographic and clinical differences between people with a probable diagnosis of panic disorder (PD) and those with PD and a probable comorbid diagnosis major depressive disorder (PD + MDD). We also sought to explore the potential contribution of cognitive variables to help differentiate between PD and PD + MDD. This was a subgroup analysis of 331 patients with PD symptoms who were included in the PsicAP clinical trial. All participants completed scales to evaluate panic, depression, somatization, cognitive and performance variables. A univariate analysis showed significant differences (p < .01) between the groups (PD vs PD + MDD) in clinical variables. Somatization was the best predictor of comorbid PD + MDD (β = .346; p < .01). Cognitive variables do not appear to play an essential role in predicting the presence of depressive symptoms in people with a screen positive for PD. These findings appear to support a transdiagnostic treatment approach for PD, which may be useful regardless of whether comorbid depression is present or not. PRACTITIONER POINTS: Somatic symptoms were associated with a higher probability of be in the PD + MDD group. Cognitive variables do not play a relevant role in the differentiation of both groups. A transdiagnostic approach can be useful for the treatment of PD or PD + MDD group.

Increased behavioral inhibition trait and negative stress coping in non-rapid eye movement parasomnias

STUDY OBJECTIVES

Reduced gray matter volume in the posterior cingulate cortex (PCC) has recently been found in patients with non-rapid eye movement (NREM) parasomnia, providing a neuroanatomical substrate for the arousal state dissociation. It remains unclear whether PCC changes in NREM parasomnias might also play a role in cognitive or affective dysfunction in these patients. The aim of this exploratory study was to investigate neurobehavioral correlates of PCC abnormalities in patients with NREM parasomnia.

METHODS

The Reinforcement Sensitivity Theory of Personality Questionnaire and the Stress Coping Questionnaire were used to assess personality and stress coping in 15 patients with NREM parasomnia and 15 age- and sex-matched healthy controls. Patients' left PCC gray matter volume was quantified with voxel-based morphometry on 3 Tesla T1-weighted magnetic resonance imaging data.

RESULTS

In the Reinforcement Sensitivity Theory of Personality Questionnaire, increased trait reactivity of the behavioral inhibition system and goal-drive persistence contributed most to the discrimination of patients and controls. In the Stress Coping Questionnaire, patients showed an increased negative coping trait (ie, anxious rumination) related to an increase in adjusted left PCC volume.

CONCLUSIONS

The results suggest subclinical behavioral abnormalities in patients with NREM parasomnias. Such traits might trigger maladaptive emotion regulation processes related to a relative PCC volume increase. The findings encourage further longitudinal studies on this topic, which can provide insights into the causal relations underlying the PCC volume-behavior correlation. Such future studies will have a more direct implication for the clinical management of patients with NREM parasomnias.

Emotional processing in panic disorder and its subtypes: An fMRI study using emotional faces

BACKGROUND

Inconsistent findings regarding the pathophysiology of panic disorder (PD) could result from clinical heterogeneity. Identifying subtypes could enhance insights into the neurobiological substrates of PD.

METHODS

An emotional faces fMRI paradigm was used in a group of PD patients (n = 73) and healthy controls (n = 58). The overall PD group was further divided into three previously identified subtypes: a cognitive-autonomic (n = 22), an autonomic (n = 16) and an aspecific (n = 35) subtype. Differences in brain activity levels in response to emotional facial expressions between groups were examined for six regions of interests, namely the amygdala, ventromedial prefrontal cortex, anterior cingulate, fusiform gyrus, lingual gyrus and insula.

RESULTS

PD patients showed lower activity in the rostral anterior cingulate in response to angry faces than healthy controls, which was mainly driven by the autonomic subtype. No significant differences were found in other brain regions when comparing PD patients with controls or when comparing across PD subtypes.

LIMITATIONS

Sample sizes in subgroups were relatively small CONCLUSIONS: The role of the rostral anterior cingulate cortex for emotional processes critical in panic disorder is highlighted by this study and provides, albeit preliminary, evidence for the use of a subtype approach to advance our neurobiological insights in PD considering its involvement in the appraisal of autonomic viscero-sensory symptoms.

Platelet and Red Blood Cell Indices in Patients with Panic Disorder: A Receiver Operating Characteristic Analysis

Objective  Panic disorder (PD) is associated with changes in platelet and red blood cell (RBC) indices. However, the diagnostic or predictive value of these indices is unknown. This study assessed the diagnostic and discriminating value of platelet and RBC indices in patients with PD. Materials and Methods  In this cross-sectional study including patients with PD ( n = 98) and healthy controls ( n = 102), we compared the following blood indices: mean platelet volume (MPV), platelet distribution width (PDW), and RBC distribution width (RDW). The receiver operating characteristic (ROC) curve was used to calculate the area under the ROC curve (AUC), sensitivity, specificity, and likelihood ratio for the platelet and RBC indices. Results  Statistically significant increase in PDW (17.01 ± 0.91 vs. 14.8 ± 2.06; p < 0.0001) and RDW (16.56 ± 2.32 vs. 15.12 ± 2.43; p < 0.0001) levels were observed in patients with PD. PDW and mean corpuscular hemoglobin concentration had larger AUC (0.89 and 0.74, respectively) and Youden's index (0.65 and 0.39, respectively), indicating their higher predictive capacity as well as higher sensitivity in discriminating patients with PD from healthy controls. Conclusion  PDW can be considered a "good" diagnostic or predictive marker in patients with PD.

Panic disorder respiratory subtype: psychopathology and challenge tests - an update

Panic disorder (PD) pathophysiology is very heterogeneous, and the discrimination of distinct subtypes could be very useful. A subtype based on respiratory symptoms is known to constitute a specific subgroup. However, evidence to support the respiratory subtype (RS) as a distinct subgroup of PD with a well-defined phenotype remains controversial. Studies have focused on characterization of the RS based on symptoms and response to CO2. In this line, we described clinical and biological aspects focused on symptomatology and CO2 challenge tests in PD RS. The main symptoms that characterize RS are dyspnea (shortness of breath) and a choking sensation. Moreover, patients with the RS tended to be more responsive to CO2 challenge tests, which triggered more panic attacks in this subgroup. Future studies should focus on discriminating respiratory-related clusters and exploring psychophysiological and neuroimaging outcomes in order to provide robust evidence to confirm RS as a distinct subtype of PD.

Symptombezogene Subgruppen von Patienten mit agoraphobischer Angst

Zusammenfassung. Theoretischer Hintergrund: Bisher ist wenig über symptombezogene Teilgruppen von Patient_innen mit agoraphobischer Angst über die Betrachtung als mit oder ohne Panikstörung hinausgehend bekannt. So sind existierende Behandlungsprogramme meist nicht modularisiert und berücksichtigen die möglicherweise vorhandenen spezifischen Bedarfe kaum. Daher untersuchten wir die Frage, welche Subgruppen anhand von symptombezogenen Variablen identifiziert werden können. Methode: N = 290 Patient_innen mit SKID-Diagnose Agoraphobie mit oder ohne Panikstörung, in einer auf die Behandlung von Angststörungen spezialisierten universitären Tagesklinik, wurden anhand von Skalenwerten des Fragebogens zu angstbezogenen Kognitionen (ACQ) sowie der Panik- und Agoraphobie-Skala (PAS) mittels einer Clusteranalyse nach dem Ward-Verfahren mit anschließender k-means-Optimierung nach inhaltlicher Interpretierbarkeit gruppiert. Die Validität wurde am externen Kriterium „Therapieerfolg“ geprüft. Ergebnisse: Neben zwei Subgruppen mit sehr hoher ( n = 67) und sehr niedriger ( n = 56) Symptomausprägung auf sämtlichen Skalen, wurden zwei qualitativ-symptomatisch differentielle Subtypen identifiziert: der Typus „Körperliche Befürchtungen“ ( n = 81) und der Typus „Verhaltenskontrollverlust“ ( n = 86). Letztere zeigten keine Unterschiede im Therapieerfolg. Schlussfolgerungen: Die Identifikation spezifischer Patient_innengruppen impliziert spezifische Therapiebedarfe und -erwartungen über das Vorliegen einer Paniksymptomatik hinaus. Es zeigte sich, dass der individuellen agoraphobischen Befürchtung bei den unterschiedlichen Patient_innengruppen besondere Bedeutung zukommt, weswegen diese bei der Therapieplanung besondere Beachtung erfahren sollte.

Toward a personalized therapy for panic disorder: preliminary considerations from a work in progress

Although several treatment options for panic disorder (PD) are available, the best intervention for each individual patient remains uncertain and the use of a more personalized therapeutic approach in PD is required. In clinical practice, clinicians combine general scientific information and personal experience in the decision-making process to choose a tailored treatment for each patient. In this sense, clinicians already use a somehow personalized medicine strategy. However, the influence of their interpretative personal models may lead to bias related to personal convictions, not sufficiently grounded on scientific evidence. Hence, an effort to give some advice based on the science of personalized medicine could have positive effects on clinicians' decisions. Based on a narrative review of meta-analyses, systematic reviews, and experimental studies, we proposed a first-step attempt of evidence-based personalized therapy for PD. We focused on some phenomenological profiles, encompassing symptoms during/outside panic attacks, related patterns of physiological functions, and some aspects of physical health, which might be worth considering when developing treatment plans for patients with PD. We considered respiratory, cardiac, vestibular, and derealization/depersonalization profiles, with related implications for treatment. Given the extensiveness of the topic, we considered only medications and some somatic interventions. Our proposal should be considered neither exhaustive nor conclusive, as it is meant as a very preliminary step toward a future, robust evidence-based personalized therapy for PD. Clearly much more work is needed to achieve this goal, and recent technological advances, such as wearable devices, big data platforms, and the application of machine learning techniques, may help obtain reliable findings. We believe that combining the efforts of different research groups in this work in progress can lead to largely shared conclusions in the near future.

Does Personality Matter? Temperament and Character Dimensions in Panic Subtypes

Introduction

Symptomatic heterogeneity in the clinical presentation of Panic Disorder (PD) has lead to several attempts to identify PD subtypes; however, no studies investigated the association between temperament and character dimensions and PD subtypes. The study was aimed to verify whether personality traits were differentially related to distinct symptom dimensions.

Methods

Seventy-four patients with PD were assessed by the Mini-International Neuropsychiatric Interview (M.I.N.I.), and the Temperament and Character Inventory (T.C.I.). Thirteen panic symptoms from the M.I.N.I. were included in a factor analysis with varimax rotation. A correlation analysis (Pearson's correlation), a linear regression analysis, and a forward stepwise regression analysis between the identified factors and T.C.I. variables were performed for evaluating the association between panic subtypes and personality features.

Results

Three factors were obtained: "Somato-dissociative", "Respiratory", and "Cardiologic" explaining respectively 18.31%, 13.71%, and 12.78% of the total variance. Correlations analyses showed that only "Somato-dissociative" factor was significantly correlated with T.C.I. "Self-directedness" (p<0.0001) and "Cooperativeness" (p=0.009) variables. Results from the regression analysis indicate that the predictor models account for 33.3% and 24.7% of the total variance respectively in "Somatic-dissociative" (p<0.0001) and "Cardiologic" (p=0.007) factors, while they do not show statistically significant effects on "Respiratory" factor (p=0.222). After performing stepwise regression analysis, "Self-directedness" resulted the unique predictor of "Somato-dissociative" factor (R²=0.186; β=-0.432; t=-4.061; p<0.0001).

Conclusion

Current results, although preliminary, suggest the importance of assessing personality and temperament features that may be potentially related to poor treatment response for a better understanding and characterization of PD subtypes.

The differences between patients with panic disorder and healthy controls in psychophysiological stress profile

BACKGROUND

Alarming somatic symptoms, in particular, cardiovascular symptoms, are the characteristic feature of panic attacks. Increased cardiac mortality and morbidity have been found in these patients. Power spectral analysis of electrocardiogram R-R intervals is known to be a particularly successful tool in the detection of autonomic instabilities in various clinical disorders. Our study aimed to compare patients with panic disorder and healthy controls in heart rate variation (HRV) parameters (very-low-frequency [VLF], low-frequency [LF], and high-frequency [HF] band components of R-R interval) in baseline and during the response to the mental task.

SUBJECTS AND METHODS

We assessed psychophysiological variables in 33 patients with panic disorder (10 men, 23 women; mean age 35.9±10.7 years) and 33 age- and gender-matched healthy controls (10 men, 23 women; mean age 35.8±12.1 years). Patients were treatment naïve. Heart rate, blood pressure, muscle tension, and HRV in basal conditions and after the psychological task were assessed. Power spectrum was computed for VLF (0.003-0.04 Hz), LF (0.04-0.15 Hz), and HF (0.15-0.40 Hz) bands using fast Fourier transformation.

RESULTS

In the baseline period, the VLF band was significantly lower in panic disorder group compared to controls (p<0.005). In the period of mental task, the LF/HF ratio was significantly higher in panic disorder patients compared to controls (p<0.05). No significant differences were found in the remaining parameters. There was a significant difference in ΔHF and ΔLF/HF ratio between patients and controls, with Δ increasing in patients and decreasing in controls.

CONCLUSION

These findings revealed that patients suffering from panic disorder were characterized by relative sympathetic dominance (reactivity) in response to mental stress compared with healthy controls.

Identifying Patterns in Complex Field Data

Abstract. Ambulatory assessment methods are well suited to examine how patients with panic disorder and agoraphobia (PD/A) undertake situational exposure. But under complex field conditions of a complex treatment protocol, the variability of data can be so high that conventional analytic approaches based on group averages inadequately describe individual variability. To understand how fear responses change throughout exposure, we aimed to demonstrate the incremental value of sorting HR responses (an index of fear) prior to applying averaging procedures. As part of their panic treatment, 85 patients with PD/A completed a total of 233 bus exposure exercises. Heart rate (HR), global positioning system (GPS) location, and self-report data were collected. Patients were randomized to one of two active treatment conditions (standard exposure or fear-augmented exposure) and completed multiple exposures in four consecutive exposure sessions. We used latent class cluster analysis (CA) to cluster heart rate (HR) responses collected at the start of bus exposure exercises (5 min long, centered on bus boarding). Intra-individual patterns of assignment across exposure repetitions were examined to explore the relative influence of individual and situational factors on HR responses. The association between response types and panic disorder symptoms was determined by examining how clusters were related to self-reported anxiety, concordance between HR and self-report measures, and bodily symptom tolerance. These analyses were contrasted with a conventional analysis based on averages across experimental conditions. HR responses were sorted according to form and level criteria and yielded nine clusters, seven of which were interpretable. Cluster assignment was not stable across sessions or treatment condition. Clusters characterized by a low absolute HR level that slowly decayed corresponded with low self-reported anxiety and greater self-rated tolerance of bodily symptoms. Inconsistent individual factors influenced HR responses less than situational factors. Applying clustering can help to extend the conventional analysis of highly variable data collected in the field. We discuss the merits of this approach and reasons for the non-stereotypical pattern of cluster assignment across exposures.

Psychiatric Illness and Parasomnias: a Systematic Review

PURPOSE OF REVIEW

Little is known about the presence of parasomnias such as nightmare disorder, sleep paralysis, REM sleep behavior disorder (RBD), and sleep-related eating disorders (SRED) in people with mental illness. A predominant view suggests that psychotropic medications might be contributing to parasomnias. This article summarizes knowledge regarding the relationships between psychiatric disorders and parasomnias, and possible confounds. A systematic search of the literature in the past 10 years identified 19 articles.

RECENT FINDINGS

There were significantly elevated rates of parasomnias in psychiatric disorders (average prevalence of nightmares was 38.9%, sleep paralysis 22.3%, SRED 9.9%, sleepwalking 8.5%, and RBD 3.8%). Medication usage was only one of many risk factors (other sleep disorders, medical comorbidities, and substance abuse) which were associated with parasomnias. A strong association exists between mental illness and parasomnias which is not fully explained by medications. Prospective longitudinal studies are needed to develop a better understanding of the unique and shared variance from multiple risk factors.

The Cyclic Vomiting Syndrome Threshold: A Framework for Understanding Pathogenesis and Predicting Successful Treatments

Cyclic vomiting syndrome (CVS) is an uncommon, idiopathic disorder defined by recurrent, sudden-onset attacks of repetitive retching and vomiting that are separated by symptom-free intervals. CVS was long regarded as a disorder primarily experienced by children but is now known to present de novo in adulthood. Adult CVS has garnered more research attention over the past 20 years, and these efforts have identified some acute and prophylactic treatments for this disorder. However, CVS still lacks a unifying disease model, and this has hindered the development of new therapies. Here adult CVS is reframed as a neurogenic disorder, driven by various endophenotypic factors that shape patterns of activity within the neural circuits required for disease expression. The concept of the "CVS threshold" is put forth in parallel with exploring the remarkable similarity of adult CVS with features of chronic migraine, epilepsy, and panic disorder. Because of such shared neural mechanisms and overlapping endophenotypes, many therapies that have been developed for these other disorders could also be useful in managing CVS. This review seeks to achieve three primary aims: (1) to develop a comprehensive, explanatory framework for adult CVS pathogenesis, (2) to use this framework for identifying potentially novel therapies for CVS, and (3) to describe future research directions that are needed to move the field forward.

Treatment-resistant panic disorder: clinical significance, concept and management

Panic disorder is commonly prevalent in the population, but the treatment response for panic disorder in clinical practice is much less effective than that in our imagination. Increasing evidence suggested existence of a chronic or remitting-relapsing clinical course in panic disorder. In this systematic review, we re-examine the definition of treatment-resistant panic disorder, and present the potential risk factors related to the treatment resistance, including the characteristics of panic disorder, other psychiatric and physical comorbidities, and psychosocial stresses. Furthermore, we summarize the potential pathophysiologies, such as genetic susceptibility, altered brain functioning, brain-derived neurotrophic factor, and long-term inflammation, to explain the treatment resistance. Finally, we conclude the current therapeutic strategies for treating treatment-resistant panic disorder from pharmacological and non-pharmacological views.

Candidate genes in panic disorder: meta-analyses of 23 common variants in major anxiogenic pathways

The utilization of molecular genetics approaches in examination of panic disorder (PD) has implicated several variants as potential susceptibility factors for panicogenesis. However, the identification of robust PD susceptibility genes has been complicated by phenotypic diversity, underpowered association studies and ancestry-specific effects. In the present study, we performed a succinct review of case-control association studies published prior to April 2015. Meta-analyses were performed for candidate gene variants examined in at least three studies using the Cochrane Mantel-Haenszel fixed-effect model. Secondary analyses were also performed to assess the influences of sex, agoraphobia co-morbidity and ancestry-specific effects on panicogenesis. Meta-analyses were performed on 23 variants in 20 PD candidate genes. Significant associations after correction for multiple testing were observed for three variants, TMEM132D rs7370927 (T allele: odds ratio (OR)=1.27, 95% confidence interval (CI): 1.15-1.40, P=2.49 × 10(-6)), rs11060369 (CC genotype: OR=0.65, 95% CI: 0.53-0.79, P=1.81 × 10(-5)) and COMT rs4680 (Val (G) allele: OR=1.27, 95% CI: 1.14-1.42, P=2.49 × 10(-5)) in studies with samples of European ancestry. Nominal associations that did not survive correction for multiple testing were observed for NPSR1 rs324891 (T allele: OR=1.22, 95% CI: 1.07-1.38, P=0.002), TPH1 rs1800532 (AA genotype: OR=1.46, 95% CI: 1.14-1.89, P=0.003) and HTR2A rs6313 (T allele: OR=1.19, 95% CI: 1.07-1.33, P=0.002) in studies with samples of European ancestry and for MAOA-uVNTR in female PD (low-active alleles: OR=1.21, 95% CI: 1.07-1.38, P=0.004). No significant associations were observed in the secondary analyses considering sex, agoraphobia co-morbidity and studies with samples of Asian ancestry. Although these findings highlight a few associations, PD likely involves genetic variation in a multitude of biological pathways that is diverse among populations. Future studies must incorporate larger sample sizes and genome-wide approaches to further quantify the observed genetic variation among populations and subphenotypes of PD.

Frontoparietal Cortical Thinning in Respiratory-Type Panic Disorder: A Preliminary Report

OBJECTIVE

Many evidences raise the possibility that the panic disorder (PD) patients with respiratory subtype (RS) may have characteristic structural abnormalities. We aimed to explore the structural differences between PD patients with and without the respiratory symptoms.

METHODS

Patients with PD were recruited from the Department of Psychiatry at Korea University Anam Hospital. Respiratory subtype (RS) was diagnosed when at least 4 out of 5 of the following respiratory symptoms were present during the panic attack: fear of dying, chest pain/discomfort, shortness of breath, paresthesias, and a choking sensation. We acquired high-resolution MRI scans and used FreeSurfer to obtain a measure of cortical thickness for each patient.

RESULTS

Cluster based analysis revealed significantly decreased cortical thickness in the left hemisphere in the caudal-middle-frontal, superior frontal, and posterior parietal areas in the RS group. No significant difference was observed in any of the limbic areas.

CONCLUSION

Respiratory symptoms of panic disorder were associated with a reduction in cortical thickness in the left frontal and parietal areas. This finding leads to the assumption that the frontoparietal network is the crucial component in a larger cortical network underlying the perception of dyspnea in RS.

Interoceptive fear learning to mild breathlessness as a laboratory model for unexpected panic attacks

Fear learning is thought to play an important role in panic disorder. Benign interoceptive sensations can become predictors (conditioned stimuli - CSs) of massive fear when experienced in the context of an initial panic attack (unconditioned stimulus - US). The mere encounter of these CSs on a later moment can induce anxiety and fear, and precipitate a new panic attack. It has been suggested that fear learning to interoceptive cues would result in unpredictable panic. The present study aimed to investigate whether fear learning to an interoceptive CS is possible without declarative knowledge of the CS-US contingency. The CS consisted of mild breathlessness (or: dyspnea), the US was a suffocation experience. During acquisition, the experimental group received six presentations of mild breathlessness immediately followed by suffocation; for the control group both experiences were always separated by an intertrial interval. In the subsequent extinction phase, participants received six unreinforced presentations of the CS. Expectancy of the US was rated continuously and startle eyeblink electromyographic, skin conductance, and respiration were measured. Declarative knowledge of the CS-US relationship was also assessed with a post-experimental questionnaire. At the end of acquisition, both groups displayed the same levels of US expectancy and skin conductance in response to the CS, but the experimental group showed a fear potentiated startle eyeblink and a different respiratory response to the CS compared to the control group. Further analyses on a subgroup of CS-US unaware participants confirmed the presence of startle eyeblink conditioning in the experimental group but not in the control group. Our findings suggest that interoceptive fear learning is not dependent on declarative knowledge of the CS-US relationship. The present interoceptive fear conditioning paradigm may serve as an ecologically valid laboratory model for unexpected panic attacks.

Lifestyle Behaviours Add to the Armoury of Treatment Options for Panic Disorder: An Evidence-Based Reasoning

This article presents an evidence-based reasoning, focusing on evidence of an Occupational Therapy input to lifestyle behaviour influences on panic disorder that also provides potentially broader application across other mental health problems (MHP). The article begins from the premise that we are all different. It then follows through a sequence of questions, examining incrementally how MHPs are experienced and classified. It analyses the impact of individual sensitivity at different levels of analysis, from genetic and epigenetic individuality, through neurotransmitter and body system sensitivity. Examples are given demonstrating the evidence base behind the logical sequence of investigation. The paper considers the evidence of how everyday routine lifestyle behaviour impacts on occupational function at all levels, and how these behaviours link to individual sensitivity to influence the level of exposure required to elicit symptomatic responses. Occupational Therapists can help patients by adequately assessing individual sensitivity, and through promoting understanding and a sense of control over their own symptoms. It concludes that present clinical guidelines should be expanded to incorporate knowledge of individual sensitivities to environmental exposures and lifestyle behaviours at an early stage.

Dimensional structure of bodily panic attack symptoms and their specific connections to panic cognitions, anxiety sensitivity and claustrophobic fears

BACKGROUND

Previous studies of the dimensional structure of panic attack symptoms have mostly identified a respiratory and a vestibular/mixed somatic dimension. Evidence for additional dimensions such as a cardiac dimension and the allocation of several of the panic attack symptom criteria is less consistent. Clarifying the dimensional structure of the panic attack symptoms should help to specify the relationship of potential risk factors like anxiety sensitivity and fear of suffocation to the experience of panic attacks and the development of panic disorder.

METHOD

In an outpatient multicentre study 350 panic patients with agoraphobia rated the intensity of each of the ten DSM-IV bodily symptoms during a typical panic attack. The factor structure of these data was investigated with nonlinear confirmatory factor analysis (CFA). The identified bodily symptom dimensions were related to panic cognitions, anxiety sensitivity and fear of suffocation by means of nonlinear structural equation modelling (SEM).

RESULTS

CFA indicated a respiratory, a vestibular/mixed somatic and a cardiac dimension of the bodily symptom criteria. These three factors were differentially associated with specific panic cognitions, different anxiety sensitivity facets and suffocation fear.

CONCLUSIONS

Taking into account the dimensional structure of panic attack symptoms may help to increase the specificity of the associations between the experience of panic attack symptoms and various panic related constructs.

Clinical characteristics of the respiratory subtype in panic disorder patients

OBJECTIVE

Panic disorder has been suggested to be divided into the respiratory and non-respiratory subtypes in terms of its clinical presentations. The present study aimed to investigate whether there are any differences in treatment response and clinical characteristics between the respiratory and non-respiratory subtypes of panic disorder patients.

METHODS

Among the 48 patients those who completed the study, 25 panic disorder patients were classified as the respiratory subtype, whereas 23 panic disorder patients were classified as the non-respiratory subtype. All patients were treated with escitalopram or paroxetine for 12 weeks. We measured clinical and psychological characteristics before and after pharmacotherapy using the Panic Disorder Severity Scale (PDSS), Albany Panic and Phobic Questionnaire (APPQ), Anxiety Sensitivity Index-Revised (ASI-R), State-Trait Anxiety Inventory (STAI-T, STAI-S), Hamilton Anxiety Rating Scale (HAM-A), and Hamilton Depression Rating Scale (HAM-D).

RESULTS

The prevalence of the agoraphobia was significantly higher in the respiratory group than the non-respiratory group although there were no differences in gender and medication between the two groups. The respiratory group showed higher scores on the fear of respiratory symptoms of the ASI-R. In addition, after pharmacotherapy, the respiratory group showed more improvement in panic symptoms than the non-respiratory group.

CONCLUSION

Panic disorder patients with the respiratory subtype showed more severe clinical presentations, but a greater treatment response to SSRIs than those with non-respiratory subtype. Thus, classification of panic disorder patients as respiratory and non-respiratory subtypes may be useful to predict clinical course and treatment response to SSRIs.

Somatic, but not cognitive, symptoms of anxiety predict lower levels of physical activity in panic disorder patients

BACKGROUND

Anxiety disorders have gathered much attention as possible risk factors for the development of cardiovascular disease (CVD), possibly mediated by an unhealthy lifestyle (e.g. low physical activity). However, prospective studies on anxiety disorders and CVD show conflicting results. A possible explanation is that somatic symptoms of anxiety may have a more specific cardiovascular effect than cognitive symptoms across different anxiety disorders. The present study investigated the association between cognitive and somatic symptoms of anxiety and physical activity (PA) in a sample of panic disorder (PD) outpatients.

METHODS

One-hundred and two outpatients with a lifetime diagnosis of PD from a previously studied cohort were contacted. Patients were evaluated throughout the MINI, the Beck Anxiety Inventory (BAI) and the International Physical Activity Questionnaire (IPAQ). After performing a multivariate regression analysis, groups were divided into high and low somatic anxiety.

RESULTS

Patients with high somatic anxiety showed a significantly higher prevalence of low level of PA as compared to those with low somatic anxiety (62.5 versus 34.3%; χ²= 5.33; df=1; P=.021). Somatic symptoms of anxiety remained the only important predictors of low level of PA (odds ratio [OR] 2.81; 95% CI 1.00-7.90; p=.050) in the multivariate model.

LIMITATIONS

The main limitations of the present study are the cross-sectional design and the small sample size.

CONCLUSIONS

Results support specific effects of somatic symptoms of anxiety on risk for low level of PA, which might explain inconsistent results regarding CVD risk in the literature.

Panic symptom profiles in social anxiety disorder: a person-centered data-analytic approach

Panic attacks (PAs) are prevalent among individuals with social anxiety disorder (SAD), but the clinical utility of panic symptom profiles is unclear. The aims of the present investigation were to empirically define panic symptom profiles in a treatment-seeking sample of individuals with SAD (N = 280) and to assess the associations of observed panic symptom profiles with clinical features of SAD. Results of a latent class analysis revealed four distinct panic symptom profiles: low panic symptoms, high typical SAD-related panic, high cardiac sensations and paresthesias, and moderate panic. Comparisons of external validators across latent classes indicated that the classes were differentially associated with clinical features of SAD. The present findings suggest that individuals with SAD experience distinct patterns of panic symptoms that may be clinically useful in conducting diagnostic assessments and determining treatment targets.

The panic disorder respiratory ratio: a dimensional approach to the respiratory subtype

OBJECTIVE

The respiratory ratio is a dimensional construct of the respiratory subtype of panic disorder (PD). The respiratory subtype has been correlated with an increased sensitivity to CO₂ inhalation, positive family history of PD and low comorbidity with depression. The objective of our study was to determine whether the respiratory ratio is correlated with CO₂-induced panic attacks and other clinical and demographic features.

METHODS

We examined 91 patients with PD and submitted them to a double-breath 35% CO₂ challenge test. The respiratory ratio was calculated based on the Diagnostic Symptom Questionnaire (DSQ) scores recorded in a diary in the days preceding the CO₂ challenge. The scores of the respiratory symptoms were summed and divided by the total DSQ score.

RESULTS

The respiratory ratio was correlated with CO₂ sensitivity, and there was a non-statistically significant trend towards a correlation with a family history of PD.

CONCLUSIONS

The positive correlation between the respiratory ratio and the anxiety elicited by the CO₂ inhalation indicates that the intensity of respiratory symptoms may be proportional to the sensitivity to carbon dioxide.

Bowel and Bladder-Control Anxiety: A Preliminary Description of a Viscerally-Centred Phobic Syndrome

Background: People with anxiety disorders occasionally report fears about losing control of basic bodily functions in public. These anxieties often occur in the absence of physical disorder and have previously been recognized as “obsessive” anxieties reflecting a preoccupation with loss of bowel/bladder control. Motivated by our observations of the non-trivial occurrence of such anxieties in our clinical practice we sought to fill a gap in the current understanding of “bowel/bladder-control anxieties”. Method: Eligible participants completed an internet survey. Results: Bowel/bladder-control anxieties (n = 140) tended to emerge in the mid to late 20s and were associated with high levels of avoidance and functional impairment. There was a high prevalence of panic attacks (78%); these were especially prevalent among those with bowel-control anxiety. Of those with panic attacks, 62% indicated that their main concern was being incontinent during a panic attack. Significantly, a proportion of respondents (~16%) reported actually being incontinent during a panic attack. Seventy percent of participants reported intrusive imagery related to loss of bowel/bladder control. Intrusion-related distress was correlated with agoraphobic avoidance and general role impairment. Some differences were noted between those with predominantly bowel-, predominantly bladder- and those with both bowel and bladder-control anxieties. Conclusion: This preliminary characterization indicates that even in a non-treatment seeking community sample, bowel/bladder-control anxieties are associated with high levels of distress and impairment. Further careful characterization of these anxieties will clarify their phenomenology and help us develop or modify treatment protocols in a way that takes account of any special characteristics of such viscerally-centred phobic syndromes.

Comparison of superoxide dismutase, glutathione peroxidase and adenosine deaminase activities between respiratory and nocturnal subtypes of patients with panic disorder

OBJECTIVE

There is mounting evidence indicating that oxidative and inflammatory processes may have an important role in the pathogenesis of panic disorder (PD). PD is a heterogeneous disease, and panic attacks are divided according to the different symptom clusters as respiratory, nocturnal, non-fearful, cognitive, or vestibular subtypes. The aim of this study was to compare whole-blood and serum superoxide dismutase (SOD), glutathione peroxidase and adenosine deaminase activities in PD patients with/without nocturnal, respiratory subtypes and healthy subjects.

METHODS

The study was conducted including 60 patients with PD and 30 healthy control subjects. The Panic Attack Symptom Checklist, Panic and Agoraphobia Scale, Hamilton Depression Rating Scale and Hamilton Anxiety Rating Scale were administered to the patients. Biochemical analyses were performed after all the blood samples were collected.

RESULTS

We found that whole-blood SOD and glutathione peroxidase activities of patients were significantly lower and adenosine deaminase activities of patients were higher than those of healthy controls. There were no statistically significant differences between respiratory and nocturnal subtypes. In addition, there were no marked relationships between the duration of illness and panic-agoraphobia scores of patients with nocturnal subtypes. Hamilton Depression Rating Scale and Hamilton Anxiety Rating Scale scores of patients with the nocturnal subtype were markedly higher than those of patients without the nocturnal subtype.

CONCLUSION

The results suggest that oxidative and inflammatory processes may play a role in the pathophysiology of PD. These findings may support the idea that both nocturnal and respiratory subtypes of PD have different symptom clusters of the same disease.

The relationship between obsessive compulsive beliefs and symptoms, anxiety and disgust sensitivity, and Swine Flu fears

Using the 2009 Swine Flu outbreak as a contemporary example of pandemic fears, this study examined the relationship between various symptoms related to anxiety sensitivity and Swine Flu fears. It was hypothesized that both obsessive-compulsive (OC) beliefs and OC symptoms would significantly predict Swine Flu fears. It was also hypothesized that symptoms of anxiety, including measures of anxiety sensitivity and disgust sensitivity would significantly mediate the relationship between both OC beliefs and OC symptoms and Swine Flu fears. A total of 393 undergraduate students completed measures of Swine Flu fears, anxiety sensitivity, OC beliefs and symptoms, and disgust sensitivity. It was found that both OC beliefs and OC symptoms significantly predicted Swine Flu fears. While disgust sensitivity significantly mediated the relationship between both OC beliefs and OC symptoms and Swine Flu fears using the Sobel test, anxiety sensitivity was a significant mediator only for OC symptoms. Additionally, path modeling showed that anxiety sensitivity mediated the relationship between OC symptoms and Swine Flu fears best. The results of this study may be useful for treating individuals suffering from anxiety in light of future pandemics, as well as continuing to research the role of anxiety symptoms in predicting pandemic fears.

A dimensional approach to measuring anxiety for DSM-5

In preparation for DSM-5's planned inclusion of dimensional assessments of psychopathology as a complement to traditional categorical diagnoses, we developed brief self-rated scales for anxiety disorders that are consistent in content and structure. In the present paper, we discuss the creation of the scales and examine their psychometric properties and clinical sensitivity. Phase One assessed psychometric properties of the initial versions of the scales in a large non-clinical sample (n = 702). Phase Two assessed the psychometric properties of revised versions of the scales, including test-retest reliability, in a non-clinical sample (n = 57). Phase Three examined the scales' psychometric properties and relationship with clinician ratings of disorder severity in a clinical sample (n = 48). The scales demonstrated internal consistency (α = 0.85-0.92), convergent validity (r(s)  = 0.39-0.69), and test-retest reliability in the non-clinical samples (ICC = 0.51-0.81). In the clinical sample, the scales demonstrated significantly higher total scores than in the non-clinical sample (Cohen's d = 0.72-1.50) and moderate to high correlations with clinician ratings of disorder severity (r = 0.43-0.82) Although further evaluation and refinement of the scales (particularly the specific phobia and agoraphobia scales) is needed, the results provide preliminary support for the use of these scales in DSM-5 and thus take an important step toward the integration of standardized dimensional measurement into the diagnosis of anxiety disorders.

Gender effect on the relationship between stress hormones and panic-agoraphobic spectrum dimensions in healthy subjects

INTRODUCTION

Alterations of the hypothalamic-pituitary-adrenal (HPA) axis and of its peripheral indices have been reported in both normal and pathological anxiety with controversial findings. The aim of the present study was to investigate the possible correlations between serum cortisol and dehydroepiandrosterone-sulfate (DHEA-S) levels and DHEA-S/cortisol ratio, and panic-agoraphobic spectrum dimensions in a sample of healthy subjects.

METHODS

Forty-two healthy subjects of both sexes, with no current or lifetime psychiatric disorders, were assessed by means of the Structured Clinical Interview for DSM-IV (SCID-I/P) and the so-called Panic Agoraphobic Spectrum-Self Report lifetime version (PAS-SR).

RESULTS

Significant, negative correlations were found between cortisol levels and the total score of the separation sensitivity, panic-like symptoms, and medication/substance sensitivity PAS-SR domains. The PAS-SR total and the panic-like symptoms domain scores were positively related to the DHEAS/cortisol ratio. When the sample was divided in women and men, these correlations were present in women only.

DISCUSSION

These findings, while indicating the presence of significant relationships between panic-agoraphobic traits and some indices of HPA axis functioning in healthy women, would suggest this as one of the factors explaining the greater vulnerability of women to cross the line between normal and pathological anxiety.

CONCLUSIONS

Further studies are needed to explore gender differences in the relationships between HPA axis alterations and the panic-agoraphobic spectrum dimensions.

Expanding stress generation theory: test of a transdiagnostic model

Originally formulated to understand the recurrence of depressive disorders, the stress generation hypothesis has recently been applied in research on anxiety and externalizing disorders. Results from these investigations, in combination with findings of extensive comorbidity between depression and other mental disorders, suggest the need for an expansion of stress generation models to include the stress generating effects of transdiagnostic pathology as well as those of specific syndromes. Employing latent variable modeling techniques to parse the general and specific elements of commonly co-occurring Axis I syndromes, the current study examined the associations of transdiagnostic internalizing and externalizing dimensions with stressful life events over time. Analyses revealed that, after adjusting for the covariation between the dimensions, internalizing was a significant predictor of interpersonal dependent stress, whereas externalizing was a significant predictor of noninterpersonal dependent stress. Neither latent dimension was associated with the occurrence of independent, or fateful, stressful life events. At the syndrome level, once variance due to the internalizing factor was partialed out, unipolar depression contributed incrementally to the generation of interpersonal dependent stress. In contrast, the presence of panic disorder produced a "stress inhibition" effect, predicting reduced exposure to interpersonal dependent stress. Additionally, dysthymia was associated with an excess of noninterpersonal dependent stress. The latent variable modeling framework used here is discussed in terms of its potential as an integrative model for stress generation research.

Revise the revised? New dimensions of the neuroanatomical hypothesis of panic disorder

In 2000, Gorman et al. published a widely acknowledged revised version of their 1989 neuroanatomical hypothesis of panic disorder (PD). Herein, a 'fear network' was suggested to mediate fear- and anxiety-related responses: panic attacks result from a dysfunctional coordination of 'upstream' (cortical) and 'downstream' (brainstem) sensory information leading to heightened amygdala activity with subsequent behavioral, autonomic and neuroendocrine activation. Given the emergence of novel imaging methods such as fMRI and the publication of numerous neuroimaging studies regarding PD since 2000, a comprehensive literature search was performed regarding structural (CT, MRI), metabolic (PET, SPECT, MRS) and functional (fMRI, NIRS, EEG) studies on PD, which will be reviewed and critically discussed in relation to the neuroanatomical hypothesis of PD. Recent findings support structural and functional alterations in limbic and cortical structures in PD. Novel insights regarding structural volume increase or reduction, hyper- or hypoactivity, laterality and task-specificity of neural activation patterns emerged. The assumption of a generally hyperactive amygdala in PD seems to apply more to state than trait characteristics of PD, and involvement of further areas in the fear circuit, such as anterior cingulate and insula, is suggested. Furthermore, genetic risk variants have been proposed to partly drive fear network activity. Thus, the present state of knowledge generally supports limbic and cortical prefrontal involvement as originally proposed in the neuroanatomical hypothesis. Some modifications might be suggested regarding a potential extension of the fear circuit, genetic factors shaping neural network activity and neuroanatomically informed clinical subtypes of PD potentially guiding future treatment decisions.

Predictors of response among patients with panic disorder treated with medications in a naturalistic follow-up: the role of adult separation anxiety

BACKGROUND

Efficacy of treatments for panic disorder is well established, but not all patients respond. Adult separation anxiety has been found to predict poorer response to CBT, but its effect on response to medication has not been previously explored.

STUDY AIM

The aim of this study is to investigate if panic-agoraphobic spectrum factors, including 'separation anxiety' factor predict treatment outcome in patients with panic disorder.

STUDY SAMPLE

Participants who met criteria for PD (n=57) completed baseline assessment and 12 months follow-up. Patients were administered the Panic Agoraphobic Spectrum Self-Report (PAS-SR, Lifetime and Last-Month Versions), and the Panic Disorder Severity Scale (PDSS). We examined patients who met the following criteria at baseline: 1) PDSS total score>7; 2) no current Axis I comorbidity with major depression; 3) no lifetime or current bipolar disorder. All patients were treated with evidence-based psychopharmacological treatment for panic disorder during the 12-month observation period.

RESULTS

Twenty eight patients (48.1%) achieved remission during the follow-up period. In a logistic regression model, controlling for baseline severity, gender and age, only the last-month PAS-SR 'separation anxiety' factor was associated with a lower likelihood of remission.

CONCLUSIONS

Signs and symptoms of separation anxiety in adulthood, as assessed with the PAS-SR Last Month version, are predictors of poor treatment outcome in patients with PD. We submit that the assessment of panic-agoraphobic spectrum features, including adult separation anxiety, should become routine of clinical assessment of patients with PD. It is likely that a better psychopathological characterization of patients may inform treatment selection, and result in better treatment outcome.

Alexithymia and its relationship to dissociation in patients with panic disorder

Conditions that impede the regulation of emotional arousal, such as alexithymia and dissociation, may underlie panic attacks. This study aimed to evaluate the relationship between alexithymia and dissociation in patients with panic disorder (PD). We assessed 95 PD outpatients with regard to alexithymia (20-item Toronto Alexithymia Scale), dissociation (Dissociation Experience Scale), and overall psychological distress (Symptom Checklist 90-Revised, Global Severity Index). Regression analyses revealed a positive correlation between alexithymia and dissociation, even when the Global Severity Index was controlled for. A specific link was observed between "difficulty in identifying feelings" and "depersonalization/derealization." Patients who showed the pathological form of dissociation had higher levels of alexithymia, with particular regard to "difficulty in identifying feelings" and, to a smaller extent, "difficulty in describing feelings." These results support a strong relationship between alexithymia and dissociation in patients with PD. Assessing alexithymia and dissociation at the outset of therapy may be helpful for individualized therapy planning.

Prevalence and correlates of respiratory and non-respiratory panic attacks in the general population

BACKGROUND

Panic attacks are heterogeneous with regards to symptom profile. Subtypes of panic attacks have been proposed, of which the most investigated is respiratory panic attacks (RPA). Limited information exists about RPA in the general population.

METHOD

The prevalence and correlates of RPA and non-respiratory panic attacks (NRPA) were examined in a subsample (n=8.796) of individuals participating in a cross-sectional survey of the adult general population of six European countries. Panic attacks, mental disorders, and chronic physical conditions were assessed with the Composite International Diagnostic Interview (CIDI) 3.0. Data on use of health services and disability were obtained.

RESULTS

The lifetime prevalence of RPA was 6.77 and the 12-month prevalence was 2.26. No robust associations of RPA with sociodemographic characteristics, mental disorders or physical conditions were found as compared to NRPA. RPA were associated with increased use of health services but similar disability in comparison to NRPA.

LIMITATIONS

Few direct data are available on the validity of the CIDI to assess RPA. Other definitions of RPA exist in the literature.

CONCLUSIONS

Our findings suggest that there are very few differences between RPA and NRPA and do not support the need of subtyping panic attacks in current classification systems.

An evidence-based causal model of panic disorder

Recently, Fava and Morton (2009) described what they termed a 'causal model' of panic disorder (Causal modeling of panic disorder theories, Clinical Psychology Review, 29, 623-637). We examined several critical tenets of this proposed model, and offer significant revisions. Our revised causal model includes elements that have received empirical support, and exclude those with known limitations in explaining the etiology and treatment of panic disorder. Chief among these revisions are (1) an increased emphasis on anxiety sensitivity, (2) elimination of the more general psychodynamic conceptualization in favor of empirically supported findings regarding early attachment, and (3) placing biological and psychophysiological reactions as outcomes of false alarm threat, rather than causal mechanisms of panic.

Smoking Behavior and Alcohol Consumption in Individuals With Panic Attacks

Individuals with anxiety often report greater smoking and drinking behaviors relative to those without a history of anxiety. In particular, smoking and alcohol use have been directly implicated among individuals experiencing panic attacks, diagnosed with panic disorder, or high on panic-relevant risk factors such as anxiety sensitivity. Less is known, however, about specific features of panic that may differentiate among those who do or do not use cigarettes or alcohol. The purpose of the current study was to replicate previous research findings of an association between panic symptomatology, cigarette smoking, and alcohol consumption, as well as extend findings by examining whether specific symptoms of panic attacks differentiated among those who do or do not use cigarettes or alcohol. Participants (n = 489) completed the Panic Attack Questionnaire-IV, a highly detailed assessment of panic attacks and symptoms, as well as self-report measures of smoking history and alcohol use. Consistent with previous research, participants who reported a history of panic attacks (n = 107) were significantly more likely to report current daily or lifetime daily cigarette smoking, and significantly greater hazardous or harmful alcohol use than participants with no panic history (n = 382). Although smoking and hazardous alcohol use were highly associated regardless of panic status, participants with panic attacks showed elevated hazardous alcohol use after controlling for daily or lifetime smoking. Surprisingly, although participants who reported having had at least one panic attack were more likely to smoke, panic attack symptoms, intensity, or frequency did not differentiate panickers who did or did not smoke. Furthermore, panic-related variables were not shown to differentially relate to problematic drinking among panickers. Implications for understanding the complex relationship between panic attacks and smoking and drinking behaviors are discussed.

Treinamento físico intervalado como ferramenta na terapia cognitivo-comportamental do transtorno de pânico

Este trabalho consiste no relato da utilização de um programa de exercícios físicos aeró-bicos intervalados no contexto da terapia cognitivo-comportamental em um caso de transtorno de pânico e agorafobia. São descritos os procedimentos utilizados, bem como os resultados positivos obtidos na redução da ansiedade cardíaca e na ansiedade cotidiana em relação a situações que exigem esforço físico.

Genetic and environmental influences on psychiatric comorbidity: a systematic review

BACKGROUND

The purpose of this review is to systematically appraise the peer-reviewed literature about the genetic and environmental determinants of psychiatric comorbidity, focusing on four of the most prevalent types of psychopathology: anxiety disorders, depression, conduct disorder and substance abuse.

METHODS

We summarize existing empirical research on the relative contribution that genetic, nonshared and shared environmental factors make to the covariance between disorders, and evidence about specific genes and environmental characteristics that are associated with comorbidity.

RESULTS

Ninety-four articles met the inclusion criteria and were assessed. Genetic factors play a particularly strong role in comorbidity between major depression and generalized anxiety disorder or posttraumatic stress disorder, while the non-shared environments make an important contribution to comorbidity in affective disorders. Genetic and non-shared environmental factors also make a moderate-to-strong contribution to the relationship between CD and SA. A range of candidate genes, such as 5HTTLPR, MAOA, and DRD1-DRD4, as well as others implicated in the central nervous system, has been implicated in psychiatric comorbidity. Pivotal social factors include childhood adversity/life events, family and peer social connections, and socioeconomic and academic difficulties.

LIMITATIONS

Methodological concerns include the use of clinical case-control samples, the focus on a restricted set of individual-level environmental risk factors, and restricted follow-up times.

CONCLUSIONS

Given the significant mental health burden associated with comorbid disorders, population-based research on modifiable risk factors for psychiatric comorbidity is vital for the design of effective preventive and clinical interventions.

Culture and the anxiety disorders: recommendations for DSM-V

BACKGROUND

The anxiety disorders specified in the fourth edition, text revision, of The Diagnostic and Statistical Manual (DSM-IV-TR) are identified universally in human societies, and also show substantial cultural particularities in prevalence and symptomatology. Possible explanations for the observed epidemiological variability include lack of measurement equivalence, true differences in prevalence, and limited validity or precision of diagnostic criteria. One central question is whether, through inadvertent "over-specification" of disorders, the post-DSM-III nosology has missed related but somewhat different presentations of the same disorder because they do not exactly fit specified criteria sets. This review canvases the mental health literature for evidence of cross-cultural limitations in DSM-IV-TR anxiety disorder criteria.

METHODS

Searches were conducted of the mental health literature, particularly since 1994, regarding cultural or race/ethnicity-related factors that might limit the universal applicability of the diagnostic criteria for six anxiety disorders.

RESULTS

Possible mismatches between the DSM criteria and the local phenomenology of the disorder in specific cultural contexts were found for three anxiety disorders in particular. These involve the unexpectedness and 10-minute crescendo criteria in Panic Disorder; the definition of social anxiety and social reference group in Social Anxiety Disorder; and the priority given to psychological symptoms of worry in Generalized Anxiety Disorder. Limited evidence was found throughout, particularly in terms of neurobiological markers, genetic risk factors, treatment response, and other DSM-V validators that could help clarify the cross-cultural applicability of criteria.

CONCLUSIONS

On the basis of the available data, options and preliminary recommendations for DSM-V are put forth that should be further evaluated and tested.