Childhood separation anxiety disorder and adult onset panic attacks share a common genetic diathesis

Genome-wide meta-analysis, functional genomics and integrative analyses implicate new risk genes and therapeutic targets for anxiety disorders

Anxiety disorders are the most prevalent mental disorders. However, the genetic etiology of anxiety disorders remains largely unknown. Here we conducted a genome-wide meta-analysis on anxiety disorders by including 74,973 (28,392 proxy) cases and 400,243 (146,771 proxy) controls. We identified 14 risk loci, including 10 new associations near CNTNAP5, MAP2, RAB9BP1, BTN1A1, PRR16, PCLO, PTPRD, FARP1, CDH2 and RAB27B. Functional genomics and fine-mapping pinpointed the potential causal variants, and expression quantitative trait loci analysis revealed the potential target genes regulated by the risk variants. Integrative analyses, including transcriptome-wide association study, proteome-wide association study and colocalization analyses, prioritized potential causal genes (including CTNND1 and RAB27B). Evidence from multiple analyses revealed possibly causal genes, including RAB27B, BTN3A2, PCLO and CTNND1. Finally, we showed that Ctnnd1 knockdown affected dendritic spine density and resulted in anxiety-like behaviours in mice, revealing the potential role of CTNND1 in anxiety disorders. Our study identified new risk loci, potential causal variants and genes for anxiety disorders, providing insights into the genetic architecture of anxiety disorders and potential therapeutic targets.

Heart rate variability: Evaluating a potential biomarker of anxiety disorders

Establishing quantifiable biological markers associated with anxiety will increase the objectivity of phenotyping and enhance genetic research of anxiety disorders. Heart rate variability (HRV) is a physiological measure reflecting the dynamic relationship between the sympathetic and parasympathetic nervous systems, and is a promising target for further investigation. This review summarizes evidence evaluating HRV as a potential physiological biomarker of anxiety disorders by highlighting literature related to anxiety and HRV combined with investigations of endophenotypes, neuroimaging, treatment response, and genetics. Deficient HRV shows promise as an endophenotype of pathological anxiety and may serve as a noninvasive index of prefrontal cortical control over the amygdala, and potentially aid with treatment outcome prediction. We propose that the genetics of HRV can be used to enhance the understanding of the genetics of pathological anxiety for etiological investigations and treatment prediction. Given the anxiety-HRV link, strategies are offered to advance genetic analytical approaches, including the use of polygenic methods, wearable devices, and pharmacogenetic study designs. Overall, HRV shows promising support as a physiological biomarker of pathological anxiety, potentially in a transdiagnostic manner, with the heart-brain entwinement providing a novel approach to advance anxiety treatment development.

The relationship of separation anxiety with the age of onset of panic disorder

AIM

This study aimed to investigate whether separation anxiety (SA) constitutes a dimension related to age at onset of panic disorder (PD), in homogeneous subgroups of outpatients with PD, based on their age of onset and symptom severity.

METHODS

A sample of 232 outpatients with PD was assessed with the Panic Disorder Severity Scale (PDSS) and the Sheehan Disability Scale (SDS) for functional impairments. Separation anxiety was evaluated using structured interviews and questionnaires. We applied a K-Means Cluster Analysis based on the standardized "PD age of onset" and "the PDSS total score" to identify distinct but homogeneous groups.

RESULTS

We identified three groups of patients: group 1 ("PD early onset/severe", N = 97, 42%, onset 23.2 ± 6.7 years), group 2 ("PD early onset/not severe", N = 76, 33%, onset 23.4 ± 6.0 years) and group 3 ("PD adult onset/not severe", N = 59, 25%, onset 42.8 ± 7.0 years). Patients with early onset/severe PD had significantly higher scores on all SA measures than PD late-onset/not severe. Regression analyses showed that SA scores, but not PDSS scores, were predictive of impairment in SDS work/school, social life, and family functioning domains.

CONCLUSIONS

Our data indicate a significant relationship between SA and PD with an earlier age of onset and an impact on individual functioning. This may have important implications for implementing preventive interventions targeting early risk factors for the subsequent onset of PD.

The cognitive anxiety sensitivity treatment (CAST) in anxiety prevention - Focus on separation anxiety and interoception

Given the high prevalence and considerable clinical and societal burden of anxiety disorders, preventive measures are urgently warranted to reduce their incidence and overall healthcare impact. Anxiety sensitivity (AS) - a key element in learning theories of anxiety disorders in the context of interoceptive conditioning - constitutes a malleable risk factor of particularly panic disorder and separation anxiety, which share developmental, nosological, epidemiological and pathomechanistic characteristics. The computer-assisted 'Cognitive Anxiety Sensitivity Treatment' (CAST) targeting interoceptive anxiety symptoms (cf. Schmidt et al., 2014) was translated, intensified and culturally adapted to German and evaluated in a sample of 105 healthy adult volunteers with elevated AS (mean ASI-3: 29.5) applying a randomized design. Success of the intervention was measured as a function of AS and separation anxiety (ASA-27) ∼6 weeks (T1) and ∼6 months (T2) after the intervention. As compared to waitlist, CAST resulted in a significant reduction of AS at both T1 and T2. Separation anxiety was not directly reduced by the intervention, but decreased mediated by a decline in AS. A composite interoceptive score capturing changes in sensitivity to respiratory symptoms during the baseline therapist-accompanied CAST session was shown to be predictive of overall response at T1. In sum, CAST-German Version was successfully established as an effective intervention reducing AS, while at the same time indirectly decreasing separation anxiety. A composite interoceptive score predicting treatment response might aid in further delineating risk markers informing targeted preventive interventions for anxiety disorders.

Separation Anxiety Disorder in Panic Disorder Patients with and without Comorbid Agoraphobia

Objective: Previous studies have focused on the relationship between childhood separation anxiety disorder (SAD) and adult panic disorder (PD)-agoraphobia. It is not clear enough whether SAD, which continues into adulthood, is associated with PD with and without comorbid agoraphobia in adult patients. Our primary hypothesis was that PD patients with comorbid agoraphobia had a higher rate of SAD that continues into adulthood than those without agoraphobia. We also hypothesized that adulthood SAD symptoms were more likely to be associated with PD-agoraphobia than PD without agoraphobia.Method: 151 patients who were diagnosed with PD with (n = 106), and without comorbid agoraphobia (n = 45) were compared using Panic and Agoraphobia Scale, Structured Clinical Interview for Separation Anxiety Symptoms, Separation Anxiety Symptom Inventory, Adult Separation Anxiety Questionnaire, and State-Trait Anxiety Inventory. We performed Student's t-test, Pearson correlation test, and multiple linear regression analysis in this study.Results: PD patients with comorbid agoraphobia were more likely to have SAD both in childhood and adulthood (p = .028), than those without agoraphobia. There were mild to moderate significant correlations between PD severity and state anxiety (p = .002), trait anxiety (p = .006), and SAD in childhood (p = .049), and in adulthood (p = .001). SAD in adulthood (β = 0.278, Exp(B) = 0.136, p = .003), and state anxiety (β = 0.236, Exp(B) = 0.164, p = .012) significantly predicted the severity of PD in patients with comorbid agoraphobia.Conclusion: SAD that continues in adulthood may be related to the severity of PD in patients with agoraphobia. Our findings might provide some evidence of the role of SAD in adulthood in patients with adult-onset PD-agoraphobia.

[Separation anxiety disorder]

In the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) separation anxiety disorder has been included in the chapter on anxiety disorders, thereby removing the age of onset restriction that previously required first onset during childhood or adolescence. Separation anxiety disorder has a lifetime prevalence of 4.8% and onset often occurs after the age of 18 years. Despite the high prevalence, separation anxiety disorder is often underdiagnosed and subsequently remains untreated. This narrative review summarizes the etiology, clinical features, diagnostic criteria as well as important differential diagnostic aspects, common comorbidity profiles and treatment implications of separation anxiety disorder. Furthermore, relevant implications for everyday practice and future perspectives for treatment and research are discussed.

A major role for common genetic variation in anxiety disorders

Anxiety disorders are common, complex psychiatric disorders with twin heritabilities of 30-60%. We conducted a genome-wide association study of Lifetime Anxiety Disorder (n_case = 25 453, n_control = 58 113) and an additional analysis of Current Anxiety Symptoms (n_case = 19 012, n_control = 58 113). The liability scale common variant heritability estimate for Lifetime Anxiety Disorder was 26%, and for Current Anxiety Symptoms was 31%. Five novel genome-wide significant loci were identified including an intergenic region on chromosome 9 that has previously been associated with neuroticism, and a locus overlapping the BDNF receptor gene, NTRK2. Anxiety showed significant positive genetic correlations with depression and insomnia as well as coronary artery disease, mirroring findings from epidemiological studies. We conclude that common genetic variation accounts for a substantive proportion of the genetic architecture underlying anxiety.

Separation anxiety in PTSD: A pilot study of mechanisms in patients undergoing IPT

INTRODUCTION

Separation anxiety disorder (SAD) comprises one aspect of attachment dysregulation or insecurity. Although SAD aggravates posttraumatic stress disorder (PTSD) risk, no clinical research has tracked how many patients with PTSD have SAD, its clinical associations, or its response to PTSD treatment. Our open trial of interpersonal psychotherapy (IPT) for veterans with PTSD assessed these SAD domains.

METHODS

Twenty-nine veterans diagnosed with chronic PTSD on the Clinician-Administered PTSD Scale were assessed for SAD using the Structured Clinical Interview for Separation Anxiety Symptoms (SCI-SAS), and for Symptom-Specific Reflective Function (SSRF), another dysregulated-attachment marker capturing patients' emotional understanding of their symptoms. Patients received 14 IPT sessions for PTSD with assessments at baseline, Week 4 (SCI-SAS and SSRF), and termination for SAD, PTSD, and depression.

RESULTS

At baseline, 69% of patients met SAD criteria. Separation anxiety did not correlate with baseline PTSD severity, depressive severity, or age when traumatized; patients with and without SAD had comparable PTSD and depression severity. Patients with baseline comorbid SAD who completed IPT (N = 17) reported significantly improved adult separation anxiety (p = .009). Adult SAD improvements predicted depressive improvement (p = .049). Patients with SAD showed a stronger relationship between early SSRF gains and subsequent adult SAD improvement (p = .021) compared with patients without SAD.

DISCUSSION

This first exploration of dysregulated/insecure attachment features among patients with PTSD found high SAD comorbidity and adult SAD improvement among patients with SAD following IPT. Highly impaired attachment patients normalized attachment posttreatment: 14-session IPT improved attachment dysregulation. This small study requires replication but begins to broaden clinical understanding of separation anxiety, attachment dysregulation, and PTSD.

A neurobiological framework of separation anxiety and related phenotypes

In the DSM-5, separation anxiety disorder (SAD) is newly classified in the chapter on anxiety, renewing research efforts into its etiology. In this narrative review, we summarize the current literature on the genetic, endocrine, physiological, neural and neuropsychological underpinnings of SAD per se, SAD in the context of panic disorder, separation anxiety symptoms, and related intermediate phenotypes. SAD aggregates in families and has a heritability of ~43%. Variants in the oxytocin receptor, serotonin transporter, opioid receptor µ1, dopamine D4 receptor and translocator protein genes have all been associated with SAD. Dysregulation of the hypothalamus-pituitary-adrenal axis, dysfunctional cortico-limbic interaction and biased cognitive processing seem to constitute further neurobiological markers of separation anxiety. Hypersensitivity to carbon dioxide appears to be an endophenotype shared by SAD, panic disorder and anxiety sensitivity. The identification of biological risk markers and its multi-level integration hold great promise regarding the prediction of SAD risk, maintenance and course, and in the future may allow for the selection of indicated preventive and innovative, personalized therapeutic interventions.

Do Youth with Separation Anxiety Disorder Differ in Anxiety Sensitivity From Youth with Other Anxiety Disorders?

Studies on the relationship between separation anxiety disorder (SAD) in childhood and panic disorder (PD) in adolescence and adulthood have yielded results which suggest a common underlying vulnerability for both disorders. In this study, we examined whether one such possible vulnerability-anxiety sensitivity-differed for youth diagnosed with SAD versus other anxiety disorders. Anxiety sensitivity was assessed using the Childhood Anxiety Sensitivity Index (CASI) in 315 clinic-referred youth (ages 6-17, 113 girls). 145 children (46%) were diagnosed with one or more primary anxiety disorder, including SAD (n = 22), generalized anxiety (GAD) (n = 79), social anxiety (SocA) (n = 55), and specific phobia (SP) (n = 45). Children with SAD reported higher levels of anxiety sensitivity and fears of physical symptoms than children with SP and SocA, but not children with GAD. We speculate that children who have SAD and GAD and high anxiety sensitivity may be more vulnerable to develop PD.

Interaction between the Opioid Receptor OPRM1 Gene and Mother-Child Language Style Matching Prospectively Predicts Children's Separation Anxiety Disorder Symptoms

Recent research suggests that lower mother-child language style matching (LSM) is associated with greater physiological reactivity and insecure attachment in school-aged children, but to date no studies have explored this measure of parent-child behavioral matching for its association with children's anxiety symptoms, a well-known correlate of attachment insecurity and heightened physiological reactivity. There is also considerable evidence of genetic risk for anxiety, including possession of the OPRM1 minor allele, 118G. In the current study (N = 44), we expand upon what is known about children's genetic and environmental risk for anxiety by examining the unique and interactive effects of mother-child LSM and the OPRM1 polymorphism A118G on school-aged children's separation anxiety disorder (SAD) symptoms. SAD symptoms were measured both concurrently with LSM and OPRM1 genotype and two years later through self-report. No significant associations emerged between LSM or OPRM1 and concurrent Time 1 SAD symptoms. However, lower LSM and 118G minor allele possession were both associated with greater SAD symptoms at Time 2; further, the interaction between LSM and OPRM1 genotype significantly predicted SAD symptoms beyond the main effects of the two variables. Possession of the minor allele was only associated with greater SAD symptoms among children in low LSM dyads, whereas children with the minor allele in high LSM dyads showed non-significantly lower SAD symptoms. These findings and a proportion affected analysis provide support for a differential susceptibility model of gene by environment interactions for the OPRM1 gene. We discuss the implications for predicting children's separation anxiety across development.

Daily maternal separations during stress hyporesponsive period decrease the thresholds of panic-like behaviors to electrical stimulation of the dorsal periaqueductal gray of the adult rat

The present study examined whether early life maternal separation (MS), a model of childhood separation anxiety, predisposes to panic at adulthood. For this purpose, male pups were submitted to 3-h daily maternal separations along postnatal (PN) days of either the 'stress hyporesponsive period' (SHRP) from PN4 to PN14 (MS11) or throughout lactation from PN2 to PN21 (MS20). Pups were further reunited to conscious (CM) or anesthetized (AM) mothers to assess the effect of mother-pup interaction upon reunion. Controls were subjected to brief handling (15 s) once a day throughout lactation (BH20). As adults (PN60), rats were tested for the thresholds to evoke panic-like behaviors upon electrical stimulation of dorsal periaqueductal gray matter and exposed to an elevated plus-maze, an open-field, a forced swim and a sucrose preference test. A factor analysis was also performed to gain insight into the meaning of behavioral tests. MS11-CM rather than MS20-CM rats showed enhanced panic responses and reductions in both swimming and sucrose preference. Panic facilitations were less intense in mother-neglected rats. Although MS did not affect anxiety, MS11-AM showed robust reductions of defecation in an open-field. Factor analysis singled out anxiety, hedonia, exploration, coping and gut activity. Although sucrose preference and coping loaded on separate factors, appetite (adult weight) correlated with active coping in both forced swim and open-field (central area exploration). Concluding, whereas 3h-daily maternal separations during SHRP increased rat's susceptibility to experimental panic attacks, separations throughout lactation had no effects on panic and enhanced active coping.

Anxiety disorders in children and adolescents: aetiology, diagnosis and treatment

The presentation of anxiety disorders in children and adolescents shares similarities and differences with that in adults, and may vary significantly, depending on the age of the individual. Assessment must differentiate anxiety disorders from developmentally appropriate fears as well as medical conditions and drugs that can mimic anxiety states. Aetiology of anxiety disorders in this group encompasses complex genetic and environmental influences. Additional insight into causation is provided by neuroimaging and research into temperament. Recommended interventions include both cognitive-behavioural therapy and pharmacology. Although childhood anxiety disorders generally remit, there remains an increased risk for anxiety and depressive disorders to emerge in adulthood, most likely through heterotypical continuity.

Early childhood trajectories of separation anxiety: Bearing on mental health, academic achievement, and physical health from mid-childhood to preadolescence

BACKGROUND

Separation anxiety disorder is the most prevalent childhood anxiety condition, but no study assessed children for separation anxiety at preschool age and followed them longitudinally and directly until mid-childhood/early adolescence.

METHODS

Multi-informant (children, teachers, family), multipoint (at age 8, 10, 12, 13) assessments of 1,290 children of the Quebec Longitudinal Study of Child Development, who had been categorized between age 1.5 and 6 into four specific separation anxiety trajectories (1, low-persistent; 2, low-increasing; 3, high-decreasing, and the less common: 4, high-increasing) by growth mixture modeling. Participants in the high-increasing trajectory were compared to participants in the other three trajectories for: (a) child's internalizing and externalizing problem behavior; (b) physical health; (c) academic achievement; (d) maternal anxiety.

RESULTS

Multivariate analyses of variance/covariance at separate time points showed the high-increasing trajectory mostly associated with: (a) higher internalizing, but not externalizing, behavior; (b) worse academic achievement (most consistently by comparisons to the normative low-persistent trajectory; (c) higher rates of maternal panic/agoraphobic anxiety; (d) worse physical health (most consistently by comparisons to the low-persistent trajectory). The high-increasing trajectory had twofold to threefold higher incidences of physical illnesses than the normative low-persistent group; this was specific for headaches at age 12 years, chronic asthma at age 10 and 13, and having received asthma-related medication during the past 12 months.

CONCLUSIONS

High-increasing separation anxiety in preschool maintains longitudinal relationships to independent health and academic outcomes, at least until preadolescence. This knowledge can inform the deployment of clinical resources at the earlier signs of the more impairing manifestations.

A hierarchical causal taxonomy of psychopathology across the life span

We propose a taxonomy of psychopathology based on patterns of shared causal influences identified in a review of multivariate behavior genetic studies that distinguish genetic and environmental influences that are either common to multiple dimensions of psychopathology or unique to each dimension. At the phenotypic level, first-order dimensions are defined by correlations among symptoms; correlations among first-order dimensions similarly define higher-order domains (e.g., internalizing or externalizing psychopathology). We hypothesize that the robust phenotypic correlations among first-order dimensions reflect a hierarchy of increasingly specific etiologic influences. Some nonspecific etiologic factors increase risk for all first-order dimensions of psychopathology to varying degrees through a general factor of psychopathology. Other nonspecific etiologic factors increase risk only for all first-order dimensions within a more specific higher-order domain. Furthermore, each first-order dimension has its own unique causal influences. Genetic and environmental influences common to family members tend to be nonspecific, whereas environmental influences unique to each individual are more dimension-specific. We posit that these causal influences on psychopathology are moderated by sex and developmental processes. This causal taxonomy also provides a novel framework for understanding the heterogeneity of each first-order dimension: Different persons exhibiting similar symptoms may be influenced by different combinations of etiologic influences from each of the 3 levels of the etiologic hierarchy. Furthermore, we relate the proposed causal taxonomy to transdimensional psychobiological processes, which also impact the heterogeneity of each psychopathology dimension. This causal taxonomy implies the need for changes in strategies for studying the etiology, psychobiology, prevention, and treatment of psychopathology. (PsycINFO Database Record

The separation of adult separation anxiety disorder

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) categorization of mental disorders places "separation anxiety disorder" within the broad group of anxiety disorders, and its diagnosis no longer rests on establishing an onset during childhood or adolescence. In previous editions of DSM, it was included within the disorders usually first diagnosed in infancy, childhood, or adolescence, with the requirement for an onset of symptoms before the age of 18 years: symptomatic adults could only receive a retrospective diagnosis, based on establishing this early onset. The new position of separation anxiety disorder is based upon the findings of epidemiological studies that revealed the unexpectedly high prevalence of the condition in adults, often in individuals with an onset of symptoms after the teenage years; its prominent place within the DSM-5 group of anxiety disorders should encourage further research into its epidemiology, etiology, and treatment. This review examines the clinical features and boundaries of the condition, and offers guidance on how it can be distinguished from other anxiety disorders and other mental disorders in which "separation anxiety" may be apparent.

Separation anxiety: at the neurobiological crossroads of adaptation and illness

Physiological and adaptive separation anxiety (SA) is intimately connected with the evolutionary emergence of new brain structures specific of paleomammalians, the growth of neomammalian—and later hominid—brain and skull size, and the appearance of bipedalism. All these evolutionary milestones have contributed to expanding the behavioral repertoire and plasticity of prehuman and human beings, at the cost of more prolonged dependency of the infant and of the child on parental care. Separation anxiety disorder (SAD) can be seen as an exaggerated/inappropriate manifestation of SA that constitutes a gateway to poorer mental and physical health. By blending epidemiological, genetic-epidemiological, endophenotypic, and animal laboratory approaches, it is possible to delineate some of the mechanisms that link childhood-adolescence SA and SAD to health problems later in life. Causal mechanisms include gene-environment interplays and likely differential regulation of genes and functional net-works that simultaneously affect multiple behavioral and physical phenotypes after exposure to early-life adversity, including parental separation/loss.

Aetiological influences on stability and change in emotional and behavioural problems across development: a systematic review

Emotional and behavioural problems in childhood and adolescence can be chronic and are predictive of future psychiatric problems. Understanding what factors drive the development and maintenance of these problems is therefore crucial. Longitudinal behavioural genetic studies using twin, sibling or adoption data can be used to explore the developmental aetiology of stability and change in childhood and adolescent psychopathology. We present a systematic review of longitudinal, behavioural genetic analyses of emotional and behavioural problems between ages 0 to 18 years. We identified 58 studies, of which 19 examined emotional problems, 30 examined behavioural problems, and 9 examined both. In the majority of studies, stability in emotional and behavioural problems was primarily genetically influenced. Stable environmental factors were also widely found, although these typically played a smaller role. Both genetic and environmental factors were involved in change across development. We discuss the findings in the context of the wider developmental literature and make recommendations for future research.

Headache symptoms consistent with migraine and tension-type headaches in children with anxiety disorders

OBJECTIVE

To examine the incidence of headache symptoms consistent with migraine and tension-type headache (TTH) in children with anxiety disorders.

METHOD

Parents of children with anxiety disorders (n=27) and children without anxiety disorders (n=36) completed a headache questionnaire based on the International Classification of Headache Disorders (2nd edition) criteria.

RESULTS

Children with anxiety disorders had a higher incidence of headache symptoms consistent with migraine and TTH compared to children without anxiety disorders. Girls with anxiety disorders and children with separation anxiety disorder had a higher incidence of headaches compared to girls without anxiety disorders and children with other anxiety disorders respectively. Children with anxiety disorders and headaches had higher self-reported anxiety symptom severity compared to children with anxiety disorders without headaches and children without anxiety disorders.

CONCLUSION

Findings highlight an overlap in anxiety and headaches in children and warrant further research on factors that contribute to the etiology and maintenance of these co-occurring problems.

Adult separation anxiety in treatment nonresponders with anxiety disorders: delineation of the syndrome and exploration of attachment-based psychotherapy and biomarkers

Clinically significant separation anxiety [SA] has been identified as being common among patients who do not respond to psychiatric interventions, regardless of intervention type (pharmacological or psychotherapeutic), across anxiety and mood disorders. An attachment formation and maintenance domain has been proposed as contributing to anxiety disorders. We therefore directly determined prevalence of SA in a population of adult treatment non-responders suffering from primary anxiety. In these separation anxious nonresponders, we pilot-tested an SA-focused, attachment-based psychotherapy for anxiety, Panic-Focused Psychodynamic Psychotherapy-eXtended Range [PFPP-XR], and assessed whether hypothesized biomarkers of attachment were engaged. We studied separation anxiety [SA] in 46 adults (ages 23-70 [mean 43.9 (14.9)]) with clinically significant anxiety symptoms (Hamilton Anxiety Rating Scale [HARS]≥15), and reporting a history of past non-response to psychotherapy and/or medication treatments. Thirty-seven (80%) had clinically significant symptoms of separation anxiety (Structured Clinical Interview for Separation Anxiety Symptoms [SCI-SAS] score≥8). Five of these subjects completed an open clinical trial of Panic Focused Psychodynamic Psychotherapy eXtended Range [PFPP-XR], a 21-24 session, 12-week manualized attachment-focused anxiolytic psychodynamic psychotherapy for anxiety. Patients improved on "adult threshold" SCI-SAS (current separation anxiety) (p=.016), HARS (p=0.002), and global severity, assessed by the Clinical Global Impression Scale (p=.0006), at treatment termination. Salivary oxytocin levels decreased 67% after treatment (p=.12). There was no significant change in high or low frequency HRV after treatment, but change in high frequency HRV inversely correlated with treatment change in oxytocin (p<.02), and change in low frequency HRV was positively associated with change in oxytocin (p<.02). SA is surprisingly prevalent among non-responders to standard anti-anxiety treatments, and it may represent a novel transdiagnostic target for treatment intervention in this population. Anxiety and global function improved in a small trial of a brief, manualized, attachment-focused psychodynamic psychotherapy, potentially supporting the clinical relevance of attachment dysfunction in this sample. The large decrease in oxytocin levels with treatment, although not statistically significant in this very small sample, suggests the need for further study of oxytocin as a putative biomarker or mediator of SA response. These pilot data generate testable hypotheses supporting an attachment domain underlying treatment-resistant anxiety, and new treatment strategies.

Comorbidity variation in patients with obsessive-compulsive disorder according to symptom dimensions: Results from a large multicentre clinical sample

BACKGROUND

Obsessive-compulsive disorder (OCD) has a heterogeneous and complex phenomenological picture, characterized by different symptom dimensions and comorbid psychiatric disorders, which frequently co-occur or are replaced by others over the illness course. To date, very few studies have investigated the associations between specific OCD symptom dimensions and comorbid disorders.

METHODS

Cross-sectional, multicenter clinical study with 1001 well-characterized OCD patients recruited within the Brazilian Research Consortium on Obsessive-Compulsive and Related Disorders. The primary instruments were the Dimensional Yale-Brown Obsessive Compulsive Scale (DY-BOCS) and the Structured Clinical Interview for DSM-IV Axis I Disorders. Bivariate analyses between symptom dimensions and comorbidities were followed by logistic regression.

RESULTS

The most common comorbidities among participants (56.8% females) were major depression (56.4%), social phobia (34.6%), generalized anxiety disorder (34.3%), and specific phobia (31.4%). The aggressive dimension was independently associated with posttraumatic stress disorder (PTSD), separation anxiety disorder, any impulse-control disorder and skin picking; the sexual-religious dimension was associated with mood disorders, panic disorder/agoraphobia, social phobia, separation anxiety disorder, non-paraphilic sexual disorder, any somatoform disorder, body dysmorphic disorder and tic disorders; the contamination-cleaning dimension was related to hypochondriasis; and the hoarding dimension was associated with depressive disorders, specific phobia, PTSD, impulse control disorders (compulsive buying, skin picking, internet use), ADHD and tic disorders. The symmetry-ordering dimension was not independently associated with any comorbidity.

LIMITATIONS

Cross-sectional design; participants from only tertiary mental health services; personality disorders not investigated.

CONCLUSIONS

Different OCD dimensions presented some specific associations with comorbid disorders, which may influence treatment seeking behaviors and response, and be suggestive of different underlying pathogenic mechanisms.

The Genetics of Stress-Related Disorders: PTSD, Depression, and Anxiety Disorders

Research into the causes of psychopathology has largely focused on two broad etiologic factors: genetic vulnerability and environmental stressors. An important role for familial/heritable factors in the etiology of a broad range of psychiatric disorders was established well before the modern era of genomic research. This review focuses on the genetic basis of three disorder categories-posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and the anxiety disorders-for which environmental stressors and stress responses are understood to be central to pathogenesis. Each of these disorders aggregates in families and is moderately heritable. More recently, molecular genetic approaches, including genome-wide studies of genetic variation, have been applied to identify specific risk variants. In this review, I summarize evidence for genetic contributions to PTSD, MDD, and the anxiety disorders including genetic epidemiology, the role of common genetic variation, the role of rare and structural variation, and the role of gene-environment interaction. Available data suggest that stress-related disorders are highly complex and polygenic and, despite substantial progress in other areas of psychiatric genetics, few risk loci have been identified for these disorders. Progress in this area will likely require analysis of much larger sample sizes than have been reported to date. The phenotypic complexity and genetic overlap among these disorders present further challenges. The review concludes with a discussion of prospects for clinical translation of genetic findings and future directions for research.

The stability and change of etiological influences on depression, anxiety symptoms and their co-occurrence across adolescence and young adulthood

BACKGROUND

Depression and anxiety persist within and across diagnostic boundaries. The manner in which common v. disorder-specific genetic and environmental influences operate across development to maintain internalizing disorders and their co-morbidity is unclear. This paper investigates the stability and change of etiological influences on depression, panic, generalized, separation and social anxiety symptoms, and their co-occurrence, across adolescence and young adulthood.

METHOD

A total of 2619 twins/siblings prospectively reported symptoms of depression and anxiety at mean ages 15, 17 and 20 years.

RESULTS

Each symptom scale showed a similar pattern of moderate continuity across development, largely underpinned by genetic stability. New genetic influences contributing to change in the developmental course of the symptoms emerged at each time point. All symptom scales correlated moderately with one another over time. Genetic influences, both stable and time-specific, overlapped considerably between the scales. Non-shared environmental influences were largely time- and symptom-specific, but some contributed moderately to the stability of depression and anxiety symptom scales. These stable, longitudinal environmental influences were highly correlated between the symptoms.

CONCLUSIONS

The results highlight both stable and dynamic etiology of depression and anxiety symptom scales. They provide preliminary evidence that stable as well as newly emerging genes contribute to the co-morbidity between depression and anxiety across adolescence and young adulthood. Conversely, environmental influences are largely time-specific and contribute to change in symptoms over time. The results inform molecular genetics research and transdiagnostic treatment and prevention approaches.

Translational approach to studying panic disorder in rats: hits and misses

Panic disorder (PD) patients are specifically sensitive to 5–7% carbon dioxide. Another startling feature of clinical panic is the counterintuitive lack of increments in ‘stress hormones’. PD is also more frequent in women and highly comorbid with childhood separation anxiety (CSA). On the other hand, increasing evidence suggests that panic is mediated at dorsal periaqueductal grey matter (DPAG). In line with prior studies showing that DPAG-evoked panic-like behaviours are attenuated by clinically-effective treatments with panicolytics, we show here that (i) the DPAG harbors a hypoxia-sensitive alarm system, which is activated by hypoxia and potentiated by hypercapnia, (ii) the DPAG suffocation alarm system is inhibited by clinically-effective treatments with panicolytics, (iii) DPAG stimulations do not increase stress hormones in the absence of physical exertion, (iv) DPAG-evoked panic-like behaviours are facilitated in neonatally-isolated adult rats, a model of CSA, and (v) DPAG-evoked responses are enhanced in the late diestrus of female rats. Data are consistent with the DPAG mediation of both respiratory and non-respiratory types of panic attacks.

Pediatric-Onset and Adult-Onset Separation Anxiety Disorder Across Countries in the World Mental Health Survey

OBJECTIVE

The age-at-onset criterion for separation anxiety disorder was removed in DSM-5, making it timely to examine the epidemiology of separation anxiety disorder as a disorder with onsets spanning the life course, using cross-country data.

METHOD

The sample included 38,993 adults in 18 countries in the World Health Organization (WHO) World Mental Health Surveys. The WHO Composite International Diagnostic Interview was used to assess a range of DSM-IV disorders that included an expanded definition of separation anxiety disorder allowing onsets in adulthood. Analyses focused on prevalence, age at onset, comorbidity, predictors of onset and persistence, and separation anxiety-related role impairment.

RESULTS

Lifetime separation anxiety disorder prevalence averaged 4.8% across countries (interquartile range [25th-75th percentiles]=1.4%-6.4%), with 43.1% of lifetime onsets occurring after age 18. Significant time-lagged associations were found between earlier separation anxiety disorder and subsequent onset of internalizing and externalizing DSM-IV disorders and conversely between these disorders and subsequent onset of separation anxiety disorder. Other consistently significant predictors of lifetime separation anxiety disorder included female gender, retrospectively reported childhood adversities, and lifetime traumatic events. These predictors were largely comparable for separation anxiety disorder onsets in childhood, adolescence, and adulthood and across country income groups. Twelve-month separation anxiety disorder prevalence was considerably lower than lifetime prevalence (1.0% of the total sample; interquartile range=0.2%-1.2%). Severe separation anxiety-related 12-month role impairment was significantly more common in the presence (42.4%) than absence (18.3%) of 12-month comorbidity.

CONCLUSIONS

Separation anxiety disorder is a common and highly comorbid disorder that can have onset across the lifespan. Childhood adversity and lifetime trauma are important antecedents, and adverse effects on role function make it a significant target for treatment.

Homesickness: A Systematic Review of the Scientific Literature

Large-scale migration in contemporary society underscores the need to learn about the complex experience of leaving home and relocating within or beyond one's own country. Separate consideration of various types of stressors associated with geographic moves is called for, because these are likely to be associated with different (but mutually exacerbating) correlates and consequences, perhaps leading to comorbidity. Homesickness (HS) is a frequent component of relocation, known to be related to certain adjustment difficulties and health problems, as well as clinical disorders. However, an up-to-date, comprehensive overview of scientific investigations of HS is lacking. Therefore, this article systematically reviews empirical research on HS, focusing on temporary sojourns from home. Fifty-five articles that conformed to adequate design and methodological criteria were identified in the literature. These studies reveal indicative patterns of findings relating to the prevalence, consequences, predictors, and prevention/treatment strategies for HS. Gaps in knowledge about phenomena and manifestations associated with HS are also discussed. Importantly, it is demonstrated that the inclusion of stressors in the new place when assessing HS limits understanding. We suggest theory-guided directions for future research.

Separation anxiety disorder across the lifespan: DSM-5 lifts age restriction on diagnosis

DSM-5 has lifted the age criterion in the definition of separation anxiety disorder thereby overturning the long-standing convention of restricting the diagnosis to childhood. Previously, adults with separation anxiety symptoms were assigned to other conventional categories such as panic disorder, agoraphobia or generalized anxiety disorder. Over the past two decades, an evolving body of research has identified separation anxiety disorder in adulthood, with 20-40% of adult psychiatric outpatients being assigned that diagnosis. In the US, the lifetime prevalence of the disorder in adulthood is 6.6%. The removal of the age restriction on diagnosis has important implications for clinical practice. Whereas parents (particularly mothers) of children with separation anxiety disorder commonly attracted the diagnosis of agoraphobia, the latter are more likely now to be diagnosed with the adult form of separation anxiety disorder, focusing attention on the importance of intervening with both members of the dyad to overcome mutual reinforcement of symptoms. In addition, adults with separation anxiety disorder have been found to manifest high levels of disability and they tend to show a poor response to conventional psychological and pharmacological treatments. There is an urgent need therefore to devise novel psychological and pharmacological interventions for the adult form of the disorder. The reformulation of separation anxiety disorder in DSM-5 therefore requires a paradigm shift in which clinicians are alerted to identifying and treating the condition in all age groups. Research across countries is needed to examine the new formulation of separation anxiety disorder amongst populations of diverse ethnic and cultural backgrounds.

Patterns of heterotypic continuity associated with the cross-sectional correlational structure of prevalent mental disorders in adults

IMPORTANCE

Mental disorders predict future occurrences of both the same disorder (homotypic continuity) and other disorders (heterotypic continuity). Heterotypic continuity is inconsistent with a view of mental disorders as fixed entities. In contrast, hierarchical-dimensional conceptualizations of psychopathology, in which each form of psychopathology is hypothesized to have both unique and broadly shared etiologies and mechanisms, predict both homotypic and heterotypic continuity.

OBJECTIVE

To test predictions derived from a hierarchical-dimensional model of psychopathology that (1) heterotypic continuity is widespread, even controlling for homotypic continuity, and that (2) the relative magnitudes of heterotypic continuities recapitulate the relative magnitudes of cross-sectional correlations among diagnoses at baseline.

DESIGN, SETTING, AND PARTICIPANTS

Ten prevalent diagnoses were assessed in the same person twice (ie, in 2 waves separated by 3 years). We used a representative sample of adults in the United States (i.e., 28,958 participants 18-64 years of age in the National Epidemiologic Study of Alcohol and Related Conditions who were assessed in both waves).

MAIN OUTCOMES AND MEASURES

Diagnoses from reliable and valid structured interviews.

RESULTS

Adjusting for sex and age, we found that bivariate associations of all pairs of diagnoses from wave 1 to wave 2 exceeded chance levels (P < .05) for all homotypic (median tetrachoric correlation of ρ = 0.54 [range, 0.41-0.79]) and for nearly all heterotypic continuities (median tetrachoric correlation of ρ = 0.28 [range, 0.07-0.50]). Significant heterotypic continuity was widespread even when all wave 1 diagnoses (including the same diagnosis) were simultaneous predictors of each wave 2 diagnosis. The rank correlation between age- and sex-adjusted tetrachoric correlation for cross-sectional associations among wave 1 diagnoses and for heterotypic associations from wave 1 to wave 2 diagnoses was ρ = 0.86 (P < .001).

CONCLUSIONS AND RELEVANCE

For these prevalent mental disorders, heterotypic continuity was nearly universal and not an artifact of failure to control for homotypic continuity. Furthermore, the relative magnitudes of heterotypic continuity closely mirrored the relative magnitudes of cross-sectional associations among these disorders, consistent with the hypothesis that both sets of associations reflect the same factors. Mental disorders are not fixed and independent entities. Rather, each diagnosis is robustly related to other diagnoses in a correlational structure that is manifested both concurrently and in patterns of heterotypic continuity across time.

Serotonergic genes (5-HTT and HTR1A) and separation life events: gene-by-environment interaction for panic disorder

BACKGROUND

The polymorphisms of serotonergic genes (5-HTTLPR and HTR1A rs6295) and separation life events have been studied to find an association with panic disorder, respectively. However, there are no studies that have yet evaluated the interaction effect between serotonergic genes and separation life events for panic disorder.

METHODS

For this study, 194 panic disorder patients and 172 healthy controls were included for genotyping and environmental factor analysis. Separation life events were assessed using the Stressful Life Events Scale and clinical interviews. To evaluate the potential endophenotypes of panic disorder, the Anxiety Sensitivity Index-revised (ASI-R), harm avoidance in the Temperament and Character Inventory (HA), and neuroticism in the Eysenck Personality Questionnaire (neuroticism) scales were administered.

RESULTS

For 5-HTTLPR and HTR1A rs6295, there was no significant main effect of each genotype on panic disorder alone. However, the number of separation life events and their interaction with 5-HTTLPR showed a statistically significant effect on panic disorder. In addition, the interaction between 5-HTTLPR and the number of separation life events significantly affected the HA for potential endophenotypes.

CONCLUSION

This study could suggest the effect of the interaction between 5-HTTLPR and separation life events on panic disorder and its potential endophenotype.

Separation anxiety disorder in adult patients with obsessive-compulsive disorder: prevalence and clinical correlates

OBJECTIVE

Individuals with obsessive-compulsive disorder (OCD) and separation anxiety disorder (SAD) tend to present higher morbidity than do those with OCD alone. However, the relationship between OCD and SAD has yet to be fully explored.

METHOD

This was a cross-sectional study using multiple logistic regression to identify differences between OCD patients with SAD (OCD+SAD, n=260) and without SAD (OCD, n=695), in terms of clinical and socio-demographic variables. Data were extracted from those collected between 2005 and 2009 via the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders project.

RESULTS

SAD was currently present in only 42 (4.4%) of the patients, although 260 (27.2%) had a lifetime diagnosis of the disorder. In comparison with the OCD group patients, patients with SAD+OCD showed higher chance to present sensory phenomena, to undergo psychotherapy, and to have more psychiatric comorbidities, mainly bulimia.

CONCLUSION

In patients with primary OCD, comorbid SAD might be related to greater personal dysfunction and a poorer response to treatment, since sensory phenomena may be a confounding aspect on diagnosis and therapeutics. Patients with OCD+SAD might be more prone to developing specific psychiatric comorbidities, especially bulimia. Our results suggest that SAD symptom assessment should be included in the management and prognostic evaluation of OCD, although the psychobiological role that such symptoms play in OCD merits further investigation.

Comorbidity of anxiety and depression in children and adolescents: 20 years after

Brady and Kendall (1992) concluded that although anxiety and depression in youths are meaningfully linked, there are important distinctions, and additional research is needed. Since then, studies of anxiety-depression comorbidity in youths have increased exponentially. Following a discussion of comorbidity, we review existing conceptual models and propose a multiple pathways model to anxiety-depression comorbidity. Pathway 1 describes youths with a diathesis for anxiety, with subsequent comorbid depression resulting from anxiety-related impairment. Pathway 2 refers to youths with a shared diathesis for anxiety and depression, who may experience both disorders simultaneously. Pathway 3 describes youths with a diathesis for depression, with subsequent comorbid anxiety resulting from depression-related impairment. Additionally, shared and stratified risk factors contribute to the development of the comorbid disorder, either by interacting with disorder-related impairment or by predicting the simultaneous development of the disorders. Our review addresses descriptive and developmental factors, gender differences, suicidality, assessments, and treatment-outcome research as they relate to comorbid anxiety and depression and to our proposed pathways. Research since 1992 indicates that comorbidity varies depending on the specific anxiety disorder, with Pathway 1 describing youths with either social phobia or separation anxiety disorder and subsequent depression, Pathway 2 applying to youths with coprimary generalized anxiety disorder and depression, and Pathway 3 including depressed youths with subsequent social phobia. The need to test the proposed multiple pathways model and to examine (a) developmental change and (b) specific anxiety disorders is highlighted.

Lifelong opioidergic vulnerability through early life separation: a recent extension of the false suffocation alarm theory of panic disorder

The present paper is the edited version of our presentations at the "First World Symposium On Translational Models Of Panic Disorder", in Vitoria, E.S., Brazil, on November 16-18, 2012. We also review relevant work that appeared after the conference. Suffocation-False Alarm Theory (Klein, 1993) postulates the existence of an evolved physiologic suffocation alarm system that monitors information about potential suffocation. Panic attacks maladaptively occur when the alarm is erroneously triggered. The expanded Suffocation-False Alarm Theory (Preter and Klein, 2008) hypothesizes that endogenous opioidergic dysregulation may underlie the respiratory pathophysiology and suffocation sensitivity in panic disorder. Opioidergic dysregulation increases sensitivity to CO2, separation distress and panic attacks. That sudden loss, bereavement and childhood separation anxiety are also antecedents of "spontaneous" panic requires an integrative explanation. Our work unveiling the lifelong endogenous opioid system impairing effects of childhood parental loss (CPL) and parental separation in non-ill, normal adults opens a new experimental, investigatory area.

Panic Disorder and Agoraphobia in OCD patients: clinical profile and possible treatment implications

OBJECTIVE

Panic Disorder (PD) and agoraphobia (AG) are frequently comorbid with obsessive-compulsive disorder (OCD), but the correlates of these comorbidities in OCD are fairly unknown. The study aims were to: 1) estimate the prevalence of PD with or without AG (PD), AG without panic (AG) and PD and/or AG (PD/AG) in a large clinical sample of OCD patients and 2) compare the characteristics of individuals with and without these comorbid conditions.

METHOD

A cross-sectional study with 1001 patients of the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders using several assessment instruments, including the Dimensional Yale-Brown Obsessive-Compulsive Scale and the Structured Clinical Interview for DSM-IV-TR Axis I Disorders. Bivariate analyses were followed by logistic regression models.

RESULTS

The lifetime prevalence of PD was 15.3% (N=153), of AG 4.9% (N=49), and of PD/AG 20.2% (N=202). After logistic regression, hypochondriasis and specific phobia were common correlates of the three study groups. PD comorbidity was also associated with higher levels of anxiety, having children, major depression, bipolar I, generalized anxiety and posttraumatic stress disorders. Other independent correlates of AG were: dysthymia, bipolar II disorder, social phobia, impulsive-compulsive internet use, bulimia nervosa and binge eating disorder. Patients with PD/AG were also more likely to be married and to present high anxiety, separation anxiety disorder, major depression, impulsive-compulsive internet use, generalized anxiety, posttraumatic stress and binge eating disorders.

CONCLUSIONS

Some distinct correlates were obtained for PD and AG in OCD patients, indicating the need for more specific and tailored treatment strategies for individuals with each of these clinical profiles.

Evidence that the periaqueductal gray matter mediates the facilitation of panic-like reactions in neonatally-isolated adult rats

Plenty of evidence suggests that childhood separation anxiety (CSA) predisposes the subject to adult-onset panic disorder (PD). As well, panic is frequently comorbid with both anxiety and depression. The brain mechanisms whereby CSA predisposes to PD are but completely unknown in spite of the increasing evidence that panic attacks are mediated at midbrain's dorsal periaqueductal gray matter (DPAG). Accordingly, here we examined whether the neonatal social isolation (NSI), a model of CSA, facilitates panic-like behaviors produced by electrical stimulations of DPAG of rats as adults. Eventual changes in anxiety and depression were also assessed in the elevated plus-maze (EPM) and forced-swimming test (FST) respectively. Male pups were subjected to 3-h daily isolations from post-natal day 2 (PN2) until weaning (PN21) allotting half of litters in individual boxes inside a sound-attenuated chamber (NSI, n = 26) whilst siblings (sham-isolated rats, SHAM, n = 27) and dam were moved to another box in a separate room. Non-handled controls (CTRL, n = 18) remained undisturbed with dams until weaning. As adults, rats were implanted with electrodes into the DPAG (PN60) and subjected to sessions of intracranial stimulation (PN65), EPM (PN66) and FST (PN67-PN68). Groups were compared by Fisher's exact test (stimulation sites), likelihood ratio chi-square tests (stimulus-response threshold curves) and Bonferroni's post hoc t-tests (EPM and FST), for P<0.05. Notably, DPAG-evoked panic-like responses of immobility, exophthalmus, trotting, galloping and jumping were markedly facilitated in NSI rats relative to both SHAM and CTRL groups. Conversely, anxiety and depression scores either did not change or were even reduced in neonatally-handled groups relative to CTRL, respectively. Data are the first behavioral evidence in animals that early-life separation stress produces the selective facilitation of panic-like behaviors in adulthood. Most importantly, results implicate the DPAG not only in panic attacks but also in separation-anxious children's predispositions to the late development of PD.

Long-lasting marked inhibition of periaqueductal gray-evoked defensive behaviors in inescapably-shocked rats

Clinical evidence suggests that depression and trauma predispose the subject to panic. Accordingly, here we examined the late effects of uncontrollable stress, a presumptive model of depression and/or traumatic disorder, on panic-like behaviors evoked by electrical stimulation of the dorsal periaqueductal gray (DPAG). Changes in anxiety and depression were also assessed in the elevated plus-maze (EPM) and forced-swimming test (FST), respectively. Rats with electrodes in the DPAG were subjected to a 7-day shuttle-box one-way escape yoked training with foot-shocks either escapable (ES) or inescapable (IS). The day after the end of one-way escape training, rats were trained in a two-way escape novel task (test-session) to ascertain the effectiveness of uncontrollable stress. DPAG stimulations were carried out in an open field, both before the escape training and 2 and 7 days after it, and EPM and FST were performed on the 8th and 10th days afterwards, respectively. Controls were either trained with fictive shocks (FS) or subjected to intracranial stimulations only. Although the ES rats performed significantly better than the IS group in the two-way escape task, groups did not differ with respect to either the anxiety or depression scores. Unexpectedly, however, IS rats showed a marked attenuation of DPAG-evoked freezing and flight behaviors relative to both the ES and FS groups, 2 and 7 days after one-way escape training. The conjoint inhibition of passive (freezing) and active (flight) defensive behaviors suggests that IS inhibits a DPAG in-built motivational system that may be implicated in depressed patients' difficulties in coping with daily-life stress.

Genetic and environmental influences on relationship between anxiety sensitivity and anxiety subscales in children

Anxiety sensitivity, a belief that symptoms of anxiety are harmful, has been proposed to influence development of panic disorder. Recent research suggests it may be a vulnerability factor for many anxiety subtypes. Moderate genetic influences have been implicated for both anxiety sensitivity and anxiety, however, little is known about the aetiology of the relationship between these traits in children. Self-reports of anxiety sensitivity and anxiety symptoms were collected from approximately 300 twin pairs at two time points. Partial correlations indicated that anxiety sensitivity at age 8 was broadly associated with most anxiety subtypes at age 10 (r=0.11-0.17, p<0.05). The associations were largely unidirectional, underpinned by stable genetic influences. Non-shared environment had unique influences on variables. Phenotypic results showed that anxiety sensitivity is a broad predictor of anxiety symptoms in childhood. Genetic results suggest that childhood is a developmental period characterised by genetic stability and time-specific environmental influences on anxiety-related traits.

Overlap of symptom domains of separation anxiety disorder in adulthood with panic disorder-agoraphobia

There is a need to explain the high level of comorbidity between separation anxiety disorder (SAD) in adulthood and panic disorder with agoraphobia (Pd-Ag). One possibility is that inadequate specification of symptom domains and/or diagnostic questions accounts for some of the comorbidity. The present anxiety clinic study examined responses of adult patients (n = 646) with SAD and/or Pd-Ag on eight symptom domains based on a previous factor analysis of a commonly used separation anxiety measure, the ASA-27, as well as on the Anxiety Sensitivity Index. We also examined questionnaire items that did not load on the factor structure. All separation anxiety domains distinguished strongly between SAD and Pd-Ag. Comparisons across three groups (SAD alone, Pd-Ag alone and comorbid SAD/Pd-Ag) revealed that two symptom domains (anxiety about embarking on trips, and sleep disturbances) showed some overlap between Pd-Ag and SAD. Two of the items of the ASA-27 that did not load with other items in the factor analysis also showed overlap with Pd-Ag, with both referring to anxieties about leaving home. Patients with SAD (with or without Pd-Ag) returned higher scores on anxiety sensitivity than those with Pd-Ag alone. The findings support the distinctiveness of the construct of SAD and the capacity of the ASA-27 to discriminate between that disorder and Pd-Ag. SAD appears to be a more severe form of anxiety than Pd-Ag. There may be a need to refine items to include the reasons for avoiding leaving home, reluctance to sleep alone and to embark on trips, to ensure accurate discrimination between Pd-Ag and SAD in adulthood.

Bringing a developmental perspective to anxiety genetics

Despite substantial recent advancements in psychiatric genetic research, progress in identifying the genetic basis of anxiety disorders has been limited. We review the candidate gene and genome-wide literatures in anxiety, which have made limited progress to date. We discuss several reasons for this hindered progress, including small samples sizes, heterogeneity, complicated comorbidity profiles, and blurred lines between normative and pathological anxiety. To address many of these challenges, we suggest a developmental, multivariate framework that can inform and enhance anxiety phenotypes for genetic research. We review the psychiatric and genetic epidemiological evidence that supports such a framework, including the early onset and chronic course of anxiety disorders, shared genetic risk factors among disorders both within and across time, and developmentally dynamic genetic influences. We propose three strategies for developmentally sensitive phenotyping: examination of early temperamental risk factors, use of latent factors to model underlying anxiety liability, and use of developmental trajectories as phenotypes. Expanding the range of phenotypic approaches will be important for advancing studies of the genetic architecture of anxiety disorders.