Genetic and environmental contributions to separation anxiety: a meta-analytic approach to twin data

Adult Separation Anxiety and Childhood Traumas: The Mediating Role of Cognitive Distortions

While there are many studies on the relationship between anxiety disorders and childhood traumas in the literature, there are limited studies on the relationship between separation anxiety disorders and traumatic experiences in early life. It is widely known that trauma and negative cognitive processes are important factors in the etiology and prognosis of psychiatric disorders. In this study, it was aimed to determine the relationship between adult separation anxiety levels and childhood traumas and cognitive distortions, and to examine the mediating role of cognitive distortions in the relationship between childhood traumas and separation anxiety. A total of 366 students attending a private university were included in the study. The scales, which were converted into online questionnaires by the researchers, were sent to the students via e-mail, and were administered online. The participants were evaluated using "Adult Separation Anxiety Questionnaire", "Childhood Trauma Questionnaire", and "Cognitive Distortions Scale". The results of the study indicated that there was a positive and significant relationship between adult separation anxiety levels and childhood sexual abuse while there was no statistically significant correlation between adult separation anxiety levels and physical and emotional abuse, or physical and emotional neglect. A positive and significant relationship was found between separation anxiety levels and the sub-dimensions of cognitive distortions' self-image, self-blame, helplessness, hopelessness, and preoccupation with danger. In addition, it was determined that the helplessness and preoccupation with danger sub-dimensions of cognitive distortions had a full mediator effect on the relationship between sexual abuse and separation anxiety. Our results show that there is a positive relationship between separation anxiety disorder and childhood sexual abuse, and cognitive distortions play a mediating role between both variables.

Is adult separation anxiety associated with offspring risk for internalizing psychiatric problems?

BACKGROUND

Awareness of adult separation anxiety (ASA) is growing, but there is a dearth of knowledge about how separation anxiety aggregates in families. We examined the intergenerational associations of separation anxiety and other forms of internalizing problems in an American community sample of 515 predominantly white children and their parents.

METHODS

Children's separation anxiety (CSA), depression, and other anxiety disorders were modeled as latent factors using diagnoses from interviews and symptom scores from questionnaires completed by mothers, fathers, and children when children were 9 years old and again 3 years later. Parents' separation anxiety was assessed via a questionnaire and parents' other anxiety, depressive, and substance use disorders were assessed with a diagnostic interview when children were nine. Relationships between parents' and children's psychopathology were modeled using s.e.m.

RESULTS

Mothers' and fathers' ASA were related to all three psychopathology factors in offspring, over and above other parental disorders, in concurrent and prospective analyses. CSA was also related to maternal depression concurrently and prospectively and to maternal anxiety prospectively. Of all paternal psychopathology variables, only ASA was significantly related to children's psychopathology in either model.

CONCLUSIONS

Results indicate that parental separation anxiety is an important, but non-specific, risk factor for children's psychopathology. The pathway by which this risk is transmitted may be genetic or environmental, and the observed statistical associations likely also encompass child-to-parent effects.

Whole-exome DNA sequencing in childhood anxiety disorders identifies rare de novo damaging coding variants

BACKGROUND

Genetic factors contribute to the development of anxiety disorders, yet few risk genes have been previously identified. One genomic approach that has achieved success in identifying risk genes in related childhood neuropsychiatric conditions is investigations of de novo variants, which has yet to be leveraged in childhood anxiety disorders.

METHODS

We performed whole-exome DNA sequencing in 76 parent-child trios (68 trios after quality control) recruited from a childhood anxiety disorder clinic and compared rates of rare and ultra-rare de novo variants with 790 previously sequenced control trios (783 trios after quality control). We then explored overlap with risk genes for other neuropsychiatric conditions and enrichment in biologic pathways.

RESULTS

Rare and ultra-rare de novo likely gene disrupting and predicted damaging missense genetic variants are enriched in anxiety disorder probands compared with controls (rare variant rate ratio 1.97, 95% confidence interval [CI]: 1.11-3.34, p = .03; ultra-rare variant rate ratio 2.59, 95% CI: 1.35-4.70, p = .008). These de novo damaging variants occur in individuals with a variety of childhood anxiety disorders and impact genes that have been associated with other neuropsychiatric conditions. Exploratory network analyses reveal enrichment of deleterious variants in canonical biological pathways.

CONCLUSIONS

These findings provide a path for identifying risk genes and promising biologic pathways in childhood anxiety disorders by de novo genetic variant detection. Our results suggest the discovery potential of applying this approach in larger anxiety disorder cohorts to advance our understanding of the underlying biology of these common and debilitating conditions.

The role of genetic and environmental factors in covariation between anxiety and anger in childhood

Higher levels of anger expression, as well as lower levels of anger control, have been reported for adults with anxiety disorders compared to individuals without anxiety disorders. Different to the research on adults, very few studies examined the relationship between anxiety and anger in childhood. In our study, we investigated 398 Italian twin pairs (74 MZ male, 70 MZ female, 134 same-sex dizygotic-53 male, 81 female-, and 120 unlike-sex dizygotic twin pairs), aged 8-17 (mean 13.06 ± 2.59): (i) the heritability of a childhood anger phenotype; (ii) the association between five anxiety domains and anger; (iii) the role of possible common etiological factors in explaining the observed comorbidity and overlap in the risk between anxiety phenotypes and anger. The study demonstrated that anger, assessed by CBCL items, is heritable in children at a similar rate to prior studies (40%). Our research found low to moderate rate of correlation between anger and anxiety (from 0.10 to 0.19). Finally, the present study found that the majority of etiological influences on anxiety and anger are independent of each other. Data showed that shared environmental influences have some small effects on the phenotypic covariation between the anxiety phenotypes and anger (12%); whereas unique environmental influences have an almost negligible effect (1%). Our analyses did not reveal the effect of genetic effects in explaining the covariation between these phenotypes.

[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.

The heritability of reading and reading-related neurocognitive components: A multi-level meta-analysis

Reading ability is a complex task requiring the integration of multiple cognitive and perceptual systems supporting language, visual and orthographic processes, working memory, attention, motor movements, and higher-level comprehension and cognition. Estimates of genetic and environmental influences for some of these reading-related neurocognitive components vary across reports. By using a multi-level meta-analysis approach, we synthesized the results of behavioral genetic research on reading-related neurocognitive components (i.e. general reading, letter-word knowledge, phonological decoding, reading comprehension, spelling, phonological awareness, rapid automatized naming, and language) of 49 twin studies spanning 4.1-18.5 years of age, with a total sample size of more than 38,000 individuals. Except for language for which shared environment seems to play a more important role, the causal architecture across most of the reading-related neurocognitive components can be represented by the following equation a² > e² > c². Moderators analysis revealed that sex and spoken language did not affect the heritability of any reading-related skills; school grade levels moderated the heritability of general reading, reading comprehension and phonological awareness.

Effect of Curcuma zedoaria hydro-alcoholic extract on learning, memory deficits and oxidative damage of brain tissue following seizures induced by pentylenetetrazole in rat

BACKGROUND

Previous studies have shown that seizures can cause cognitive disorders. On the other hand, the Curcuma zedoaria (CZ) has beneficial effects on the nervous system. However, there is little information on the possible effects of the CZ extract on seizures. The aim of this study was to investigate the possible effects of CZ extract on cognitive impairment and oxidative stress induced by epilepsy in rats.

METHODS

Rats were randomly divided into different groups. In all rats (except the sham group), kindling was performed by intraperitoneal injection of pentylenetetrazol (PTZ) at a dose of 35 mg/kg every 48 h for 14 days. Positive group received 2 mg/kg diazepam + PTZ; treatment groups received 100, 200 or 400 mg/kg CZ extract + PTZ; and one group received 0.5 mg/kg flumazenil and CZ extract + PTZ. Shuttle box and Morris Water Maze tests were used to measure memory and learning. On the last day of treatments PTZ injection was at dose of 60 mg/kg, tonic seizure threshold and mortality rate were recorded in each group. After deep anesthesia, blood was drawn from the rats' hearts and the hippocampus of all rats was removed.

RESULTS

Statistical analysis of the data showed that the CZ extract significantly increased the tonic seizure threshold and reduced the pentylenetetrazol-induced mortality and the extract dose of 400 mg/kg was selected as the most effective dose compared to the other doses. It was also found that flumazenil (a GABA_A receptor antagonist) reduced the tonic seizure threshold compared to the effective dose of the extract. The results of shuttle box and Morris water maze behavioral tests showed that memory and learning decreased in the negative control group and the CZ extract treatment improved memory and learning in rats. The CZ extract also increased antioxidant capacity, decreased MDA and NO in the brain and serum of pre-treated groups in compared to the negative control group.

CONCLUSION

It is concluded that the CZ extract has beneficial effects on learning and memory impairment in PTZ-induced epilepsy model, which has been associated with antioxidant effects in the brain or possibly exerts its effects through the GABAergic system.

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.

The genetic and environmental structure of fear and anxiety in juvenile twins

Fear and anxiety are conceptualized as responses to acute or potential threat, respectively. Adult twin studies found substantial interplay between genetic and environmental factors influencing fear disorders (phobias) and anxiety disorders. Research in children, however, has largely examined these factors independently. Thus, there exists a substantial knowledge gap regarding the underlying etiologic structure of these closely-related constructs during development. Symptom counts for five fear (criticism, the unknown, death, animal, medical) and four anxiety (generalized, panic, separation, social) dimensions were obtained for 373 twin pairs ages 9-14. Multivariate twin modeling was performed to elucidate the genetic and environmental influences distributed amongst these dimensions. The best fitting model contained one genetic, two familial environmental, and two unique environmental factors shared between fear and anxiety symptoms plus dimension-specific genetic and unique environmental factors. Although several environmental factors were shared between fear and anxiety dimensions, one latent factor accounted for genetic influences across both domains. While adult studies find somewhat distinct etiological differences between anxiety and phobic disorders, the current results suggest that their relative genetic and environmental influences are not as clearly demarcated in children. These etiological distinctions are more nuanced, likely contributing to the highly diffuse symptom patterns seen during development.

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.

Please Don't Leave Me-Separation Anxiety and Related Traits in Borderline Personality Disorder

PURPOSE OF REVIEW

In light of the apparent symptomatic resemblance of separation anxiety disorder (SAD) symptoms on the one hand and abandonment fears, anxiousness, and separation insecurity central to borderline personality disorder (BPD) on the other hand, a comprehensive overview of separation anxiety and related traits in BPD is provided.

RECENT FINDINGS

Epidemiological, environmental, psychological, and neurobiological data connecting BPD to separation events, feelings of loneliness, insecure attachment styles, dimensional separation anxiety as well as SAD per se suggest a partly shared etiological pathway model underlying BPD and SAD. Differential diagnostic aspects and implications for treatment are discussed, highlighting separation anxiety as a promising transdiagnostic target for specific psychotherapeutic and pharmacological treatment approaches in BPD. This innovative angle on cross-disorder symptomatology might carry potential for novel preventive and therapeutic avenues in clinical practice by guiding the development of interventions specifically targeting separation anxiety and attachment-related issues in BPD.

A Preliminary Examination of the Link Between Maternal Experiential Avoidance and Parental Accommodation in Anxious and Non-anxious Children

Studies point to parental experiential avoidance (EA) as a potential correlate of maladaptive parenting behaviors associated with child anxiety. However, research has not examined the relationship between EA and parental accommodation of child anxiety, nor the extent to which parental negative beliefs about child anxiety help explain such a relationship. In a sample of mothers (N = 45) of anxious and non-anxious children, the present study investigated the potential link between maternal EA and accommodation of child anxiety and whether this link may be indirectly accounted for via maternal negative beliefs about child anxiety. EA was significantly and positively associated with accommodation of child anxiety, but when negative beliefs about child anxiety were incorporated into the model this direct effect was no longer significant. Findings highlight the contribution of parental emotions and cognitions to behaviors that may exacerbate child anxiety, and may inform treatment and prevention efforts with families of anxious youth.

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.

Separation Anxiety Disorder in School-Age Children: What Health Care Providers Should Know

Separation anxiety disorder (SAD) is the most common childhood anxiety disorder, and it has many consequences, particularly for school-age children. These consequences include excessive worry, sleep problems, distress in social and academic settings, and a variety of physical symptoms that, left untreated, can cause social and academic decline. Pediatric providers routinely see children in the primary care office and have the unique opportunity to diagnose, treat, and manage children with SAD. Despite this, SAD continues to be underdiagnosed and undertreated because of a gap in the literature regarding evidence-based practice guidelines for pediatric providers. The purpose of this article is to discuss the diagnosis and management of SAD in school-age children and highlight the role of pediatric providers in managing separation anxiety.

Evaluation of Mother-Child Agreement and Factorial Structures of the SCARED Questionnaire in an Italian Clinical Sample

Background: A great part of the literature has confirmed the importance of both child and parents reports as source of factual information, especially for childhood emotional syndromes. In our study we aimed at: (i) calculating mother-child agreement and (ii) evaluating factorial structure of the Screen for Child Anxiety Related Emotional Disorders (SCARED) questionnaire in an Italian clinical sample. The novelty of this contribution is two-fold: first, from a clinical point of view, we investigated the parent-child agreement level and examined separately the factorial structures of both parent and child versions of the SCARED for the first time in an Italian clinical sample. Second, unlike previous studies, we used statistical approaches specifically suited to account for the ordinal nature of the collected variables.

Method: In a clinical sample of 171 children and adolescents aged 8–18 and their mothers we evaluated inter-rater agreement using weighted kappa indices to assess agreement for each item belonging to a certain SCARED subscale. Exploratory factor analysis for ordinal data was then performed on the polychoric correlation matrix calculated on SCARED items. Differences in the numbers of symptoms reported by children and parents were evaluated as well.

Results and Conclusions: Our results reveal moderate to strong mother-child agreement. A significant age effect is present. Two different factorial solutions emerged for parent and child SCARED versions (a 5 factor structure for parents and a 6 factor solution in the child version, including a new factor “Worry about Parents”). This study confirmed the importance of evaluating both child and parent reports in assessment protocols for anxiety disorders. Our findings could help clinicians to determine which information, and from which rater, must be accounted for in evaluating treatment decisions. Moreover, we find that patients characteristics, such as gender and age, should be taken into account when assessing agreement.

Biological markers for anxiety disorders, OCD and PTSD - a consensus statement. Part I: Neuroimaging and genetics

OBJECTIVES

Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and post-traumatic stress disorder (PTSD).

METHODS

Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network.

RESULTS

The present article (Part I) summarises findings on potential biomarkers in neuroimaging studies, including structural brain morphology, functional magnetic resonance imaging and techniques for measuring metabolic changes, including positron emission tomography and others. Furthermore, this review reports on the clinical and molecular genetic findings of family, twin, linkage, association and genome-wide association studies. Part II of the review focuses on neurochemistry, neurophysiology and neurocognition.

CONCLUSIONS

Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high-quality research has accumulated that will improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD.

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.

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.

Distinct trajectories of separation anxiety in the preschool years: persistence at school entry and early-life associated factors

BACKGROUND

Little is known about how children differ in the onset and evolution of separation anxiety (SA) symptoms during the preschool years, and how SA develops into separation anxiety disorder. In a large, representative population-based sample, we investigated the developmental trajectories of SA symptoms from infancy to school entry, their early associated risk factors, and their associations with teachers' ratings of SA in kindergarten.

METHODS

Longitudinal assessment of SA trajectories and risk factors in a cohort of 1,933 families between the ages of 1.5 and 6 years.

RESULTS

Analyses revealed a best-fitting, 4-trajectory solution, including a prevailing, unaffected Low-Persistent group (60.2%), and three smaller groups of distinct developmental course: a High-Increasing (6.9%), a High-Decreasing (10.8%), and a Low-Increasing group (22.1%). The High-Increasing group remained high throughout the preschool years and was the only trajectory to predict teacher-assessed SA at age 6 years. Except for the High-Increasing, all trajectories showed substantial reduction in symptoms by age 6 years. The High-Increasing and High-Decreasing groups shared several early risk factors, but the former was uniquely associated with higher maternal depression, maternal smoking during pregnancy, and parental unemployment.

CONCLUSIONS

Most children with high SA profile at age 1.5 years are expected to progressively recover by age 4-5. High SA at age 1.5 that persists over time deserves special attention, and may predict separation anxiety disorder. A host of child perinatal, parental and family-contextual risk factors were associated with the onset and developmental course of SA across the preschool years.

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.

Genetic and environmental contributions to social anxiety across different ages: a meta-analytic approach to twin data

Social anxiety disorder (SAD) and social anxiety symptoms (SAS) have been largely studied both epidemiologically and genetically, however, estimates of genetic and environmental influences for these phenotypes widely vary across reports. Based upon available literature, 13 cohorts (42,585 subjects) were included in 3 meta-analytic estimates of the standardized variance components of aetiological influences on SAD/SAS, on the effect of age and of phenotype (symptoms vs. diagnosis). The proportions of variance accounted for by genetic and environmental factors were calculated by averaging estimates among studies, and pondered by the number of individuals in each sample. Meta-analytic estimations showed that genetic and non-shared environmental factors explain most of individual differences for SAD/SAS. In adults, the genetic contribution was half than that in younger patients, with higher contribution of non-shared environmental influences. In contrast, the shared environmental factors seem to be less relevant.

Prevalence and heritability of obsessive-compulsive spectrum and anxiety disorder symptoms: A survey of the Australian Twin Registry

While past twin studies indicate moderate levels of heritability of "obsessive-compulsive related" and anxiety disorder symptoms, no single study has reported such estimates in the same twin population nor examined potential genetic sex differences. We assessed symptoms of obsessive-compulsive disorder, body dysmorphic disorder, hoarding disorder, hypochondriasis, panic disorder, social phobia and generalized anxiety disorder in 2,495 adult twins (1,468 female). Prevalence estimates for the corresponding symptom measures were determined using empirically derived cut-off scores. Twin resemblance was assessed by Pearson correlations and biometrical model-fitting analyses, incorporating sex-specific effects, using OpenMx. Prevalence estimates ranged from 1.6% in the symptoms of generalized anxiety to 16.9% for social phobia. Female twins demonstrated significantly higher prevalence rates across all domains with the exception of obsessive-compulsive symptoms. Additive genetic factors accounted for a moderate proportion of the total liability to each symptom domain. Evidence suggesting qualitative genetic sex differences (i.e., distinct genetic influences between genders) was observed for body dysmorphic concern and panic symptoms, while quantitative differences were observed for hoarding and social phobia symptoms, indicating stronger heritability in females. Novel findings in this study include the observation of probable genetic sex differences in liability towards hoarding symptoms and dysmorphic concern, as well as the lack of such differences in hypochondriasis. The trend towards qualitative sex differences in panic symptoms has some intuitive appeal with regard to biological-experimental models of panic.