Genetics of anxiety: would the genome recognize the DSM?

Normal Versus Pathological Mood: Implications for Diagnosis

Is there a clear line between normal and abnormal mood? Studies of manifest and latent structure provide strong support for a continuum that extends from asymptomatic to subsyndromal to syndromal cases of increasing severity. Subsyndromal symptoms are impairing, predict syndrome onset and relapse, and account for more doctor's visits and suicide attempts than the full syndromes, yet they are not recognized in the current classification. For most research and some clinical activities, dimensional diagnoses are recommended, and examples are offered for how such diagnoses could be made. For clinical activities requiring decisions, a multithreshold model is proposed in which both lower (e.g., mild depression, capturing subsyndromal cases) and upper (e.g., major depression, capturing clinically significant cases) diagnostic categories are used to inform clinical care. Beyond its implications for diagnosis, the dimensionality of depression and anxiety has implications for etiology and for research aimed at understanding how emotions become disrupted in psychopathology.

Effects of COMT rs4680 and BDNF rs6265 polymorphisms on brain degree centrality in Han Chinese adults who lost their only child

Losing one's only child is a major traumatic life event that may lead to posttraumatic stress disorder (PTSD); however, not all parents who experience this trauma develop PTSD. Genetic variants are associated with the risk of developing PTSD. Catechol-O-methyltransferase (COMT) rs4680 and brain-derived neurotrophic factor (BDNF) rs6265 are two most well-described single-nucleotide polymorphisms that relate to stress response; however, the neural mechanism underlying their effects on adults who lost an only child remains poorly understood. Two hundred and ten Han Chinese adults who had lost their only child (55 with PTSD and 155 without PTSD) were included in this imaging genetics study. Participants were divided into subgroups according to their COMT rs4680 and BDNF rs6265 genotypes. Degree Centrality (DC)-a resting-state fMRI index reflecting the brain network communication-was compared with a three-way (PTSD diagnosis, COMT, and BDNF polymorphisms) analysis of covariance. Diagnosis state had a significant effect on DC in bilateral inferior parietal lobules and right middle frontal gyrus (MFG), where PTSD adults showed weaker DC. BDNF × diagnosis interaction effect was found in the right MFG and hippocampus, and these two regions were reversely modulated. Also, there was a significant COMT × BDNF interaction effect in left cuneus, middle temporal gyrus, right inferior occipital gyrus, and bilateral putamen, independent of PTSD diagnosis. These findings suggest that the modulatory effect of BDNF polymorphism on the MFG and hippocampus may contribute to PTSD development in bereaved adults. Interactions of COMT × BDNF polymorphisms modulate some cortices and basal ganglia, irrespective of PTSD development.

Factors Associated with Psychiatric Comorbidity in Depression Patients in Primary Health Care in Chile

OBJECTIVE

To identify the clinical and psychosocial factors associated with psychiatric comorbidity in patients consulting for depression in Primary Health Care (PHC) in Chile.

METHODS

394 patients with a diagnosis of major depression being treated in a Chilean PHC were evaluated using a sociodemographic and clinical interview, the mini-international neuropsychiatric interview (MINI), a childhood trauma events (CTEs) screening, the intimate partner violence (IPV) scale, the Life Experiences Survey (LES), and the Hamilton Depression Rating Scale (HDRS).

RESULTS

Positive correlations were established between higher number of psychiatric comorbidities and severity of depressive symptoms (r = 0.358), frequency of CTEs (r = 0.228), frequency of IPV events (r = 0.218), frequency of recent stressful life events (r = 0.188), number of previous depressive episodes (r = 0.340), and duration of these (r = 0.120). Inverse correlations were determined with age at the time of the first consultation (r = -0.168), age of onset of depression (r = -0.320), and number of medical comorbidities (r = -0.140). Of all associated factors, early age of the first depressive episode, CTEs antecedents, and recent stressful life events explain 13.6% of total variability in psychiatric comorbidities.

CONCLUSIONS

A higher prevalence of psychiatric comorbidity among subjects seeking help for depression in Chilean PHCs is associated with early onset of depression, clinical severity, chronicity, and interpersonal adversity experienced since childhood.

Genome-wide significant loci for addiction and anxiety

BACKGROUND

Psychiatric comorbidity is common among individuals with addictive disorders, with patients frequently suffering from anxiety disorders. While the genetic architecture of comorbid addictive and anxiety disorders remains unclear, elucidating the genes involved could provide important insights into the underlying etiology.

METHODS

Here we examine a sample of 1284 Mexican-Americans from randomly selected extended pedigrees. Variance decomposition methods were used to examine the role of genetics in addiction phenotypes (lifetime history of alcohol dependence, drug dependence or chronic smoking) and various forms of clinically relevant anxiety. Genome-wide univariate and bivariate linkage scans were conducted to localize the chromosomal regions influencing these traits.

RESULTS

Addiction phenotypes and anxiety were shown to be heritable and univariate genome-wide linkage scans revealed significant quantitative trait loci for drug dependence (14q13.2-q21.2, LOD=3.322) and a broad anxiety phenotype (12q24.32-q24.33, LOD=2.918). Significant positive genetic correlations were observed between anxiety and each of the addiction subtypes (ρg=0.550-0.655) and further investigation with bivariate linkage analyses identified significant pleiotropic signals for alcohol dependence-anxiety (9q33.1-q33.2, LOD=3.054) and drug dependence-anxiety (18p11.23-p11.22, LOD=3.425).

CONCLUSIONS

This study confirms the shared genetic underpinnings of addiction and anxiety and identifies genomic loci involved in the etiology of these comorbid disorders. The linkage signal for anxiety on 12q24 spans the location of TMEM132D, an emerging gene of interest from previous GWAS of anxiety traits, whilst the bivariate linkage signal identified for anxiety-alcohol on 9q33 peak coincides with a region where rare CNVs have been associated with psychiatric disorders. Other signals identified implicate novel regions of the genome in addiction genetics.

Interaction of CD38 Variant and Chronic Interpersonal Stress Prospectively Predicts Social Anxiety and Depression Symptoms Over Six Years

Variation in the CD38 gene, which regulates secretion of the neuropeptide oxytocin, has been associated with several social phenotypes. Specifically, rs3796863 A allele carriers have demonstrated increased social sensitivity. In 400 older adolescents, we used trait-state-occasion modeling to investigate how rs3796863 genotype, baseline ratings of chronic interpersonal stress, and their gene-environment (GxE) interaction predicted trait social anxiety and depression symptoms over six years. We found significant GxE effects for CD38 A-carrier genotypes and chronic interpersonal stress at baseline predicting greater social anxiety and depression symptoms. A significant GxE effect of smaller magnitude was also found for C/C genotype and chronic interpersonal stress predicting greater depression; however, this effect was small compared to the main effect of chronic interpersonal stress. Thus, in the context of chronic interpersonal stress, heightened social sensitivity associated with the rs3796863 A allele may prospectively predict risk for social anxiety and (to a lesser extent) depression.

The cycle of classification: DSM-I through DSM-5

The Diagnostic and Statistical Manual of Mental Disorders (DSM) was created in 1952 by the American Psychiatric Association so that mental health professionals in the United States would have a common language to use when diagnosing individuals with mental disorders. Since the initial publication of the DSM, there have been five subsequent editions of this manual published (including the DSM-III-R). This review discusses the structural changes in the six editions and the research that influenced those changes. Research is classified into three domains: (a) issues related to the DSMs as measurement systems, (b) studies of clinicians and how clinicians form diagnoses, and (c) taxonomic issues involving the philosophy of science and metatheoretical ideas about how classification systems function. The review ends with recommendations about future efforts to revise the DSMs.

Clinical decision making about child and adolescent anxiety disorders using the Achenbach system of empirically based assessment

Anxiety disorders are common among children but can be difficult to diagnose. An actuarial approach to the diagnosis of anxiety may improve the efficiency and accuracy of the process. The objectives of this study were to determine the clinical utility of the Achenbach Child Behavior Checklist (CBCL) and Youth Self Report (YSR), two widely used assessment tools, for diagnosing anxiety disorders in youth and to aid clinicians in incorporating scale scores into an actuarial approach to diagnosis through a clinical vignette. Demographically diverse youth, 5 to 18 years of age, were drawn from two samples; one (N = 1,084) was recruited from a research center, and the second (N = 651) was recruited from an urban community mental health center. Consensus diagnoses integrated information from semistructured interview, family history, treatment history, and clinical judgment. The CBCL and YSR internalizing problems T scores discriminated cases with any anxiety disorder or with generalized anxiety disorder from all other diagnoses in both samples (ps < .0005); the two scales had equivalent discriminative validity (ps > .05 for tests of difference). No other scales, nor any combination of scales, significantly improved on the performance of the Internalizing scale. In the highest risk group, Internalizing scores greater than 69 (CBCL) or greater than 63 (YSR) resulted in a Diagnostic Likelihood Ratio of 1.5; low scores reduced the likelihood of anxiety disorders by a factor of 4. Combined with other risk factor information in an actuarial approach to assessment and diagnosis, the CBCL and YSR Internalizing scales provide valuable information about whether a youth is likely suffering from an anxiety disorder.

The α-endomannosidase gene (MANEA) is associated with panic disorder and social anxiety disorder

Unbiased genome-wide approaches can provide novel insights into the biological pathways that are important for human behavior and psychiatric disorder risk. The association of α-endomannosidase gene (MANEA) variants and cocaine-induced paranoia (CIP) was initially described in a study that used a whole-genome approach. Behavioral effects have been reported for other mannosidase genes, but MANEA function in humans and the clinical potential of the previous findings remain unclear. We hypothesized that MANEA would be associated with psychiatric phenotypes unrelated to cocaine use. We used a multi-stage association study approach starting with four psychiatric disorders to show an association between a MANEA single-nucleotide polymorphism (SNP; rs1133503) and anxiety disorders. In the first study of 2073 European American (EA) and 2459 African American subjects mostly with comorbid drug or alcohol dependence, we observed an association in EAs of rs1133503 with panic disorder (PD) (191 PD cases, odds ratio (OR)=1.7 (95% confidence interval (CI): 1.22-2.41), P=0.002). We replicated this finding in an independent sample of 142 PD cases (OR =1.53 (95% CI: 1.00-2.31), P=0.043) and extended it in an independent sample of 131 generalized social anxiety disorder cases (OR=2.15 (95% CI: 1.27-3.64), P=0.004). MANEA alleles and genotypes were also associated with gene expression differences in whole blood cells. Using publically available data, we observed a consistent effect on expression in brain tissue. We conclude that pathways involving α-endomannosidase warrant further investigation in relation to anxiety disorders.

Genome-wide association study of co-occurring anxiety in major depression

OBJECTIVES

Co-morbidity between depression and anxiety disorders is common. In this study we define a quantitative measure of anxiety by summating four anxiety items from the SCAN interview in a large collection of major depression (MDD) cases to identify genes contributing to this complex phenotype.

METHODS

A total of 1522 MDD cases dichotomised according to those with at least one anxiety item scored (n = 1080) and those without anxiety (n = 442) were analysed, and also compared to 1588 healthy controls at a genome-wide level, to identify genes that may contribute to anxiety in MDD.

RESULTS

For the quantitative trait, suggestive evidence of association was detected for two SNPs, and for the dichotomous anxiety present/absent ratings for three SNPs at genome-wide level. In the genome-wide analysis of MDD cases with co-morbid anxiety and healthy controls, two SNPs attained P values of < 5 × 10⁻⁶. Analysing candidate genes, P values ≤ 0.0005 were found with three SNPs for the quantitative trait and three SNPs for the dichotomous trait.

CONCLUSIONS

This study provides an initial genome-wide assessment of possible genetic contribution to anxiety in MDD. Although suggestive evidence of association was found for several SNPs, our findings suggest that there are no common variants strongly associated with anxious depression.

Performance of polygenic scores for predicting phobic anxiety

Context

Anxiety disorders are common, with a lifetime prevalence of 20% in the U.S., and are responsible for substantial burdens of disability, missed work days and health care utilization. To date, no causal genetic variants have been identified for anxiety, anxiety disorders, or related traits.

Objective

To investigate whether a phobic anxiety symptom score was associated with 3 alternative polygenic risk scores, derived from external genome-wide association studies of anxiety, an internally estimated agnostic polygenic score, or previously identified candidate genes.

Design

Longitudinal follow-up study. Using linear and logistic regression we investigated whether phobic anxiety was associated with polygenic risk scores derived from internal, leave-one out genome-wide association studies, from 31 candidate genes, and from out-of-sample genome-wide association weights previously shown to predict depression and anxiety in another cohort.

Setting and Participants

Study participants (n = 11,127) were individuals from the Nurses' Health Study and Health Professionals Follow-up Study.

Main Outcome Measure

Anxiety symptoms were assessed via the 8-item phobic anxiety scale of the Crown Crisp Index at two time points, from which a continuous phenotype score was derived.

Results

We found no genome-wide significant associations with phobic anxiety. Phobic anxiety was also not associated with a polygenic risk score derived from the genome-wide association study beta weights using liberal p-value thresholds; with a previously published genome-wide polygenic score; or with a candidate gene risk score based on 31 genes previously hypothesized to predict anxiety.

Conclusion

There is a substantial gap between twin-study heritability estimates of anxiety disorders ranging between 20–40% and heritability explained by genome-wide association results. New approaches such as improved genome imputations, application of gene expression and biological pathways information, and incorporating social or environmental modifiers of genetic risks may be necessary to identify significant genetic predictors of anxiety.

A review of systems for psychology and psychiatry: adaptive systems, personality psychopathology five (PSY-5), and the DSM-5

We outline a crisis in clinical description, in which atheoretical categorical descriptors, as in the Diagnostic and Statistical Manual of Mental Disorders (DSM), has turned focus away from the obvious: evolved major adaptive systems. Adaptive systems, at the core of a medical review of systems (ROS), allow models of pathology to be layered over an understanding of systems as they normally function. We argue that clinical psychology and psychiatry would develop more programmatically by incorporating 5 systems evolved for adaptation to the external environment: reality modeling for action, short-term danger detection, long-term cost-benefit projection, resource acquisition, and agenda protection. These systems, although not exhaustive, coincide with great historical issues in psychology, psychopathology, and individual differences. Readers of this journal should be interested in this approach because personality is seen as a relatively stable property of these systems. Thus, an essential starting point in ROS-based clinical description involves personality assessment. But this approach also places demands on scientist-practitioners to integrate across sciences. An ROS promotes theories that are (a) compositional, answering the question: What elements comprise the system?; (b) dynamic, answering: How do the elements and other systems interact?; and (c) developmental: How do systems change over time? The proposed ROS corresponds well with the National Institute of Mental Health's recent research domain criteria (RDoC) approach. We urge that in the RDoC approach, measurement variables should be treated as falsifiable and theory-laden markers, not unfalsifiable criteria. We argue that our proposed ROS promotes integration across sciences, rather than fostering the isolation of sciences allowed by atheoretical observation terms, as in the DSM.

Clinical and molecular genetics of psychotic depression

This review provides a comprehensive overview of clinical and molecular genetic as well as pharmacogenetic studies regarding the clinical phenotype of "psychotic depression." Results are discussed with regard to the long-standing debate on categorical vs dimensional disease models of affective and psychotic disorders on a continuum from unipolar depression over bipolar disorder and schizoaffective disorder to schizophrenia. Clinical genetic studies suggest a familial aggregation and a considerable heritability (39%) of psychotic depression partly shared with schizoaffective disorder, schizophrenia, and affective disorders. Molecular genetic studies point to potential risk loci of psychotic depression shared with schizoaffective disorder (1q42, 22q11, 19p13), depression, bipolar disorder, and schizophrenia (6p, 8p22, 10p13-12, 10p14, 13q13-14, 13q32, 18p, 22q11-13) and several vulnerability genes possibly contributing to an increased risk of psychotic symptoms in depression (eg, BDNF, DBH, DTNBP1, DRD2, DRD4, GSK-3beta, MAO-A). Pharmacogenetic studies implicate 5-HTT, TPH1, and DTNBP1 gene variation in the mediation of antidepressant treatment response in psychotic depression. Genetic factors are suggested to contribute to the disease risk of psychotic depression in partial overlap with disorders along the affective-psychotic spectrum. Thus, genetic research focusing on psychotic depression might inspire a more dimensional, neurobiologically and symptom-oriented taxonomy of affective and psychotic disorders challenging the dichotomous Kraepelinian view. Additionally, pharmacogenetic studies might aid in the development of a more personalized treatment of psychotic depression with an individually tailored antidepressive/antipsychotic pharmacotherapy according to genotype.

Behavioral genetics of affective and anxiety disorders

As shown by clinical genetic studies, affective and anxiety disorders are complex genetic disorders with genetic and environmental factors interactively determining their respective pathomechanism. Advances in molecular genetic techniques including linkage studies, association studies, and genome-wide association studies allow for the detailed dissection of the genetic influence on the development of these disorders. Besides the molecular genetic investigation of categorical entities according to standardized diagnostic criteria, intermediate phenotypes comprising neurobiological or neuropsychological traits (e.g., neuronal correlates of emotional processing) that are linked to the disease of interest and that are heritable, have been proposed to be closer to the underlying genotype than the overall disease phenotype. These intermediate phenotypes are dimensional and more precisely defined than the categorical disease phenotype, and therefore have attracted much interest in the genetic investigation of affective and anxiety disorders. Given the complex genetic nature of affective and anxiety disorders with an interaction of multiple risk genes and environmental influences, the interplay of genetic factors with environmental factors is investigated by means of gene-environment interaction (GxE) studies. Pharmacogenetic studies aid in the dissection of the genetically influenced heterogeneity of psychotropic drug response and may contribute to the development of a more individualized treatment of affective and anxiety disorders. Finally, there is some evidence for genetic factors potentially shared between affective and anxiety disorders pointing to a possible overlapping phenotype between anxiety disorders and depression.

Can psychopharmacological treatment change personality traits in patients with panic disorder?

OBJECTIVE

The aim of this study was to evaluate the effects that a particular psychopharmacological treatment has on personality patterns in patients with panic disorder.

METHOD

Forty-seven patients with panic disorder and 40 controls were included in the study. The Mini International Neuropsychiatric Interview and Minnesota Multiphasic Personality Inventory were used to assess Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnoses and personality traits, respectively. Patients were treated with sertraline for 16 weeks.

RESULTS

There was a significant decrease in the score on 8 of the 10 Minnesota Multiphasic Personality Inventory scales. In addition, neurotic triad and psychasthenia personality scores were higher among panic disorder patients, even during the posttreatment asymptomatic phase, than among controls.

CONCLUSION

In the asymptomatic phase of the disease, panic disorder patients present a particular neurotic/anxious personality pattern. This pattern, although altered in the presence of acute symptoms, could be a focus of research.

The multidimensional evaluation and treatment of anxiety in children and adolescents: rationale, design, methods and preliminary findings

OBJECTIVE: This study aims to describe the design, methods and sample characteristics of the Multidimensional Evaluation and Treatment of Anxiety in Children and Adolescents - the PROTAIA Project. METHOD: Students between 10 and 17 years old from all six schools belonging to the catchment area of the Primary Care Unit of Hospital de Clínicas de Porto Alegre were included in the project. It comprises five phases: (1) a community screening phase; (2) a psychiatric diagnostic phase; (3) a multidimensional assessment phase evaluating environmental, neuropsychological, nutritional, and biological factors; (4) a treatment phase, and (5) a translational phase. RESULTS: A total of 2,457 subjects from the community were screened for anxiety disorders. From those who attended the diagnostic interview, we identified 138 individuals with at least one anxiety disorder (apart from specific phobia) and 102 individuals without any anxiety disorder. Among the anxiety cases, generalized anxiety disorder (n = 95; 68.8%), social anxiety disorder (n = 57; 41.3%) and separation anxiety disorder (n = 49; 35.5%) were the most frequent disorders. CONCLUSION: The PROTAIA Project is a promising research project that can contribute to the knowledge of the relationship between anxiety disorders and anxiety-related phenotypes with several genetic and environmental risk factors.

Convergent functional genomics of anxiety disorders: translational identification of genes, biomarkers, pathways and mechanisms

Anxiety disorders are prevalent and disabling yet understudied from a genetic standpoint, compared with other major psychiatric disorders such as bipolar disorder and schizophrenia. The fact that they are more common, diverse and perceived as embedded in normal life may explain this relative oversight. In addition, as for other psychiatric disorders, there are technical challenges related to the identification and validation of candidate genes and peripheral biomarkers. Human studies, particularly genetic ones, are susceptible to the issue of being underpowered, because of genetic heterogeneity, the effect of variable environmental exposure on gene expression, and difficulty of accrual of large, well phenotyped cohorts. Animal model gene expression studies, in a genetically homogeneous and experimentally tractable setting, can avoid artifacts and provide sensitivity of detection. Subsequent translational integration of the animal model datasets with human genetic and gene expression datasets can ensure cross-validatory power and specificity for illness. We have used a pharmacogenomic mouse model (involving treatments with an anxiogenic drug--yohimbine, and an anti-anxiety drug--diazepam) as a discovery engine for identification of anxiety candidate genes as well as potential blood biomarkers. Gene expression changes in key brain regions for anxiety (prefrontal cortex, amygdala and hippocampus) and blood were analyzed using a convergent functional genomics (CFG) approach, which integrates our new data with published human and animal model data, as a translational strategy of cross-matching and prioritizing findings. Our work identifies top candidate genes (such as FOS, GABBR1, NR4A2, DRD1, ADORA2A, QKI, RGS2, PTGDS, HSPA1B, DYNLL2, CCKBR and DBP), brain-blood biomarkers (such as FOS, QKI and HSPA1B), pathways (such as cAMP signaling) and mechanisms for anxiety disorders--notably signal transduction and reactivity to environment, with a prominent role for the hippocampus. Overall, this work complements our previous similar work (on bipolar mood disorders and schizophrenia) conducted over the last decade. It concludes our programmatic first pass mapping of the genomic landscape of the triad of major psychiatric disorder domains using CFG, and permitted us to uncover the significant genetic overlap between anxiety and these other major psychiatric disorders, notably the under-appreciated overlap with schizophrenia. PDE10A, TAC1 and other genes uncovered by our work provide a molecular basis for the frequently observed clinical co-morbidity and interdependence between anxiety and other major psychiatric disorders, and suggest schizo-anxiety as a possible new nosological domain.

How the neurocircuitry and genetics of fear inhibition may inform our understanding of PTSD

Exposure to traumatic events that produce extreme fear and horror is all too common in both military and civilian populations, but not all individuals develop posttraumatic stress disorder (PTSD) as a result of the exposure. What mediates risk and resilience in the development of PTSD and other stress-related psychopathology is of paramount importance to our further understanding of trauma-related psychopathology as well as the development of new treatment approaches. Biological factors, such as genotype and neurobiology, interact with environmental factors, such as childhood background and trauma load, to affect vulnerability and resilience in the aftermath of trauma exposure. One of the core symptoms of PTSD is the inability to control fear, which has led some investigators and clinicians to conceptualize PTSD as a disorder of fear or, more importantly, its inhibition. This review focuses on translational methods that have been used to examine fear conditioning and inhibition of fear in PTSD and summarizes genetic and neurobiological factors related to fear inhibition. The authors also discuss different pharmacological approaches that enhance fear inhibition and may improve treatment outcomes for patients with PTSD.

Neuropeptide Y (NPY) gene: Impact on emotional processing and treatment response in anxious depression

Neuropeptide Y (NPY) has been found to play a role in the pathomechanism of both anxiety and depression. Thus, NPY is a promising candidate in the investigation of the clinical phenotype of "anxious depression". Five NPY gene variants were investigated for an influence on antidepressant treatment response in a sample of 256 patients with depression. Additionally, NPY gene impact on amygdala activation during facial emotion processing was analyzed in a subsample of 35 depressed patients. Particularly in anxious depression, the less active NPY rs16147 -399C allele conferred slow response after 2weeks and failure to achieve remission after four weeks of treatment. The rs16147 C allele was further associated with stronger bilateral amygdala activation in response to threatening faces in an allele-dose fashion. The present results point towards a possible influence of functional NPY gene variation on antidepressant treatment response in anxious depression, potentially conveyed by altered emotional processing.

Genetics of anxiety disorders: the complex road from DSM to DNA

Anxiety disorders are among the most common psychiatric disorders, affecting one in four individuals over a lifetime. Although our understanding of the etiology of these disorders is incomplete, familial and genetic factors are established risk factors. However, identifying the specific casual genes has been difficult. Within the past several years, advances in molecular and statistical genetic methods have made the genetic dissection of complex disorders a feasible project. Here we provide an overview of these developments, with a focus on their implications for genetic studies of anxiety disorders. Although the genetic and phenotypic complexity of the anxiety disorders present formidable challenges, advances in neuroimaging and experimental animal models of anxiety and fear offer important opportunities for discovery. Real progress in identifying the genetic basis of anxiety disorders will require integrative approaches that make use of these biologic tools as well as larger-scale genomic studies. If successful, such efforts may yield novel and more effective approaches for the prevention and treatment of these common and costly disorders.

Challenges in psychiatric classification: the case of generalized anxiety disorder

Objective: This paper aims to describe some of the challenges in psychiatric classification, using generalized anxiety disorder (GAD) as an example. A range of different conceptualizations of GAD are presented. Some are based on theoretical formulations, while others draw on epidemiological data. Each has merit, but also deficiencies. The evolution of diagnostic criteria is not simply a theoretical exercise, but reflects assumptions about the nature of the underlying pathology and the relationships between different disorders. Furthermore, these criteria determine which subjects are included in research and in clinical trials, so they shape the further development of psychiatric classification systems. Conclusion: The controversies about the classification of GAD illustrate the complexities and challenges of developing a valid classification system for psychiatric disorders.

Anxiety in boys with attention-deficit/hyperactivity disorder with and without chronic multiple tic disorder

OBJECTIVE

This study examined the psychosocial and behavioral concomitants of anxiety in clinic-referred boys with attention-deficit/hyperactivity disorder (ADHD) with and without chronic multiple tic disorder (CMTD).

METHOD

ADHD boys with (n = 65) and without (n = 94) CMTD were evaluated with measures of psychiatric symptoms, mental health risk factors, and academic and social performance.

RESULTS

Boys with CMTD evidenced more severe anxiety and less social competence and were more likely to be living with only one biological parent than the ADHD Only group, but the magnitude of group differences was generally small. The severity of generalized anxiety, separation anxiety, social phobia, and obsessive-compulsive symptoms were uniquely associated with a different pattern of risk factors, and there was some evidence that these patterns differed for the two groups of boys.

CONCLUSION

Boys with CMTD had a relatively more severe and complex pattern of anxiety that was associated with different clinical features, all of which suggests that ADHD plus CMTD might better be conceptualized as a distinct clinical entity from ADHD Only. However, findings from the extant literature are mixed, and therefore this remains a topic for further study.

Association of COMT (Val158Met) and BDNF (Val66Met) gene polymorphisms with anxiety, ADHD and tics in children with autism spectrum disorder

The aim of the study is to examine rs4680 (COMT) and rs6265 (BDNF) as genetic markers of anxiety, ADHD, and tics. Parents and teachers completed a DSM-IV-referenced rating scale for a total sample of 67 children with autism spectrum disorder (ASD). Both COMT (p = 0.06) and BDNF (p = 0.07) genotypes were marginally significant for teacher ratings of social phobia (etap (2) = 0.06). Analyses also indicated associations of BDNF genotype with parent-rated ADHD (p = 0.01, etap (2) = 0.10) and teacher-rated tics (p = 0.04; etap (2) = 0.07). There was also evidence of a possible interaction (p = 0.02, etap (2) = 0.09) of BDNF genotype with DAT1 3' VNTR with tic severity. BDNF and COMT may be biomarkers for phenotypic variation in ASD, but these preliminary findings remain tentative pending replication with larger, independent samples.

Fear of harm, a possible phenotype of pediatric bipolar disorder: a dimensional approach to diagnosis for genotyping psychiatric syndromes

BACKGROUND

In a prior concordance study of affected sibling pairs with a community diagnosis of pediatric bipolar disorder (PBD) a behavioral phenotype termed Fear of Harm (FOH) was found to have one of the strongest concordance coefficients (rho) between probands and siblings, and the widest contrasts between the rho-estimates for the proband/sibling vs. proband/comparison pairs [Papolos, D., Hennen, J., Cockerham, M.S, Lachman, H., 2007]. A strategy for identifying phenotypic subtypes: concordance of symptom dimensions between sibling pairs who met screening criteria for a genetic linkage study of childhood-onset bipolar disorder using the Child Bipolar Questionnaire (CBQ) was employed. J. Affect. Disord. 99, 27-36.]. We used the Child Bipolar Questionnaire (OUT) (CBQ) to further elucidate this behavioral phenotype of PBD. We hypothesized that selective factors including parent reported symptoms of mania and depression, would be distinguishing features of impairment between groups defined by 1) the magnitude of their score on a continuous measure of FOH, and 2) the high FOH group would have significantly greater levels of severity on course of illness variables. These measures included earlier age of onset of first psychiatric symptoms, first hospitalization, and frequency of psychiatric hospitalizations, as well as, degree of social impairment as determined by exposure to the juvenile justice system and school performance problems.

METHODS

The sample was comprised of children with community diagnoses of bipolar disorder or at risk for the illness based on enriched family history with multiple first degree relatives diagnosed with BPD (N=5335). Included were all subjects who had >40 positively endorsed CBQ symptom items at frequencies of very often, almost always, and always. This group was divided randomly into two groups, the exploratory group (N=2668) and the hypothesis testing (study) group (N=2666). The exploratory group was used for the development of hypotheses and the study group was used to test these hypotheses on a new set of data. All results reported here derive from the latter group. In subsequent analyses, we classified each child as having a high degree of FOH, low FOH, or no FOH. We examined a subset of the sample for differences in age of onset of first psychiatric symptoms, course of illness and measures of symptom severity. These groups were compared using the chi-square procedure for categorical data and the Analysis of Variance (ANOVA) with Scheffe pair wise tests for continuous variables. The Child Bipolar Questionnaire V.2.0, the Yale-Brown Obsessive Compulsive Scale (YBOCS) and the Overt Aggression Scale (OAS) were the principal instruments used to obtain diagnostic information for this study.

RESULTS

We found that children representative of the FOH phenotype when compared to children with PBD who lack this trait had higher indices of severity of mania and depression, as well as other indices that reflect severity and course of illness. Trait factors were derived from a factor analysis of CBQ in a large population of children diagnosed with or at risk for PBD, and used to further elucidate trait features of children with FOH. Children with the FOH traits were also more likely to be defined by six CBQ factors; Sleep/Arousal, Harm to Self and Others, Territorial Aggression, Anxiety, Self-esteem, Psychosis/Parasomnias/Sweet Cravings/Obsessions (PPSO).

LIMITATIONS

This data is derived from samples enriched with bipolar disorder cases. Further validation is needed with samples in which childhood-onset BD is rarer and diagnoses more diverse. Clinician diagnosis was not validated via research interview.

CONCLUSIONS

The FOH phenotype, as defined by a metric derived from combining items from the YBOCS/OAS, is a clinically homogeneous behavioral phenotype of PBD with early age of onset, severe manic and depressive symptoms, and significant social impairment that is strongly associated with 6 CBQ factors and can be easily identified using the CBQ. Through the examination of dimensional features of PBD in an enriched sample of large size, we were able to further refine a phenotype and identify clinical dimensions potentially linked to endophenotypic markers that may prove fruitful in differential diagnosis, treatment and etiological studies of PBD. The nature of the sets of specific symptoms that comprise the FOH factors enabled us to propose a biological model for the phenotype (OUT) that involves a complex orexigenic circuit which links hypothalamic, limbic, and other brain nuclei primarily responsible for the regulation of behavioral and proposed physiological features of the FOH phenotype.

Genetic variations associated with red hair color and fear of dental pain, anxiety regarding dental care and avoidance of dental care

BACKGROUND

Red hair color is caused by variants of the melanocortin-1 receptor (MC1R) gene. People with naturally red hair are resistant to subcutaneous local anesthetics and, therefore, may experience increased anxiety regarding dental care. The authors tested the hypothesis that having natural red hair color, a MC1R gene variant or both could predict a patient's experiencing dental care-related anxiety and dental care avoidance.

METHODS

The authors enrolled 144 participants (67 natural red-haired and 77 dark-haired) aged 18 to 41 years in a cross-sectional observational study. Participants completed validated survey instruments designed to measure general and dental care-specific anxiety, fear of dental pain and previous dental care avoidance. The authors genotyped participants' blood samples to detect variants associated with natural red hair color.

RESULTS

Eighty-five participants had MC1R gene variants (65 of the 67 red-haired participants and 20 of the 77 dark-haired participants) (P < .001). Participants with MC1R gene variants reported significantly more dental care-related anxiety and fear of dental pain than did participants with no MC1R gene variants. They were more than twice as likely to avoid dental care as were the participants with no MC1R gene variants, even after the authors controlled for general trait anxiety and sex.

CONCLUSION

Dental care-related anxiety, fear of dental pain and avoidance of dental care may be influenced by genetic variations.

CLINICAL IMPLICATIONS

Dentists should evaluate all patients, but especially those with naturally red hair, for dental care-related anxiety and use appropriate modalities to manage the patients' anxiety.

Generalized anxiety disorder: between now and DSM-V

This article presents the current evidence base for pharmacotherapy of generalized anxiety disorder (GAD) and an update on the phenomenology of GAD and its association with other psychiatric and somatic conditions. It discusses nosological issues and suggests ways to improve recognition, treatment, and care for patients who have GAD.