Familiality of factor analysis-derived YBOCS dimensions in OCD-affected sibling pairs from the OCD Collaborative Genetics Study

Latin American Trans-ancestry INitiative for OCD genomics (LATINO): Study protocol

Obsessive-compulsive disorder (OCD) is a debilitating psychiatric disorder. Worldwide, its prevalence is ~2% and its etiology is mostly unknown. Identifying biological factors contributing to OCD will elucidate underlying mechanisms and might contribute to improved treatment outcomes. Genomic studies of OCD are beginning to reveal long-sought risk loci, but >95% of the cases currently in analysis are of homogenous European ancestry. If not addressed, this Eurocentric bias will result in OCD genomic findings being more accurate for individuals of European ancestry than other ancestries, thereby contributing to health disparities in potential future applications of genomics. In this study protocol paper, we describe the Latin American Trans-ancestry INitiative for OCD genomics (LATINO, https://www.latinostudy.org). LATINO is a new network of investigators from across Latin America, the United States, and Canada who have begun to collect DNA and clinical data from 5000 richly phenotyped OCD cases of Latin American ancestry in a culturally sensitive and ethical manner. In this project, we will utilize trans-ancestry genomic analyses to accelerate the identification of OCD risk loci, fine-map putative causal variants, and improve the performance of polygenic risk scores in diverse populations. We will also capitalize on rich clinical data to examine the genetics of treatment response, biologically plausible OCD subtypes, and symptom dimensions. Additionally, LATINO will help elucidate the diversity of the clinical presentations of OCD across cultures through various trainings developed and offered in collaboration with Latin American investigators. We believe this study will advance the important goal of global mental health discovery and equity.

Clinical characteristics of probands with obsessive-compulsive disorder from simplex and multiplex families

Genetic and non-genetic factors contribute to obsessive-compulsive disorder (OCD), with strong evidence of familial clustering. Genomic studies in psychiatry have used the concepts of families that are "simplex" (one affected) versus "multiplex" (multiple affected). Our study compares demographic and clinical data from OCD probands in simplex and multiplex families to uncover potential differences. We analyzed 994 OCD probands (501 multiplex, 493 simplex) from the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders (C-TOC). Clinicians administered the Structured Clinical Interview for DSM-IV (SCID-IV) to diagnose, Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) to assess severity, and Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS) to assess symptom dimensionality. Demographics, clinical history, and family data were collected. Compared to simplex probands, multiplex probands had earlier onset, higher sexual/religious and hoarding dimensions severity, increased comorbidity with other obsessive-compulsive-related disorders (OCRD), and higher family history of psychiatric disorders. These comparisons provide the first insights into demographic and clinical differences between Latin American simplex and multiplex families with OCD. Distinct clinical patterns may suggest diverse genetic and environmental influences. Further research is needed to clarify these differences, which have implications for symptom monitoring and management.

Latin American Trans-ancestry INitiative for OCD genomics (LATINO): Study Protocol

Obsessive-compulsive disorder (OCD) is a debilitating psychiatric disorder. Worldwide, its prevalence is ~2% and its etiology is mostly unknown. Identifying biological factors contributing to OCD will elucidate underlying mechanisms and might contribute to improved treatment outcomes. Genomic studies of OCD are beginning to reveal long-sought risk loci, but >95% of the cases currently in analysis are of homogenous European ancestry. If not addressed, this Eurocentric bias will result in OCD genomic findings being more accurate for individuals of European ancestry than other ancestries, thereby contributing to health disparities in potential future applications of genomics. In this study protocol paper, we describe the Latin American Trans-ancestry INitiative for OCD genomics (LATINO, www.latinostudy.org). LATINO is a new network of investigators from across Latin America, the United States, and Canada who have begun to collect DNA and clinical data from 5,000 richly-phenotyped OCD cases of Latin American ancestry in a culturally sensitive and ethical manner. In this project, we will utilize trans-ancestry genomic analyses to accelerate the identification of OCD risk loci, fine-map putative causal variants, and improve the performance of polygenic risk scores in diverse populations. We will also capitalize on rich clinical data to examine the genetics of treatment response, biologically plausible OCD subtypes, and symptom dimensions. Additionally, LATINO will help elucidate the diversity of the clinical presentations of OCD across cultures through various trainings developed and offered in collaboration with Latin American investigators. We believe this study will advance the important goal of global mental health discovery and equity.

Modeling of Compulsive Behavior Types of Obsessive-Compulsive Disorder Patients by Using the Data Mining Method

Data mining is a method that is used to find data that are precise, previously uncertain, and logical values from a comprehensive set of information. Data mining is used as a tool for determining the accuracy of classifications of data obtained in the field of bioinformatics by using different algorithm approaches. In this study, the data mining method was used to classify the accuracy of different algorithms and predict the types of compulsive behavior of patients with obsessive compulsive disorder. Data collected from a total of 164 people, 70 males and 94 females, were analyzed. The age range of the people participating in the study was between 7 and 73, and the calculated mean age was 32.4. Data about sociodemographic characteristics, course of disease, treatments, family histories, obsession, and compulsion types of the participants were collected through data collection instruments. Classification algorithm methods found in WEKA software were chosen to process the data. The effect of the types of obsession on the types of compulsion was determined using regression models. The levels of success of the generated models were compared. The results of the study demonstrated the presence of a moderate positive correlation (.35) between these two variables. According to the coefficient of determination, obsession explained 11% of the variance in compulsion. These findings supported the established hypothesis that the effect of the types of obsession was effective on the types of compulsion.

Obsessive compulsive disorder during the COVID-19 pandemic: A brief review of course, psychological assessment and treatment considerations

Obsessive-compulsive disorder (OCD) is an impairing mental health condition defined by intense distress in the presence of unwanted, recurrent thoughts, images, or impulses which are accompanied by compulsions and avoidance performed to reduce distress. During the COVID-19 pandemic, OCD has continued to be an impairing mental health condition regardless of symptom dimensionality (e.g., contamination, harm, etc.) with varying reports of the overall clinical course. However, changes in the assessment, treatment, and diagnosis of OCD have occurred to personalize care and be aligned with public health guidelines. Exposure and response prevention and pharmacotherapy remain the treatment of choice, even though the setting in which treatment is conducted may have shifted. Telehealth in particular has been a 'game-changer' for clinicians and patients alike. Given the continued health risk posed by the pandemic, treatment personalization should still be made to ensure safety for both patients and providers while balancing efficacy and patient preferences.

A dimensional perspective on the genetics of obsessive-compulsive disorder

This review covers recent findings in the genomics of obsessive-compulsive disorder (OCD), obsessive-compulsive symptoms, and related traits from a dimensional perspective. We focus on discoveries stemming from technical and methodological advances of the past five years and present a synthesis of human genomics research on OCD. On balance, reviewed studies demonstrate that OCD is a dimensional trait with a highly polygenic architecture and genetic correlations to multiple, often comorbid psychiatric phenotypes. We discuss the phenotypic and genetic findings of these studies in the context of the dimensional framework, relying on a continuous phenotype definition, and contrast these observations with discoveries based on a categorical diagnostic framework, relying on a dichotomous case/control definition. Finally, we highlight gaps in knowledge and new directions for OCD genetics research.

Symmetry Dimension in Obsessive-Compulsive Disorder: Prevalence, Severity and Clinical Correlates

Background: Obsessive–compulsive disorder (OCD) is a very heterogeneous condition that frequently includes symptoms of the “symmetry dimension” (i.e., obsessions and/or compulsions of symmetry, ordering, repetition, and counting), along with aggressive, sexual/religious, contamination/cleaning, and hoarding dimensions. Methods: This cross-sectional study aimed to investigate the prevalence, severity, and demographic and clinical correlates of the symmetry dimension among 1001 outpatients from the Brazilian Research Consortium on Obsessive–Compulsive Spectrum Disorders. The main assessment instruments used were the Dimensional Yale–Brown Obsessive–Compulsive Scale, the Yale–Brown Obsessive–Compulsive Scale, the USP-Sensory Phenomena Scale, the Beck Depression and Anxiety Inventories, the Brown Assessment of Beliefs Scale, and the Structured Clinical Interview for DSM-IV Axis I Disorders. Chi-square tests, Fisher’s exact tests, Student’s t-tests, and Mann–Whitney tests were used in the bivariate analyses to compare patients with and without symptoms of the symmetry dimension. Odds ratios (ORs) with confidence intervals and Cohen’s D were also calculated as effect size measures. Finally, a logistic regression was performed to control for confounders. Results: The symmetry dimension was highly prevalent (86.8%) in this large clinical sample and, in the logistic regression, it remained associated with earlier onset of obsessive–compulsive symptoms, insidious onset of compulsions, more severe depressive symptoms, and presence of sensory phenomena. Conclusions: A deeper knowledge about specific OCD dimensions is essential for a better understanding and management of this complex and multifaceted disorder.

Are There Familial Patterns of Symptom Dimensions in Obsessive-Compulsive Disorder?

Background: Obsessive-compulsive disorder (OCD) is a heterogeneous illness, and emerging evidence suggests that different symptom dimensions may have distinct underlying neurobiological mechanisms. We aimed to look for familial patterns in the occurrence of these symptom dimensions in a sample of families with at least two individuals affected with OCD. Methods: Data from 153 families (total number of individuals diagnosed with DSM-5 OCD = 330) recruited as part of the Accelerator Program for Discovery in Brain Disorders using Stem Cells (ADBS) was used for the current analysis. Multidimensional Item Response Theory (IRT) was used to extract dimensional scores from the Yale-Brown Obsessive-Compulsive Scale (YBOCS) checklist data. Using linear mixed-effects regression models, intra-class correlation coefficients (ICC), for each symptom dimension, and within each relationship type were estimated. Results: IRT yielded a four-factor solution with Factor 1 (Sexual/Religious/Aggressive), Factor 2 (Doubts/Checking), Factor 3 (Symmetry/Arranging), and Factor 4 (Contamination/Washing). All except for Factor 1 were found to have significant ICCs, highest for Factor 3 (0.41) followed by Factor 4 (0.29) and then Factor 2 (0.27). Sex-concordant dyads were found to have higher ICC values than discordant ones, for all the symptom dimensions. No major differences in the ICC values between parent-offspring and sib-pairs were seen. Conclusions: Our findings indicate that there is a high concordance of OCD symptom dimensions within multiplex families. Symptom dimensions of OCD might thus have significant heritability. In view of this, future genetic and neurobiological studies in OCD should include symptom dimensions as a key parameter in their analyses.

Is it time to change the gold standard of obsessive-compulsive disorder severity assessment? Factor structure of the Yale-Brown Obsessive-Compulsive Scale

OBJECTIVES

The Yale-Brown Obsessive-Compulsive Scale has been considered the gold standard scale to assess obsessive-compulsive disorder severity. Previous studies using exploratory factor analysis and confirmatory factor analysis with this scale showed mixed findings in terms of factor structure and fit of models. Therefore, we used confirmatory factor analysis to compare different Yale-Brown Obsessive-Compulsive Scale models in a large sample aiming to identify the best model fit.

METHODS

We assessed adult obsessive-compulsive disorder patients (n = 955) using three measures: Yale-Brown Obsessive-Compulsive Scale severity ratings, the Dimensional Yale-Brown Obsessive-Compulsive Scale and the clinical global impression scale. We tested all factor structures reported by previous studies to investigate which model best fitted the data: one-factor, two-factor, three-factor and their equivalent high-order solutions. We also investigated Yale-Brown Obsessive-Compulsive Scale items correlations with scores from the other measures of obsessive-compulsive disorder severity.

RESULTS

Confirmatory factor analysis models presented mediocre to fair goodness-of-fit indexes. Severity items related to resistance to obsessions and compulsions presented low factor loadings. The model with the best fit indexes was a high-order model without obsessive-compulsive disorder resistance items. These items also presented small correlations with other obsessive-compulsive disorder severity measures.

CONCLUSION

The obsessive-compulsive disorder field needs to discuss further improvements in the Yale-Brown Obsessive-Compulsive Scale and/or continue to search for better measures of obsessive-compulsive disorder severity.

Looking into the genetic bases of OCD dimensions: a pilot genome-wide association study

The multidimensional nature of obsessive-compulsive disorder (OCD) has been consistently reported. Clinical and biological characteristics have been associated with OCD dimensions in different ways. Studies suggest the existence of specific genetic bases for the different OCD dimensions. In this study, we analyze the genomic markers, genes, gene ontology and biological pathways associated with the presence of aggressive/checking, symmetry/order, contamination/cleaning, hoarding, and sexual/religious symptoms, as assessed via the Dimensional Yale-Brown Obsessive Compulsive Scale (DY-BOCS) in 399 probands. Logistic regression analyses were performed at the single-nucleotide polymorphism (SNP) level. Gene-based and enrichment analyses were carried out for common (SNPs) and rare variants. No SNP was associated with any dimension at a genome-wide level (p < 5 × 10^-8). Gene-based analyses showed one gene to be associated with hoarding (SETD3, p = 1.89 × 10^-08); a gene highly expressed in the brain and which plays a role in apoptotic processes and transcriptomic changes, and another gene associated with aggressive symptoms (CPE; p = 4.42 × 10^-6), which is involved in neurotrophic functions and the synthesis of peptide hormones and neurotransmitters. Different pathways or biological processes were represented by genes associated with aggressive (zinc ion response and lipid metabolism), order (lipid metabolism), sexual/religious (G protein-mediated processes) and hoarding (metabolic processes and anion transport) symptoms after FDR correction; while no pathway was associated with contamination. Specific genomic bases were found for each dimension assessed, especially in the enrichment analyses. Further research with larger samples and different techniques, such as next-generation sequencing, are needed to better understand the differential genetics of OCD dimensions.

Review of source-monitoring processes in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a severe mental illness characterized by persistent, intrusive and distressing obsessions and/or compulsions. Such symptoms have been conceptualized as resulting from a failure in source-monitoring processes, suggesting that patients with OCD fail to distinguish actions they perform from those they just imagine doing. In this study, we aimed to provide an updated and exhaustive review of the literature examining the relationship between source-monitoring and OCD. A systematic search in the literature through January 2019 allowed us to identify 13 relevant publications investigating source-monitoring abilities in patients with OCD or participants with subclinical compulsive symptoms. Most of the retrieved studies did not report any source-monitoring deficits in clinical and subclinical subjects compared with healthy volunteers. However, most of the studies reported that patients with OCD and subclinical subjects displayed reduced confidence in source-monitoring judgments or global cognitive confidence compared to controls. The present review highlighted some methodological and statistical limitations. Consequently, further studies are needed to explore source monitoring with regard to the subcategories of OCD symptoms (i.e., symmetry-ordering, contamination-washing, hoarding, aggressive obsession-checking, sexual-religious thoughts) and to clarify the relationship between source-monitoring subtypes (i.e., reality or internal source-monitoring) and confidence in these populations.

Nordic OCD & Related Disorders Consortium: Rationale, design, and methods

Obsessive-compulsive disorder (OCD) is a debilitating psychiatric disorder, yet its etiology is unknown and treatment outcomes could be improved if biological targets could be identified. Unfortunately, genetic findings for OCD are lagging behind other psychiatric disorders. Thus, there is a pressing need to understand the causal mechanisms implicated in OCD in order to improve clinical outcomes and to reduce morbidity and societal costs. Specifically, there is a need for a large-scale, etiologically informative genetic study integrating genetic and environmental factors that presumably interact to cause the condition. The Nordic countries provide fertile ground for such a study, given their detailed population registers, national healthcare systems and active specialist clinics for OCD. We thus formed the Nordic OCD and Related Disorders Consortium (NORDiC, www.crowleylab.org/nordic), and with the support of NIMH and the Swedish Research Council, have begun to collect a large, richly phenotyped and genotyped sample of OCD cases. Our specific aims are geared toward answering a number of key questions regarding the biology, etiology, and treatment of OCD. This article describes and discusses the rationale, design, and methodology of NORDiC, including details on clinical measures and planned genomic analyses.

A comparison of cluster and factor analytic techniques for identifying symptom-based dimensions of obsessive-compulsive disorder

A growing body of literature suggests that obsessive-compulsive disorder (OCD) is a heterogeneous condition. The studies investigating symptom dimensions have been limited by numerous methodological differences and sample characteristics. The purpose of this study was to compare the two most commonly applied statistical techniques used in addressing this question in the same large cohort of individuals with OCD. Both cluster analysis and factor analysis were used to examine OCD symptom data as measured by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) Symptom Checklist for 355 individuals with a primary diagnosis of OCD. The factor analysis revealed a three-factor model best described as symmetry obsessions/ordering compulsions, contamination obsessions/cleaning compulsions and aggressive obsessions/checking compulsions. In contrast, the cluster analysis yielded a stable four-cluster solution best described as symmetry obsessions/ordering compulsions, contamination obsessions/cleaning compulsions, aggressive-somatic-religious obsessions/checking compulsions and a mixed symptom profile. Although there was overlap in the models resulting from these two statistical approaches, cluster analysis better captured the dimensional nature of OCD by demonstrating the prevalence of symptom categories in each subgroup. Though both analyses are capable of providing similar outputs, the validity of these results is limited given the input of a priori symptom categories from the Y-BOCS.

Early intervention for obsessive compulsive disorder: An expert consensus statement

Obsessive-compulsive disorder (OCD) is common, emerges early in life and tends to run a chronic, impairing course. Despite the availability of effective treatments, the duration of untreated illness (DUI) is high (up to around 10 years in adults) and is associated with considerable suffering for the individual and their families. This consensus statement represents the views of an international group of expert clinicians, including child and adult psychiatrists, psychologists and neuroscientists, working both in high and low and middle income countries, as well as those with the experience of living with OCD. The statement draws together evidence from epidemiological, clinical, health economic and brain imaging studies documenting the negative impact associated with treatment delay on clinical outcomes, and supporting the importance of early clinical intervention. It draws parallels between OCD and other disorders for which early intervention is recognized as beneficial, such as psychotic disorders and impulsive-compulsive disorders associated with problematic usage of the Internet, for which early intervention may prevent the development of later addictive disorders. It also generates new heuristics for exploring the brain-based mechanisms moderating the 'toxic' effect of an extended DUI in OCD. The statement concludes that there is a global unmet need for early intervention services for OC related disorders to reduce the unnecessary suffering and costly disability associated with under-treatment. New clinical staging models for OCD that may be used to facilitate primary, secondary and tertiary prevention within this context are proposed.

Examining the factor structure of the self-report Yale-Brown Obsessive Compulsive Scale Symptom Checklist

Obsessive-compulsive symptom dimensions are important in studies about the pathogenesis and treatment of obsessive-compulsive disorder. More than 30 factor analytic studies using the Yale-Brown Obsessive Compulsive Scale Symptom Checklist (Y-BOCS-SC) interview version have been published. However, a drawback of the Y-BOCS-SC interview is that it is time-consuming for the clinician. Baer's self-report version of the Y-BOCS-SC could be a less time-consuming alternative. The purpose of this study was to examine the factor structure of Baer's self-report Y-BOCS-SC. In a sample of 286 patients, we performed two factor analyses, one using categories and one using items of the Y-BOCS-SC. Using category-level data, we identified four factors; when using items we identified six factors. Symptom dimensions for contamination/cleaning, symmetry/repeating/counting/ordering and hoarding were found in both analyses. The impulsive aggression, pathological doubt, sexual, religious somatic and checking categories formed one factor in the analysis using category-level data and divided into three factors using item-level data. These factors correspond with studies using the interview version and support our hypothesis that the self-report version of the Y-BOCS-SC could be an alternative for the interview version.

Systematic review of co-occurring OCD and TD: Evidence for a tic-related OCD subtype?

OBJECTIVE

The aim of this review is to summarize the current knowledge of associated features of co-occurring obsessive-compulsive disorder (OCD) and tic disorders (TD) and to critically evaluate hypotheses regarding the nature of their comorbidity.

METHOD

We conducted a systematic review following PRISMA guidelines. To this aim, the PubMed, PsychInfo and ISI Web of Knowledge databases were searched up to August 30, 2018. For gender and age-of-onset we additionally conducted meta-analyses.

RESULTS

One hundred eighty-nine studies met inclusion criteria. We substantiate some acknowledged features and report evidence for differential biological mechanisms and treatment response. In general, studies were of limited methodological quality.

CONCLUSIONS

Several specific features are reliable associated with co-occurring OCD + TD. The field lacks methodological sound studies. The review found evidence against and in favor for different hypotheses regarding the nature of comorbidity of OCD and TD. This could indicate the existence of a stepwise model of co-morbidity, or could be an artefact of the low methodological quality of studies.

A call for prevention and early intervention in obsessive-compulsive disorder

BACKGROUND

Evidence suggests that many people with obsessive-compulsive disorder (OCD) have subclinical symptoms years before the development of their disorder and that early treatment may reduce its severity.

AIM

To explore prevention and early intervention strategies for OCD.

METHODS

A narrative literature review was conducted.

RESULTS

The literature in relation to the prevention of OCD is sparse. Genetic and environmental factors appear to be relevant to the aetiology of OCD, for example, the observation that hoarding symptoms and contamination/cleaning symptoms are more likely to also be present in first-degree relatives. Psychoeducation and the reduction of family accommodation, that is the act of parents, siblings or partners accommodating to the high-risk individual's requests to comply with their compulsions, are promising areas for prevention and early intervention in high-risk groups. Tertiary prevention has also been limited by an inadequate number of trained clinicians to deliver evidence-based treatments.

CONCLUSIONS

Much more research is needed in relation to the prevention of OCD. There is limited scope for primary prevention with respect to biological aetiological factors, but there is potential for strategies addressing environmental factors (eg, family factors). The effectiveness of psychoeducation for parents with OCD as a primary prevention strategy for OCD in their children requires scientific evaluation. Improving access to effective treatments for OCD would also improve tertiary prevention.

Obsessive-compulsive symptoms in children with first degree relatives diagnosed with obsessive-compulsive disorder

Objective:

A first-degree relative affected by obsessive-compulsive disorder (OCD) and obsessive-compulsive symptoms (OCS) in childhood is an important risk factor for developing the disorder in adulthood. The relationship between a family history of OCD and the presence of OCS and its correlates in childhood is not well established.

Methods:

A total of 66 children whose parents or siblings have been diagnosed with OCD were assessed for the presence of OCS and clinical correlates.

Results:

Three children (4.5%) were reported to have received an OCD diagnosis and another 26 (39.4%) were identified as having OCS. Children with OCS had higher rates of coercive behavior and came from families with lower socioeconomic status. Contamination/cleaning dimension symptoms in the proband were associated with OCS in the assessed children.

Conclusion:

OCS are frequent among family members of individuals with OCD and are associated with socioeconomic status, coercive behaviors and proband contamination/cleaning symptoms. Future longitudinal studies should test the risk of developing OCD in association with these characteristics.

Factor analysis of symptom profile in early onset and late onset OCD

This study aimed to assess the factor structure of early and late onset OCD. Additionally, cluster analysis was conducted in the same sample to assess the applicability of the factors. 345 participants were assessed with Yale Brown Obsessive Compulsive Scale symptom checklist. Patients were classified as early onset (onset of symptoms at age ≤ 18 years) and late onset (onset at age > 18 years) OCD depending upon the age of onset of the symptoms. Factor analysis and cluster analysis of early-onset and late-onset OCD was conducted. The study sample comprised of 91 early onset and 245 late onset OCD subjects. Males were more common in the early onset group. Differences in the frequency of phenomenology related to contamination related, checking, repeating, counting and ordering/arranging compulsions were present across the early and late onset groups. Factor analysis of YBOCS revealed a 3 factor solution for both the groups, which largely concurred with each other. These factors were named as hoarding and symmetry (factor-1), contamination (factor-2) and aggressive, sexual and religious factor (factor-3). To conclude this study shows that factor structure of symptoms of OCD seems to be similar between early-onset and late-onset OCD.

Association of the functional serotonin transporter haplotype with familial form of obsessive compulsive disorder in Iranian patients

OBJECTIVE

Several polymorphisms have been reported in the 5-HTTLPR of the serotonin transporter gene (SLC6A4). Family-based evidences for the association of 5-HTTLPR polymorphisms with OCD were previously reported but results were controversial. The present study investigated the possible correlation of SLC6A4 polymorphisms (5-HTTLPR, rs25532, rs25531) in Iranian OCD patients considering gender, age of onset, family history of psychiatric disorders, obsessive and compulsive subtypes and severities.

METHODS

The included OCD patients fulfilled the criteria for DSM-IV-TR whom Y-BOCS score was more than 9. Blood samples (184 cases and 192 controls) were genotyped by means of PCR-RFLP.

RESULTS

Mean of Y-BOCS scores of included patients was 20.1 ± 0.69. Rs25532 CC genotype showed significant association with OCD in men and were detected more in the patients reported positive family history of psychiatric disorders but the other single loci (5-HTTLPR and rs25531) did not associate with OCD. Haplotype analysis showed significant association of 14-A variant with OCD and revealed the association of 14-A/14-A genotype with familial form of OCD.

CONCLUSIONS

The findings of this study showed the association of SLC6A4 variants with familial form of OCD and proposed stratified analyses in the genetic studies facilitate identification of genetic risk factors for this heterogeneous disorder.

Symptom dimensions in obsessive-compulsive disorder as predictors of neurobiology and treatment response

Purpose of review

Specific symptom dimensions of obsessive-compulsive disorder (OCD) have been suggested as an approach to reduce the heterogeneity of obsessive-compulsive disorder, predict treatment outcome, and relate to brain structure and function. Here, we review studies addressing these issues.

Recent findings

The contamination and symmetry/ordering dimensions have not been reliably associated with treatment outcome. Some studies found that greater severity of sexual/aggressive/religious symptoms predicted a worse outcome after cognitive behavioral therapy (CBT) and a better outcome after serotonin reuptake inhibitors (SRIs). Contamination symptoms have been related to increased amygdala and insula activation in a few studies, while sexual/aggressive/religious symptoms have also been related to more pronounced alterations in the function and structure of the amygdala. Increased pre-treatment limbic responsiveness has been related to better outcomes of CBT, but most imaging studies show important limitations and replication in large-scale studies is needed. We review possible reasons for the strong limbic involvement of the amygdala in patients with more sexual/aggressive/religious symptoms, in relation to their sensitivity to CBT.

Summary

Symptom dimensions may predict treatment outcome, and patients with sexual/religious/aggressive symptoms are at a greater risk of not starting or delaying treatment. This is likely partly due to more shame and perceived immorality which is also related to stronger amygdala response. Competently delivered CBT is likely to help these patients improve to the same degree as patients with other symptoms.

Impaired Antisaccades in Obsessive-Compulsive Disorder: Evidence From Meta-Analysis and a Large Empirical Study

Increasing evidence indicates that patients with obsessive-compulsive disorder (OCD) exhibit alterations in fronto-striatal circuitry. Performance deficits in the antisaccade task would support this model, but results from previous small-scale studies have been inconclusive as either increased error rates, prolonged antisaccade latencies, both or neither have been reported in OCD patients. In order to address this issue, we investigated antisaccade performance in a large sample of OCD patients (n = 169) and matched control subjects (n = 183). As impaired antisaccade performance constitutes a potential endophenotype of OCD, unaffected first-degree relatives of OCD patients (n = 100) were assessed, as well. Furthermore, we conducted a quantitative meta-analysis to integrate our data with previous findings. In the empirical study, OCD patients exhibited significantly increased antisaccade latencies, intra-subject variability (ISV) of antisaccade latencies, and antisaccade error rates. The latter effect was driven by errors with express latency (80-130 ms), as patients did not differ significantly from controls with regards to regular errors (>130 ms). Notably, unaffected relatives of OCD patients showed elevated antisaccade express error rates and increased ISV of antisaccade latencies, as well. Antisaccade performance was not associated with state anxiety within groups. Among relatives, however, we observed a significant correlation between antisaccade error rate and harm avoidance. Medication status of OCD patients, symptom severity, depressive comorbidity, comorbid anxiety disorders and OCD symptom dimensions did not significantly affect antisaccade performance. Meta-analysis of 10 previous and the present empirical study yielded a medium-sized effect (SMD = 0.48, p < 0.001) for higher error rates in OCD patients, while the effect for latencies did not reach significance owing to strong heterogeneity (SMD = 0.51, p = 0.069). Our results support the assumption of impaired antisaccade performance in OCD, although effects sizes were only moderately large. Furthermore, we provide the first evidence that increased antisaccade express error rates and ISV of antisaccade latencies may constitute endophenotypes of OCD. Findings regarding these more detailed antisaccade parameters point to potentially underlying mechanisms, such as early pre-stimulus inhibition of the superior colliculus.

Quantifying dimensional severity of obsessive-compulsive disorder for neurobiological research

Current research to explore genetic susceptibility factors in obsessive-compulsive disorder (OCD) has resulted in the tentative identification of a small number of genes. However, findings have not been readily replicated. It is now broadly accepted that a major limitation to this work is the heterogeneous nature of this disorder, and that an approach incorporating OCD symptom dimensions in a quantitative manner may be more successful in identifying both common as well as dimension-specific vulnerability genetic factors. As most existing genetic datasets did not collect specific dimensional severity ratings, a specific method to reliably extract dimensional ratings from the most widely used severity rating scale, the Yale-Brown Obsessive Compulsive Scale (YBOCS), for OCD is needed. This project aims to develop and validate a novel algorithm to extrapolate specific dimensional symptom severity ratings in OCD from the existing YBOCS for use in genetics and other neurobiological research. To accomplish this goal, we used a large data set comprising adult subjects from three independent sites: the Brazilian OCD Consortium, the Sunnybrook Health Sciences Centre in Toronto, Canada and the Hospital of Bellvitge, in Barcelona, Spain. A multinomial logistic regression was proposed to model and predict the quantitative phenotype [i.e., the severity of each of the five homogeneous symptom dimensions of the Dimensional YBOCS (DYBOCS)] in subjects who have only YBOCS (categorical) data. YBOCS and DYBOCS data obtained from 1183 subjects were used to build the model, which was tested with the leave-one-out cross-validation method. The model's goodness of fit, accepting a deviation of up to three points in the predicted DYBOCS score, varied from 78% (symmetry/order) to 84% (cleaning/contamination and hoarding dimensions). These results suggest that this algorithm may be a valuable tool for extracting dimensional phenotypic data for neurobiological studies in OCD.

Relationships between neuropsychological variables and factor-analysed symptom dimensions in obsessive compulsive disorder

Despite mounting evidence for the distinctiveness of symptom dimensions in obsessive-compulsive disorder, neuropsychological studies have been few, focused on small samples, and relying on classification of participants based on mutually exclusive symptom categories, resulting in lack of concordance across neuropsychological and imaging studies. Neuropsychological assessment was undertaken with 150 individuals with DSM IV OCD, and neuropsychological variables were analysed in relation to symptom dimension scores derived from factor analysis. Five dimensions were derived from principal components analysis with varimax rotation - contamination/washing, doubts/checking, symmetry/ordering, forbidden thoughts, and hoarding. After controlling for severity of depression and OCD, antipsychotic and benzodiazepine use, and all other symptom dimensions, washing was associated with poorer attention/working memory, visuo-spatial construction and better planning time; checking was related to poorer alternation learning; symmetry linked with poorer verbal fluency; forbidden thoughts with better visuospatial scanning and working memory; hoarding with poorer immediate verbal recall and better visuospatial working memory. The neuropsychological associations are explained in the context of existing neuroimaging evidence, and the clinical picture of each symptom dimension. The use of factor-analysed symptom dimensions and a large sample of individuals with OCD are strengths of the study.

Parental bonding and hoarding in obsessive-compulsive disorder

BACKGROUND

Hoarding behavior may indicate a clinically and possibly etiologically distinct subtype of obsessive-compulsive disorder (OCD). Empirical evidence supports a relationship between hoarding and emotional over-attachment to objects. However, little is known about the relationship between hoarding and parental attachment in OCD.

METHOD

The study sample included 894 adults diagnosed with DSM-IV OCD who had participated in family and genetic studies of OCD. Participants were assessed for Axis I disorders, personality disorders, and general personality dimensions. The Parental Bonding Instrument (PBI) was used to assess dimensions of perceived parental rearing (care, overprotection, and control). We compared parental PBI scores in the 334 hoarding and 560 non-hoarding participants, separately in men and women. We used logistic regression to evaluate the relationship between parenting scores and hoarding in women, adjusting for other clinical features associated with hoarding.

RESULTS

In men, there were no significant differences between hoarding and non-hoarding groups in maternal or paternal parenting scores. In women, the hoarding group had a lower mean score on maternal care (23.4 vs. 25.7, p<0.01); a higher mean score on maternal protection (9.4 vs. 7.7, p<0.001); and a higher mean score on maternal control (7.0 vs. 6.2, p<0.05), compared to the non-hoarding group. The magnitude of the relationships between maternal bonding dimensions and hoarding in women did not change after adjustment for other clinical features. Women who reported low maternal care/high maternal protection had significantly greater odds of hoarding compared to women with high maternal care/low maternal protection (OR=2.54, 95% CI=1.60-4.02, p<0.001).

CONCLUSIONS

Perceived poor maternal care, maternal overprotection, and maternal overcontrol are associated with hoarding in women with OCD. Parenting dimensions are not related to hoarding in men. These findings provide further support for a hoarding subtype of OCD and for sex-specific differences in etiologic pathways for hoarding in OCD.

Examination of a Bifactor Model of Obsessive-Compulsive Symptom Dimensions

Although obsessive-compulsive (OC) symptoms are observed along four dimensions (contamination, responsibility for harm, order/symmetry, and unacceptable thoughts), the structure of the dimensions remains unclear. The current study evaluated a bifactor model of OC symptoms among those with and without obsessive-compulsive disorder (OCD). The goals were (a) to evaluate if OC symptoms should be conceptualized as unidimensional or whether distinct dimensions should be interpreted and (b) to use structural equation modeling to examine the convergence of the OC dimensions above and beyond a general dimension with related criteria. Results revealed that a bifactor model fit the data well and that OC symptoms were influenced by a general dimension and by four dimensions. Measurement invariance of the bifactor model was also supported among those with and without OCD. However, the general OC dimension accounted for only half of the variability in OC symptoms, with the remaining variability accounted for by distinct dimensions. Despite evidence of multidimensionality, the dimensions were unreliable after covarying for the general OC dimension. However, the four dimensions did significantly converge with a latent OC spectrum factor above and beyond the general OC dimension. The implications of these findings for conceptualizing the structure of OCD are discussed.

Validation of the Spanish version of the Dimensional Yale-Brown Obsessive-Compulsive Scale (DYBOCS) in children and adolescents

BACKGROUND

Obsessive-compulsive disorder (OCD) is best understood as a complex overlap of obsessive-compulsive (OC) symptom dimensions with specific clinical and etiological characteristics. The Dimensional Yale-Brown Obsessive-Compulsive Scale (DYBOCS) was developed to assess the presence and severity of each of these OC symptom dimensions. Despite showing excellent psychometric properties in adults, the psychometric properties of the DYBOCS have not been widely investigated in children and adolescents.

METHODS

We examined the psychometric properties of the DYBOCS Spanish version in a sample of 97 OCD children and adolescents.

RESULTS

The results of the psychometric analyses were excellent overall. The internal consistency for each OC symptom dimension was high, although somewhat lower than in previous studies with adult samples. The DYBOCS showed overall good convergent and divergent validity. Factors obtained from a principal component analysis corresponded with the five DYBOCS dimensions (aggressive; sexual/religious; contamination; symmetry; and hoarding) and each one accounted for approximately 20% of the variance.

CONCLUSIONS

The DYBOCS is a valid instrument for assessing the frequency and severity of OC symptom dimensions in children and adolescents with OCD. The principal component analysis supported the division of OC symptoms into five dimensions. OCD is a heterogeneous disorder, and a dimensional approach can help to understand its clinical, etiological and treatment response characteristics.

The familiality of specific symptoms of obsessive-compulsive disorder

This study aimed to assess whether a family history of specific OCD symptoms was associated with the same OCD symptoms in study participants. Participants were sampled from the Nepean OCD study (N=206) and were assessed with the Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC) and the Vancouver Obsessional Compulsive Inventory (VOCI) in order to determine their OCD symptoms. A family history screen was used to determine whether participants had a first-degree relative with a history of any of the following specific symptoms: hoarding, contamination/cleaning, symmetry/ordering, doubt/checking and/or other OCD symptoms. The characteristics of participants with a family history of a specific OCD symptom were compared to those of participants with a family history of any other OCD symptom. This was repeated for each specific OCD symptom. The roles of co-occurring tics and age of onset of OCD were also assessed. Distinct familial associations were detected for the symptoms of hoarding and contamination/cleaning. Age of onset of OCD was significantly younger in participants who reported a family history of "other" symptoms. These findings suggest that certain OCD symptom dimensions are more familial than others, which has significant implications for aetiology of OCD.

DISTINCT ETIOLOGICAL INFLUENCES ON OBSESSIVE-COMPULSIVE SYMPTOM DIMENSIONS: A MULTIVARIATE TWIN STUDY

BACKGROUND

Obsessive-compulsive disorder (OCD) is characterized by five major dimensions, including contamination/washing, harm/checking, symmetry/ordering, hoarding, and forbidden thoughts. How these dimensions may relate etiologically to the symptoms of other obsessive-compulsive related disorders (OCRDs) and anxiety disorders (ADs) is not well known. The aim of this study was to examine the genetic and environmental overlap between each major obsessive-compulsive dimension with the symptoms of other OCRDs and ADs.

METHODS

Two thousand four hundred ninety-five twins of both sexes, aged between 18 and 45 years, were recruited from the Australian Twin Registry. Measures used scores on four dimensions (obsessing (forbidden thoughts), washing, checking, and ordering) of the Obsessive-Compulsive Inventory-Revised, Dysmorphic Concerns Questionnaire, Hoarding Rating Scale, Anxiety Sensitivity Index, Social Phobia Inventory, and Stress subscale of the Depression, Anxiety, and Stress Scale. Multivariate twin modeling methods using continuous and categorized variables were performed, also controlling for age and gender.

RESULTS

Our findings suggested that forbidden thoughts and washing demonstrated the strongest genetic overlap with other AD symptoms, while ordering was genetically related to OCRD symptoms. Common genetic influences on checking symptoms were best estimated when modeling OCRDs together with AD symptoms. Common environmental factors of ordering and checking were shared with AD symptoms.

CONCLUSIONS

Important shared genetic and environmental risk factors exist between OCD, OCRDs, and ADs, but which vary alongside the expression of its major dimensions.

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.

Incompleteness, aesthetic sensitivity, and the obsessive-compulsive need for symmetry

BACKGROUND AND OBJECTIVES

The "need for symmetry" is a well recognized yet little understood feature of obsessive-compulsive (OC) experience. In light of the strong associations between the OC-related trait of incompleteness and symmetry-related behaviors and symptoms, and between perceptual symmetry and aesthetic judgments, this study examined whether trait incompleteness is associated with enhanced natural aesthetic skill and/or aesthetic sensitivity, particularly as they pertain to visual symmetry.

METHODS

A quasi-experimental design was used to compare the responses of nonclinical individuals with high versus average levels of trait incompleteness on self-report measures and two performance measures of aesthetic judgment.

RESULTS

Compared to controls, participants high in incompleteness reported higher levels of self-perceived symmetry-related concerns and behaviors, and displayed greater aesthetic sensitivity in the form of substantially heightened preferences for symmetry in images. Contrary to the hypothesis relating to aesthetic skill, however, the two groups did not differ in their capacity to estimate accurately the objective aesthetic value of images. Nor did they differ in self-reported aesthetics interests and background.

LIMITATIONS

A clinical sample was not included.

CONCLUSIONS

Findings provide evidence that high trait incompleteness is associated not just with symptomatic symmetry-related concerns but with a nonspecific heightened preference for visual symmetry. Conceptual implications are discussed, particularly the potential value of the perceptual fluency theory of symmetry and aesthetic response for explaining the association between incompleteness and symmetry preferences and symptoms.

Evaluating effect of symptoms heterogeneity on decision-making ability in obsessive-compulsive disorder

AIMS

Despite having a univocal definition, obsessive-compulsive disorder (OCD) shows a remarkably phenotypic heterogeneity. The published reports show impaired decision-making in OCD patients, using tasks such as the Iowa Gambling Task (IGT). We wanted to verify the hypothesis of an IGT worse performance in a large sample of OCD patients and healthy control (HC) subjects and to examine the relation between neuropsychological performance in IGT and the OCD symptoms heterogeneity.

METHODS

Binary data from the Yale-Brown Obsessive Compulsive Scale collected on a large sample of OCD patients were analyzed using a multidimensional item response theory model to explore the underlying structure of data, thus revealing latent factors. Factor scores were categorized into quartiles. Then, for each factor, we identified patients respectively with the highest versus lowest score. We evaluated whether symptom dimensions affect the probability of a correct answer over time generalized, during IGT performance, fitting a generalized linear mixed model.

RESULTS

We found a general deficit in ambiguous decision-making in OCD compared to HC. Moreover, our findings suggested that OCD symptoms heterogeneity affects decision-making learning abilities during IGT. In fact, while 'Symmetry' and 'Washing' patients showed a learning curve during the task, other subgroups did not.

CONCLUSIONS

Our study confirmed previous findings suggesting that OCD is characterized by a deficit in decision-making under uncertainty. Moreover, our study gave evidence about biological specificity for each symptom dimension in OCD. Data were discussed in the context of the somatic marker hypothesis, which was hypothesized to be reduced in OCD patients.

Electrophysiology of facilitation priming in obsessive-compulsive and panic disorders

OBJECTIVE

Repeated experience with stimuli often primes faster, more efficient neuronal and behavioural responses. Exaggerated repetition priming effects have previously been reported in obsessive-compulsive disorder (OCD), however little is known of their underlying neurobiology or disorder-specificity, hence we investigated these factors.

METHODS

We examined event-related potentials (ERPs) and behaviour while participants with OCD, panic disorder and healthy controls (20 per group) performed a Go/NoGo task which manipulated target repetition sequences.

RESULTS

Both clinical groups showed stronger reaction time (RT) priming than HCs, which in OCD was greater in a checking, than washing, subgroup. Both clinical groups had similar RT deficits and ERP anomalies across several components, which correlated with psychopathology and RT priming. In OCD alone, N1 latency tended to increase to repeated stimuli, correlated with O-C symptoms, whereas it decreased in other groups. OCD-checkers had smaller target P2 amplitude than all other groups.

CONCLUSIONS

Enhanced neural priming is not unique to OCD and may contribute to salient sensory-cognitive experiences in anxiety generally. These effects are related to symptom severity and occur to neutral stimuli and in the context of overall RT impairment, suggesting they may be clinically relevant and pervasive. The results indicate overlapping information-processing and neurobiological factors across disorders, with indications of OCD-specific trends and subgroup differences.

SIGNIFICANCE

This first electrophysiological investigation of OCD priming in OCD to include anxious controls and OCD subgroups allows for differentiation between overlapping and OCD-specific phenomena, to advance neurobiological models of OCD.

Pure Obsessive Compulsive Disorder in Three Generations

Introduction:

Obsessive-compulsive disorder (OCD) is a psychiatric disorder, which has been shown to affect 2 - 3.5% of people, during their lifetimes. Identification of familial more homogenous characteristics of OCD may help to define relevant subtypes and increase the power of genetic and neurobiological studies of OCD.

Case Presentation;

This case report describes an adult woman suffering from symptoms of energy loss, insomnia, lack of appetite, and depressed mood. The patient history was positive for counting coercion. The patient’s genogram revealed counting coercion in three generations of her family.

Conclusions:

This case highlights the issue whether counting can be a distinctive feature among inflicted and not inflicted individuals, such as hoarding. Also, it is still unclear what is it really transferred; the vulnerability to disease, which is transferred among three generations, or the symptoms of counting itself, by genes. Further studies are required to answer the debates on this issue.

Obsessive-compulsive symptom dimensions in a population-based, cross-sectional sample of school-aged children

BACKGROUND

Obsessive-compulsive disorder can be expressed as four potentially overlapping obsessive-compulsive symptom (OCS) dimensions (OCSD) ("symmetry/ordering", "contamination/cleaning", "aggressive/sexual/religious" and "collecting/hoarding"). In clinical samples, some dimensions are more familial and associated with increased psychiatric comorbidity and malfunctioning. However, data concerning OCS and OCSD are scarce in non-clinical samples, particularly among children. The present study aims to estimate: (1) the prevalence and sex/age distribution of OCS/OCSD in a community-based sample of schoolchildren; (2) the association between OCS and additional clinical factors; and (3) the degree of familial aggregation of OCS/OCSD.

METHODS

OCS and OCSD were evaluated in 9937 Brazilian school-children (6-12 years-old) and their biological relatives using the Family History Screen. Data analyses included gradient estimated equations and post-hoc tests.

RESULTS

We included data on 9937 index-children, 3305 siblings (13-18 years-old), and 16,218 parents. Biological mothers were the informants in 87.6% of the interviews. OCS were present in 14.7% of the index-children; 15.6% of their siblings; 34.6% of their mothers and 12.1% of their fathers. The prevalence of OCS and each of the OCSD gradually increased from ages 6 to 12 years. Overall, OCS in children were associated with the presence of other psychiatric symptoms, as well as behavioral/school impairment. OCS and each of the four OCSD aggregated significantly within families.

CONCLUSIONS

OCS are prevalent and associated with psychiatric symptoms and clinical impairment among school-aged children. OCSD aggregate within families in a dimension-specific fashion. These findings suggest a natural continuum between OCS and OCD with regard to their dimensional character.

[Comorbidity of depression and nonaffective - schizophrenia spectrum disorders: the clinical-epidemiological study EDIP]

AIM

To explore the association between depression and heterogenic nonaffective symptom complexes in the study EDIP (Epidemiology of Depression and nonaffective Psychiatric disorders).

MATERIAL AND METHODS

The study consisted of two stages. The first stage (91 patients) aimed to resolve organizational and methodological issues, the second stage was performed in the epidemiological sample of 705 patients.

RESULTS AND CONCLUSION

The heterogeneity (inequivalence and bidirectionality) of associations between depression and heteronomous nonaffective disorders have been identified. The associations are distinguished in three types: 1) affinity (agonism); 2) repulsion (antagonism); 3) lack of selective interaction (inertness) between depression and nonaffective disorders. The results obtained are discussed in a context of two conceptually polar psychopathological models of comorbidity between depression and nonaffective disorders: 1) based on a nosological dichotomy «affective disease - schizophrenia» and 2) denying the abovementioned dichotomy. The first model places depression among disorders of a mild psychiatric register. The second model supposes the integration of depression with syndromes typical for schizophrenia in a common "affect-symptoms" space and considers the increase of depression frequency proportionally to duration and severity of schizophrenia. Our own results have shown that depression is observed not only among disorders of mild psychiatric registers, but also in schizophrenia, though with a significantly lower frequency (as a nonobligatory compound of a syndrome). Thus, depression influence in comorbid delusional, schizophrenic and other severe nonaffective disorders is greatly diminished.

Neuropsychological performance across symptom dimensions in pediatric obsessive compulsive disorder

BACKGROUND

Few studies have examined neuropsychological functioning among youth with obsessive compulsive disorder (OCD), with inconclusive results. Although methodological differences may contribute to inconsistent findings, clinical factors may also account for differential performance. Symptom dimensions are associated with specific patterns of genetic transmission, comorbidity, and treatment outcome, and may also be uniquely associated with neuropsychological performance. This study examined differences in cognitive sequelae and neurocognitive impairment across symptom dimensions among youth with OCD.

METHOD

Participants included 93 treatment-seeking youth diagnosed with OCD. A trained clinician administered the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) to parents and children together. Afterward, youth completed a battery of neuropsychological tests that assessed nonverbal memory and fluency, verbal memory, verbal fluency, verbal learning, processing speed, and inhibition/switching.

RESULTS

Across five symptom dimensions, youth exhibiting Hoarding symptoms (χ(2) = 5.21, P = .02) and Symmetry/Ordering symptoms had a greater occurrence of cognitive sequelae (χ(2) = 4.86, P = .03). Additionally, youth with Symmetry/Ordering symptoms had a greater magnitude of cognitive impairment (Mann-Whitney U = 442.50, Z = -2.49, P < .02), with specific deficits identified on nonverbal fluency (P < .01), processing speed (P < .01), and inhibition and switching (P < .02).

CONCLUSIONS

Neuropsychological deficits identified in youth with Hoarding and Symmetry/Ordering symptoms may suggest that these symptoms have characteristics specific to neurocognitive impairment. Alternatively, symptoms associated with these dimensions may impede youth's performance during testing. Findings advise neuropsychological testing for youth with symptoms on either of these dimensions when concerns about neuropsychological and/or academic impairment are present.

Metabotropic glutamate receptor 5 binding in patients with obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a disabling, mostly chronic, psychiatric condition with significant social and economic impairments and is a major public health issue. However, numerous patients are resistant to currently available pharmacological and psychological interventions. Given that recent animal studies and magnetic resonance spectroscopy research points to glutamate dysfunction in OCD, we investigated the metabotropic glutamate receptor 5 (mGluR5) in patients with OCD and healthy controls. We determined mGluR5 distribution volume ratio (DVR) in the brain of ten patients with OCD and ten healthy controls by using [11C]ABP688 positron-emission tomography. As a clinical measure of OCD severity, the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) was employed. We found no significant global difference in mGluR5 DVR between patients with OCD and healthy controls. We did, however, observe significant positive correlations between the Y-BOCS obsession sub-score and mGluR5 DVR in the cortico-striatal-thalamo-cortical brain circuit, including regions of the amygdala, anterior cingulate cortex, and medial orbitofrontal cortex (Spearman's ρ's⩾ = 0.68, p < 0.05). These results suggest that obsessions in particular might have an underlying glutamatergic pathology related to mGluR5. The research indicates that the development of metabotropic glutamate agents would be useful as a new treatment for OCD.

Obsessive compulsive symptom dimensions and neuroticism: An examination of shared genetic and environmental risk

Individuals with obsessive compulsive disorder can display diverse and heterogeneous patterns of symptoms. Little is known about the relationship between obsessive-compulsive symptom (OCS) dimensions and normal personality traits, particularly those that increase risk for other internalizing disorders. In this study of 1,382 individuals from female-female twin pairs, we examined the relationship between self-report OCS dimensions derived from the Padua Inventory and Eysenck's personality traits neuroticism and extraversion. We conducted factor analysis to determine their phenotypic structure followed by twin analyses to determine their genetic and environmental sources of covariation. A three-factor solution, with dimensions corresponding to checking, aggressive obsessions, and contamination, was the best fit for the Padua OCS items. These dimensions were significantly and somewhat variably associated with neuroticism but negligibly associated with extraversion. The genetic correlations between neuroticism and these three OCS dimensions were moderate to high (0.66 with checking, 0.89 with aggressive obsessions, and 0.40 with contamination). However, the estimated genetic correlation between neuroticism and a unified latent OCS construct was smaller (0.32). Overall this study suggests that genetic, and to a smaller extent environmental, factors underlying neuroticism may act differentially as risk factors for OCS dimensions.

Hoarding in an Asian Population: Prevalence, Correlates, Disability and Quality of Life

Introduction: Hoarding is defined as the acquisition of, and inability to discard items even though they appear to others to have no value. The objectives of the study were to establish the prevalence of hoarding behaviour among the general population and among individuals with obsessive-compulsive disorder (OCD) in a cross-sectional study conducted in Singapore. Materials and Methods: The Singapore Mental Health Study was a cross-sectional epidemiological survey of a nationally representative sample of residents aged 18 years or older, living in households. The diagnoses of mental disorders were established using Version 3.0 of Composite International Diagnostic Interview (CIDI 3.0). Differences between 3 groups i.e. those diagnosed with lifetime/12-month Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) OCD with hoarding, those diagnosed with lifetime/12-month DSM-IV OCD without hoarding and those with lifetime hoarding behaviour without diagnosis of DSM-IV OCD were determined. Results: The weighted prevalence of lifetime hoarding behaviour was 2% and that of hoarding among those with OCD was 22.6%. Those who met the criteria for hoarding behaviour alone were associated with lower odds of having obsessions of contamination, harming, ordering as well as compulsions of ordering and other compulsions than those who met criteria for both OCD and hoarding. Conclusion: Hoarders without OCD were less impaired, in terms of comorbid psychopathology, than those with OCD with and without hoarding, and had a higher quality of life versus those with both OCD and hoarding, though still lower than that of the general population. Keywords: Obsessive-compulsive disorder, Singapore, Survey

Comparison of clinical characteristics of familial and sporadic obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) is a heterogeneous condition with evidence of familiality in a considerable proportion of patients. A classification into familial and sporadic forms has been proposed to explain the heterogeneity. The current study aims to compare the demographic, clinical and comorbidity patterns of patients with and without a family history of OCD in first-degree relatives.

METHOD

802 consecutive patients who consulted a specialty OCD Clinic at a tertiary care psychiatric hospital in India were evaluated with the Mini-International Neuropsychiatric Interview, the Yale-Brown Obsessive-Compulsive Scale, and the Clinical Global Impression Scale. Family history was assessed by interviewing patients and at least one first-degree relative.

RESULTS

Family history of OCD was seen in 152 patients (19%). Family history was associated with juvenile onset (Χ(2)=19.472, p<0.001), obsessions of contamination (Χ(2)=6.658, p=0.01), hoarding (Χ(2)=4.062, p=0.032), need for symmetry (Χ(2)=3.95, p=0.047), washing compulsion (Χ(2)=7.923, p=0.005), ordering compulsions (Χ(2)=6.808, p=0.009), repeating compulsions (Χ(2)=4.950, p=0.026) and compulsions by proxy (Χ(2)=7.963, p=0.005). Family history was also associated with greater severity of OCD (t=-2.31, p=0.022) and compulsions (t=-3.09, p=0.002) and longer duration of illness at presentation (t=-2.93, p=0.004).

CONCLUSION

Our findings suggest that familial OCD may have distinctive clinical features. Studying familial forms of OCD may offer unique insight in to understanding the genetic basis of OCD.

Latent class analysis of obsessive-compulsive symptoms in a clinical sample

OBJECTIVE

Obsessive-compulsive disorder (OCD) is probably a heterogeneous condition. To date, research investigating the symptom structure of OCD has generally focused on variable-classification approaches, primarily factor analysis. Our aim was to use the latent class analysis, an advanced individual-classification method, in order to define homogeneous sub-groups based on the Yale-Brown Obsessive-Compulsive Scale Check List (Y-BOCS CL) assessments within 193 outpatients with OCD.

METHOD

Latent class analysis of 13 obsessive-compulsive symptom-clusters measured by the Yale-Brown Obsessive-Compulsive Scale Check List was performed. Associations of demographic and clinical features with latent class membership were tested by using logistic regression models. Differences in severity of obsessive-compulsive symptoms, obsessive beliefs, and depressive symptomotology between latent classes were evaluated with the chi-square likelihood test.

RESULTS

Latent class analysis models of best fit yielded 3 latent classes: "autogenous obsessions", "reactive obsessive-compulsive", and "reactive obsessions". Outpatients in reactive obsessive-compulsive group reported significantly higher scores on the Y-BOCS global, obsessions, and compulsions scales than outpatients in other two sub-groups. Participants in reactive obsessive-compulsive group were predominantly female, single, and had a history of family psychopathology; whereas autogenous and reactive obsessions groups were predominantly male. There were no differences in severity of depression and obsessive belief domains.

CONCLUSIONS

The results provide support for the validity of autogenous/reactive distinction for OCD. These three classes may have important implications for research and clinical purposes.

Genetics of obsessive–compulsive disorder: a research update

The genetic study of obsessive-compulsive disorder (OCD) has made significant gains in the past decade. However, etiological gene findings are still elusive. Epidemiological studies, including family and twin studies, strongly support a genetic component for OCD. In addition, complex segregation analyses suggest the presence of at least one major gene. The neurobiology of OCD also lends support to the notion that programmed CNS-based biological processes underlie OCD symptom expression, with mapping of brain circuits to fronto-subcortical circuits in a consistent manner. Genetic linkage studies of OCD, using families with multiple affected relatives, have generated several suggestive linkage peaks, regions that may harbor a gene or genes for OCD. However, the presence of multiple linkage peaks has added to the complexity of OCD genetics, suggesting that the exploration of gene-gene interactions and gene-environment interactions, in addition to the exploration of alternate phenotypes based on symptom expression, age at onset or comorbid conditions, may be key in locating etiologic genes. Finally, candidate gene studies, while promising, are not yet associated with linkage regions, except in the case of the glutamate transporter gene SLC1A1 in 9p24. While OCD appears to have a genetic component, additional innovative research is needed to unravel the genetic influences in the disorder.

Novel "thrifty" models of increased eating behaviour

The thrifty genotype and phenotype hypotheses were developed to explain the rapid increase in diabetes and obesity in developed countries around the world. Most subsequent "thrifty" research has focused on the early developmental origins of the metabolic syndrome and cardio-metabolic disease. The goal of this manuscript is to review an emerging line of research that uses a similar thrifty framework to understand the early developmental origins of eating-related phenotypes that have primary relevance to many psychiatric disorders. Given the important role of environmental adversity in various psychiatric disorders that involve overeating, and their early age of onset, it is likely that several thrifty mechanisms are relevant in this regard. Understanding the early origins of increased eating behaviour based on a thrifty model might point the way to highly targeted preventative interventions during critical periods of development, and provide a new way of addressing these common and difficult to treat disorders.

The characteristics of unacceptable/taboo thoughts in obsessive-compulsive disorder

BACKGROUND

In the quest to unravel the heterogeneity of obsessive-compulsive disorder (OCD), an increasing number of factor analytic studies are recognising unacceptable/taboo thoughts as one of the symptom dimensions of OCD.

AIMS

This study aims to examine the characteristics associated with unacceptable/taboo thoughts.

METHODS

Using the Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC) with 154 individuals with OCD, obsessive-compulsive symptoms were subjected to principal components analysis. The characteristics associated with the resulting symptom dimensions were then assessed using logistic and linear regression techniques.

RESULTS

Unacceptable/taboo thoughts comprised of sexual, religious and impulsive aggressive obsessions, and mental rituals. Higher scores on an unacceptable/taboo thoughts symptom dimension were predicted by higher Y-BOCS obsession subscores, Y-BOCS time preoccupied by obsessions scores, Y-BOCS distress due to obsessions scores, importance of control of thought ratings, male gender, and having had treatment prior to entering into the study. Unacceptable/taboo thoughts were also predicted by greater levels of hostility, and a past history of non-alcohol substance dependence.

CONCLUSIONS

An unacceptable/taboo thought symptom dimension of OCD is supported by a unique set of associated characteristics that should be considered in the assessment and treatment of individuals with these symptoms.

Symptom dimensions, clinical course and comorbidity in men and women with obsessive-compulsive disorder

The study aimed to compare male and female patients with obsessive-compulsive disorder (OCD) across symptom dimensions, clinical course and comorbidity. A cross-sectional study was undertaken with 858 adult OCD patients (DSM-IV) from the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders. Patients were evaluated using structured interviews, including the Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS) and the Structured Clinical Interview for DSM-IV Axis I disorders (SCID-I). The sample was composed of 504 women (58.7%) and 354 men (41.3%) with a mean age of 35.4 years-old (range: 18-77). Men were younger, more frequently single and presented more tics, social phobia and alcohol use disorders. Among men, symptom interference occurred earlier and symptoms of the sexual/religious dimension were more common and more severe. Conversely, women were more likely to present symptoms of the aggressive, contamination/cleaning and hoarding dimension and comorbidity with specific phobias, anorexia nervosa, bulimia, trichotillomania, skin picking and "compulsive" buying. In the logistic regression, female gender remained independently associated with the aggressive and contamination/cleaning dimensions. In both genders the aggressive dimension remained associated with comorbid post-traumatic stress disorder, the sexual/religious dimension with major depression and the hoarding dimension with tic disorders. Gender seems to be relevant in the determination of OCD clinical presentation and course and should be considered an important aspect when defining more homogeneous OCD subgroups.

Is ADHD in childhood associated with lifetime hoarding symptoms? An epidemiological study

BACKGROUND

Although hoarding symptoms have been traditionally conceptualized as part of obsessive-compulsive disorder (OCD), recent data suggest that they may be more closely related to attention-deficit hyperactivity (ADHD) symptoms and, in particular, inattention. The aim of the present epidemiological study was to investigate the association between retrospectively reported ADHD symptoms in childhood and lifetime hoarding symptoms.

METHODS

Retrospectively reported childhood ADHD, and lifetime hoarding and obsessive-compulsive symptoms were assessed with the Composite International Diagnostic Interview 3.0 in a random subsample of individuals (n = 2,963) participating in a cross-sectional survey of the adult general population of nine European countries, as part of the World Mental Health (WMH) Surveys.

RESULTS

Lifetime hoarding symptoms were more common among individuals with childhood ADHD symptoms than those without ADHD symptoms (8.9% versus 2.7%, P = 0.024). Childhood inattention (but not hyperactivity) was associated with lifetime hoarding symptoms (OR = 6.04, 95% CI = 3.59-10.1) and this association remained significant after controlling for the presence of obsessive-compulsive symptoms.

CONCLUSION

Longitudinal studies are now needed to explore the hypothesis that inattention symptoms in childhood may be a precursor of hoarding difficulties later in life.