Symptom dimensions and subtypes of obsessive-compulsive disorder: a developmental perspective

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.

Management and Treatment of Obsessive-Compulsive Disorder (OCD): A Literature Review

Obsessive-compulsive disorder (OCD) is a prevalent and debilitating mental health condition. This literature review examines the latest strategies in managing and treating OCD, with an emphasis on psychotherapy, pharmacological interventions, and neurosurgical options. A comprehensive literature search utilizing PubMed, Google Scholar, ClinicalKey, and Embase databases was conducted. Utilizing chosen keywords, the resulting articles were filtered based on inclusion and exclusion criteria. Included articles were used to discuss current research regarding OCD treatment and management. Findings reveal the efficacy and obstacles of treatments such as cognitive-behavioral therapy, selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and evidence-based neurosurgical methods, offering a broad perspective on OCD management. We discuss the limitations of these established treatments and examine the innovative response of neurosurgery in treating patients with OCD. This review highlights the importance of individualized treatment plans and areas for future research.

Exploring latent clusters in pediatric OCD based on symptoms, severity, age, gender, and comorbidity

Given diverse symptom expression and high rates of comorbid conditions, the present study explored underlying commonalities among OCD-affected children and adolescents to better conceptualize disorder presentation and associated features. Data from 830 OCD-affected participants presenting to OCD specialty centers was aggregated. Dependent mixture modeling was used to examine latent clusters based on their age- and gender adjusted symptom severity (as measured by the Children's Yale-Brown Obsessive-Compulsive Scale; CY-BOCS), symptom type (as measured by factor scores calculated from the CY-BOCS symptom checklist), and comorbid diagnoses (as assessed via diagnostic interviews). Fit statistics favored a four-cluster model with groups distinguished primarily by symptom expression and comorbidity type. Fit indices for 3-7 cluster models were only marginally different and characteristics of the clusters remained largely stable between solutions with small clusters of distinct presentations added in more complex models. Rather than identifying a single classification system, the findings support the utility of integrating dimensional, developmental, and transdiagnostic information in the conceptualization of OCD-affected children and adolescents. Identified clusters point to the centrality of contamination concerns to OCD, relationships between broader symptom expression and higher levels of comorbidity, and the potential for complex/neurodevelopmental presentations.

The epidemiology of obsessive-compulsive disorder in the Kingdom of Saudi Arabia: Data from the Saudi National Mental Health Survey

AIMS

There is ongoing debate about the extent to which the epidemiology of OCD is similar across the world, given the lack of nationally representative data from key regions like the Middle East and North Africa. Using the nationally representative dataset from the Saudi National Mental Health Survey (SNMHS), we aimed to delineate the epidemiological profile of OCD in the Saudi population.

METHODS

A subsample of 1981 participants from the SNMHS was assessed. Prevalence estimates and correlates of OCD were determined using logistic regressions and cross tabulations.

RESULTS

The lifetime, 12-month, and 30-day prevalence estimates for OCD were 4.2%, 1.8%, and 1.6%, respectively, with hoarding being the most common symptom dimension. The mean age-of-onset of OCD was 16.8 years. In over two-thirds of respondents with lifetime (72.2%) or 12-month (71.2%), OCD was accompanied by comorbid mental disorder, particularly impulse control, anxiety, and mood disorders. Among individuals with 12-month OCD, 77.5% reported severe impairment, and only 9.2% received treatment.

CONCLUSIONS

In Saudi Arabia, OCD is a prevalent and persistent condition, characterized by early onset, high odds of mental comorbidity, and significant associated impairment. These findings emphasize the universality of OCD epidemiology and the need for improved diagnosis and treatment globally.

A clinical investigation of psychotic vulnerability in early-onset Obsessive-Compulsive Disorder through Cognitive-Perceptive basic symptoms

Childhood-onset Obsessive-Compulsive Disorder (OCD) shows distinct comorbidity patterns and developmental pathways, as well as an increased risk of psychosis with respect to adult-onset forms. Nevertheless, little is known about the prodromal symptoms of psychosis in children and adolescents with a primary diagnosis of OCD. The present study was aimed at evaluating the occurrence of Cognitive-Perceptual basic symptoms (COPER) and high- risk criterion Cognitive Disturbances (COGDIS) in pediatric and adults OCD patients, verifying if they might vary according to the age of onset of OCD. The study included 90 outpatients with a primary diagnosis of obsessive-compulsive disorder. The study sample was collapsed into three groups according to the age at onset: 1) very early onset group (< 10 years); 2) early onset group (11-18 years); 3) adult-onset group (> 18 years). All patients were administered the Yale-Brown Obsessive- Compulsive Scale (Y-BOCS) and its Child version (CY-BOCS), the Schizophrenia Proneness Instrument-Adult (SPIA) and its Child and Adolescent version (SPI-CY) and the Social and Occupational Functioning Assessment Scale (SOFAS). COPER and COGDIS symptoms were positively associated with OCD severity and detectable, respectively, in 28.9 and 26.7% of our study sample. The very early onset group significantly had higher COPER and COGDIS symptoms than the adult-onset group. Our data suggest that COPER and COGDIS symptoms are frequent in obsessive patients, in particular in those with earlier onset; therefore, their detection in childhood-onset OCD may represent an early and specific indicator of psychotic vulnerability.

Mechanisms of pathogenesis and environmental moderators in preclinical models of compulsive-like behaviours

Obsessive-compulsive and related disorders (OCRD) is an emergent class of psychiatric illnesses that contributes substantially to the global mental health disease burden. In particular, the prototypical illness, obsessive-compulsive disorder (OCD), has a profoundly deleterious effect on the quality of life of those with lived experience. Both clinical and preclinical studies have investigated the genetic and environmental influences contributing to the pathogenesis of obsessive-compulsive and related disorders. Significant progress has been made in recent years in our understanding of the genetics of OCD, along with the critical role of common environmental triggers (e.g., stress). Some of this progress can be attributed to the sophistication of rodent models used in the field, particularly genetic mutant models, which demonstrate promising construct, face, and predictive validity. However, there is a paucity of studies investigating how these genetic and environmental influences interact to precipitate the behavioural, cellular, and molecular changes that occur in OCD. In this review, we assert that preclinical studies offer a unique opportunity to carefully manipulate environmental and genetic factors, and in turn to interrogate gene-environment interactions and relevant downstream sequelae. Such studies may serve to provide a mechanistic framework to build our understanding of the pathogenesis of complex neuropsychiatric disorders such as OCD. Furthermore, understanding gene-environment interactions and pathogenic mechanisms will facilitate precision medicine and other future approaches to enhance treatment, reduce side-effects of therapeutic interventions, and improve the lives of those suffering from these devastating disorders.

A prospective investigation of impacts of comorbid attention deficit hyperactivity disorder (ADHD) on clinical features and long-term treatment response in adult patients with obsessive-compulsive disorder (OCD)

BACKGROUND

A close association between obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD) in children and adolescents has been investigated in previous studies. However, few studies examined the relationship between lifetime comorbidity of ADHD and OCD in adults. Therefore, we sought to investigate the clinical and psychopathological features related to comorbid ADHD in Japanese adult patients with OCD.

METHODS

We assessed lifetime comorbidity of ADHD in 93 adult Japanese patients with OCD. Additionally, we used the Japanese version of Conners' Adult ADHD Rating Scales to assess the characteristics and severity of ADHD in each participant. According to the results, we excluded OCD patients that did not have ADHD but who exhibited elevated levels of ADHD traits. We compared OCD patients with ADHD (ADHD+ group) and those without ADHD or its trait (ADHD- group) in terms of background profiles and clinical features, such as OCD symptomatology and psychometric test results. Additionally, the 6-month treatment outcome was compared prospectively between groups.

RESULTS

Of the 93 OCD participants, the prevalence of lifetime comorbidity of ADHD was estimated as 16.1%. Compared with the ADHD- group, participants in the ADHD+ group had an earlier age of onset of OCD, higher frequencies of hoarding symptoms, higher levels of depressive and anxiety symptoms and lower quality of life, more elevated levels of impulsivity, and higher rates of substance or behavioral addiction and major depression. Finally, the mean improvement rate on the Yale-Brown Obsessive Compulsive Scale after 6 months of standardized OCD treatment in the ADHD+ group (16.1%) was significantly lower than that in the ADHD- group (44.6%).

CONCLUSION

The lifetime comorbidity of ADHD is likely to exert a significant effect on clinical features and treatment outcome in adult patients with OCD. It is important to consider that underlying ADHD pathology may function as a facilitator for increased severity of global clinical features and treatment refractory conditions in OCD patients. Further studies are required to examine treatment strategies for such patients.

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.

Early Identification and Intervention in Pediatric Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a psychiatric disorder characterized by persistent thoughts with subsequent repetitive behaviors. Interventions that are effective for adult OCD cannot simply be generalized to pediatric OCD, since OCD in children and adolescents usually has a different clinical presentation, etiology and course from adult OCD. Delayed and inadequate treatment is associated with a worse prognosis, making the need for early identification and intervention in pediatric OCD very urgent. In this paper, we reflected on the current constraints that make early interventions for pediatric OCD unpromoted and reviewed the approaches with potential application for early identification and early intervention in pediatric OCD, categorized by three-level prevention stages corresponding to a clinical staging model. Since the etiology of pediatric OCD is still unclear, primary prevention is most lacking, and early interventions for pediatric OCD are currently focused on the secondary prevention stage, which aims to prevent the conversion of obsessive-compulsive symptoms into full-blown OCD; tertiary prevention mostly focuses on the alleviation of mild to moderate OCD, while interventions for co-morbidities are still in their infancy. We closed by considering the important research questions on this topic.

The Sapap3-/- mouse reconsidered as a comorbid model expressing a spectrum of pathological repetitive behaviours

Symptom comorbidity is present amongst neuropsychiatric disorders with repetitive behaviours, complicating clinical diagnosis and impeding appropriate treatments. This is of particular importance for obsessive-compulsive disorder (OCD) and Tourette syndrome. Here, we meticulously analysed the behaviour of Sapap3 knockout mice, the recent rodent model predominantly used to study compulsive-like behaviours, and found that its behaviour is more complex than originally and persistently described. Indeed, we detected previously unreported elements of distinct pathologically repetitive behaviours, which do not form part of rodent syntactic cephalo-caudal self-grooming. These repetitive behaviours include sudden, rapid body and head/body twitches, resembling tic-like movements. We also observed that another type of repetitive behaviour, aberrant hindpaw scratching, might be responsible for the flagship-like skin lesions of this mouse model. In order to characterise the symptomatological nature of observed repetitive behaviours, we pharmacologically challenged these phenotypes by systemic aripiprazole administration, a first-line treatment for tic-like symptoms in Tourette syndrome and trichotillomania. A single treatment of aripiprazole significantly reduced the number of head/body twitches, scratching, and single-phase grooming, but not syntactic grooming events. These observations are in line with the high comorbidity of tic- and compulsive-like symptoms in Tourette, OCD and trichotillomania patients.

Hypothesizing That Pediatric Autoimmune Neuropsychiatric Associated Streptococcal (PANDAS) Causes Rapid Onset of Reward Deficiency Syndrome (RDS) Behaviors and May Require Induction of "Dopamine Homeostasis"

Pediatric autoimmune neuropsychiatric disorders associated with group A streptococcal infections (PANDAS) is a concept that is used to characterize a subset of children with neuropsychiatric symptoms, tic disorders, or obsessive-compulsive disorder (OCD), whose symptoms are exacerbated by group A streptococcal (GAS) infection. PANDAS has been known to cause a sudden onset of reward deficiency syndrome (RDS). RDS includes multiple disorders that are characterized by dopaminergic signaling dysfunction in the brain reward cascade (BRC), which may result in addiction, depression, avoidant behaviors, anxiety, tic disorders, and/or OCD. According to research by Blum et al., the dopamine receptor D2 (DRD2) gene polymorphisms are important prevalent genetic determinants of RDS. The literature demonstrates that infections like Borrelia and Lyme, as well as other infections like group A beta-hemolytic streptococcal (GABHS), can cause an autoimmune reaction and associated antibodies target dopaminergic loci in the mesolimbic region of the brain, which interferes with brain function and potentially causes RDS-like symptoms/behaviors. The treatment of PANDAS remains controversial, especially since there have been limited efficacy studies to date. We propose an innovative potential treatment for PANDAS based on previous clinical trials using a pro-dopamine regulator known as KB220 variants. Our ongoing research suggests that achieving "dopamine homeostasis" by precision-guided DNA testing and pro-dopamine modulation could result in improved therapeutic outcomes.

Development of a scale to assess obsessive-compulsive tendencies among Japanese university students

Obsessive-compulsive (OC) tendencies refer to obsessions and compulsions in a nonclinical group, which are risk factors for obsessive-compulsive disorder (OCD). OC tendencies and OC symptoms are mainly assessed using five factors: ordering, obsessions, cleaning, hoarding, and checking. However, since hoarding is now classified as an independent diagnosis in the DSM-V, this factor was not included and was instead replaced by indecisiveness. Furthermore, many established scales used for measuring OC tendencies were originally created for OCD patients; thus, they cannot adequately capture OC tendencies. Therefore, this study aimed to develop a scale to assess OC tendencies among Japanese university students with a revised five-factor structure: ordering, obsessions, cleaning, indecisiveness, and checking. We examined the factor structure, reliability, criterion-related validity, and convergent validity of the OC tendencies scale by administering two surveys. In Survey 1 (N = 216), an exploratory factor analysis (EFA) was conducted to examine the criterion-related and convergent validity and reliability of the OC tendencies scale. In Survey 2 (N = 202), a confirmatory factor analysis (CFA) was conducted. EFA and CFA utilized a five-factor structure comprising checking, ordering, indecisiveness, cleaning, and obsessions. Correlations with other scales indicated that the OC tendencies scale had efficient convergent validity, criterion-related validity, internal consistency, and test-retest reliability. This study validated the five-factor structure of OC tendency in Japanese university students. However, indecisiveness was also strongly correlated with trait-anxiety. As this scale is easy to administer among large groups, it has the potential to contribute to mental health support for university students by measuring OC tendencies experienced on a daily basis, which have not been adequately measured in the past.

Bidirectional Behavioral Selection in Mice: A Novel Pre-clinical Approach to Examining Compulsivity

Obsessive-compulsive disorder (OCD) and related disorders (OCRD) is one of the most prevalent neuropsychiatric disorders with no definitive etiology. The pathophysiological attributes of OCD are driven by a multitude of factors that involve polygenic mechanisms, gender, neurochemistry, physiological status, environmental exposures and complex interactions among these factors. Such complex intertwining of contributing factors imparts clinical heterogeneity to the disorder making it challenging for therapeutic intervention. Mouse strains selected for excessive levels of nest- building behavior exhibit a spontaneous, stable and predictable compulsive-like behavioral phenotype. These compulsive-like mice exhibit heterogeneity in expression of compulsive-like and other adjunct behaviors that might serve as a valuable animal equivalent for examining the interactions of genetics, sex and environmental factors in influencing the pathophysiology of OCD. The current review summarizes the existing findings on the compulsive-like mice that bolster their face, construct and predictive validity for studying various dimensions of compulsive and associated behaviors often reported in clinical OCD and OCRD.

Preschool-onset OCD: A review of literature and clinical experience

Obsessive-compulsive disorder (OCD) has been described in preschool children as young as 2-3 years old. A preschool age onset of OCD has unique diagnostic and therapeutic challenges. In this article, the authors review published literature on preschool onset OCD and present data on preschool-onset OCD (age of onset ≤ 5 years) from clinical records at a tertiary care child and adolescent psychiatry center in India. Literature suggests that OCD that starts this early is phenomenologically similar to OCD in older individuals; however, it has very high rates of comorbidity and a family history of OCD. There is a paucity of data on course, treatment, and long-term outcome in this group. At their center, the authors found a 3% prevalence of preschool-onset OCD, with a male predominance (69%) and fairly high comorbidity rates (62%). Qualitative review highlighted delay in treatment seeking, poor follow-up rates, frequent use of pharmacological treatment, and a high remission rate in those treated adequately.

Investigating the Association Between Obsessive-Compulsive Disorder Symptom Subtypes and Health Anxiety as Impacted by the COVID-19 Pandemic: A Cross-Sectional Study

Background

Since the COVID-19 outbreak was declared a global pandemic, public health messages have emphasised the importance of frequent handwashing in limiting the transmission of the virus. Whilst crucial in controlling transmission, such messaging may have an adverse effect on individuals with OCD.

Methods

A cross-sectional study was conducted, with a total of 332 participants recruited. Participants who scored above the optimal cut-off score on the Obsessive-Compulsive Inventory Revised edition (OCI-R) were included in the analysis (n = 254). Scores on the six subscales of the OCI-R were correlated with responses to a COVID-19 Impact measure.

Results

Factor analysis of the COVID-19 Impact measure revealed that items loaded on two components of the measure (handwashing and distress-avoidance). Canonical correlation analyses revealed significant associations between the OCI-R subscales and COVID-19 Impact measure, F (12, 490) = 8.14, p = 0.001, and the SHAI subscales with the COVID-19 Impact Measure, F (4, 498) = 8.18, p = 0.001). Specifically, washing and checking OCI-R subscales correlated with both components of the COVID-19 Impact measure, as did the health anxiety and beliefs SHAI subscales. Content analysis revealed disruption to treatment delivery and worsening symptom severity in participants with contamination-related OCD.

Discussion

Contamination and checking OCD subtypes have been associated with increased hand-washing behaviour and avoidance of distress-inducing cues. Consideration should be given to targeted support tailored to patients with these subtypes of OCD.

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.

Knowledge and competency standards for specialized cognitive behavior therapy for pediatric obsessive-compulsive disorder

Although exposure-based cognitive behavior therapy (CBT) and pharmacotherapy have demonstrated efficacy for obsessive-compulsive disorder (OCD), the lack of clinicians effectively trained in these treatments significantly limit effective intervention options for affected youth. This is very unfortunate since child onset is reported by 50% of adults with OCD. To ameliorate this serious global issue the 14 nation International Obsessive-Compulsive Disorders Accreditation Task Force (ATF) of The Canadian Institute for Obsessive Compulsive Disorders (CIOCD) has developed knowledge and competency standards recommended for specialized treatments for OCD through the lifespan. Currently available guidelines are considered by experts to be essential but insufficient because there are not enough clinicians with requisite knowledge and competencies to effectively treat OCD. This manuscript presents knowledge and competency standards recommended for specialized cognitive behavior therapy (CBT) for pediatric OCD, derived from comprehensive literature review and expert synthesis. In addition to standards covering the elements of individual CBT-based assessment and treatment, family and school interventions are addressed given the critical role these domains play in the psychosocial development of youths. The ATF standards presented in these phase two papers will be foundational to the upcoming development of certification (individuals) and accreditation (sites) for specialized treatments in OCD through the lifespan.

A population-based family clustering study of tic-related obsessive-compulsive disorder

In the latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), obsessive-compulsive disorder (OCD) included a new "tic-related" specifier. However, strong evidence supporting tic-related OCD as a distinct subtype of OCD is lacking. This study investigated whether, at the population level, tic-related OCD has a stronger familial load than non-tic-related OCD. From a cohort of individuals born in Sweden between 1967 and 2007 (n = 4,085,367; 1257 with tic-related OCD and 20,975 with non-tic-related OCD), we identified all twins, full siblings, maternal and paternal half siblings, and cousins. Sex- and birth year-adjusted hazard ratios (aHR) were calculated to estimate the risk of OCD in relatives of individuals with OCD with and without comorbid tics, compared with relatives of unaffected individuals. We found that OCD is a familial disorder, regardless of comorbid tic disorder status. However, the risk of OCD in relatives of individuals with tic-related OCD was considerably greater than the risk of OCD in relatives of individuals with non-tic-related OCD (e.g., risk for full siblings: aHR = 10.63 [95% CI, 7.92-14.27] and aHR = 4.52 [95% CI, 4.06-5.02], respectively; p value for the difference < 0.0001). These differences remained when the groups were matched by age at first OCD diagnosis and after various sensitivity analyses. The observed familial patterns of OCD in relation to tics were not seen in relation to other neuropsychiatric comorbidities. Tic-related OCD is a particularly familial subtype of OCD. The results have important implications for ongoing gene-searching efforts.

Differentiation of 2 Obsessive-Compulsive Disorder Subgroups with Regard to Demographic and Phenomenological Characteristics Combining Multiple Correspondence and Latent Class Analysis

INTRODUCTION

Classic factor analysis of obsessive-compulsive disorder (OCD) dimensions and attempts to identify valid subgroups have not yet produced definitive conclusions.

OBJECTIVE AND METHODS

This study aims to examine possible homogeneous subgrouping of demographic and phenomenological characteristics in 134 treatment-seeking OCD patients. A combination of multiple correspondence analysis (MCA) and latent class analysis (LCA) was used.

RESULTS

MCA showed 2 distinct subgroups of OCD patients and LCA confirmed this result by a two-class solution. Both analyses demonstrated (a) a clear subgroup of female patients with washing compulsions, obsessions related to contamination, and late age of onset and (b) a subgroup comprised mostly of male patients with earlier onset of OCD, checking rituals, and doubts or aggressive obsessions. Mental, ordering, hoarding compulsions, religious, or sexual obsessions and images appeared exclusively in this subgroup.

CONCLUSIONS

Using 2 different analytic methods, we confirmed at least 2 subgroups in a clinical sample of Greek OCD patients. Future research combining dimensional and latent approaches could facilitate our understanding of the heterogeneous phenotype of OCD.

Animal Models for OCD Research

OCD has lagged behind other psychiatric illnesses in the identification of molecular treatment targets, due in part to a lack of significant findings in genome-wide association studies. However, while progress in this area is being made, OCD's symptoms of obsessions, compulsions, and anxiety can be deconstructed into distinct neural functions that can be dissected in animal models. Studies in rodents and non-human primates have highlighted the importance of cortico-basal ganglia-thalamic circuits in OCD pathophysiology, and emerging studies in human post-mortem brain tissue point to glutamatergic synapse abnormalities as a potential cellular substrate for observed dysfunctional behaviors. In addition, accumulated evidence points to a potential role for neuromodulators including serotonin and dopamine in both OCD pathology and treatment. Here, we review current efforts to use animal models for the identification of molecules, cell types, and circuits relevant to OCD pathophysiology. We start by describing features of OCD that can be modeled in animals, including circuit abnormalities and genetic findings. We then review different strategies that have been used to study OCD using animal model systems, including transgenic models, circuit manipulations, and dissection of OCD-relevant neural constructs. Finally, we discuss how these findings may ultimately help to develop new treatment strategies for OCD and other related disorders.

Large nest building and high marble-burying: Two compulsive-like phenotypes expressed by deer mice (Peromyscus maniculatus bairdii) and their unique response to serotoninergic and dopamine modulating intervention

This study aimed to further dissect the deer mouse (Peromyscus maniculatus bairdii) model of compulsive-like behavior with respect to two persistent-like behavioral phenotypes viz. large nest building (LNB) and high marble-burying (HMB), which may be relevant to understanding the neurobiology of different symptom dimensions in obsessive-compulsive and related disorders. Since LNB is sensitive to chronic, high dose escitalopram intervention but HMB is not, we assessed whether the two behaviors could be further distinguished based on their response to 4 weeks of uninterrupted serotoninergic intervention (i.e. escitalopram; ESC; 50 mg/kg/day), dopaminergic antagonism, i.e. flupentixol; FLU; 0.9 mg/kg/day), dopaminergic potentiation (i.e. rasagiline; RAS; 5 mg/kg/day), and their respective combinations with escitalopram (ESC/FLU and ESC/RAS). Here we show LNB to be equally responsive to chronic ESC and ESC/FLU. HMB was insensitive to either of these interventions but was responsive to ESC/RAS. Additionally, we report that scoring preoccupied interaction with marbles over several trials is an appropriate measure of compulsive-like behavioral persistence in addition to the standard marble burying test. Taken together, these data provide further evidence that LNB and HMB in deer mice have distinctive neurobiological underpinnings. Thus, the naturally occurring compulsive-like behaviors expressed by deer mice may be useful in providing a platform to test unique treatment targets for different symptom dimensions of OCD and related disorders.

Meta-analysis of neurocognitive deficits in unaffected relatives of obsessive-compulsive disorder (OCD): comparison with healthy controls and patients with OCD

BACKGROUND

Obsessive-compulsive disorder (OCD) has been associated with cognitive deficits, particularly with executive functions. These findings support fronto-striatal dysfunction in OCD. However, it is not certain whether these findings are trait features of OCD. In recent years, a number of studies have investigated cognitive functions in unaffected relatives of OCD (OCDrel) but the findings of these studies are contradictory.

METHODS

A systematic review in Pubmed and Scopus databases was performed until 18 March 2019, to locate the studies comparing cognitive functions of OCDrel with healthy controls and OCD patients (OCDpt). A random-effects meta-analysis was conducted.

RESULTS

Current meta-analysis included 16 studies including 527 OCDrel, 445 OCDpt and 639 healthy controls. Healthy controls overperformed OCDpt in all cognitive domains (d = 0.36-0.86). OCDrel underperformed healthy controls in inhibition (d = 0.58, CI = 0.29-0.86), planning (d = 0.45, CI = 0.28-0.63), decision-making (d = 0.58, CI = 0.19-0.98). OCDrel also had small-sized deficits in set-shifting (d = 0.37, CI = 0.04-0.69) and visual memory (d = 0.28, CI = 0.08-0.49). OCDpt underperformed OCDrel in visual memory (d = 0.45, CI = 0.22-0.67) and set-shifting (d = 0.23, CI = 0.04-0.42).

CONCLUSIONS

Current findings suggest that abnormalities in inhibition, planning/problem solving and reward-based decision-making are shared features of OCDrel and OCDpt and might be trait markers related to vulnerability for developing OCD. Visual memory and set-shifting deficits might potentially be biomarkers of incipient illness or subthreshold OCD presentation among OCDrel. Further exploration of cognitive heterogeneity in OCDrel and investigating the effects of the subtypes of OCD in probands on cognitive impairment in OCDrel are needed.

Childhood trauma and attachment style predict the four-year course of obsessive compulsive disorder: Findings from the Netherlands obsessive compulsive disorder study

INTRODUCTION

Obsessive compulsive disorder (OCD) is a chronic psychiatric disorder where most patients do not reach full symptomatic remission. Identifying predictors of course can improve patients' care by informing clinicians on prognosis and enhancing treatment strategies. Several predictors associated with improved outcome of OCD were identified. However, research focused mainly on clinical, illness-related predictors of the course of OCD. This study examined the contribution of environmental and interpersonal predictors on the long-term outcome of OCD, in addition to the previously identified clinical indicators.

METHODS

We used the baseline, two and four-year data of 382 adult OCD patients participating in the naturalistic cohort study of the Netherlands Obsessive Compulsive Disorder Association (NOCDA). Remission was assessed using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Predictors of outcome were assessed at baseline, via clinician-rated and self-report instruments.

RESULTS

Remission at two and at four-year follow-up ranged from 11% to 26%. Early age of onset and the presence of childhood trauma predicted a worse four-year course. Secure attachment style emerged as a protective predictor of improved outcome.

LIMITATIONS

The naturalistic design of our study did not enable a systematic estimation the effect of treatments received during the follow-up period. Furthermore, age of onset and childhood trauma were assessed retrospectively, which may contribute to recall bias.

CONCLUSION

Results coincide with previous prediction research and stress the importance of adaptive interpersonal functioning in the course of OCD. Clinical implications and future research directions are discussed.

Diagnosis in PANDAS: An Update

Background:

The last twenty years have seen major advancements in unraveling the etiology and the identification of biological markers of Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococci (PANDAS). However, this body of evidence has not yet been translated into a clinical setting.

Objective:

We will review the most important studies to date on PANDAS, emphasizing those whose advances could improve the diagnosis of these disorders. We also suggest the need for updated diagnosis criteria integrating the recent findings from the hereby included studies.

Methods:

Consulting the PubMed database, a literature review of the last twenty-one years (between 1998 and 2019) was carried out using the terms “PANDAS” and “pediatric autoimmune neuropsychiatric disorders” in combination with “diagnosis” and “markers”. The search resulted in 175 hits from which we selected clinical cases, original investigations, and clinical reviews.

Results:

This review offers a compilation of the most important studies performed to date regarding the clinical presentation and potential biological markers of PANDAS. Moreover, we suggest the refinement of some aspects in the current diagnosis criteria, such as focusing on specific symptoms and the inclusion of neuroimaging and peripheral markers.

Conclusion:

The identification of specific biological markers in PANDAS is crucial for its diagnosis and opportune treatment. Future research will determine whether PANDAS require separated diagnostic and therapeutic measures or if it should be included in recently proposed categories such as Pediatric Acute Neuropsychiatric Syndrome (PANS) or Childhood Acute Neuropsychiatric Syndrome (CANS).

What is at the core of OCD? A network analysis of selected obsessive-compulsive symptoms and beliefs

BACKGROUND

Obsessive-compulsive disorder (OCD) is a heterogeneous condition that consists of distinct subtypes, and identification of its core symptoms may inform how to best conceptualize the heterogeneity. Accordingly, we used network analysis to evaluate which symptoms (and associations between symptoms) are most central to OCD symptoms and beliefs.

METHODS

Participants consisted of a combined sample of adults with a primary diagnosis of OCD (N = 150), those with other primary diagnoses (N = 114), and an unselected nonclinical sample (N = 310). Network analysis was used to identify the most central symptoms (nodes) and associations between symptoms (edges) assessed by the Obsessive-Compulsive Inventory-Revised and the Obsessional Beliefs Questionnaire-44.

RESULTS

The most central symptoms in the network were negative appraisals of intrusive thoughts (i.e., Having intrusive thoughts means I'm out of control). Some of the strongest associations between symptoms were also observed for those pertaining to intrusive thoughts and their negative appraisal. Furthermore, central symptoms in the network predicted depression and anxiety (over and above peripheral symptoms) among those with a primary diagnosis of OCD, but not the severity of OCD symptoms.

LIMITATIONS

The approach was exploratory rather than experimental and relied solely on self-report measures of OCD symptoms and beliefs.

CONCLUSIONS

Negative appraisals of intrusive thoughts were the most central symptoms in the OCD network, and they uniquely predict co-occurring symptoms of anxiety and depression, suggesting that these symptoms should be prioritized in theoretical and treatment models of OCD.

Neuroanatomical features and its usefulness in classification of patients with PANDAS

OBJECTIVE

An obsessive-compulsive disorder (OCD) subtype has been associated with streptococcal infections and is called pediatric autoimmune neuropsychiatric disorders associated with streptococci (PANDAS). The neuroanatomical characterization of subjects with this disorder is crucial for the better understanding of its pathophysiology; also, evaluation of these features as classifiers between patients and controls is relevant to determine potential biomarkers and useful in clinical diagnosis. This was the first multivariate pattern analysis (MVPA) study on an early-onset OCD subtype.

METHODS

Fourteen pediatric patients with PANDAS were paired with 14 healthy subjects and were scanned to obtain structural magnetic resonance images (MRI). We identified neuroanatomical differences between subjects with PANDAS and healthy controls using voxel-based morphometry, diffusion tensor imaging (DTI), and surface analysis. We investigated the usefulness of these neuroanatomical differences to classify patients with PANDAS using MVPA.

RESULTS

The pattern for the gray and white matter was significantly different between subjects with PANDAS and controls. Alterations emerged in the cortex, subcortex, and cerebellum. There were no significant group differences in DTI measures (fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity) or cortical features (thickness, sulci, volume, curvature, and gyrification). The overall accuracy of 75% was achieved using the gray matter features to classify patients with PANDAS and healthy controls.

CONCLUSION

The results of this integrative study allow a better understanding of the neural substrates in this OCD subtype, suggesting that the anatomical gray matter characteristics could have an immune origin that might be helpful in patient classification.

Association between early-life trauma and obsessive compulsive symptoms in community youth

BACKGROUND

Obsessive-compulsive symptoms (OCS) in youth are common, have heterogeneous manifestations, and have been shown to be associated with serious psychopathology. While early-life trauma exposure is associated with increased risk for obsessive-compulsive disorder (OCD), its association with different OCS and its clinical relevance for serious psychopathology is unclear. Here we aimed to evaluate associations among traumatic stressful events (TSE), OCS, and serious psychiatric conditions in community youth.

METHODS

We studied nonmental-help seeking youths from the Philadelphia Neurodevelopmental Cohort (N = 7054, aged 11-21, 54% females, 52% prepubertal), assessed for lifetime TSE exposure and OCS. Regression models investigated cross-sectional associations of TSEs with OCS, and associations with depression, suicide ideation and psychosis. Models examined sex and puberty effects, controlling for age and socioeconomic status.

RESULTS

Trauma exposure was associated with higher OCS rates, especially in females (Trauma × Sex interaction Wald = 7.93, p = 0.005) and prepuberty (Trauma × Puberty interaction Wald = 7.68, p = 0.006). TSEs were associated with all OCS manifestations, most prominently with bad intrusive thoughts (odds ratio [OR] = 1.63). Assaultive TSEs, especially sexual assault, showed stronger associations with OCS compared with nonassaultive TSEs. While TSEs and OCS were independently associated with depression, suicide ideation, and psychosis, a significant interaction was observed only in association with increased rates of psychosis (Trauma × OCS interaction Wald = 5.08, p = 0.024).

CONCLUSION

Early-life trauma is associated with OCS in a dose-response manner, more so in females and prepuberty. The trauma-OCS association varied by load, type of trauma, and by OCS subtypes. Trauma-OCS appears a detrimental combination in association with psychosis.

Obsessive-compulsive symptom dimensions: Association with comorbidity profiles and cognitive-behavioral therapy outcome in pediatric obsessive-compulsive disorder

Our aims were to examine: (1) classes of comorbid disorders in a sample of children and adolescents with Obsessive-Compulsive Disorder (OCD), (2) how these classes relate to obsessive-compulsive symptom dimensions, and (3) the extent to which obsessive-compulsive symptom dimensions predict Cognitive-Behavioral Therapy (CBT) outcome. Participants (N = 269) were assessed with the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS-PL) and the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS). Latent Class Analysis (LCA) was used to identify comorbidity classes. Regression analyses were used to evaluate symptom dimensions as predictors of treatment outcome and their relation to comorbidity classes. Comorbidity was included in the treatment outcome analyses as it can affect outcome. Comorbidity was best categorized by a three-class model and each class was distinctively correlated with the OCD symptom dimensions. Higher scores on the symmetry/hoarding factor increased the chance of responding to CBT by an odds ratio of 1.56 (p = 0.020) when controlled for age, gender, and comorbidity class. The harm/sexual factor (p = 0.675) and contamination/cleaning factor (p = 0.122) did not predict CBT outcome. Three clinically relevant comorbidity subgroups in pediatric OCD were identified. Patients who exhibited higher levels of symmetry/hoarding dimension were more prone to respond to CBT.

A pilot study of early onset obsessive-compulsive disorder: Symptom dimensions and association analysis with polymorphisms of the serotonin transporter gene

Our aim was to introduce more homogenous phenotypes for studying genetic variations in the clinically heterogeneous obsessive compulsive disorder (OCD) beside classical case-control analysis. Symptoms were assessed with Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS), and principle component analysis of the lifetime symptom categories yielded four factors (Cleaning, Obsessive, Compulsive, Sexual). The comparison of serotonin transporter linked polymorphic region (5-HTTLPR) in 102 OCD patients and 223 controls showed an increased L-allele frequency but no difference was observed when rs25531 was included. Intronic variants of the serotonin transporter gene did not show association with either OCD, nor with the obtained factors.

Uncommon and/or bizarre features of dementia: Part III

Clinical neurologists have long recognized that dementia can present as atypical or variant syndromes/symptoms. This study aimed at describing uncommon or bizarre symptoms/syndromes observed in patients suffering from dementia. Medline and Google scholar searches were conducted for relevant articles, chapters, and books published before 2018. Search terms used included compulsion, dementia, extracampine hallucination, disordered gambling, humour, and obsession. Publications found through this indexed search were reviewed for further relevant references. The uncommon/bizarre feature of dementia was described as case reports and there were no systematic investigations.

Moderators and predictors of response to cognitive behaviour therapy for pediatric obsessive-compulsive disorder: A systematic review

We report a systematic review of moderators of CBT efficacy for pediatric OCD relative to other treatments. CENTRAL, MEDLINE, EMBASE, CINAHL, and PsycINFO were searched for RCTs reporting on effect moderation for CBT outcomes. Five studies (N = 365) examined 17 variables with three significant moderators identified. Compared to pill-placebo, CBT monotherapy was not effective for children with a family history of OCD but was for those without a family history. For children with a family history, CBT plus sertraline efficacy was attenuated but remained significant. For children with tics, CBT but not sertraline remained superior to pill-placebo. For non-responders to initial treatment with CBT, continuing CBT was inferior to commencing sertraline for those with tics but was not different for those without tics. A supplementary review identified older age, symptom and impairment severity, co-morbidity and family accommodation as consistent predictors of a poorer outcome to CBT. Current evidence for moderation effects is post-hoc, from single RCTs, has small Ns and requires replication. The review identifies family history of OCD and the presence of tics as factors requiring further examination in properly conducted trials and about which clinicians need to show care in their treatment recommendations.

Brain Structural Correlates of Subclinical Obsessive-Compulsive Symptoms in Healthy Children

OBJECTIVE

Subclinical obsessive-compulsive (OC) symptoms are frequently observed in children and have been reported to predict a subsequent diagnosis of OC disorder (OCD). Therefore, identifying the putative neurobiological signatures of such risk is crucial, because it would allow for the characterization of the underpinnings of OCD without the interfering effects of chronicity, medication, or comorbidities, especially when interpreted within the context of OCD clinical heterogeneity and taking into account normal neurodevelopmental changes. The present study aimed to identify the brain volumetric features associated with subclinical OC symptoms and the potential modulatory effects of sex and age in a large sample of healthy children.

METHOD

Two hundred fifty-five healthy children were assessed using the Obsessive-Compulsive Inventory-Child Version and underwent a brain structural magnetic resonance examination. The relation between total and symptom-specific scores and regional gray and white matter (GM and WM) volumes was evaluated. Participants were grouped according to sex and age (younger versus older) to assess the effect of these factors on symptom-brain morphometry associations.

RESULTS

Ordering symptoms were negatively related to GM volumes in the ventral caudate. Hoarding symptoms were positively associated with GM and WM volumes in the left inferior frontal gyrus, and obsessing symptoms correlated negatively with GM and WM volumes in the right temporal pole. Doubt-checking symptoms correlated positively with WM volumes in the right inferior fronto-occipital fasciculus and the corpus callosum. Sex and age modulated some of these associations.

CONCLUSION

Subclinical OC symptoms are associated with specific brain volumetric features, which could be considered potential neural signatures of increased risk for OCD.

Register-based study of the incidence, comorbidities and demographics of obsessive-compulsive disorder in specialist healthcare

BACKGROUND

Incidence of obsessive-compulsive disorder (OCD) has been suspected to increase but nationwide epidemiological studies are limited. This study aims to examine sex-specific incidence time trends and characterize psychiatric and neurodevelopmental comorbidities and sociodemographic risk factors of OCD in specialist healthcare in Finland.

METHODS

A nationwide register-based study using data from four Finnish registers identified 3372 OCD cases and 13,372 matched controls (1:4). Cumulative incidence in subjects born between 1987 and 2001 was estimated at ages of 10, 15, 20 and 23 years. Conditional logistic regression was used to examine the sociodemographic factors.

RESULTS

The cumulative incidence of OCD was 0.4% by age 23. Incidence by age 15 among three cohorts increased from 12.4 to 23.7 /10000 live born males and 8.5 to 28.0 /10000 live born females. 73% of the sample had a comorbid condition. Males were significantly more comorbid with psychotic and developmental disorders; females were more comorbid with depressive and anxiety disorders (p <0.001). Higher maternal SES was associated with an increased risk of OCD (OR 1.4; 95% CI 1.1-1.6).

CONCLUSIONS

These findings suggest that incidence of treated OCD in specialist healthcare has increased. The reason may be increased awareness and rate of referrals but a true increase cannot be ruled out. Further research on risk factors of OCD is warranted.

Strain and sex based characterization of behavioral expressions in non-induced compulsive-like mice

There is currently a lack of understanding how genetic background and sex differences attribute to the heterogeneity of obsessive-compulsive disorder (OCD). An animal model of compulsive-like behaviors has been developed through bidirectional selection of house mice (Mus musculus) for high (big cotton nests; BIG mice) and low levels (small nests; SMALL mice) of nest-building behavior. The BIG male strains have predictive and face validity as a spontaneous animal model of OCD. Here, we evaluated compulsive-, anxiety-, cognitive-, and depression-like behaviors among male and proestrus female replicate strains each of BIG (BIG1, BIG2) and SMALL (SML1, SML2) nest-builders, and randomly-bred Controls (C1, C2). BIG1 and BIG2 males and females had higher nesting scores when compared to SMALL and Control strains. Male BIG1 and BIG2 strains showed more compulsive-like nesting than BIG1 and BIG2 proestrus females, which was not observed among the other strains. Nesting scores were also different between BIG replicate male strains. A similar pattern was observed in the compulsive-like marble burying behavior with BIG strains burying more marbles than SMALL and Control strains. Significant replicate and sex differences were also observed in marble burying among the BIG strains. The open field test revealed replicate effects while the BIG strains showed less anxiety-like behavior in the elevated plus maze test compared to the SMALL strains. For novel object recognition only the Control strains showed replicate and sex differences. In the depression-like forced swim test proestrus females demonstrated less depression-like behavior than males. BIG and SMALL nest-building strains had a higher corticosterone stress response than the Control strains. Together these results indicate a strong interplay of genetic background and sex in influencing expression of behaviors in our compulsive-like mouse model. These results are in congruence with the clinical heterogeneity of OCD.

Ovarian Sex Hormones Modulate Compulsive, Affective and Cognitive Functions in A Non-Induced Mouse Model of Obsessive-Compulsive Disorder

There is currently a lack of understanding of how surgical menopause can influence obsessions, compulsions and associated affective and cognitive functions in female obsessive-compulsive disorder (OCD) patients. Early menopause in women due to surgical removal of ovaries not only causes dramatic hormonal changes, but also may induce affective and cognitive disorders. Here, we tested if surgical removal of ovaries (ovariectomy, OVX), which mimics surgical menopause in humans, would result in exacerbation of compulsive, affective and cognitive behaviors in mice strains that exhibit a spontaneous compulsive-like phenotype. Female mice from compulsive-like BIG, non-compulsive SMALL and randomly-bred Control strains were subjected to OVX or sham-surgery. After 7 days animals were tested for nest building and marble burying to measure compulsive-like behavior. The elevated plus maze and open field tests measured anxiety-like behaviors, while memory was assessed by the novel object recognition. Acute OVX resulted in exacerbation of compulsive-like and anxiety-like behaviors in compulsive-like BIG mice. No significant effects of OVX were observed for the non-compulsive SMALL and Control strains. Object recognition memory was impaired in compulsive-like BIG female mice compared to the Control mice, without an effect of OVX on the BIG mice. We also tested whether 17 β-estradiol (E2) or progesterone (P4) could reverse the effects of OVX. E2, but not P4, attenuated the compulsive-like behaviors in compulsive-like BIG OVX female mice. The actions of the sex steroids on anxiety-like behaviors in OVX females were strain and behavioral test dependent. Altogether, our results indicate that already existing compulsions can be worsened during acute ovarian deprivation concomitant with exacerbation of affective behaviors and responses to hormonal intervention in OVX female mice can be influenced by genetic background.

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.

Clinical significance of psychiatric comorbidity in children and adolescents with obsessive-compulsive disorder: subtyping a complex disorder

A promising approach in relation to reducing phenotypic heterogeneity involves the identification of homogeneous subtypes of OCD based on age of onset, gender, clinical course and comorbidity. This study aims to assess the sociodemographic characteristics and clinical features of OCD patients in relation to gender and the presence or absence of another comorbid disorder. The sample comprised 112 children and adolescents of both sexes and aged 8-18 years, all of whom had a diagnosis of OCD. Overall, 67 % of OCD patients had one comorbid diagnosis, 20.5 % had two such diagnoses and 2.6 % had three comorbid diagnoses. The group of OCD patients with a comorbid neurodevelopmental disorder had significantly more family history of OCD in parents (p = .049), as compared with the no comorbidity group and the group with a comorbid internalizing disorder, and they also showed a greater predominance of males (p = .013) than did the group with a comorbid internalizing disorder. The group of OCD patients with internalizing comorbidity had a later age of onset of OCD (p = .001) compared with both the other groups. Although the initial severity was similar in all three groups, the need for pharmacological treatment and for hospitalization due to OCD symptomatology was greater in the groups with a comorbid neurodevelopmental disorder (p = .038 and p = .009, respectively) and a comorbid internalizing disorder (p = .008 and p = .004, respectively) than in the group without comorbidity. Our findings suggest that two subtypes of OCD can be defined on the basis of the comorbid pathology presented. The identification of different subtypes according to comorbidity is potentially useful in terms of understanding clinical variations, as well as in relation to treatment management and the use of therapeutic resources.

Psychometric properties of the DY-BOCS in a Turkish sample of children and adolescents

BACKGROUND

Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS) is a promising scale for assessing frequency and severity of symptom dimensions. The main objective of the study was to assess the psychometric properties of the DY-BOCS in a large sample of children and adolescents from Turkey.

METHODS

We studied 143 children and adolescents, 7-18years, with well characterized DSM-IV-R OCD, ascertained from seven collaborating university or state hospital sites. We compared the DY-BOCS scores with the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS), the Children's Depression Inventory (CDI), the Yale Global Tic Severity Scale (YGTSS) and the Child Behavior Checklist 6-18years (CBCL 6-18).

RESULTS

The internal consistency of the DY-BOCS symptom dimensions and inter-rater agreement of component scores were excellent. The agreement between global DY-BOCS score and the total CY-BOCS score was highly significant (Pearson's r=0.55, p<0.0001). Severity scores for individual symptom dimensions were independent of one another, only modestly correlating with the global ratings, and were also differentially related to ratings of depression, anxiety and tic severity.

CONCLUSION

The DY-BOCS is a reliable and valid instrument for assessing multiple aspects of OCD symptom severity in children and adolescents from Turkey.

Genetic and Environmental Contributions to Stability in Adult Obsessive Compulsive Behavior

This study investigates the relative contribution of genetic and environmental factors to the stability of obsessive-compulsive (OC) symptoms in an adult population-based sample. We collected data from twin pairs and their siblings, using the Padua Inventory Revised Abbreviated, from the population-based Netherlands Twin Register (NTR) in 2002 (n = 10.134) and 2008 (n = 15.720). Multivariate twin analyses were used to estimate the stability of OC symptoms as a function of genetic and environmental components. OC symptoms were found to be highly stable, with a longitudinal phenotypic correlation of 0.63. Longitudinal broad sense heritability was found to be 56.0%. Longitudinal correlations for genetic (r = 0.58 for additive, r = 1 for non-additive genetic factors) and non-shared environment (r = 0.46) reflected stable effects, indicating that both genes and environment are influencing the stability of OC symptoms in adults. For the first time, evidence is reported for non-additive genetic effects on the stability of OC symptoms. In conclusion, this study showed that OC symptoms are highly stable across time in adults, and that genetic effects contribute mostly to this stability, both in an additive and non-additive way, besides non-shared environmental factors. These data are informative with respect to adult sample selection for future genetic studies, and suggest that gene–gene interaction studies are needed to further understand the dominance effect found in this study.

Development and validation of the Youth Obsessive-Compulsive Symptoms Scale (YOCSS)

From the existing self-report measures for youth Obsessive-Compulsive (OC) symptoms, several challenges can be delineated to further improve the assessment of youth OC-related pathology. The current manuscript incorporates these challenges and reports on the development and validation of a new self-report OC scale for younger age groups, that was labeled the Youth Obsessive-Compulsive Symptoms Scale (YOCSS), assessing OC symptoms and impairment in adolescents (three independent samples: N = 336; N = 289; and N = 209). Study 1 reports on the construction of the items and facets, and their higher-order structure, whereas Study 2 focuses on the confirmation of this structure, measurement invariance across age, and on the convergent and incremental predictive validity. These psychometric analyses resulted in ten symptom facets (structured in three domains) and one impairment facet, and further suggest that the YOCSS is a promising tool for describing early OC symptoms along a dimensional perspective.

Assessing neurocognitive function in psychiatric disorders: a roadmap for enhancing consensus

It has been challenging to identify core neurocognitive deficits that are consistent across multiple studies in patients with Obsessive Compulsive Disorder (OCD). In turn, this leads to difficulty in translating findings from human studies into animal models to dissect pathophysiology. In this article, we use primary data from a working memory task in OCD patients to illustrate this issue. Working memory deficiencies have been proposed as an explanatory model for the evolution of checking compulsions in a subset of OCD patients. However, findings have been mixed due to variability in task design, examination of spatial vs. verbal working memory, and heterogeneity in patient populations. Two major questions therefore remain: first, do OCD patients have disturbances in working memory? Second, if there are working memory deficits in OCD, do they cause checking compulsions? In order to investigate these questions, we tested 19 unmedicated OCD patients and 23 matched healthy controls using a verbal working memory task that has increased difficulty/task-load compared to classic digit-span tasks. OCD patients did not significantly differ in their performance on this task compared to healthy controls, regardless of the outcome measure used (i.e. reaction time or accuracy). Exploratory analyses suggest that a subset of patients with predominant doubt/checking symptoms may have decreased memory confidence despite normal performance on trials with the highest working memory load. These results suggest that other etiologic factors for checking compulsions should be considered. In addition, they serve as a touchstone for discussion, and therefore help us to generate a roadmap for increasing consensus in the assessment of neurocognitive function in psychiatric disorders.

Obsessive compulsive disorder and the glutamatergic system

PURPOSE OF REVIEW

Evidence-based pharmacological interventions for obsessive compulsive disorder (OCD) are targeted mainly at the serotonergic and dopaminergic pathways, and are not always effective. It is timely to review the growing evidence from animal models and clinical research (e.g., brain imaging, genetics) on the role of the glutamatergic system in OCD.

RECENT FINDINGS

Emerging evidence from both animal models and clinical research (including brain imaging, neurogenetics) supports the glutamatergic system as a potential target for pharmacotherapy in OCD. Although there have been relatively few randomized controlled trials of glutamatergic agents in pediatric or adult OCD to date, there is some work on riluzole, memantine, ketamine, topiramate, lamotrigine, N-acetylcysteine, and D-cycloserine.

SUMMARY

Given the need for more efficacious treatments in OCD, and given emergent findings on the role of the glutamatergic system in this disorder, there is a need for additional pharmacotherapy trials on glutamatergic agents in OCD. Possible research designs for such trials might include stand-alone approaches, pharmacotherapy augmentation, or psychotherapy augmentation.

Age of onset in obsessive-compulsive disorder: admixture analysis with a large sample

BACKGROUND

Research into age of onset in obsessive-compulsive disorder (OCD) has indicated significant differences between patients with early and late onset of the disorder. However, multiple criteria have been used arbitrarily for differentiating between early- and late-onset OCD, rendering inconsistent results that are difficult to interpret.

METHOD

In the current study, admixture analysis was conducted in a sample of 377 OC patients to determine the number of underlying populations of age of onset and associated demographic and clinical characteristics. Various measures of anxiety, depression, co-morbidity, autism, OCD, tics and attention deficit hyperactivity disorder (ADHD) symptoms were administered.

RESULTS

A bimodal age of onset was established and the best-fitting cut-off score between early and late age of onset was 20 years (early age of onset ≤19 years). Patients with early age of onset were more likely to be single. Early age of onset patients demonstrated higher levels of OCD severity and increased symptoms on all OCD dimensions along with increased ADHD symptoms and higher rates of bipolar disorder.

CONCLUSIONS

It is suggested that 20 years is the recommended cut-off age for the determination of early versus late age of onset in OCD. Early age of onset is associated with a generally graver OCD clinical picture and increased ADHD symptoms and bipolar disorder rates, which may be related to greater functional implications of the disorder. We propose that age of onset could be an important marker for the subtyping of OCD.

Are the symptoms of obsessive-compulsive disorder temporally stable in children/adolescents? A prospective naturalistic study

Obsessive-compulsive disorder (OCD) symptoms tend to be temporally stable in adults, but much less is known about their stability in young people. We examined the temporal stability of OCD symptoms in a clinical pediatric sample. As part of a naturalistic longitudinal study, 74 children and adolescents with OCD were assessed with the Children's Yale-Brown Obsessive Compulsive Scale on two separate occasions ranging from 1 to 11 years apart (average 5 years). Analysis of variance and multiple regression models examined changes within and between symptoms and symptom dimensions. Changes within individual symptom categories were observed in approximately 15-45% of the cases, depending on the specific symptom. In most of those cases, symptoms went from present to absent at follow-up rather than from absent to present. Changes were no longer significant when individuals who were in remission at follow-up were excluded. Multiple regression analyses indicated that the strongest predictor of a particular symptom dimension at follow-up was the presence of the same dimension at baseline. Shifts from one dimension to another were rare. The content of OCD symptoms is relatively stable across time in young people. Most changes observed were attributable to clinical improvement/remission and occurred within rather than between symptom dimensions.

Clinical features of tic-related obsessive-compulsive disorder: results from a large multicenter study

OBJECTIVE

To evaluate the clinical features of obsessive-compulsive disorder (OCD) patients with comorbid tic disorders (TD) in a large, multicenter, clinical sample.

METHOD

A cross-sectional study was conducted that included 813 consecutive OCD outpatients from the Brazilian OCD Research Consortium and used several instruments of assessment, including the Yale-Brown Obsessive-Compulsive Scale, the Dimensional Yale-Brown Obsessive-Compulsive Scale, the Yale Global Tic Severity Scale (YGTSS), the USP Sensory Phenomena Scale, and the Structured Clinical Interview for DSM-IV Axis I Disorders.

RESULTS

The sample mean current age was 34.9 years old (SE 0.54), and the mean age at obsessive-compulsive symptoms (OCS) onset was 12.8 years old (SE 0.27). Sensory phenomena were reported by 585 individuals (72% of the sample). The general lifetime prevalence of TD was 29.0% (n = 236), with 8.9% (n = 72) presenting Tourette syndrome, 17.3% (n = 141) chronic motor tic disorder, and 2.8% (n = 23) chronic vocal tic disorder. The mean tic severity score, according to the YGTSS, was 27.2 (SE 1.4) in the OCD + TD group. Compared to OCD patients without comorbid TD, those with TD (OCD + TD group, n = 236) were more likely to be males (49.2% vs. 38.5%, p < .005) and to present sensory phenomena and comorbidity with anxiety disorders in general: separation anxiety disorder, social phobia, specific phobia, generalized anxiety disorder, post-traumatic stress disorder, attention-deficit hyperactivity disorder, impulse control disorders in general, and skin picking. Also, the "aggressive," "sexual/religious," and "hoarding" symptom dimensions were more severe in the OCD + TD group.

CONCLUSION

Tic-related OCD may constitute a particular subgroup of the disorder with specific phenotypical characteristics, but its neurobiological underpinnings remain to be fully disentangled.

Glutamate abnormalities in obsessive compulsive disorder: neurobiology, pathophysiology, and treatment

Obsessive compulsive disorder is prevalent, disabling, incompletely understood, and often resistant to current therapies. Established treatments consist of specialized cognitive-behavioral psychotherapy and pharmacotherapy with medications targeting serotonergic and dopaminergic neurotransmission. However, remission is rare, and more than a quarter of OCD sufferers receive little or no benefit from these approaches, even when they are optimally delivered. New insights into the disorder, and new treatment strategies, are urgently needed. Recent evidence suggests that the ubiquitous excitatory neurotransmitter glutamate is dysregulated in OCD, and that this dysregulation may contribute to the pathophysiology of the disorder. Here we review the current state of this evidence, including neuroimaging studies, genetics, neurochemical investigations, and insights from animal models. Finally, we review recent findings from small clinical trials of glutamate-modulating medications in treatment-refractory OCD. The precise role of glutamate dysregulation in OCD remains unclear, and we lack blinded, well-controlled studies demonstrating therapeutic benefit from glutamate-modulating agents. Nevertheless, the evidence supporting some important perturbation of glutamate in the disorder is increasingly strong. This new perspective on the pathophysiology of OCD, which complements the older focus on monoaminergic neurotransmission, constitutes an important focus of current research and a promising area for the ongoing development of new therapeutics.

Obsessive-compulsive disorder in children and adolescents: symptom dimensions in a naturalistic setting

BACKGROUND

Obsessive-compulsive disorder (OCD) is a frequent and clinically heterogeneous disorder. The complex clinical presentation can be summarized using a few consistent and temporally stable symptom dimensions. Only few studies in children and adolescents have examined the importance of symptom dimensions.

AIMS

This retrospective study was undertaken to describe the relation between symptom dimensions, pattern of comorbidity and family disposition, in a sample of Danish children and adolescents with OCD assessed in a naturalistic setting.

METHODS

A retrospective study of children and adolescents (n=83) diagnosed with OCD in the period 1998-2004, at the Psychiatric Hospital for Children and Adolescents, Risskov, Denmark. Information from clinical records was systematically collected and Children's Yale-Brown Obsessive-compulsive Scale (CY-BOCS) scores and symptom checklists were obtained.

RESULTS

High scores on the symmetry/ordering dimension were related to OCD in first-degree relatives and high scores on the aggressive/checking dimension were associated to comorbidity with tic disorders. We showed a correlation between limited insight and younger age.

CONCLUSION

This is one of the first studies to examine symptom dimensions in children and adolescents in naturalistic settings. The results were comparable with those in adult studies, showing an association between the occurrence of the symmetry/ordering dimension and family OCD and the occurrence of the aggressive/checking dimension and comorbid tic disorders. In small children, insight into symptoms may be limited.