Genetics of obsessive-compulsive disorder

Towards the correlates of stressful life events as precipitants of obsessive-compulsive disorder: a systematic review and metanalysis

Obsessive-compulsive disorder (OCD) is a prevalent condition with multifactorial etiology involving genetic and environmental factors. The present study aims to summarize the correlates of stressful life events (SLEs) in OCD by reviewing studies comparing OCD associated or not with SLEs before its onset. To do so, a systematic review was performed by searching PubMed, Web of Science, Scopus, and PsycINFO databases for studies published between the database's inception and November 27, 2023. Studies including individuals whose OCD was precipitated or not by SLEs (SLEs OCD and NSLEs OCD, respectively) were assessed. Effect sizes or odds ratios were then calculated to identify the strength of association between SLEs and clinical characteristics, such as gender, age of onset, family history of OCD, severity of OCD symptoms, depressive symptoms, and mood comorbidities among patients with OCD. Out of the 4083 records initially identified, 5 studies met the inclusion criteria and 3 were comparable through a meta-analysis. Notably, the analyses were limited by the small number of studies available in the literature. The meta-analysis demonstrated SLEs OCD to be associated with female gender, later OCD onset, and increased comorbidity rates with mood disorders. Despite the cross-sectional nature of the reviewed studies, women may be more vulnerable to develop a later onset of OCD following SLEs, which may also lead to mood disorders. Caution is needed to avoid prematurely classifying this presentation as a distinct subtype of OCD.

Obsessive compulsive disorder: overview of the condition and its nursing management

Obsessive compulsive disorder (OCD) is a complex condition characterised by intrusive and distressing thoughts (obsessions) and repetitive behaviours or mental acts (compulsions). The symptoms of OCD cause significant distress and anxiety and can have a debilitating effect on a person's daily functioning. This article gives an overview of OCD, including its prevalence, aetiology, symptoms and treatment strategies, with the aim of enhancing nurses' understanding of the condition and its adverse effects on a person's life. The author also discusses some of the ways in which nurses in any setting can support a person with OCD.

Association of granulocyte macrophage colony-stimulating factor and interleukin-17 levels with obsessive-compulsive disorder: a case-control study findings

Obsessive-compulsive disorder (OCD) is a mental condition that affects many people and is characterized by recurring obsessions and compulsions. It significantly impacts individuals' ability to function ordinarily daily, affecting people of all ages. This study aimed to investigate whether or not the cytokines granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin-17 (IL-17) are involved in the pathophysiology of OCD. A case-control study with 50 OCD patients and 38 healthy volunteers served as the controls for this investigation. The levels of GM-CSF and IL-17 in the serum of both groups were measured with enzyme-linked immunosorbent assay (ELISA) kits. In addition, the sociodemographic characteristics of the population under study were studied. Based on the findings of this study, OCD patients had significantly elevated levels of IL-17 than the controls, it appears that there may be a function for IL-17 in the pathophysiology of OCD. It was also discovered that the severity of OCD and IL-17 levels had a significant positive correlation. On the other hand, when comparing the levels of GM-CSF, there was no significant difference between the patients and the controls. This study provides evidence supporting the involvement of cytokine IL-17 in the pathophysiology of OCD. This study suggests IL-17 as a diagnostic biomarker for OCD and adds to our knowledge of the function that the immune system plays in this condition.

Comorbidity of Obsessive-Compulsive Symptomatology and Bowel and Bladder Dysfunction in a Tertiary Children's Hospital: A Case Series

OBJECTIVE

To improve understanding of co-occurring obsessive-compulsive disorder (OCD) and bowel and bladder dysfunction (BBD) in an outpatient pediatric urology clinic setting. To provide a series of clinical care recommendations to enhance the identification and integrated medical and behavioral health treatment of these disorders.

METHODS

Authors participated in a series of discussions to define the patient population and specific aims for the study. Efforts were made to select index patients of diverse background despite limited sample availability. Three patients were ultimately selected for the study.

RESULTS

The case studies highlight the connection between urinary issues and underlying OCD symptoms. All patients were initially seen for medical treatment of urological symptoms, then referred for psychological evaluation, and were diagnosed with and received treatment for OCD. Similarities among the cases, including experience of phantom urinary incontinence, stressors present that contributed to symptoms, and obsessive fears of incontinence that led to compulsive behavior, were discussed. Differences between the cases, including patient age, sex, and compulsive behavior demonstrated (ie, urinary frequency, excessive wiping) were also reviewed.

CONCLUSION

Access to a behavioral health provider can enhance the identification of comorbid psychological disorders and can reduce duration of symptoms through appropriate psychological treatment. Authors provide recommendations for screening measures and reinforce importance of including basic education on psychiatric diagnoses and impact on urological symptoms in urology and pediatric fellowship training programs. Future research exploring prevalence of comorbid psychiatric conditions and efficacy of treatment interventions in a pediatric urology population would be beneficial.

Role of Sonic Hedgehog Signaling Activation in the Prevention of Neurological Abnormalities Associated with Obsessive-Compulsive Disorder

The smoothened sonic hedgehog (Smo-Shh) pathway is one mechanism that influences neurogenesis, including brain cell differentiation and development during childhood. Shh signaling dysregulation leads to decreased target gene transcription, which contributes to increased neuronal excitation, apoptosis, and neurodegeneration, eventually leading to neurological deficits. Neuropsychiatric disorders such as OCD and related neurological dysfunctions are characterized by neurotransmitter imbalance, neuroinflammation, oxidative stress, and impaired neurogenesis, disturbing the cortico-striato-thalamo-cortical (CSTC) link neuronal network. Despite the availability of several treatments, such as selective serotonin reuptake inhibitors, some individuals may not benefit much from them. Several trials on the use of antipsychotics in the treatment of OCD have also produced inadequate findings. This evidence-based review focuses on a potential pharmacological approach to alleviating OCD and associated neuronal deficits by preventing neurochemical alterations, in which sonic hedgehog activators are neuroprotective, lowering neuronal damage while increasing neuronal maintenance and survival. As a result, stimulating SMO-Shh via its potential activators may have neuroprotective effects on neurological impairment associated with OCD. This review investigates the link between SMO-Shh signaling and the neurochemical abnormalities associated with the progression of OCD and associated neurological dysfunctions. Role of Smo-Shh signaling in serotonergic neurogenesis and in maintaining their neuronal identity. The Shh ligand activates two main transcriptional factors known as Foxa2 and Nkx2.2, which again activates another transcriptional factor, GATA (GATA2 and GATA3), in post mitotic precursor cells of serotonergic neurons-following increased expression of Pet-1 and Lmx1b after GATA regulates the expression of many serotonergic enzymes such as TPH2, SERT, VMAT, slc6a4, Htr1a, Htr1b (Serotonin receptor enzymes), and MAO that regulate and control the release of serotonin and maintain their neuronal identity after their maturation. Abbreviation: Foxa2: Forkhead box; GATA: Globin transcription factor; Lmx1b: LIM homeobox transcription factor 1 beta; TPH2: Tryptophan hydroxylase 2; Htr1a: Serotonin receptor 1a; Htr1b: Serotonin receptor 1b; SERT: Serotonin transporter; VMAT: Vesicular monoamine transporter; MAO: Monoamine oxidase.

Deep brain stimulation for refractory obsessive-compulsive disorder: A review and analysis of the FDA MAUDE database

Background:

Deep brain stimulation (DBS) is used as a treatment option for patients diagnosed with a form of obsessive-compulsive disorder (OCD) that is highly resistant to conventional treatment methods. In 2009, DBS was granted a humanitarian device exemption-approval by the Food and Drug Administration after promising preliminary data. Monitoring of long-term safety data through post market surveillance of adverse events has not yet been conducted for DBS in OCD patients. This study aims to address this critical knowledge gap.

Methods:

All patient- and device-related (PR; DR) reports from January 1, 2012, to December 31, 2021, were downloaded and compiled from the manufacturer and user facility device experience (MAUDE) database pertaining to DBS for OCD using the product class name “Deep Brain Stimulator For OCD.” Data in this study were examined using descriptive statistics to evaluate for frequency of reporting.

Results:

The most frequently reported PR adverse event categories included psychiatric (40%), neurological (19%), other (14%), decreased therapeutic response (10%), and infections (10%). The most frequent DR reports were high impedance (14%), energy output problem (7%), battery problem (7%), malposition of device (7%), and improper/incorrect procedure or method (7%).

Conclusion:

The PR and DR adverse events in our study align with the previous findings of adverse events. They also further solidify that DBS for refractory OCD may be a viable option for the right patient population. However, further studies are essential given the limitations of the MAUDE database.

Imbalance between the caudate and putamen connectivity in obsessive-compulsive disorder

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The imbalance between the caudate and putamen connectivity in OCD patient arises from the abnormal connection of caudate.

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The abnormal caudate connectivity mainly results from the outward extension of cortico-striato-thalamo-cortical loop.

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The caudate connectivity of OCD patients is negatively associated with their task-switch performance.

Background

Compulsive behaviors in obsessive–compulsive disorder (OCD) have been suggested to result from an imbalance in cortico-striatal connectivity. However, the nature of this impairment, the relative involvement of different striatal areas, their imbalance in genetically related but unimpaired individuals, and their relationship with cognitive dysfunction in OCD patients, remain unknown.

Methods

In the current study, striatal (i.e., caudate and putamen) whole-brain connectivity was computed in a sample of OCD patients (OCD, n = 62), unaffected first-degree relatives (UFDR, n = 53) and healthy controls (HC, n = 73) by ROI-based resting-state functional magnetic resonance imaging (rs-fMRI). A behavioral task switch paradigm outside of the scanner was also performed to measure cognitive flexibility in OCD patients.

Results

There were significantly increased strengths (Z-transformed Pearson correlation coefficient) in caudate connectivity in OCD patients. A significant correlation between the two types of connectivity strengths in the relevant regions was observed only in the OCD patient group. Furthermore, the caudate connectivity of patients was negatively associated with their task-switch performance.

Conclusions

The imbalance between the caudate and putamen connectivity, arising from the abnormal increase of caudate activity, may serve as a clinical characteristic for obsessive–compulsive disorder.

Obsessive-compulsive symptoms in schizophrenia patients and their first-degree relatives and the association with subclinical psychotic symptoms

OBJECTIVE

This study aimed to investigate the presence of obsessive-compulsive symptoms (OCS) in patients being followed for schizophrenia and their first-degree relatives (mother, father, siblings, and children) and the relationship between OCS and clinical/subclinical psychotic symptoms.

MATERIALS AND METHODS

The study included 110 schizophrenia patients followed up in a community mental health center and their first-degree relatives. Patients and relatives were evaluated using the SCID-I (Structured Clinical Interview Form for DSM-IV Axis-I Disorders) to ascertain their diagnosis and exclude other axis-I diagnoses. The Yale-Brown Obsessive Compulsive Scale was used to measure OCS severity. Psychotic symptom severity was evaluated in patients using the Positive and Negative Syndrome Scale (PANSS) and subthreshold psychotic symptoms and psychosis proneness were assessed in relatives using the Schizotypal Personality Questionnaire.

RESULTS

The prevalence of clinically significant OCS was 41.8% in schizophrenia patients and 28.2% in their relatives. PANSS positive and general psychopathology subscale scores were higher in patients with OCS. Suspiciousness and interpersonal schizotypy scores were significantly higher in relatives with OCS compared to those without. The first-degree relatives of patients with OCS did not exhibit a higher prevalence of OCS or psychotic symptoms compared to the relatives of patients without OCS.

CONCLUSION

Our study demonstrates that obsessive-compulsive phenomena are common in schizophrenia patients and their relatives. Although there seems to be a positive association between OCS and psychotic symptoms in patients and their first-degree relatives, the intergenerational transmission of these two symptom groups may occur independently.

Could the Thyroid Gland Dominate the Brain in Obsessive-Compulsive Disorder?

Thyroid hormones have an essential role in brain maturation and neuronal functioning. The comorbidity of thyroid disorders and several mental disturbances is frequently reported. We aimed to evaluate the literature on the potential relationship between thyroid disorders and obsessive-compulsive disorder (OCD) and obsessive-compulsive symptoms (OCS). We searched the literature using PUBMED, ProQuest, Google Scholar, and PsycInfo electronic databases for original studies (cross-sectional, case series, case report) on the association between thyroid dysfunctions and OCD and OCS between 1977 and 2021. Eleven studies met the inclusion criteria. Despite some methodological limitations, the OCD rates in patients with autoimmune thyroid disorders were found to be higher than the normal population in two studies. The findings on thyroid dysfunction in OCD patients were inconclusive. In the light of available data, it could be proposed that there might be a possible association between thyroid disorders and OCD. Some shared immunological mechanisms could play a role in the pathophysiology of both thyroid diseases and OCD. New research is needed to confirm this association and elucidate the underlying common mechanisms between these disorders.

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.

Exome sequencing in obsessive-compulsive disorder reveals a burden of rare damaging coding variants

Obsessive-compulsive disorder (OCD) affects 1-2% of the population, and, as with other complex neuropsychiatric disorders, it is thought that rare variation contributes to its genetic risk. In this study, we performed exome sequencing in the largest OCD cohort to date (1,313 total cases, consisting of 587 trios, 41 quartets and 644 singletons of affected individuals) and describe contributions to disease risk from rare damaging coding variants. In case-control analyses (n = 1,263/11,580), the most significant single-gene result was observed in SLITRK5 (odds ratio (OR) = 8.8, 95% confidence interval 3.4-22.5, P = 2.3 × 10-6). Across the exome, there was an excess of loss of function (LoF) variation specifically within genes that are LoF-intolerant (OR = 1.33, P = 0.01). In an analysis of trios, we observed an excess of de novo missense predicted damaging variants relative to controls (OR = 1.22, P = 0.02), alongside an excess of de novo LoF mutations in LoF-intolerant genes (OR = 2.55, P = 7.33 × 10-3). These data support a contribution of rare coding variants to OCD genetic risk.

Carga cognitiva y control atencional en puertorriqueños con trastorno obsesivocompulsivo

Trasfondo:El control ejecutivo de la atención media la resolución de problemas y la acción voluntaria y está implicado en la regulación de las emociones. Se ha reportado que el control atencional está afectado en personas con trastorno obsesivo-compulsivo (TOC). Sin embargo, no se ha considerado la influencia de la carga cognitiva y la distracción en la ejecución de tareas, lo que pudiera tener un impacto en el control atencional. En este estudio evaluamos si la carga cognitiva alta y baja influyen en el control atencional de personas con TOC, en comparación con un grupo control. Método:Quince adultos puertorriqueños con TOC (M=31.60, DE=10.70) y 26 saludables (M=28.42, DE=10.73) participaron en el estudio. Se administró el Attention Network Test y una tarea de carga cognitiva para evaluar el control atencional. Resultados:No se observaron diferencias significativas en las puntuaciones de alerta, orientación y control atencional entre los grupos en ambas condiciones de carga cognitiva (p>0.05). Solo se observó una diferencia significativa en el control atencional de los participantes con TOC (z=1.99, p=0.047) y del grupo control (z=-2.83, p=0.005) durante tareas con carga cognitiva baja y alta. Conclusiones:Ambos grupos experimentaron menor interferencia de distractores bajo alta carga cognitiva, lo que sugiere un mayor control de la atención durante esta condición. Es posible que el aumento de carga cognitiva pueda reducir la distracción en puertorriqueños saludables y aquellos con TOC. Tomar en cuenta la carga cognitiva puede facilitar el entrenamiento cognitivo para el control atencional y aumentar la flexibilidad cognitiva, mejorando la respuesta al tratamiento.  

Abnormal brain functional network dynamics in obsessive-compulsive disorder patients and their unaffected first-degree relatives

We utilized dynamic functional network connectivity (dFNC) analysis to compare participants with obsessive–compulsive disorder (OCD) with their unaffected first‐degree relative (UFDR) and healthy controls (HC). Resting state fMRI was performed on 46 OCD, 24 UFDR, and 49 HCs, along with clinical assessments. dFNC analyses revealed two distinct connectivity states: a less frequent, integrated state characterized by the predominance of between‐network connections (State I), and a more frequent, segregated state with strong within‐network connections (State II). OCD patients spent more time in State II and less time in State I than HC, as measured by fractional windows and mean dwell time. Time in each state for the UFDR were intermediate between OCD patients and HC. Within the OCD group, fractional windows of time spent in State I was positively correlated with OCD symptoms (as measured by the obsessive compulsive inventory‐revised [OCI‐R], r = .343, p<.05, FDR correction) and time in State II was negatively correlated with symptoms (r = −.343, p<.05, FDR correction). Within each state we also examined connectivity within and between established intrinsic connectivity networks, and found that UFDR were similar to the OCD group in State I, but more similar to the HC groups in State II. The similarities between OCD and UFDR groups in temporal properties and State I connectivity indicate that these features may reflect the endophenotype for OCD. These results indicate that the temporal dynamics of functional connectivity could be a useful biomarker to identify those at risk.

Investigation of glycaemic traits in psychiatric disorders using Mendelian randomisation revealed a causal relationship with anorexia nervosa

Data from observational studies have suggested an involvement of abnormal glycaemic regulation in the pathophysiology of psychiatric illness. This may be an attractive target for clinical intervention as glycaemia can be modulated by both lifestyle factors and pharmacological agents. However, observational studies are inherently confounded, and therefore, causal relationships cannot be reliably established. We employed genetic variants rigorously associated with three glycaemic traits (fasting glucose, fasting insulin, and glycated haemoglobin) as instrumental variables in a two-sample Mendelian randomisation analysis to investigate the causal effect of these measures on the risk for eight psychiatric disorders. A significant protective effect of a natural log transformed pmol/L increase in fasting insulin levels was observed for anorexia nervosa after the application of multiple testing correction (OR = 0.48 [95% CI: 0.33-0.71]-inverse-variance weighted estimate). There was no consistently strong evidence for a causal effect of glycaemic factors on the other seven psychiatric disorders considered. The relationship between fasting insulin and anorexia nervosa was supported by a suite of sensitivity analyses, with no statistical evidence of instrument heterogeneity or horizontal pleiotropy. Further investigation is required to explore the relationship between insulin levels and anorexia.

An Epigenetically Distinct Subset of Children With Autism Spectrum Disorder Resulting From Differences in Blood Cell Composition

Background: Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that often involves impaired cognition, communication difficulties and restrictive, repetitive behaviors. ASD is extremely heterogeneous both clinically and etiologically, which represents one of the greatest challenges in studying the molecular underpinnings of ASD. While hundreds of ASD-associated genes have been identified that confer varying degrees of risk, no single gene variant accounts for >1% of ASD cases. Notably, a large number of ASD-risk genes function as epigenetic regulators, indicating potential epigenetic dysregulation in ASD. As such, we compared genome-wide DNA methylation (DNAm) in the blood of children with ASD (n = 265) to samples from age- and sex-matched, neurotypical controls (n = 122) using the Illumina Infinium HumanMethylation450 arrays. Results: While DNAm patterns did not distinctly separate ASD cases from controls, our analysis identified an epigenetically unique subset of ASD cases (n = 32); these individuals exhibited significant differential methylation from both controls than the remaining ASD cases. The CpG sites at which this subset was differentially methylated mapped to known ASD risk genes that encode proteins of the nervous and immune systems. Moreover, the observed DNAm differences were attributable to altered blood cell composition, i.e., lower granulocyte proportion and granulocyte-to-lymphocyte ratio in the ASD subset, as compared to the remaining ASD cases and controls. This ASD subset did not differ from the rest of the ASD cases in the frequency or type of high-risk genomic variants. Conclusion: Within our ASD cohort, we identified a subset of individuals that exhibit differential methylation from both controls and the remaining ASD group tightly associated with shifts in immune cell type proportions. This is an important feature that should be assessed in all epigenetic studies of blood cells in ASD. This finding also builds on past reports of changes in the immune systems of children with ASD, supporting the potential role of altered immunological mechanisms in the complex pathophysiology of ASD. The discovery of significant molecular and immunological features in subgroups of individuals with ASD may allow clinicians to better stratify patients, facilitating personalized interventions and improved outcomes.

DNA Methylation of the Oxytocin Receptor Across Neurodevelopmental Disorders

Many neurodevelopmental disorders (NDDs) share common learning and behavioural impairments, as well as features such as dysregulation of the oxytocin hormone. Here, we examined DNA methylation (DNAm) in the 1st intron of the oxytocin receptor gene, OXTR, in patients with autism spectrum (ASD), attention deficit and hyperactivity (ADHD) and obsessive compulsive (OCD) disorders. DNAm of OXTR was assessed for cohorts of ASD (blood), ADHD (saliva), OCD (saliva), which uncovered sex-specific DNAm differences compared to neurotypical, tissue-matched controls. Individuals with ASD or ADHD exhibiting extreme DNAm values had lower IQ and more social problems, respectively, than those with DNAm within normative ranges. This suggests that OXTR DNAm patterns are altered across NDDs and may be correlated with common clinical outcomes.

The Effect of Virtual Reality on Emotional Response and Symptoms Provocation in Patients With OCD: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to evaluate the effectiveness of virtual reality (VR)-based technology on emotional response and symptoms in patients with obsessive-compulsive disorder (OCD). We systematically searched major electronic databases, including PubMed/Medline, Scopus, Embase, ISI Web of Science, PsycINFO, and Cochrane central, up to April 14, 2021, with no data or language limits. We performed reference, related articles, and citation searches to find additional articles. We included original articles comparing and studying VR-based technology in patients with OCD against the control group. We observed that VR significantly increases in anxiety (SMD = 2.92; 95% CI 1.89-3.94, p < 0.0001; I ² = 95%), disgust (SMD = 2.52; 95% CI 1.36-3.68, p < 0.0001; I ² = 95%), urge to wash (SMD = 3.12; 95% CI 1.92-4.32, p < 0.0001; I ² = 94%), checking time (SMD = 1.06; 95% CI 0.71-1.4, p < 0.0001; I ² = 44%), number of checking behavior (SMD = 1.45; 95% CI 0.06-2.83, p = 0.04; I ² = 93%), and uncertainty (SMD = 2.59; 95% CI 0.90-4.27, p = 0.003; I ² = 70%) in OCD patients compared with healthy controls using a random-effect model. This meta-analysis found that this environment has a moderate enhancement in emotional response and symptoms test scores of patients with OCD. However, our findings should be generalized with caution due to the lack of standardized methods and high heterogeneity among included evidence. The appropriate mode of integrating VR-based technology for patients with OCD requires more exploration.

The association of HTR2A polymorphisms with obsessive-compulsive disorder and its subtypes: A meta-analysis

BACKGROUND

Genetic risk factors that contribute to obsessive-compulsive disorder (OCD) have yet to be elucidated. Historically, serotonergic dysfunction has been implicated. Evidence from the literature points towards the serotonin receptor 2A gene (HTR2A) as a primary candidate. Our meta-analysis investigated whether polymorphisms in HTR2A are associated with OCD or its subtypes, based on sex and age of onset.

METHODS

Studies employing case-control or family-based designs were systematically searched, and those meeting eligibility underwent quality assessment, resulting in 18 studies. A random-effects meta-analysis using standard inverse-variance weighting to compute odds ratio (OR) was conducted. To examine sensitivity, results were also obtained using a more conservative statistical method.

RESULTS

Three HTR2A variants were identified: T102C, G-1438A, and C516T. T102C and G-1438A were analyzed together due to strong linkage disequilibrium, where the 102T allele co-occurs with -1438A allele. Results reported as OR [95%CI] showed that the T/A allele were significantly associated with OCD, 1.14 [1.01, 1.29]. After stratification, results remained significant for females, 1.20 [1.00, 1.45], and early-onset OCD, 1.27 [1.02, 1.58], but not males, 1.06 [0.91, 1.23]. No associations were found for late-onset OCD, 0.98 [0.70, 1.37], or C516T, 1.22 [0.14, 10.37], but conclusions cannot be drawn from two studies.

LIMITATIONS

Associations no longer reached significance with the conservative statistical approach. HTR2A alone cannot explain OCD complexity and limited samples reporting genetic data according to subtypes.

CONCLUSIONS

These results suggest a possible association of HTR2A polymorphisms with OCD, but further investigations considering sex and age of onset with larger samples is needed.

Examining overlap and homogeneity in ASD, ADHD, and OCD: a data-driven, diagnosis-agnostic approach

The validity of diagnostic labels of autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and obsessive compulsive disorder (OCD) is an open question given the mounting evidence that these categories may not correspond to conditions with distinct etiologies, biologies, or phenotypes. The objective of this study was to determine the agreement between existing diagnostic labels and groups discovered based on a data-driven, diagnosis-agnostic approach integrating cortical neuroanatomy and core-domain phenotype features. A machine learning pipeline, called bagged-multiview clustering, was designed to discover homogeneous subgroups by integrating cortical thickness data and measures of core-domain phenotypic features of ASD, ADHD, and OCD. This study was conducted using data from the Province of Ontario Neurodevelopmental Disorders (POND) Network, a multi-center study in Ontario, Canada. Participants (n = 226) included children between the ages of 6 and 18 with a diagnosis of ASD (n = 112, median [IQR] age = 11.7[4.8], 21% female), ADHD (n = 58, median [IQR] age = 10.2[3.3], 14% female), or OCD (n = 34, median [IQR] age = 12.1[4.2], 38% female), as well as typically developing controls (n = 22, median [IQR] age = 11.0[3.8], 55% female). The diagnosis-agnostic groups were significantly different than each other in phenotypic characteristics (SCQ: χ²(9) = 111.21, p < 0.0001; SWAN: χ²(9) = 142.44, p < 0.0001) as well as cortical thickness in 75 regions of the brain. The analyses revealed disagreement between existing diagnostic labels and the diagnosis-agnostic homogeneous groups (normalized mutual information < 0.20). Our results did not support the validity of existing diagnostic labels of ASD, ADHD, and OCD as distinct entities with respect to phenotype and cortical morphology.

Sex differences in the genetic architecture of obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a highly heritable complex phenotype that demonstrates sex differences in age of onset and clinical presentation, suggesting a possible sex difference in underlying genetic architecture. We present the first genome-wide characterization of the sex-specific genetic architecture of OCD, utilizing the largest set of OCD cases and controls available from the Psychiatric Genomics Consortium. We assessed evidence for several mechanisms that may contribute to sex differences including a sex-dependent liability threshold, the presence of individual sex-specific risk variants on the autosomes and the X chromosome, and sex-specific pleiotropic effects. Furthermore, we tested the hypothesis that genetic heterogeneity between the sexes may obscure associations in a sex-combined genome-wide association study. We observed a strong genetic correlation between male and female OCD and no evidence for a sex-dependent liability threshold model, suggesting that sex-combined analysis does not suffer from widespread loss of power because of genetic heterogeneity between the sexes. While we did not detect any significant sex-specific genome-wide single nucleotide polymorphisms (SNP) associations, we did identify two significant gene-based associations in females: GRID2 and GRP135, which showed no association in males. We observed that the SNPs with sexually differentiated effects showed an enrichment of regulatory variants influencing expression of genes in brain and immune tissues. These findings suggest that future studies with larger sample sizes hold great promise for the identification of sex-specific genetic risk factors for OCD.

Eye movement tracking in pediatric obsessive compulsive disorder

Till date researchers have elucidated the neurobiological substrates in OCD using methods like neuroimaging. However, a potential biomarker is still elusive. The present study is an attempt to identify a potential biomarker in pediatric OCD using eye tracking. The present study measured pro-saccade and anti-saccade parameters in 36 cases of pediatric OCD and 31 healthy controls. There was no significant difference between cases and controls in the error rate, peak velocity, position gain and latency measures in both pro-saccade and anti-saccade eye tracking tasks. With age, anti-saccades become slower in velocity, faster in response and more accurate irrespective of disorder status of the child. Pro-saccades also show a similar effect that is less prominent than anti-saccades. Gain measures more significantly vary with age in children with OCD than the controls, whereas latency measures positively correlated with age in children with OCD as opposed to being negatively correlated in the controls. Findings of this study do not support any of the eye tracking measures as putative diagnostic bio-markers in OCD. However, latency and gain parameters across different age groups in anti-saccade tasks need to be explored in future studies.

Gene variations in PBX1, LMX1A and SLITRK1 are associated with obsessive-compulsive disorder and its clinical features

Genetic factors probably influence OCD development and a current hypothesis proposes that genes involved in the development of the central nervous system (CNS) are related to OCD. The aim of this study was to analyze six Single Nucleotide Polymorphisms (SNPs) in five genes with functions related to neurodevelopment in OCD. A total of 203 patient and 203 control samples were genotyped using the TaqMan® methodology. Statistically significant associations between OCD and PBX1 (rs2275558) in total sample (P = 0.002) and in males (P = 0.0003) were observed. Concerning symptom dimensions, the expression of neutralization showed a statistical significant association with LMX1A (rs4657411, P = 0.004) in total sample. We also observed significant association between LMX1A (rs4657411) and washing dimension in females (P = 0.01). Additionally, SLITRK1 (rs9593835) was significantly associated with checking dimension in male patients (P = 0.04). Our results indicate an important influence of neurodevelopment genes in the OCD susceptibility. Additional studies with larger samples are needed to confirm these results.

Challenges in the diagnosis and treatment of pediatric obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) affects 1%-3% of children worldwide and has a profound impact on quality of life for patients and families. Although our understanding of the underlying etiology remains limited, data from neuroimaging and genetic studies as well as the efficacy of serotonergic medications suggest the disorder is associated with the fundamental alterations in the function of cortico-striato-thalamocortical circuits. Significant delays to diagnosis are common, ultimately leading to more severe functional impairment with long-term developmental consequences. The clinical assessment requires a detailed history of specific OCD symptoms as well as psychiatric and medical comorbidities. Standardized assessment tools may aid in evaluating and tracking symptom severity and both individual and family functioning. In the majority of children, an interdisciplinary approach that combines cognitive behavioral therapy with a serotonin reuptake inhibitor leads to meaningful symptom improvement, although some patients experience a chronic, episodic course. There are limited data to guide the management of treatment-refractory illness in children, although atypical antipsychotics and glutamate-modulating agents may be used cautiously as augmenting agents. This review outlines a clinical approach to the diagnosis and management of OCD, highlighting associated challenges, and limitations to our current knowledge.

BDNF gene and obsessive compulsive disorder risk, symptom dimensions and treatment response

AIM

Genetic etiology of Obsessive Compulsive Disorder (OCD) has been investigated extensively, with mixed results across candidate gene studies. The dimensional subtypes of OCD are shown to better correlate with brain imaging endophenotypes and thus could potentially enhance the power of genetic association. In this study, we perform a case control analysis of association of a single nucleotide polymorphism rs6265(Val66Met) in Brain Derived Neurotrophic Factor gene, that has been previously implicated in a variety of psychiatric syndromes, and examine its association with symptom dimensions of OCD.

METHODS

Individuals diagnosed to have OCD (n=377) and controls (n=449) of South Indian origin were genotyped for polymorphism rs6265 (196G/A, Val66Met). Detailed phenotypic assessment of the cases were carried out in the cases using structured instruments. The genotypic association was tested for clinical variables such as age of onset, gender, family history, co-morbidity, treatment response, and factor analyzed OCD symptom dimensions.

RESULTS

The allele 'A' frequency was found to be significantly higher in the controls, as compared to cases suggesting a protective effect. The contamination/washing symptom dimension score was significantly lower in carriers of 'A' allele which remained significant even after testing for confounding effects on linear regression.

CONCLUSIONS

Our results support findings from previous studies on a possible protective effect of the 'Met' allele at the Val66Met locus in OCD. Its association with lower scores on the contamination/washing dimension is a novel finding of this study.

My Child's thoughts frighten me: Maladaptive effects associated with parents' interpretation and management of children's intrusive thoughts

BACKGROUND AND OBJECTIVES

Environmental factors explain substantial variance in youth's obsessive-compulsive symptoms (OCS) and much of this research has focused upon overt parenting behaviors (e.g., accommodation). No work, however, has examined how parents' internal processes (e.g., perception of children's intrusions) influence youth's OCS. Based upon the cognitive theory of obsessions, we propose that parents' misappraisal of children's intrusions as threatening will be positively associated with (a) the number of maladaptive intrusion management strategies recommended by the parent, as well as (b) children's obsessive beliefs, (c) interpretation biases, and (d) OCS severity.

METHODS

Twenty-seven children (M = 12.81; SD = 3.43) and the parent most involved in childcare completed diagnostic interviews and self-report questionnaires. In the laboratory, we induced obsessional anxiety in youth through a standardized in vivo paradigm (e.g., think about a personalized harm-related negative event occurring). Parents rated how they interpreted their children's unwanted thought and the intrusion management strategies they would recommend.

RESULTS

Parents who interpreted their children's intrusions as threatening recommended more maladaptive intrusion management strategies and their misappraisal positively and significantly correlated with the severity of children's obsessive beliefs, interpretation biases, and OCS, even after controlling for co-occurring internalizing symptoms.

LIMITATIONS

Small sample and cross-sectional design precludes causal conclusions.

CONCLUSIONS

Parents' misinterpretation of children's intrusions may operate as a mechanism by which OCS are generationally transmitted. Results can inform OC prevention programs that target parents' cognitive biases in their own psychotherapy.

Eighteen-year-old man with autism, obsessive compulsive disorder and a SHANK2 variant presents with severe anorexia that responds to high-dose fluoxetine

The SHANK2 gene codes for a protein involved in organising the postsynaptic density and disruptions have been associated with autism spectrum disorders (ASDs). ASDs are frequently comorbid with intellectual disability and anxiety disorders and emerging evidence suggests potentially common aetiologies. Here, we report the case of an 18-year-old man with ASD who presented with severe anorexia due to fear of food contamination, food avoidance and stereotypies attributable to underlying obsessive compulsive disorder (OCD). The patient was found to be heterozygous for c.2518C>T (p.Pro840Ser), a likely damaging coding variant in the proline rich region of SHANK2 Interestingly, the patient's disordered eating behaviour began to improve only after high-dose fluoxetine was initiated to target OCD symptoms. Overall, this case highlights the utility of molecular genetic testing in clinical psychiatry and provides an example of how genetic information can inform clinicians in the treatment of complex neuropsychiatric syndromes.

The morphometric co-atrophy networking of schizophrenia, autistic and obsessive spectrum disorders

By means of a novel methodology that can statistically derive patterns of co-alterations distribution from voxel-based morphological data, this study analyzes the patterns of brain alterations of three important psychiatric spectra-that is, schizophrenia spectrum disorder (SCZD), autistic spectrum disorder (ASD), and obsessive-compulsive spectrum disorder (OCSD). Our analysis provides five important results. First, in SCZD, ASD, and OCSD brain alterations do not distribute randomly but, rather, follow network-like patterns of co-alteration. Second, the clusters of co-altered areas form a net of alterations that can be defined as morphometric co-alteration network or co-atrophy network (in the case of gray matter decreases). Third, within this network certain cerebral areas can be identified as pathoconnectivity hubs, the alteration of which is supposed to enhance the development of neuronal abnormalities. Fourth, within the morphometric co-atrophy network of SCZD, ASD, and OCSD, a subnetwork composed of eleven highly connected nodes can be distinguished. This subnetwork encompasses the anterior insulae, inferior frontal areas, left superior temporal areas, left parahippocampal regions, left thalamus and right precentral gyri. Fifth, the co-altered areas also exhibit a normal structural covariance pattern which overlaps, for some of these areas (like the insulae), the co-alteration pattern. These findings reveal that, similarly to neurodegenerative diseases, psychiatric disorders are characterized by anatomical alterations that distribute according to connectivity constraints so as to form identifiable morphometric co-atrophy patterns.

Mapping Compulsivity in the DSM-5 Obsessive Compulsive and Related Disorders: Cognitive Domains, Neural Circuitry, and Treatment

Compulsions are repetitive, stereotyped thoughts and behaviors designed to reduce harm. Growing evidence suggests that the neurocognitive mechanisms mediating behavioral inhibition (motor inhibition, cognitive inflexibility) reversal learning and habit formation (shift from goal-directed to habitual responding) contribute toward compulsive activity in a broad range of disorders. In obsessive compulsive disorder, distributed network perturbation appears focused around the prefrontal cortex, caudate, putamen, and associated neuro-circuitry. Obsessive compulsive disorder-related attentional set-shifting deficits correlated with reduced resting state functional connectivity between the dorsal caudate and the ventrolateral prefrontal cortex on neuroimaging. In contrast, experimental provocation of obsessive compulsive disorder symptoms reduced neural activation in brain regions implicated in goal-directed behavioral control (ventromedial prefrontal cortex, caudate) with concordant increased activation in regions implicated in habit learning (presupplementary motor area, putamen). The ventromedial prefrontal cortex plays a multifaceted role, integrating affective evaluative processes, flexible behavior, and fear learning. Findings from a neuroimaging study of Pavlovian fear reversal, in which obsessive compulsive disorder patients failed to flexibly update fear responses despite normal initial fear conditioning, suggest there is an absence of ventromedial prefrontal cortex safety signaling in obsessive compulsive disorder, which potentially undermines explicit contingency knowledge and may help to explain the link between cognitive inflexibility, fear, and anxiety processing in compulsive disorders such as obsessive compulsive disorder.

Obsessive-Compulsive Disorder in a 19-Year-Old Female Adolescent With Turner Syndrome

Obsessive-compulsive disorder (OCD) in patients with Turner syndrome (TS) is an uncommon neuropsychiatric presentation that has not been well characterized in the scientific literature. Though no clear psychiatric component is syndromic to TS, the clinical manifestations of certain neuropsychiatric disorders, including mood, anxiety and eating disorders, have all been well documented in patients with TS. However, the presence of OCD in these patients has not been previously described. This report details a 19-year-old TS patient who presented with OCD since the age of 13, comorbid with several other psychiatric pathologies, including bipolar I disorder, anorexia nervosa and attention deficit hyperactivity disorder (ADHD). It will also discuss those comorbidities in relation to the patient’s genetic syndrome and mention the contribution it makes to her multiple disabilities diagnosis as well as her patient-specific therapy. Patients with TS often present to treating physicians for overwhelming somatic complaints, likely resulting in poor recognition of psychiatric disorders. Thus, OCD may be significantly under-diagnosed in patients with TS and should be explored by clinicians treating this vulnerable population.

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.

Whole-genome association analysis of treatment response in obsessive-compulsive disorder

Up to 30% of patients with obsessive-compulsive disorder (OCD) exhibit an inadequate response to serotonin reuptake inhibitors (SRIs). To date, genetic predictors of OCD treatment response have not been systematically investigated using genome-wide association study (GWAS). To identify specific genetic variations potentially influencing SRI response, we conducted a GWAS study in 804 OCD patients with information on SRI response. SRI response was classified as 'response' (n=514) or 'non-response' (n=290), based on self-report. We used the more powerful Quasi-Likelihood Score Test (the MQLS test) to conduct a genome-wide association test correcting for relatedness, and then used an adjusted logistic model to evaluate the effect size of the variants in probands. The top single-nucleotide polymorphism (SNP) was rs17162912 (P=1.76 × 10(-8)), which is near the DISP1 gene on 1q41-q42, a microdeletion region implicated in neurological development. The other six SNPs showing suggestive evidence of association (P<10(-5)) were rs9303380, rs12437601, rs16988159, rs7676822, rs1911877 and rs723815. Among them, two SNPs in strong linkage disequilibrium, rs7676822 and rs1911877, located near the PCDH10 gene, gave P-values of 2.86 × 10(-6) and 8.41 × 10(-6), respectively. The other 35 variations with signals of potential significance (P<10(-4)) involve multiple genes expressed in the brain, including GRIN2B, PCDH10 and GPC6. Our enrichment analysis indicated suggestive roles of genes in the glutamatergic neurotransmission system (false discovery rate (FDR)=0.0097) and the serotonergic system (FDR=0.0213). Although the results presented may provide new insights into genetic mechanisms underlying treatment response in OCD, studies with larger sample sizes and detailed information on drug dosage and treatment duration are needed.

Mild White Matter Changes in Un-medicated Obsessive-Compulsive Disorder Patients and Their Unaffected Siblings

Objective: Obsessive-compulsive disorder (OCD) is a common neuropsychiatric disorder with moderate genetic influences and white matter abnormalities in frontal-striatal and limbic regions. Inconsistencies in reported white matter results from diffusion tensor imaging (DTI) studies can be explained, at least partly, by medication use and between-group differences in disease profile and stage. We used a family design aiming to establish whether white matter abnormalities, if present in un-medicated OCD patients, also exist in their unaffected siblings.

Method: Forty-four OCD patients, un-medicated for at least the past 4 weeks, 15 of their unaffected siblings, and 37 healthy controls (HC) underwent DTI using a 3-Tesla MRI-scanner. Data analysis was done using tract-based spatial statistics (TBSS). Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) values were compared within seven skeletonised regions of interest (ROIs), i.e., corpus callosum, bilateral cingulum bundle, bilateral inferior longitudinal fasciculus/frontal-occipital fasciculus (ILF/FOF) and bilateral superior longitudinal fasciculus (SLF).

Results: Un-medicated OCD patients, compared with HC, had significantly lower FA in the left cingulum bundle. FA was trend-significantly lower in all other ROIs, except for the corpus callosum. Significant three-group differences in FA (and in RD at trend-significant level) were observed in the left cingulum bundle, with the unaffected siblings representing an intermediate group between OCD patients and HC.

Conclusions: OCD patients showed lower FA in the left cingulum bundle, partly driven by trend-significantly higher values in RD. Since the unaffected siblings were found to be an intermediate group between OCD patients and HC, this white matter alteration may be considered an endophenotype for OCD.

Trait-related decision making impairment in obsessive-compulsive disorder: evidence from decision making under ambiguity but not decision making under risk

This study aimed to investigate whether deficits in decision making were potential endophenotype markers for OCD considering different phases of the disease. Fifty-seven non-medicated OCD patients (nmOCD), 77 medicated OCD patients (mOCD), 48 remitted patients with OCD (rOCD) and 115 healthy controls were assessed with the Iowa Gambling Task (IGT), which measured decision making under ambiguity, and the Game of Dice Task (GDT), which measured decision making under risk. While the three patients groups showed impaired performance on the IGT compared with healthy controls, all patients showed intact performance on the GDT. Furthermore, the rOCD patients showed a preference for deck B, indicating that they showed more sensitivity to the frequency of loss than to the magnitude of loss, whereas the mOCD patients showed a preference for deck A, indicating that they had more sensitivity to the magnitude of loss than to the frequency of loss. These data suggested that OCD patients had trait-related impairments in decision making under ambiguity but not under risk, and that dissociation of decision making under ambiguity and under risk is an appropriate potential neurocognitive endophenotype for OCD. The subtle but meaningful differences in decision making performance between the OCD groups require further study.

Association between genetic variants related to glutamatergic, dopaminergic and neurodevelopment pathways and white matter microstructure in child and adolescent patients with obsessive-compulsive disorder

BACKGROUND

Alterations in white matter (WM) integrity observed in patients with obsessive-compulsive disorder (OCD) may be at least partly determined genetically. Neuroimaging measures of WM microstructure could serve as promising intermediate phenotypes for genetic analysis of the disorder. The objective of the present study was to explore the association between variability in genes related to the pathophysiology of OCD and altered WM microstructure previously identified in child and adolescent patients with the disease.

METHODS

Fractional anisotropy (FA) and mean diffusivity (MD) measured by diffusion tensor imaging (DTI) and 262 single nucleotide polymorphisms (SNPs) in 35 candidate genes were assessed concomitantly in 54 child and adolescent OCD patients.

RESULTS

Six polymorphisms located in the glutamate transporter gene (SLC1A1 rs3087879), dopamine transporter gene (SLC6A3 rs4975646), dopamine receptor D3 (DRD3 rs3773679), nerve growth factor receptor gene (NGFR rs734194 and rs2072446), and cadherin 9 gene (CDH9 rs6885387) showed significant p-values after Bonferroni correction (p≤0.00019). More specifically, the vast majority of these associations were detected with MD in the right and left anterior and posterior cerebellar lobes.

LIMITATIONS

Patients were under pharmacological treatment at the time of the DTI examination. Sample size is limited.

CONCLUSIONS

The results provide the first evidence of the involvement of genetic variants related to glutamatergic, dopaminergic, and neurodevelopmental pathways in determining the WM microstructure of child and adolescent patients with OCD, which could be related to the neurobiology of the disorder.

Predictive value of familiality, stressful life events and gender on the course of obsessive-compulsive disorder

BACKGROUND

Familiality, stressful life events (SLE) and gender significantly affect the onset of obsessive-compulsive disorder (OCD). However, their combined impact on the probability of OCD chronicity is largely unknown. With the objective of clarifying their predictive value, we tested a model of interaction effects between these influences.

METHODS

A sample of 449 patients with OCD was systematically assessed for familial loading, exposure to stressful life events, gender and course of the disease at the OCD referral unit at Bellvitge University Hospital. Multiple ordinal logistic regression was used to test interaction models.

RESULTS

Familiality presented a main negative association with chronicity (OR=0.83, CI97.5%=0.70-0.98). This association was additively moderated by both exposure to SLE before onset and gender, and showed a positive slope among female patients not exposed to SLE before onset (Familiality*SLEbo: OR=0.69, CI97.5%=0.47-1; Familiality*gender: OR=1.30, CI97.5%=0.91-1.84).

LIMITATIONS

The findings are based on cross-sectional data. Assessment of course is based on a retrospective measure, which may imply the possibility of overestimation of chronicity.

CONCLUSIONS

The predictive value of familiality on the course of OCD is only partially informative as both SLEbo and gender modify the association. When other risk factors are included in the model, familiality may predict decreased chances of chronicity. The mediation effects identified could explain the discrepancies found in previous research on this topic. Increased chances of presenting a chronic course of OCD may be found in association with familial vulnerability among female patients not exposed to SLEbo.

Developmental plasticity and evolution--quo vadis?

The role of developmental (phenotypic) plasticity in ecology and evolution is receiving a growing appreciation among the biologists, and many plasticity-specific concepts have become well established as part of the mainstream evolutionary biological thinking. In this essay, I posit that despite this progress several key perspectives in developmental plasticity remain remarkably traditional, and that it may be time to re-evaluate their continued usefulness in the face of the available evidence as the field looks to its future. Specifically, I discuss the utility of viewing plastic development as ultimately rooted in genes and genomes, and investigate the common notion that the environment--albeit a critical source of information--nevertheless remains passive, external to and separable from the organism responding to it. I end by highlighting conceptual and empirical opportunities that may permit developmental plasticity research to transcend its current boundaries and to continue its contributions toward a holistic and realistic understanding of organismal development and evolution.

Association study of dopamine transporter gene (DAT1) variable tandem repeat sequence (VNTR) with obsessive-compulsive disorder in Chinese Han Population

OBJECTIVE

Multiple evidence suggests an involvement of the dopamine neurotransmitter system in Obsessive-compulsive disorder (OCD). Therefore, we explore the association of 3'UTR region of 40 bp variable tandem repeat (VNTR) polymorphism in Dopamine Transporter Gene (DAT1) in Chinese Han population.

METHODS

A total of 305 OCD patients and 435 healthy individuals were recruited for the study. OCD was diagnosed with the Forth Edition (DSM-IV) diagnostic criteria. After polymerase chain reaction of VNTR was used to evaluate the 40 bp VNTR polymorphism in DAT1, a case-control association analysis was performed by the χ(2) test.

RESULTS

The results showed that no association was found between OCD patients and controls for the genotype distribution (X(2) =0.743, P=0.690, df=2) as well as allelic (X(2)=0.172, P=0.678, OR=0.928, 95% Cl=0.885-1.224) distribution.

CONCLUSIONS

Our data suggest that the 40 bp VNTR polymorphism in DAT1 may not be associated with susceptibility to OCD in the Chinese Han population studied. However, this result needed to be replicated from different populations.

Dissociation of decision making under ambiguity and decision making under risk: a neurocognitive endophenotype candidate for obsessive-compulsive disorder

Evidence in the literature suggests that executive dysfunction is regarded as an endophenotype candidate for obsessive-compulsive disorder (OCD). Decision making is an important domain of executive function. However, few studies that have investigated whether decision making is a potential endophenotype for OCD have produced inconsistent results. Differences in the findings across these studies may be attributed to several factors: different study materials, comorbidity, medication, etc. There are at least two types of decision making that differ mainly in the degree of uncertainty and how much useful information about consequences and their probabilities are provided to the decision maker: decision making under ambiguity and decision making under risk. The aim of the present study was to simultaneously examine decision making under ambiguity as assessed by the Iowa Gambling Task (IGT) and decision making under risk as measured by the Game of Dice Task (GDT) in OCD patients and their unaffected first-degree relative (UFDR) for the first time. The study analyzed 55 medication-naïve, non-depressed OCD patient probands, 55 UFDRs of the OCD patients and 55 healthy matched comparison subjects (CS) without a family history of OCD with the IGT, the GDT and a neuropsychological test battery. While the OCD patients and the UFDRs performed worse than the CS on the IGT, they were unimpaired on the GDT. Our study supports the claim that decision making under ambiguity differs from decision making under risk and suggests that dissociation of decision making under ambiguity and decision making under risk may qualify to be a neurocognitive endophenotypes for OCD.

Genome-wide association study in obsessive-compulsive disorder: results from the OCGAS

Obsessive-compulsive disorder (OCD) is a psychiatric condition characterized by intrusive thoughts and urges and repetitive, intentional behaviors that cause significant distress and impair functioning. The OCD Collaborative Genetics Association Study (OCGAS) is comprised of comprehensively assessed OCD patients with an early age of OCD onset. After application of a stringent quality control protocol, a total of 1065 families (containing 1406 patients with OCD), combined with population-based samples (resulting in a total sample of 5061 individuals), were studied. An integrative analyses pipeline was utilized, involving association testing at single-nucleotide polymorphism (SNP) and gene levels (via a hybrid approach that allowed for combined analyses of the family- and population-based data). The smallest P-value was observed for a marker on chromosome 9 (near PTPRD, P=4.13 × 10(-)(7)). Pre-synaptic PTPRD promotes the differentiation of glutamatergic synapses and interacts with SLITRK3. Together, both proteins selectively regulate the development of inhibitory GABAergic synapses. Although no SNPs were identified as associated with OCD at genome-wide significance level, follow-up analyses of genome-wide association study (GWAS) signals from a previously published OCD study identified significant enrichment (P=0.0176). Secondary analyses of high-confidence interaction partners of DLGAP1 and GRIK2 (both showing evidence for association in our follow-up and the original GWAS study) revealed a trend of association (P=0.075) for a set of genes such as NEUROD6, SV2A, GRIA4, SLC1A2 and PTPRD. Analyses at the gene level revealed association of IQCK and C16orf88 (both P<1 × 10(-)(6), experiment-wide significant), as well as OFCC1 (P=6.29 × 10(-)(5)). The suggestive findings in this study await replication in larger samples.

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.

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.

The neurobiological link between OCD and ADHD

Obsessive compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD) are two of the most common neuropsychiatric diseases in paediatric populations. The high comorbidity of ADHD and OCD with each other, especially of ADHD in paediatric OCD, is well described. OCD and ADHD often follow a chronic course with persistent rates of at least 40–50 %. Family studies showed high heritability in ADHD and OCD, and some genetic findings showed similar variants for both disorders of the same pathogenetic mechanisms, whereas other genetic findings may differentiate between ADHD and OCD. Neuropsychological and neuroimaging studies suggest that partly similar executive functions are affected in both disorders. The deficits in the corresponding brain networks may be responsible for the perseverative, compulsive symptoms in OCD but also for the disinhibited and impulsive symptoms characterizing ADHD. This article reviews the current literature of neuroimaging, neurochemical circuitry, neuropsychological and genetic findings considering similarities as well as differences between OCD and ADHD.

Wie biologisch sind Zwangsstörungen?

Zwangsstörungen sind im Kindes- und Jugendalter sowie im Erwachsenenalter häufige und sehr beeinträchtigende Erkrankungen. Es scheint eine hohe biologische Vulnerabilität und auch Erblichkeit vorzuliegen, wobei genetische und Umweltfaktoren gleichwertig zu sein scheinen und miteinander interagieren. In den meisten bisherigen molekulargenetischen Studien ist es noch nicht gelungen, Gene mit hohen Effektstärken zu detektieren. Die vielversprechendsten Befunde umfassen Gene in serotonergen und glutamatergen Systemen. Mittels EEG kann man zeitlich und mittels MRT kann man räumlich sehr gute Auflösungen erreichen. Auffälligkeiten finden sich vor allem in kortiko-striato-thalamischen Kreisläufen. Funktionelle Studien zeigen Auffälligkeiten z.b. bei Lern- und Konfliktverarbeitungsaufgaben. Die konsistentesten Befunde bezüglich Abweichungen in Hirnstruktur und Hirnfunktion sind im anterioren cingulum zu finden, einer Struktur die eine wichtige Rolle für die regulatorische Kontrolle und die Optimierung von zielgerichtetem Verhalten einnimmt.

Obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a common heterogeneous psychiatric disorder manifesting with obsessions and compulsions. Obsessions are intrusive, recurrent, and persistent unwanted thoughts. Compulsions are repetitive behaviors or mental acts that an individual feels driven to perform in response to the obsessions. The heterogeneity of OCD includes themes of obsessions, types of rituals, presence or absence of tics, etiology, genetics, and response to pharmacotherapy. Complications of OCD include interpersonal difficulties, unemployment, substance abuse, criminal justice issues, and physical injuries. Areas of the brain involved in the pathophysiology include the orbitofrontal cortex, anterior cingulate gyrus, and basal ganglia. Overall, OCD may be due to a malfunction in the cortico-striato-thalamo-cortical circuit in the brain. Neurotransmitters implicated in OCD include serotonin, dopamine, and glutamate. Numerous drugs such as atypical antipsychotics and dopaminergic agents can cause or exacerbate OCD symptoms. The etiology includes genetics and neurological insults. Treatment of OCD includes psychotherapy, pharmacotherapy, electroconvulsive therapy, transcranial magnetic simulation, and in extreme cases surgery. Exposure and response prevention is the most effective form of psychotherapy. Selective serotonin reuptake inhibitors (SSRIs) are the preferred pharmacotherapy. Higher doses than listed in the package insert and a longer trial are often needed for SSRIs than compared to other psychiatric disorders. Alternatives to SSRIs include clomipramine and serotonin/norepinephrine reuptake inhibitors. Treatment of resistant cases includes augmentation with atypical antipsychotics, pindolol, buspirone, and glutamate-blocking agents.

[The obsessive compulsive disorder]

The obsessive compulsive disorder (OCD) is a frequent disease with a high comorbidity. The usual treatment is a combination of pharmacological and psychotherapeutic treatment. However, 30% of patients still have persistent and severe symptoms, with an important functional impact. These last years, the integration of the new neuroanatomical, neurochemical, neuropsychological, genetic and phenomenological data, allows a better understanding of the physiopathology and the development of new treatments for OCD, as neuromodulation for the severe and refractory cases.

Study of symptom dimensions and clinical characteristics in Chinese patients with OCD

BACKGROUND

The current study explored the main symptom dimensions and clinical characteristics of obsessive-compulsive disorder (OCD) in Chinese patients.

METHODS

Obsessive-compulsive (OC) symptoms of participants (N=512) were assessed through the Yale-Brown Obsessive Compulsive Scale Checklist (YBOCS-CL). Exploratory category-level and item-level factor analyses were performed. Regression analysis was carried out to study the relationships between clinical characteristics in our sample and the symptom dimensions obtained. Relationships among the clinical characteristics were explored using the chi-square test.

RESULTS

We found five symptom dimensions in the category-level analysis and six similar symptom dimensions in the item-level analysis. Moreover, the factors identified in our study overlapped with the results of prior studies. Association between gender and the symptom dimension of 'contamination/cleaning' was observed, with females showing more significant association with this dimension than males. Age of onset was associated with the symptom dimension of 'symmetry/arranging/repeating/counting', with the early-onset group more actively associated with this dimension than the late-onset group. Early-onset patients with OCD were more likely to be male and show tic comorbidity.

LIMITATIONS

Data from only one site do not represent the full range of Chinese OCD patients. Furthermore, past symptoms may show memory bias. Inherent problems in the YBOCS-CL have also been identified.

CONCLUSION

Symptoms in Chinese OCD patients are multidimensional. The main components of symptom dimensions of OCD patients show similarity or consistency among different regions and sociocultural backgrounds. The pathogenic mechanism of OCD may show potential distinctions.

The functional coding variant Asn107Ile of the neuropeptide S receptor gene (NPSR1) influences age at onset of obsessive-compulsive disorder

Neuropeptide S (NPS) is a novel central acting neuropeptide that modulates several brain functions. NPS has shown strong anxiolytic-like effects and interactions with other central transmitter systems, including serotonin and glutamate. A coding variation (Asn107Ile) of the NPS receptor gene (NPSR1) was associated with panic disorder and schizophrenia. Based on these encouraging findings, the present study aimed at exploring a potential role of NPSR1 in obsessive–compulsive disorder (OCD). A sample of 232 OCD patients was successfully genotyped for the NPSR1 Asn107Ile variant (rs324981). Age at onset was taken into account to address the heterogeneity of the OCD phenotype. The NPSR1 genotype significantly affected age at onset of the OCD patients, with a mean age at onset approximately 4 yr earlier in homozygous carriers of the low-functioning Asn107 variant compared to patients with at least one Ile107 variant (p=0.032). Case–control analyses with 308 healthy control subjects reveal a highly significant association of the Asn107 variant with early onset OCD (odds ratio=2.36, p=0.0004) while late onset OCD or the OCD group as a whole were unrelated to the NPSR1 genotype. Based on our association finding relating NPSR1 genotype to early onset OCD, we suggest a differential role of the NPS system in OCD. In particular, the early onset OCD subtype seems to be characterized by a genetically driven low NPS tone, which might affect other OCD-related transmitter systems, including the serotonin and glutamate systems. In agreement with preclinical research, we suggest that NPS may be a promising pharmacological candidate with anti-obsessional properties.

Meta-analysis of association between obsessive-compulsive disorder and the 3' region of neuronal glutamate transporter gene SLC1A1

The neuronal glutamate transporter gene SLC1A1 is a candidate gene for obsessive-compulsive disorder (OCD) based on linkage studies and convergent evidence implicating glutamate in OCD etiology. The 3' end of SLC1A1 is the only genomic region with consistently demonstrated OCD association, especially when analyzing male-only probands. However, specific allele associations have not been consistently replicated, and recent OCD genome-wide association and meta-analysis studies have not incorporated all previously associated SLC1A1 SNPs. To clarify the nature of association between SLC1A1 and OCD, pooled analysis was performed on all available relevant raw study data, comprising a final sample of 815 trios, 306 cases and 634 controls. This revealed weak association between OCD and one of nine tested SLC1A1 polymorphisms (rs301443; uncorrected P = 0.046; non-significant corrected P). Secondary analyses of male-affecteds only (N = 358 trios and 133 cases) demonstrated modest association between OCD and a different SNP (rs12682807; uncorrected P = 0.012; non-significant corrected P). Findings of this meta-analysis are consistent with the trend of previous candidate gene studies in psychiatry and do not clarify the putative role of SLC1A1 in OCD pathophysiology. Nonetheless, it may be important to further examine the potential associations demonstrated in this amalgamated sample, especially since the SNPs with modest associations were not included in the more highly powered recent GWAS or in a past meta-analysis including five SLC1A1 polymorphisms. This study underscores the need for much larger sample sizes in future genetic association studies and suggests that next-generation sequencing may be beneficial in examining the potential role of rare variants in OCD.

Isoforms of the neuronal glutamate transporter gene, SLC1A1/EAAC1, negatively modulate glutamate uptake: relevance to obsessive-compulsive disorder

The SLC1A1 gene, which encodes the neuronal glutamate transporter, EAAC1, has consistently been implicated in obsessive-compulsive disorder (OCD) in genetic studies. Moreover, neuroimaging, biochemical and clinical studies support a role for glutamatergic dysfunction in OCD. Although SLC1A1 is an excellent candidate gene for OCD, little is known about its regulation at the genomic level. Here, we report the identification and characterization of three alternative SLC1A1/EAAC1 mRNAs: a transcript derived from an internal promoter, termed P2 to distinguish it from the transcript generated by the primary promoter (P1), and two alternatively spliced mRNAs: ex2skip, which is missing exon 2, and ex11skip, which is missing exon 11. All isoforms inhibit glutamate uptake from the full-length EAAC1 transporter. Ex2skip and ex11skip also display partial colocalization and interact with the full-length EAAC1 protein. The three isoforms are evolutionarily conserved between human and mouse, and are expressed in brain, kidney and lymphocytes under nonpathological conditions, suggesting that the isoforms are physiological regulators of EAAC1. Moreover, under specific conditions, all SLC1A1 transcripts were differentially expressed in lymphocytes derived from subjects with OCD compared with controls. These initial results reveal the complexity of SLC1A1 regulation and the potential clinical utility of profiling glutamatergic gene expression in OCD and other psychiatric disorders.

Clinical correlates of social adjustment in patients with obsessive-compulsive disorder

BACKGROUND

Patients with obsessive-compulsive disorder (OCD) frequently show poor social adjustment, which has been associated with OCD severity. Little is known about the effects that age at symptom onset, specific OCD symptoms, and psychiatric comorbidities have on social adjustment. The objective of this study was to investigate the clinical correlates of social functioning in OCD patients.

METHODS

Cross-sectional study involving 815 adults with a primary DSM-IV diagnosis of OCD participating in the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders. Patients were assessed with the Social Adjustment Scale, the Medical Outcomes Study 36-item Short-Form Health Survey, the Yale-Brown Obsessive-Compulsive Scale, the Dimensional Yale-Brown Obsessive-Compulsive Scale, and the Structured Clinical Interview for DSM-IV Axis I Disorders. Clinical correlates of social adjustment were assessed with generalized linear models with gamma distribution.

RESULTS

Poor overall social functioning was associated with greater OCD severity (p = 0.02); hoarding symptoms (p = 0.004); sexual/religious obsessions (p = 0.005); current major depressive disorder (p = 0.004); current post-traumatic stress disorder (p = 0.002); and current eating disorders (p = 0.02). Poor social adjustment was also associated with impaired quality of life.

CONCLUSIONS

Patients with OCD have poor social functioning in domains related to personal relationships and professional performance. Hoarding symptoms and sexual/religious obsessions seem to have the strongest negative effects on social functioning. Early age at OCD symptom onset seems to be associated with professional and academic underachievement and impairment within the family unit, whereas current psychiatric comorbidity worsen overall social functioning. In comparison with quality of life, social adjustment measures seem to provide a more comprehensive overview of the OCD-related burden.