Imaging genetics in obsessive-compulsive disorder: linking genetic variations to alterations in neuroimaging

Correlations between single nucleotide polymorphisms in obsessive-compulsive disorder with the clinical features or response to therapy

Obsessive-compulsive disorder (OCD) is a debilitating neuropsychiatric disorder, in which the patient endures intrusive thoughts or is compelled to perform repetitive or ritualized actions. Many cases of OCD are considered to be familial or heritable in nature. It has been shown that a variety of internal and external risk factors are involved in the pathogenesis of OCD. Among the internal factors, genetic modifications play a critical role in the pathophysiological process. Despite many investigations performed to determine the candidate genes, the precise genetic factors involved in the disease remain largely undetermined. The present review summarizes the single nucleotide polymorphisms that have been proposed to be associated with OCD symptoms, early onset disease, neuroimaging results, and response to therapy. This information could help us to draw connections between genetics and OCD symptoms, better characterize OCD in individual patients, understand OCD prognosis, and design more targeted personalized treatment approaches.

Dopamine transporter silencing in the rat: systems-level alterations in striato-cerebellar and prefrontal-midbrain circuits

Silencing of dopamine transporter (DAT), a main controlling factor of dopaminergic signaling, results in biochemical and behavioral features characteristic for neuropsychiatric diseases with presumed hyperdopaminergia including schizophrenia, attention deficit hyperactivity disorder (ADHD), bipolar disorder, and obsessive-compulsive disorder (OCD). Investigation of DAT silencing thus provides a transdiagnostic approach towards a systems-level understanding of common underlying pathways. Using a high-field multimodal imaging approach and a highly sensitive cryogenic coil, we integrated structural, functional and metabolic investigations in tandem with behavioral assessments on a newly developed preclinical rat model, comparing DAT homozygous knockout (DAT-KO, N = 14), heterozygous knockout (N = 8) and wild-type male rats (N = 14). We identified spatially distributed structural and functional brain alterations encompassing motor, limbic and associative loops that demonstrated strong behavioral relevance and were highly consistent across imaging modalities. DAT-KO rats manifested pronounced volume loss in the dorsal striatum, negatively correlating with cerebellar volume increase. These alterations were associated with hyperlocomotion, repetitive behavior and loss of efficient functional small-world organization. Further, prefrontal and midbrain regions manifested opposite changes in functional connectivity and local network topology. These prefrontal disturbances were corroborated by elevated myo-inositol levels and increased volume. To conclude, our imaging genetics approach provides multimodal evidence for prefrontal-midbrain decoupling and striato-cerebellar neuroplastic compensation as two key features of constitutive DAT blockade, proposing them as transdiagnostic mechanisms of hyperdopaminergia. Thus, our study connects developmental DAT blockade to systems-level brain changes, underlying impaired action inhibition control and resulting in motor hyperactivity and compulsive-like features relevant for ADHD, schizophrenia and OCD.

Obsessive-Compulsive Disorder Interactome Profile Analysis: A Perspective From Molecular Mechanism

Introduction:

Obsessive-Compulsive Disorder (OCD) is one of the complex neuropsychiatric conditions. This disorder disables individuals in many different aspects of their personal and social life. Interactome analysis may provide a better understanding of this disorder’s molecular origin and its underlying mechanisms.

Methods:

In this study, the OCD-associated genes were extracted from the literature. The criterion for gene selection was to choose genes with at least one significant report. Furthermore, by applying Cytoscape and its plugins, protein-protein interaction network, and gene ontology of the 31 candidate genes related to OCD from genetic association studies is examined. The cross-validation method was used for network centrality assessment.

Results:

A scale-free network, including 1940 nodes and 3269 edges for 31 genes, was constructed. According to the network centrality evaluation, ESR1, TNFα, DRD2, DRD4, HTR1B, HTR2A, and CDH2 showed the highest values and can be considered hub-bottlenecks elements. It is also confirmed by the number of 123 cross-validation tests that the frequency of these essential genes remains unaltered against the initial seed genes’ changes with the accuracy of 0.962. Besides, enrichment analysis identified four highlighted biological processes related to the 31 candidate genes. The top biological processes are determined as dopamine transport, learning, memory, and monoamine transport.

Conclusion:

Among 31 initial genes, 7 were introduced as crucial elements for onset and development in OCD and can be suggested for further investigations. Furthermore, the complex molecular origin of OCD requires high-throughput screening for diagnosis and treatment goals. The findings are a possible valuable source to establish molecular-based diagnostic tools for OCD.

Polygenic risk for obsessive-compulsive disorder (OCD) predicts brain response during working memory task in OCD, unaffected relatives, and healthy controls

Alterations in frontal and parietal neural activations during working memory task performance have been suggested as a candidate endophenotype of obsessive-compulsive disorder (OCD) in studies involving first-degree relatives. However, the direct link between genetic risk for OCD and neuro-functional alterations during working memory performance has not been investigated to date. Thus, the aim of the current functional magnetic resonance imaging (fMRI) study was to test the direct association between polygenic risk for OCD and neural activity during the performance of a numeric n-back task with four working memory load conditions in 128 participants, including patients with OCD, unaffected first-degree relatives of OCD patients, and healthy controls. Behavioral results show a significant performance deficit at high working memory load in both patients with OCD and first-degree relatives (p < 0.05). A whole-brain analysis of the fMRI data indicated decreased neural activity in bilateral inferior parietal lobule and dorsolateral prefrontal cortex in both patients and relatives. Most importantly, OCD polygenic risk scores predicted neural activity in orbitofrontal cortex. Results indicate that genetic risk for OCD can partly explain alterations in brain response during working memory performance, supporting the notion of a neuro-functional endophenotype for OCD.

In vitro monitoring of HTR2A-positive neurons derived from human-induced pluripotent stem cells

The serotonin 5-HT_2A receptor (5-HT_2AR) has been receiving increasing attention because its genetic variants have been associated with a variety of neurological diseases. To elucidate the pathogenesis of the neurological diseases associated with 5-HT_2AR gene (HTR2A) variants, we have previously established a protocol to induce HTR2A-expressing neurons from human-induced pluripotent stem cells (hiPSCs). Here, we investigated the maturation stages and electrophysiological properties of HTR2A-positive neurons induced from hiPSCs and constructed an HTR2A promoter-specific reporter lentivirus to label the neurons. We found that neuronal maturity increased over time and that HTR2A expression was induced at the late stage of neuronal maturation. Furthermore, we demonstrated successful labelling of the HTR2A-positive neurons, which had fluorescence and generated repetitive action potentials in response to depolarizing currents and an inward current during the application of TCB-2, a selective agonist of 5-HT_2ARs, respectively. These results indicated that our in vitro model mimicked the in vivo dynamics of 5-HT_2AR. Therefore, in vitro monitoring of the function of HTR2A-positive neurons induced from hiPSCs could help elucidate the pathophysiological mechanisms of neurological diseases associated with genetic variations of the HTR2A gene.

On the Development of OCD

OCD most often arises before adulthood with adolescence being a particularly vulnerable period. This is also a time when both brain and cognition undergo fundamental developmental change and reorganisation. However, the neurocognitive mechanisms that drive the emergence of OCD during development are still largely unknown. In this chapter, I review the relatively sparse literature on the developmental aspects of OCD and I discuss the symptomatic, cognitive and neural patterns in OCD and the developing mind. I highlight how we need to understand the emergence of cognitive impairments and neural alteration in a developmental context if we want to understand more about the mechanisms that give rise to OCD. Moreover, I outline how we best approach this challenge to overcome the current limitations in research.

Inhibition-Related Cortical Hypoconnectivity as a Candidate Vulnerability Marker for Obsessive-Compulsive Disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) is a prevalent neuropsychiatric condition, with biological models implicating disruption of cortically mediated inhibitory control pathways, ordinarily serving to regulate our environmental responses and habits. The aim of this study was to evaluate inhibition-related cortical dysconnectivity as a novel candidate vulnerability marker of OCD.

METHODS

In total, 20 patients with OCD, 18 clinically asymptomatic first-degree relatives of patients with OCD, and 20 control participants took part in a neuroimaging study comprising a functional magnetic resonance imaging stop signal task. Brain activations during the contrasts of interest were cluster thresholded, and a three-dimensional watershed algorithm was used to decompose activation maps into discrete clusters. Functional connections between these key neural nodes were examined using a generalized psychophysiological interaction model.

RESULTS

The three groups did not differ in terms of age, education level, gender, IQ, or behavioral task parameters. Patients with OCD exhibited hyperactivation of the bilateral occipital cortex during the task versus the other groups. Compared with control participants, patients with OCD and their relatives exhibited significantly reduced connectivity between neural nodes, including frontal cortical, middle occipital cortical, and cerebellar regions, during the stop signal task.

CONCLUSIONS

These findings indicate that hypoconnectivity between anterior and posterior cortical regions during inhibitory control represents a candidate vulnerability marker for OCD. Such vulnerability markers, if found to generalize, may be valuable to shed light on etiological processes contributing not only to OCD but also obsessive-compulsive-related disorders more widely.

Exploring the role of BDNF DNA methylation and hydroxymethylation in patients with obsessive compulsive disorder

Obsessive-compulsive disorder (OCD) is a clinically heterogeneous neuropsychiatric condition associated with profound disability, whose susceptibility, stemming from genetic and environmental factors that intersect with each other, is still under investigation. In this perspective, we sought to explore the transcriptional regulation of Brain Derived Neurotrophic Factor (BDNF), a promising candidate biomarker in both development and etiology of different neuropsychiatric conditions, in peripheral blood mononuclear cells from OCD patients and healthy controls. In particular, we focused on BDNF gene expression and interrogated in depth DNA methylation and hydroxymethylation at gene promoters (exons I, IV and IX) in a sample of OCD patients attending a tertiary OCD Clinic to receive guidelines-recommended treatment, and matched controls. Our preliminary data showed a significant increase in BDNF gene expression and a significant correlation with changes in the two epigenetic modifications selectively at promoter exon I, with no changes in the other promoters under study. We can conclude that transcriptional regulation of BDNF in OCD engages epigenetic mechanisms, and can suggest that this is likely evoked by the long-term pharmacotherapy. It is important to underline that many different factors need to be taken into account (i.e. age, sex, duration of illness, treatment), and thus further studies are mandatory to investigate their role in the epigenetic regulation of BDNF gene. Of note, we provide unprecedented evidence for the importance of analyzing 5-hydroxymethylcytosine levels to correctly evaluate 5-methylcytosine changes.

Initial findings of striatum tripartite model in OCD brain samples based on transcriptome analysis

Obsessive-compulsive disorder (OCD) is a psychiatric disorder characterized by obsessions and/or compulsions. Different striatal subregions belonging to the cortico-striato-thalamic circuitry (CSTC) play an important role in the pathophysiology of OCD. The transcriptomes of 3 separate striatal areas (putamen (PT), caudate nucleus (CN) and accumbens nucleus (NAC)) from postmortem brain tissue were compared between 6 OCD and 8 control cases. In addition to network connectivity deregulation, different biological processes are specific to each striatum region according to the tripartite model of the striatum and contribute in various ways to OCD pathophysiology. Specifically, regulation of neurotransmitter levels and presynaptic processes involved in chemical synaptic transmission were shared between NAC and PT. The Gene Ontology terms cellular response to chemical stimulus, response to external stimulus, response to organic substance, regulation of synaptic plasticity, and modulation of synaptic transmission were shared between CN and PT. Most genes harboring common and/or rare variants previously associated with OCD that were differentially expressed or part of a least preserved coexpression module in our study also suggest striatum subregion specificity. At the transcriptional level, our study supports differences in the 3 circuit CSTC model associated with OCD.

Abnormal Regional Homogeneity in Patients With Obsessive-Compulsive Disorder and Their Unaffected Siblings: A Resting-State fMRI Study

Objective: Previous studies suggest that abnormal brain structure and function may be neuroimaging endophenotypes of obsessive-compulsive disorder (OCD). Comparing the intrinsic brain activity of OCD patients and their unaffected siblings will help to further understand the susceptibility to, and pathological mechanisms of, OCD. We used a case-control study design aiming to establish whether the abnormal regional homogeneity (ReHo) found in OCD patients also exists in their unaffected siblings. Method: Fifteen unmedicated OCD patients, 15 of their unaffected siblings, and 30 healthy controls (HCs) received resting-state functional magnetic resonance imaging (r-s fMRI) scanning and clinical evaluation. We used the ReHo method to analyze the inter-regional synchronized activity of all participants. One-way analysis of covariance with post hoc tests was used to compare the ReHo maps across groups. A Pearson correlation analysis was conducted to assess the correlations between clinical characteristics and abnormal ReHo in OCD patients. Results: Relative to HCs, OCD patients and their unaffected siblings showed overlapping higher ReHo values in the right dorsolateral prefrontal cortex (DLPFC). Patients with OCD showed increased ReHo in left middle frontal gyrus (MFG) relative to both their unaffected siblings and HCs. In addition to the right DLPFC and left MFG, OCD patients, compared with HCs, also showed abnormal ReHo in other regions, including higher ReHo in the right superior parietal cortex and lower ReHo in the left inferior parietal cortex, right parahippocampal region, left thalamus, and right inferior temporal cortex. Compared with HCs, the unaffected siblings of patients with OCD had significantly higher ReHo in the right inferior parietal cortex, right MFG, and right supplementary motor area. There was no association between clinical symptoms and abnormal ReHo values in OCD patients. Conclusions: This study found overlapping higher ReHo values in the right DLPFC of OCD patients and their unaffected siblings. Our results suggest that the higher ReHo in the right DLPFC may be a potential neuroimaging endophenotype, which may reflect an increased genetic risk of OCD.

The genetic architecture of schizophrenia, bipolar disorder, obsessive-compulsive disorder and autism spectrum disorder

Considerable evidence suggests that autism spectrum disorders (ASD), schizophrenia (SCZ), bipolar disorder (BD) and obsessive-compulsive disorder (OCD) share a common molecular aetiology, despite their unique clinical diagnostic criteria. The aim of this study was therefore to determine and characterise the common and unique molecular architecture of ASD, SCZ, BD and OCD. Gene lists were obtained from previously published studies for ASD, BD, SCZ and for OCD. Genes identified to be common to all disorders, or unique to one specific disorder, were included for enrichment analyses using the web-server tool Enrichr. Ten genes were identified to be commonly associated with the aetiology of ASD, SCZ, BD and OCD. Enrichment analyses determined that these genes are predominantly involved in the dopaminergic and serotonergic pathways, the voltage-gated calcium ion channel gene network, folate metabolism, regulation of the hippo signaling pathway, and the regulation of gene silencing and expression. In addition to well-characterised and previously described pathways, regulation of the hippo signaling pathway was commonly associated with ASD, SCZ, BD and OCD, implicating neural development and neuronal maintenance as key in neuropsychiatric disorders. In contrast, a large number of previously associated genes were shown to be disorder-specific. And unique disorder-specific pathways and biological processes were presented for ASD, BD, SCZ and OCD aetiology. Considering the current global incidence and prevalence rates of mental health disorders, focus should be placed on cross-disorder commonalities in order to realise actionable and translatable results to combat mental health disorders.

High resolution chromosomal microarray analysis in paediatric obsessive-compulsive disorder

Background

Obsessive-Compulsive Disorder (OCD) is a common and chronic disorder in which a person has uncontrollable, reoccurring thoughts and behaviours. It is a complex genetic condition and, in case of early onset (EO), the patients manifest a more severe phenotype, and an increased heritability. Large (>500 kb) copy number variations (CNVs) previously associated with autism and schizophrenia have been reported in OCD. Recently, rare CNVs smaller than 500 kb overlapping risk loci for other neurodevelopmental conditions have also been reported in OCD, stressing the importance of examining CNVs of any size range. The aim of this study was to further investigate the role of rare and small CNVs in the aetiology of EO-OCD.

Methods

We performed high-resolution chromosomal microarray analysis in 121 paediatric OCD patients and in 124 random controls to identify rare CNVs (>50 kb) which might contribute to EO-OCD.

Results

The frequencies and the size of the observed rare CNVs in the patients did not differ from the controls. However, we observed a significantly higher frequency of rare CNVs affecting brain related genes, especially deletions, in the patients (OR = 1.98, 95% CI 1.02–3.84; OR = 3.61, 95% CI 1.14–11.41, respectively). Similarly, enrichment-analysis of CNVs gene content, performed with three independent methods, confirmed significant clustering of predefined genes involved in synaptic/brain related functional pathways in the patients but not in the controls. In two patients we detected de-novo CNVs encompassing genes previously associated with different neurodevelopmental disorders (NRXN1, ANKS1B, UHRF1BP1).

Conclusions

Our results further strengthen the role of small rare CNVs, particularly deletions, as susceptibility factors for paediatric OCD.

Electronic supplementary material

The online version of this article (10.1186/s12920-017-0299-5) contains supplementary material, which is available to authorized users.

Increased fronto-striatal reward prediction errors moderate decision making in obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) has been linked to functional abnormalities in fronto-striatal networks as well as impairments in decision making and learning. Little is known about the neurocognitive mechanisms causing these decision-making and learning deficits in OCD, and how they relate to dysfunction in fronto-striatal networks.

METHOD

We investigated neural mechanisms of decision making in OCD patients, including early and late onset of disorder, in terms of reward prediction errors (RPEs) using functional magnetic resonance imaging. RPEs index a mismatch between expected and received outcomes, encoded by the dopaminergic system, and are known to drive learning and decision making in humans and animals. We used reinforcement learning models and RPE signals to infer the learning mechanisms and to compare behavioural parameters and neural RPE responses of the OCD patients with those of healthy matched controls.

RESULTS

Patients with OCD showed significantly increased RPE responses in the anterior cingulate cortex (ACC) and the putamen compared with controls. OCD patients also had a significantly lower perseveration parameter than controls.

CONCLUSIONS

Enhanced RPE signals in the ACC and putamen extend previous findings of fronto-striatal deficits in OCD. These abnormally strong RPEs suggest a hyper-responsive learning network in patients with OCD, which might explain their indecisiveness and intolerance of uncertainty.

Association of GRIN2B gene polymorphism and Obsessive Compulsive disorder and symptom dimensions: A pilot study

The etiology of OCD is largely unknown, but neuroimaging and pharmacological studies suggest that glutamatergic system plays a significant role on OCD development. We genotyped one polymorphism at GRIN2B (rs1019385) by real time Polymerase Chain Reaction in a sample of Brazilian Obsessive-Compulsive patients and healthy controls, and evaluated its influence on OCD. We found the T-allele and TT genotype to be significantly associated with OCD and ordering dimension. The T-allele was also significantly associated with checking. These preliminary results demonstrated that the GRIN2B gene may confer to some extent the susceptibility to OCD and its symptoms.

Association between genetic variants of serotonergic and glutamatergic pathways and the concentration of neurometabolites of the anterior cingulate cortex in paediatric patients with obsessive-compulsive disorder

OBJECTIVES

The present study aimed to assess the relationship between variability in genes related to the pathophysiology of obsessive-compulsive disorder (OCD) and the concentration of different neurometabolites in the anterior cingulate cortex (ACC).

METHODS

We concomitantly assessed neurometabolite concentrations using 3-T (1)H-MRS and 262 single nucleotide polymorphism (SNPs) in 35 genes in 41 paediatric OCD patients.

RESULTS

There were significant associations, after Bonferroni correction, between the concentration of inositol, glutamate and glutamine, and total choline and five polymorphisms located in genes related to serotonin and glutamate (i.e., the vesicular monoamine transporter 1 gene, SLC18A1 [rs6586896]; the serotonin receptor 1B gene, HTR1B [rs6296 and rs6298]; and the glutamate receptor, ionotropic, AMPA1 gene, GRIA1 [rs707176 and rs2963944]).

CONCLUSIONS

The association observed between these polymorphisms and the neurometabolite concentrations could indicate the presence of a biological interaction between the serotonin and the glutamate pathways that could be involved in the pathophysiology of OCD. More studies with this methodology could increase our understanding of the aetiology and pathophysiology of OCD in children.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Neuronal vs glial glutamate uptake: Resolving the conundrum

Neither normal brain function nor the pathological processes involved in neurological diseases can be adequately understood without knowledge of the release, uptake and metabolism of glutamate. The reason for this is that glutamate (a) is the most abundant amino acid in the brain, (b) is at the cross-roads between several metabolic pathways, and (c) serves as the major excitatory neurotransmitter. In fact most brain cells express glutamate receptors and are thereby influenced by extracellular glutamate. In agreement, brain cells have powerful uptake systems that constantly remove glutamate from the extracellular fluid and thereby limit receptor activation. It has been clear since the 1970s that both astrocytes and neurons express glutamate transporters. However the relative contribution of neuronal and glial transporters to the total glutamate uptake activity, however, as well as their functional importance, has been hotly debated ever since. The present short review provides (a) an overview of what we know about neuronal glutamate uptake as well as an historical description of how we got there, and (b) a hypothesis reconciling apparently contradicting observations thereby possibly resolving the paradox.

The importance of the excitatory amino acid transporter 3 (EAAT3)

The neuronal excitatory amino acid transporter 3 (EAAT3) is fairly ubiquitously expressed in the brain, though it does not necessarily maintain the same function everywhere. It is important in maintaining low local concentrations of glutamate, where its predominant post-synaptic localization can buffer nearby glutamate receptors and modulate excitatory neurotransmission and synaptic plasticity. It is also the main neuronal cysteine uptake system acting as the rate-limiting factor for the synthesis of glutathione, a potent antioxidant, in EAAT3 expressing neurons, while on GABAergic neurons, it is important in supplying glutamate as a precursor for GABA synthesis. Several diseases implicate EAAT3, and modulation of this transporter could prove a useful therapeutic approach. Regulation of EAAT3 could be targeted at several points for functional modulation, including the level of transcription, trafficking and direct pharmacological modulation, and indeed, compounds and experimental treatments have been identified that regulate EAAT3 function at different stages, which together with observations of EAAT3 regulation in patients is giving us insight into the endogenous function of this transporter, as well as the consequences of altered function. This review summarizes work done on elucidating the role and regulation of EAAT3.

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.