Subcortical and cortical morphological anomalies as an endophenotype in obsessive-compulsive disorder

Neuroimaging alterations in relatives of patients with obsessive-compulsive disorder: A review of magnetic resonance imaging studies

BACKGROUND

Obsessive-Compulsive Disorder (OCD) demonstrates substantial heritability, implicating a genetic contribution to its pathophysiology. Neuroimaging studies of unaffected first-degree relatives offer insight into the neurobiology of the disorder.

METHODS

A systematic search of PubMed, Web of Science, and Scopus was conducted in August 2024 to identify Magnetic Resonance Imaging (MRI) studies comparing unaffected relatives of individuals with OCD to healthy controls. Significant findings were reported based on patterns of brain changes in individuals with OCD and their relatives.

RESULTS

A total of 32 studies were reviewed, including 18 functional MRI, 8 structural MRI, and 7 diffusion tensor imaging studies. Despite inconsistencies arising from heterogeneity in imaging modalities, age groups, and analytic methods, certain regions and patterns emerged repeatedly. Results were grouped into four clusters. Cluster 1, the most consistently reported, involved shared or intermediate alterations in relatives, suggesting putative endophenotypes. Frequently implicated regions included the insula, thalamus, dorsolateral and ventromedial prefrontal cortices, and parietal cortex. Cluster 2 described more pronounced alterations in relatives than in OCD patients, often in frontoparietal regions, possibly reflecting preclinical vulnerability or protective features. Cluster 3 showed opposite trends in relatives, particularly in occipital and parietal regions, which may indicate compensatory or protective processes. Although very few, there were some findings that were specific to relatives (cluster 4).

CONCLUSION

This review identifies neuroimaging findings in unaffected relatives of individuals with OCD. Most studies suggest potential endophenotypes, with some reflecting compensatory mechanisms. These findings support further research to validate the proposed clusters and clarify heritable neural markers of OCD.

Decision-making using the Iowa gambling test in unaffected first-degree relatives of obsessive-compulsive disorder: Comparison with healthy controls and patients with obsessive-compulsive disorder

Decision-making has been suggested as an endophenotype candidate for obsessive-compulsive disorder (OCD). However, few studies have examined whether decision-making under ambiguity is an endophenotype of OCD. This study aimed to investigate decision-making under ambiguity, as assessed by the Iowa Gambling Task (IGT), in patients with OCD and unaffected first-degree relatives (UFDR). Forty-seven non-medicated, non-co-morbid patients with OCD, 30 UFDR, and 47 healthy controls (HC) were compared in terms of decision-making using the IGT. The correlation between obsessive-compulsive symptoms and IGT performance was also investigated. Patients with OCD and UFDR performed worse than HC on the IGT. No correlation was found between obsessive-compulsive symptoms and IGT performance. A deficit in decision-making under ambiguity may be a trait and an endophenotype candidate for OCD.

A coordinate-based meta-analysis of grey matter volume differences between adults with obsessive-compulsive disorder (OCD) and healthy controls

According to the cortico-striato-thalamo-cortical (CSTC) model of obsessive-compulsive disorder (OCD), the striatum plays a primary role in its neuropathophysiology. Hypothesising that volumetric alterations are more pronounced in subcortical areas of patients within the CSTC circuit compared to healthy controls (HCs), we conducted a coordinate-based meta-analysis of magnetic resonance imaging (MRI) studies. We included 26 whole-brain MRI studies, comprising 3,010 subjects: 1,508 patients (788 men, 720 women; mean age: 30.26 years, SD = 8.16) and 1,502 HCs (801 men, 701 women; mean age: 29.47 years, SD = 7.88). This meta-analysis demonstrated significant grey matter volume increases in the bilateral putamen, lateral globus pallidus, left parietal cortex, right pulvinar, and left cerebellum in adults with OCD, alongside decreases in the right hippocampus/caudate, bilateral medial frontal gyri, and other cortical regions. Volume increases were predominantly observed in subcortical areas, with the exception of the left parietal cortex and cerebellar dentate, while volume decreases were primarily cortical, aside from the right hippocampus/caudate. Further exploration of these neuropathophysiological correlates could inform specific prevention and treatment strategies, advancing precision mental health in clinical applications.

No significant alteration in white matter microstructure in first-degree relatives of patients with obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is characterized by structural alteration within white matter tissues of cortico-striato-thalamo-cortical, temporal and occipital circuits. However, the presence of microstructural changes in the white matter tracts of unaffected first-degree relatives of patients with OCD as a vulnerability marker remains unclear. Therefore, here, diffusion-tensor magnetic resonance imaging (DTI) data were obtained from 29 first-degree relatives of patients with OCD and 59 healthy controls. We investigated the group differences in FA using whole-brain analysis (DTI analysis). For additional regions of interest (ROI) analysis, we focused on the posterior thalamic radiation and sagittal stratum, shown in recent meta-analysis of patients with OCD. In both whole-brain and ROI analyses, using a strict statistical threshold (family-wise error rate [FWE] corrected p<.05 for whole-brain analyses, and p<.0125 (0.05/4) with Bonferroni correction for ROI analyses), we found no significant group differences in FA. Subtle reductions were observed in the anterior corona radiata, forceps minor, cingulum bundle, and corpus callosum only when a lenient statistical was applied (FWE corrected p<.20). These findings suggest that alterations in the white matter microstructure of first-degree relatives, as potential vulnerability markers for OCD, are likely subtle.

Genetic architecture of brain morphology and overlap with neuropsychiatric traits

Uncovering the genetic architectures of brain morphology offers valuable insights into brain development and disease. Genetic association studies of brain morphological phenotypes have discovered thousands of loci. However, interpretation of these loci presents a significant challenge. One potential solution is exploring the genetic overlap between brain morphology and disorders, which can improve our understanding of their complex relationships, ultimately aiding in clinical applications. In this review, we examine current evidence on the genetic associations between brain morphology and neuropsychiatric traits. We discuss the impact of these associations on the diagnosis, prediction, and treatment of neuropsychiatric diseases, along with suggestions for future research directions.

Neural mechanisms of acceptance-commitment therapy for obsessive-compulsive disorder: a resting-state and task-based fMRI study

BACKGROUND

There is growing evidence for the use of acceptance-commitment therapy (ACT) for the treatment of obsessive-compulsive disorder (OCD). However, few fully implemented ACT have been conducted on the neural mechanisms underlying its effect on OCD. Thus, this study aimed to elucidate the neural correlates of ACT in patients with OCD using task-based and resting-state functional magnetic resonance imaging (fMRI).

METHODS

Patients with OCD were randomly assigned to the ACT (n = 21) or the wait-list control group (n = 21). An 8-week group-format ACT program was provided to the ACT group. All participants underwent an fMRI scan and psychological measurements before and after 8 weeks.

RESULTS

Patients with OCD showed significantly increased activation in the bilateral insula and superior temporal gyri (STG), induced by the thought-action fusion task after ACT intervention. Further psycho-physiological interaction analyses with these regions as seeds revealed that the left insular-left inferior frontal gyrus (IFG) connectivity was strengthened in the ACT group after treatment. Increased resting-state functional connectivity was also found in the posterior cingulate cortex (PCC), precuneus, and lingual gyrus after ACT intervention Most of these regions showed significant correlations with ACT process measures while only the right insula was correlated with the obsessive-compulsive symptom measure.

CONCLUSIONS

These findings suggest that the therapeutic effect of ACT on OCD may involve the salience and interoception processes (i.e. insula), multisensory integration (i.e. STG), language (i.e. IFG), and self-referential processes (i.e. PCC and precuneus). These areas or their interactions could be important for understanding how ACT works psychologically.

Cortical and subcortical contributions to non-motor inhibitory control: an fMRI study

Inhibition is a core executive cognitive function. However, the neural correlates of non-motor inhibitory control are not well understood. We investigated this question using functional Magnetic Resonance Imaging (fMRI) and a simple Count Go/NoGo task (n = 23), and further explored the causal relationships between activated brain regions. We found that the Count NoGo task activated a distinct pattern in the subcortical basal ganglia, including bilateral ventral anterior/lateral nucleus of thalamus (VA/VL), globus pallidus/putamen (GP/putamen), and subthalamic nucleus (STN). Stepwise regressions and mediation analyses revealed that activations in these region(s) were modulated differently by only 3 cortical regions i.e. the right inferior frontal gyrus/insula (rIFG/insula), along with left IFG/insula, and anterior cingulate cortex/supplementary motor area (ACC/SMA). The activations of bilateral VA/VL were modulated by both rSTN and rIFG/insula (with rGP/putamen as a mediator) independently, and the activation of rGP/putamen was modulated by ACC/SMA, with rIFG/insula as a mediator. Our findings provide the neural correlates of inhibitory control of counting and causal relationships between them, and strongly suggest that both indirect and hyperdirect pathways of the basal ganglia are involved in the Count NoGo condition.

Acetyl-11-keto-beta boswellic acid(AKBA) modulates CSTC-pathway by activating SIRT-1/Nrf2-HO-1 signalling in experimental rat model of obsessive-compulsive disorder: Evidenced by CSF, blood plasma and histopathological alterations

Obsessive-Compulsive disorder (OCD) is a long-term and persistent mental illness characterised by obsessive thoughts and compulsive behaviours. Numerous factors can contribute to the development or progression of OCD. These factors may result from the dysregulation of multiple intrinsic cellular pathways, including SIRT-1, Nrf2, and HO-1. Inhibitors of selective serotonin reuptake (SSRIs) are effective first-line treatments for OCD. In our ongoing research, we have investigated the role of SIRT-1, Nrf2, and HO-1, as well as the neuroprotective potential of Acetyl-11-keto-beta boswellic acid (AKBA) against behavioural and neurochemical changes in rodents treated with 8-OH-DPAT. In addition, the effects of AKBA were compared to those of fluvoxamine (FLX), a standard OCD medication. Injections of 8-OH-DPAT into the intra-dorso raphe nuclei (IDRN) of rats for seven days induced repetitive and compulsive behaviour accompanied by elevated oxidative stress, inflammatory processes, apoptosis, and neurotransmitter imbalances in CSF, blood plasma, and brain samples. Chronic administration of AKBA at 50 mg/kg and 100 mg/kg p.o. restored histopathological alterations in the cortico-striatal-thalamo-cortical (CSTC) pathway, including the cerebral cortex, striatum, and hippocampal regions. Our investigation revealed that when AKBA and fluvoxamine were administered together, the alterations were restored to a greater degree than when administered separately. These findings demonstrate that the neuroprotective effect of AKBA can serve as an effective basis for developing a novel OCD treatment.

Perinatal maternal mental health and amygdala morphology in young adulthood

The pre- and perinatal environment is thought to play a critical role in shaping brain development. Specifically, maternal mental health and maternal care have been shown to influence offspring brain development in regions implicated in emotional regulation such as the amygdala. In this study, we used data from a neuroimaging follow-up of a prenatal birth-cohort, the European Longitudinal Study of Pregnancy and Childhood, to investigate the impact of early postnatal maternal anxiety/co-dependence, and prenatal and early-postnatal depression and dysregulated mood on amygdala volume and morphology in young adulthood (n = 103). We observed that in typically developing young adults, greater maternal anxiety/co-dependence after birth was significantly associated with lower volume (right: t = -2.913, p = 0.0045, β = -0.523; left: t = -1.471, p = 0.144, β = -0.248) and non-significantly associated with surface area (right: t = -3.502, q = 0.069, <10%FDR, β = -0.090, left: t = -3.137, q = 0.117, <10%FDR, = -0.088) of the amygdala in young adulthood. Conversely, prenatal maternal depression and mood dysregulation in the early postnatal period was not associated with any volumetric or morphological changes in the amygdala in young adulthood. Our findings provide evidence for subtle but long-lasting alterations to amygdala morphology associated with differences in maternal anxiety/co-dependence in early development.

Shape analysis of subcortical structures in obsessive-compulsive disorder and the relationship with comorbid anxiety, depression, and medication use: A meta-analysis by the OCD Brain Imaging Consortium

OBJECTIVE

Neuroimaging studies of obsessive-compulsive disorder (OCD) patients have highlighted the important role of deep gray matter structures. Less work has however focused on subcortical shape in OCD patients.

METHODS

Here we pooled brain MRI scans from 412 OCD patients and 368 controls to perform a meta-analysis utilizing the ENIGMA-Shape protocol. In addition, we investigated modulating effects of medication status, comorbid anxiety or depression, and disease duration on subcortical shape.

RESULTS

There was no significant difference in shape thickness or surface area between OCD patients and healthy controls. For the subgroup analyses, OCD patients with comorbid depression or anxiety had lower thickness of the hippocampus and caudate nucleus and higher thickness of the putamen and pallidum compared to controls. OCD patients with comorbid depression had lower shape surface area in the thalamus, caudate nucleus, putamen, hippocampus, and nucleus accumbens and higher shape surface area in the pallidum. OCD patients with comorbid anxiety had lower shape surface area in the putamen and the left caudate nucleus and higher shape surface area in the pallidum and the right caudate nucleus. Further, OCD patients on medication had lower shape thickness of the putamen, thalamus, and hippocampus and higher thickness of the pallidum and caudate nucleus, as well as lower shape surface area in the hippocampus and amygdala and higher surface area in the putamen, pallidum, and caudate nucleus compared to controls. There were no significant differences between OCD patients without co-morbid anxiety and/or depression and healthy controls on shape measures. In addition, there were also no significant differences between OCD patients not using medication and healthy controls.

CONCLUSIONS

The findings here are partly consistent with prior work on brain volumes in OCD, insofar as they emphasize that alterations in subcortical brain morphology are associated with comorbidity and medication status. Further work is needed to understand the biological processes contributing to subcortical shape.

Aberrant cortico-striatal white matter connectivity and associated subregional microstructure of the striatum in obsessive-compulsive disorder

The striatum and its cortical circuits play central roles in the pathophysiology of obsessive-compulsive disorder (OCD). The striatum is subdivided by cortical connections and functions; however, the anatomical aberrations in different cortico-striatal connections and coexisting microstructural anomalies in striatal subregions of OCD patients are poorly understood. Thus, we aimed to elucidate the aberrations in cortico-striatal white matter (WM) connectivity and the associated subregional microstructure of the striatum in patients with OCD. From diffusion tensor/kurtosis imaging of 107 unmedicated OCD patients and 110 matched healthy controls (HCs), we calculated the cortico-striatal WM connectivity and segmented the striatum using probabilistic tractography. For the segmented striatal subregions, we measured average diffusion kurtosis values, which represent microstructural complexity. Connectivity and mean kurtosis values in each cortical target and associated striatal subregions were compared between groups. We identified significantly reduced orbitofrontal WM connectivity with its associated striatal subregion in patients with OCD compared to that in HCs. However, OCD patients exhibited significantly increased caudal-motor and parietal connectivity with the associated striatal subregions. The mean kurtosis values of the striatal subregions connected to the caudal-motor and parietal cortex were significantly decreased in OCD patients. Our results highlighted contrasting patterns of striatal WM connections with the orbitofrontal and caudal-motor/parietal cortices, thus supporting the cortico-striatal circuitry imbalance model of OCD. We suggest that aberrations in WM connections and the microstructure of their downstream regions in the caudal-motor-/parietal-striatal circuits may underlie OCD pathophysiology and further provide potential neuromodulation targets for the treatment of OCD.

Functional Connectivity within the Frontal–Striatal Network Differentiates Checkers from Washers of Obsessive-Compulsive Disorder

Background: Obsessive-compulsive disorder (OCD) is a psychiatric disorder with high clinical heterogeneity manifested by the presence of obsessions and/or compulsions. The classification of the symptom dimensional subtypes is helpful for further exploration of the pathophysiological mechanisms underlying the clinical heterogeneity of OCD. Washing and checking symptoms are the two major symptom subtypes in OCD, but the neural mechanisms of the different types of symptoms are not yet clearly understood. The purpose of this study was to compare regional and network functional alterations between washing and checking OCD based on resting-state functional magnetic resonance imaging (rs-fMRI). Methods: In total, 90 subjects were included, including 15 patients in the washing group, 30 patients in the checking group, and 45 healthy controls (HCs). Regional homogeneity (ReHo) was used to compare the differences in regional spontaneous neural activity among the three groups, and local indicators were analyzed by receiver operating characteristic (ROC) curves as imaging markers for the prediction of the clinical subtypes of OCD. Furthermore, differently activated local brain areas, as regions of interest (ROIs), were used to explore differences in altered brain functioning between washing and checking OCD symptoms based on a functional connectivity (FC) analysis. Results: Extensive abnormalities in spontaneous brain activity involving frontal, temporal, and occipital regions were observed in the patients compared to the HCs. The differences in local brain functioning between checking and washing OCD were mainly concentrated in the bilateral middle frontal gyrus, right supramarginal gyrus, right angular gyrus, and right inferior occipital gyrus. The ROC curve analysis revealed that the hyperactivation right middle frontal gyrus had a better discriminatory value for checking and washing OCD. Furthermore, the seed-based FC analysis revealed higher FC between the left medial superior frontal gyrus and right caudate nucleus compared to that in the healthy controls. Conclusions: These findings suggest that extensive local differences exist in intrinsic spontaneous activity among the checking group, washing group, and HCs. The neural basis of checking OCD may be related to dysfunction in the frontal–striatal network, which distinguishes OCD from washing OCD.

Cortical thickness and surface area in patients with obsessive compulsive disorder and their unaffected siblings

Little is known about the underlying neurobiological mechanisms in patients with obsessive-compulsive disorder (OCD). We aimed to examine cortical thickness and surface area in individuals with OCD and their unaffected siblings, comparing them to healthy controls. 30 patients with OCD, 21 unaffected siblings (SIB) and 30 controls underwent structural magnetic resonance imaging. Structural images were analyzed using the FreeSurfer software package (version 6.0). Compared to healthy controls, both OCD and SIB groups showed significantly lower cortical thickness in the right anterior insula. Surface areas of the superior frontal gyrus, paracentral gyrus and precuneus of the right hemisphere were also reduced in OCD patients compared to controls. There were no significant differences in cortical thickness and surface area between the OCD and SIB groups. We did not detect any significant differences in subcortical volumes between groups. Lower cortical thickness in the right anterior insula in both OCD patients and unaffected siblings may represent a potential structural endophenotype for OCD.

Imaging Genetics in Epilepsy: Current Knowledge and New Perspectives

Epilepsy is a neurological network disease with genetics playing a much greater role than was previously appreciated. Unfortunately, the relationship between genetic basis and imaging phenotype is by no means simple. Imaging genetics integrates multidimensional datasets within a unified framework, providing a unique opportunity to pursue a global vision for epilepsy. This review delineates the current knowledge of underlying genetic mechanisms for brain networks in different epilepsy syndromes, particularly from a neural developmental perspective. Further, endophenotypes and their potential value are discussed. Finally, we highlight current challenges and provide perspectives for the future development of imaging genetics in epilepsy.

The thalamus and its subnuclei-a gateway to obsessive-compulsive disorder

Larger thalamic volume has been found in children with obsessive-compulsive disorder (OCD) and children with clinical-level symptoms within the general population. Particular thalamic subregions may drive these differences. The ENIGMA-OCD working group conducted mega- and meta-analyses to study thalamic subregional volume in OCD across the lifespan. Structural T₁-weighted brain magnetic resonance imaging (MRI) scans from 2649 OCD patients and 2774 healthy controls across 29 sites (50 datasets) were processed using the FreeSurfer built-in ThalamicNuclei pipeline to extract five thalamic subregions. Volume measures were harmonized for site effects using ComBat before running separate multiple linear regression models for children, adolescents, and adults to estimate volumetric group differences. All analyses were pre-registered ( https://osf.io/73dvy ) and adjusted for age, sex and intracranial volume. Unmedicated pediatric OCD patients (<12 years) had larger lateral (d = 0.46), pulvinar (d = 0.33), ventral (d = 0.35) and whole thalamus (d = 0.40) volumes at unadjusted p-values <0.05. Adolescent patients showed no volumetric differences. Adult OCD patients compared with controls had smaller volumes across all subregions (anterior, lateral, pulvinar, medial, and ventral) and smaller whole thalamic volume (d = -0.15 to -0.07) after multiple comparisons correction, mostly driven by medicated patients and associated with symptom severity. The anterior thalamus was also significantly smaller in patients after adjusting for thalamus size. Our results suggest that OCD-related thalamic volume differences are global and not driven by particular subregions and that the direction of effects are driven by both age and medication status.

Thalamic Subregions and Obsessive-Compulsive Symptoms in 2,500 Children From the General Population

OBJECTIVE

Pediatric obsessive-compulsive disorder (OCD) and clinically relevant obsessive-compulsive symptoms in the general population are associated with increased thalamic volume. It is unknown whether this enlargement is explained by specific thalamic subregions. The relation between obsessive-compulsive symptoms and volume of thalamic subregions was investigated in a population-based sample of children.

METHOD

Obsessive-compulsive symptoms were measured in children (9-12 years of age) from the Generation R Study using the Short Obsessive-Compulsive Disorder Screener (SOCS). Thalamic nuclei volumes were extracted from structural 3T magnetic resonance imaging scans using the ThalamicNuclei pipeline and regrouped into anterior, ventral, intralaminar/medial, lateral, and pulvinar subregions. Volumes were compared between children with symptoms above clinical cutoff (probable OCD cases, SOCS ≥ 6, n = 156) and matched children without symptoms (n = 156). Linear regression models were fitted to investigate the association between continuous SOCS score and subregional volume in the whole sample (N = 2500).

RESULTS

Children with probable OCD had larger ventral nuclei compared with children without symptoms (d = 0.25, p = .025, false discovery rate adjusted p = .126). SOCS score showed a negative association with pulvinar volume when accounting for overall thalamic volume (β = -0.057, p = .009, false discovery rate adjusted p = .09). However, these associations did not survive multiple testing correction.

CONCLUSION

The results suggest that individual nuclei groups contribute in varying degrees to overall thalamic volume in children with probable OCD, although this did not survive multiple comparisons correction. Understanding the role of thalamic nuclei and their associated circuits in pediatric OCD could lead toward treatment strategies targeting these circuits.

An overview of the first 5 years of the ENIGMA obsessive-compulsive disorder working group: The power of worldwide collaboration

Neuroimaging has played an important part in advancing our understanding of the neurobiology of obsessive-compulsive disorder (OCD). At the same time, neuroimaging studies of OCD have had notable limitations, including reliance on relatively small samples. International collaborative efforts to increase statistical power by combining samples from across sites have been bolstered by the ENIGMA consortium; this provides specific technical expertise for conducting multi-site analyses, as well as access to a collaborative community of neuroimaging scientists. In this article, we outline the background to, development of, and initial findings from ENIGMA's OCD working group, which currently consists of 47 samples from 34 institutes in 15 countries on 5 continents, with a total sample of 2,323 OCD patients and 2,325 healthy controls. Initial work has focused on studies of cortical thickness and subcortical volumes, structural connectivity, and brain lateralization in children, adolescents and adults with OCD, also including the study on the commonalities and distinctions across different neurodevelopment disorders. Additional work is ongoing, employing machine learning techniques. Findings to date have contributed to the development of neurobiological models of OCD, have provided an important model of global scientific collaboration, and have had a number of clinical implications. Importantly, our work has shed new light on questions about whether structural and functional alterations found in OCD reflect neurodevelopmental changes, effects of the disease process, or medication impacts. We conclude with a summary of ongoing work by ENIGMA-OCD, and a consideration of future directions for neuroimaging research on OCD within and beyond ENIGMA.

Optogenetic inhibition of indirect pathway neurons in the dorsomedial striatum reduces excessive grooming in Sapap3-knockout mice

Excessive grooming of Sapap3-KO mice has been used as a model of obsessive-compulsive disorder (OCD). Previous studies suggest that dysregulation of cortico-striatal circuits is critically important in the generation of compulsive behaviors, and it has been proposed that the alteration in the activity patterns of striatal circuitry underlies the excessive grooming observed in Sapap3-KO mice. To test this hypothesis, we used in-vivo calcium imaging of individual cells to record striatal activity in these animals and optogenetic inhibition to manipulate this activity. We identified striatal neurons that are modulated during grooming behavior and found that their proportion is significantly larger in Sapap3-KO mice compared to wild-type littermates. Inhibition of striatal cells in Sapap3-KO mice increased the number of grooming episodes observed. Remarkably, the specific inhibition of indirect pathway neurons decreased the occurrence of grooming events. Our results indicate that there is striatal neural activity related to excessive grooming engagement in Sapap3-KO mice. We also demonstrate, for the first time, that specific inhibition of striatal indirect pathway neurons reduces this compulsive phenotype, suggesting that treatments that alleviate compulsive symptoms in OCD patients may exert their effects through this specific striatal population.

Analyses of microstructural variation in the human striatum using non-negative matrix factorization

The striatum is a major subcortical connection hub that has been heavily implicated in a wide array of motor and cognitive functions. Here, we developed a normative multimodal, data-driven microstructural parcellation of the striatum using non-negative matrix factorization (NMF) based on multiple magnetic resonance imaging-based metrics (mean diffusivity, fractional anisotropy, and the ratio between T1- and T2-weighted structural scans) from the Human Connectome Project Young Adult dataset (n = 329 unrelated participants, age range: 22-35, F/M: 185/144). We further explored the biological and functional relationships of this parcellation by relating our findings to motor and cognitive performance in tasks known to involve the striatum as well as demographics. We identified 5 spatially distinct striatal components for each hemisphere. We also show the gain in component stability when using multimodal versus unimodal metrics. Our findings suggest distinct microstructural patterns in the human striatum that are largely symmetric and that relate mostly to age and sex. Our work also highlights the putative functional relevance of these striatal components to different designations based on a Neurosynth meta-analysis.

Disrupted functional connectivity of precuneus subregions in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a chronic and disablingpsychiatric disorder with high lifetime prevalence, yet the underlying pathogenesis remains not fully understood. Increasing neuroimaging evidence has shown that the disrupted activity of brain functional hubs might contribute to the pathophysiology of OCD. Precuneus is an important brain hub which showed structural and functional abnormalities in OCD patients. However, the functional heterogeneity of the precuneus subregion has not been considered and its relation to OCD symptomatology remains to be elucidated. In this paper, a total of 73 unmedicated OCD patients and 79 matched healthy subjects were recruited and the heterogeneous functional connectivities (FCs) of the precuneus subregions were investigated using resting-state functional magnetic resonance imaging. The FC-based subdivision of the precuneus was performed using the K-means clustering algorithm, which led to a tripartite functional parcellation of precuneus. For each subregion, the distinct connectivity pattern with the whole brain was shown, using both voxel-wise and module-wise analysis, respectively. Decreased FC between dorsal posterior precuneus and vermis (corrected p<0.01) was shown in the patient group, which was negatively correlated with patient compulsions score (ρ = - 0.393, p = 0.001), indicating its contribution to the compulsive behavior inhibition of OCD. Our work might provide new insights into the understanding of precuneus subregion function and the importance of dorsal precuneus-cerebellum functional connectivity in OCD pathophysiology.

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.

Altered Resting-State Brain Activity in Schizophrenia and Obsessive-Compulsive Disorder Compared With Non-psychiatric Controls: Commonalities and Distinctions Across Disorders

Backgrounds: Schizophrenia (SCZ) and obsessive-compulsive disorder (OCD) are classified as two chronic psychiatric disorders with high comorbidity rate and shared clinical symptoms. Abnormal spontaneous brain activity within the cortical-striatal neural circuits has been observed in both disorders. However, it is unclear if the common or distinct neural abnormalities underlie the neurobiological substrates in the resting state. Methods: Resting-state fMRI data were collected from 88 patients with SCZ, 58 patients with OCD, and 72 healthy control subjects. First, we examined differences in amplitude of low-frequency fluctuations (ALFF) among three groups. Resting-state functional connectivity (rsFC) analysis with the brain region that showed different ALFF as the seed was then conducted to identify the changes in brain networks. Finally, we examined the correlation between the altered activities and clinical symptoms. Results: Both the patients with SCZ and OCD showed increased ALFF in the right hippocampus and decreased ALFF in the left posterior cingulate cortex (PCC). SCZ patients exhibited increased ALFF in the left caudate [voxel-level family-wise error (FWE) P < 0.05] and decreased rsFC between the left caudate and right cerebellum, which correlated with positive symptoms. The left caudate showed increased rsFC with the right thalamus and bilateral supplementary motor complex (SMC) in OCD patients (cluster-level FWE P < 0.05). Conclusions: The hippocampus and PCC are common regions presenting abnormal local spontaneous neuronal activities in both SCZ and OCD, while the abnormality of the striatum can reflect the differences. Increased ALFF in the striatum and symptom-related weakened rsFC between the caudate and cerebellum showed SCZ specificity. Enhanced rsFC between the caudate and SMC may be a key characteristic in OCD. Our research shows the similarities and differences between the two diseases from the perspective of resting-state fMRI, which provides clues to understand the disease and find methods for treatment.

Set-shifting-related basal ganglia deformation as a novel familial marker of obsessive-compulsive disorder

The symptoms of obsessive-compulsive disorder (OCD) are suggestive of cognitive rigidity, and previous work identified impaired flexible responding on set-shifting tasks in such patients. The basal ganglia are central to habit learning and are thought to be abnormal in OCD, contributing to inflexible, rigid habitual patterns of behaviour. Here, we demonstrate that increased cognitive inflexibility, indexed by poor performance on the set-shifting task, correlated with putamen morphology, and that patients and their asymptomatic relatives had common curvature abnormalities within this same structure. The association between the structure of the putamen and the extradimensional errors was found to be significantly familial in OCD proband-relative pairs. The data implicate changes in basal ganglia structure linked to cognitive inflexibility as a familial marker of OCD. This may reflect a predisposing heightened propensity toward habitual response patterns and deficits in goal-directed planning.

Smaller volume of posterior thalamic nuclei in patients with obsessive-compulsive disorder

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Thalamic subregional volumes were compared between medication-free OCD and HC groups.

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Left posterior thalamic nuclei volumes were smaller in OCD patients compared to HCs.

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The smaller thalamic subregional volumes were associated with later onset of OCD.

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Posterior thalamic nuclei volume may reflect OCD subtype related to the age of onset.

Aim

Although the thalamus is a key structure in the pathophysiology of obsessive–compulsive disorder (OCD), reports regarding thalamic volume alterations in OCD patients have been inconsistent. Because the thalamus has a complex structure with distinct functions, we investigated subregional volume changes in the thalamus and their relationship with clinical attributes in a large sample of medication-free OCD patients.

Methods

We collected T1-weighted magnetic resonance imaging data from 177 OCD patients and 152 healthy controls (HCs). Using FreeSurfer, we segmented the thalamus into 12 nuclei groups; subregional volumes were compared between groups using an analysis of covariance. The relationships between altered thalamic volumes and OC symptom severity and OCD onset age were investigated.

Results

Compared to HCs, OCD patients showed a smaller volume of the left posterior thalamic nuclei. Other thalamic subregions did not show significant group differences. There was a significant negative correlation between the volume of the left posterior thalamic nuclei and the age of OCD onset but no significant correlation with OC symptom severity.

Conclusions

This is the first study to report reduced volume of the posterior thalamic nuclei in a large sample of medication-free OCD patients. Our results suggest that the volume of posterior thalamic nuclei may reflect different pathophysiological mechanisms of OCD subtypes related to the age of onset. Additional studies with pediatric samples are required to clarify the relationship between thalamic alterations and the onset age of OCD.

Brain Morphology Associated With Obsessive-Compulsive Symptoms in 2,551 Children From the General Population

OBJECTIVE

Obsessive-compulsive (OC) symptoms are common in the general population, but it is unclear whether subclinical OC symptoms and obsessive-compulsive disorder (OCD) are part of a neuroanatomical continuum. The goal of this study was to investigate the relation between OC symptoms and subcortical and cortical morphology in a population-based sample of children.

METHOD

The study included 2,551 participants, aged 9-12 years, from the population-based Generation R Study. OC symptoms were measured using the 7-item caregiver-rated Short Obsessive-Compulsive Disorder Screener (SOCS). Structural (3T) magnetic resonance imaging scans were processed using FreeSurfer to study the thalamus and other subcortical volumes, intracranial volume, vertexwise cortical thickness, and surface area. We used linear regression models to investigate the association between OC symptoms and brain morphology. Emulating case-control studies from the literature, we compared children scoring above the clinical cutoff of the SOCS (probable OCD cases, n = 164) with matched children without symptoms.

RESULTS

Children with probable OCD had larger thalami compared with the control group (d 0.16, p = .044). Vertexwise analysis showed a positive association between OC symptoms and thickness of the right inferior parietal cortex, which disappeared after adjusting for total behavioral problems. SOCS scores correlated negatively with intracranial volume (B = -2444, p = .038).

CONCLUSION

Children with probable OCD showed thalamus alterations similar to those previously reported in unmedicated children with OCD. OC symptoms showed a stronger association with total intracranial volume than regional brain measures. Longitudinal studies are needed to further elucidate similarities and distinctions between neural correlates of subclinical and clinical OC symptoms.

Functional connectivity changes and symptoms improvement after personalized, double-daily dosing, repetitive transcranial magnetic stimulation in obsessive-compulsive disorder: A pilot study

BACKGROUND

intrusive thoughts and compulsive behaviors that characterize obsessive compulsive disorder (OCD) are associated to aberrant resting state functional connectivity (rsFC) patterns within the cortico-striatal-thalamo-cortical (CSTC) circuits. A high percentage of OCD patients do not respond to conventional pharmacological treatments or psychotherapy. In these patients, inhibitory repetitive transcranial magnetic stimulation (rTMS) of the Supplementary Motor Area (SMA) resulted in a significant clinical benefit.

METHODS

In the current study, we applied a novel protocol of 1-week MRI-guided individualized double-daily sessions of rTMS treatment (1-Hz; 110% of resting Motor Threshold/7200 pulses/day), to bilateral SMA in 9 OCD patients. We tested its (i) feasibility-safety, (ii) clinical efficacy and (iii) rsFC related changes.

RESULTS

Patients reported no side effects during and after rTMS. Personalized rTMS treatment led to a significant improvement of OCD symptoms (average 25%; p = .005) and persistence of benefit up to 3-month follow-up. rsFC analysis revealed a significant reduction of connectivity patterns between bilateral SMA and subcortical regions, specifically in the basal ganglia and thalamus. Additional analysis showed that OCD symptoms severity correlates with a higher connectivity pattern between bilateral SMA and subcortical regions.

CONCLUSIONS

rTMS double-daily sessions are safe, feasible and effective in OCD. The clinical outcomes, that are consistent with those found in our previous RCT, are linked to a decreased connectivity between SMA and subcortical brain areas implicated in control over obsessions and maladaptive compulsive behavior.

A transdiagnostic perspective of constructs underlying obsessive-compulsive and related disorders: An international Delphi consensus study

BACKGROUND

The Research Domain Criteria seeks to bridge knowledge from neuroscience with clinical practice by promoting research into valid neurocognitive phenotypes and dimensions, irrespective of symptoms and diagnoses as currently conceptualized. While the Research Domain Criteria offers a vision of future research and practice, its 39 functional constructs need refinement to better target new phenotyping efforts. This study aimed to determine which Research Domain Criteria constructs are most relevant to understanding obsessive-compulsive and related disorders, based on a consensus between experts in the field of obsessive-compulsive and related disorders.

METHODS

Based on a modified Delphi method, 46 experts were recruited from Australia, Africa, Asia, Europe and the Americas. Over three rounds, experts had the opportunity to review their opinion in light of feedback from the previous round, which included how their response compared to other experts and a summary of comments given.

RESULTS

Thirty-four experts completed round one, of whom 28 (82%) completed round two and 24 (71%) completed round three. At the final round, four constructs were endorsed by ⩾75% of experts as 'primary constructs' and therefore central to understanding obsessive-compulsive and related disorders. Of these constructs, one came from the Positive Valence System (Habit), two from the Cognitive Control System (Response Selection/Inhibition and Performance Monitoring) and the final construct was an additional item suggested by experts (Compulsivity).

CONCLUSION

This study identified four Research Domain Criteria constructs that, according to experts, cut across different obsessive-compulsive and related disorders. These constructs represent key areas for future investigation, and may have potential implications for clinical practice in terms of diagnostic processes and therapeutic management of obsessive-compulsive and related disorders.

Caudate nuclei volume alterations and cognition and mood dysfunctions in adolescents with single ventricle heart disease

Adolescents with single ventricle heart disease (SVHD) exhibit mood and cognitive deficits, which may result from injury to the basal ganglia structures, including the caudate nuclei. However, the integrity of the caudate in SVHD adolescents is unclear. Our aim was to examine the global and regional caudate volumes, and evaluate the relationships between caudate volumes and cognitive and mood scores in SVHD and healthy adolescents. We acquired two high-resolution T1-weighted images from 23 SVHD and 37 controls using a 3.0-Tesla MRI scanner, as well as assessed mood (Patient Health Questionnaire-9 [PHQ-9]; Beck Anxiety Inventory [BAI]) and cognition (Montreal Cognitive Assessment [MoCA]; Wide Range Assessment of Memory and Learning-2; General Memory Index [GMI]) functions. Both left and right caudate nuclei were outlined, which were then used to calculate and compare volumes between groups using ANCOVA (covariates: age, gender, and head-size), as well as perform 3D surface morphometry. Partial correlations (covariates: age, gender, and head-size) were used to examine associations between caudate volumes, cognition, and mood scores in SVHD and controls. SVHD subjects showed significantly higher PHQ-9 and BAI scores, indicating more depressive and anxiety symptoms, as well as reduced GMI scores, suggesting impaired cognition, compared to controls. SVHD patients showed significantly reduced caudate volumes (left, 3,198.8 ± 490.1 vs. 3,605.0 ± 480.4 mm³ , p < 0.004; right, 3,162.1 ± 475.4 vs. 3,504.8 ± 465.9 mm³ , p < 0.011) over controls, and changes were localized in the rostral, mid-dorsolateral, and caudal areas. Significant negative correlations emerged between caudate volumes with PHQ-9 and BAI scores and positive correlations with GMI and MoCA scores in SVHD and controls. SVHD adolescents show significantly reduced caudate volumes, especially in sites that have projections to regulate mood and cognition, which may result from developmental and/or hypoxia-/ischemia-induced processes.

Toward identifying reproducible brain signatures of obsessive-compulsive profiles: rationale and methods for a new global initiative

BACKGROUND

Obsessive-compulsive disorder (OCD) has a lifetime prevalence of 2-3% and is a leading cause of global disability. Brain circuit abnormalities in individuals with OCD have been identified, but important knowledge gaps remain. The goal of the new global initiative described in this paper is to identify robust and reproducible brain signatures of measurable behaviors and clinical symptoms that are common in individuals with OCD. A global approach was chosen to accelerate discovery, to increase rigor and transparency, and to ensure generalizability of results.

METHODS

We will study 250 medication-free adults with OCD, 100 unaffected adult siblings of individuals with OCD, and 250 healthy control subjects at five expert research sites across five countries (Brazil, India, Netherlands, South Africa, and the U.S.). All participants will receive clinical evaluation, neurocognitive assessment, and magnetic resonance imaging (MRI). The imaging will examine multiple brain circuits hypothesized to underlie OCD behaviors, focusing on morphometry (T1-weighted MRI), structural connectivity (Diffusion Tensor Imaging), and functional connectivity (resting-state fMRI). In addition to analyzing each imaging modality separately, we will also use multi-modal fusion with machine learning statistical methods in an attempt to derive imaging signatures that distinguish individuals with OCD from unaffected siblings and healthy controls (Aim #1). Then we will examine how these imaging signatures link to behavioral performance on neurocognitive tasks that probe these same circuits as well as to clinical profiles (Aim #2). Finally, we will explore how specific environmental features (childhood trauma, socioeconomic status, and religiosity) moderate these brain-behavior associations.

DISCUSSION

Using harmonized methods for data collection and analysis, we will conduct the largest neurocognitive and multimodal-imaging study in medication-free subjects with OCD to date. By recruiting a large, ethno-culturally diverse sample, we will test whether there are robust biosignatures of core OCD features that transcend countries and cultures. If so, future studies can use these brain signatures to reveal trans-diagnostic disease dimensions, chart when these signatures arise during development, and identify treatments that target these circuit abnormalities directly. The long-term goal of this research is to change not only how we conceptualize OCD but also how we diagnose and treat it.

Brain structural covariance networks in obsessive-compulsive disorder: a graph analysis from the ENIGMA Consortium

Brain structural covariance networks reflect covariation in morphology of different brain areas and are thought to reflect common trajectories in brain development and maturation. Large-scale investigation of structural covariance networks in obsessive-compulsive disorder (OCD) may provide clues to the pathophysiology of this neurodevelopmental disorder. Using T1-weighted MRI scans acquired from 1616 individuals with OCD and 1463 healthy controls across 37 datasets participating in the ENIGMA-OCD Working Group, we calculated intra-individual brain structural covariance networks (using the bilaterally-averaged values of 33 cortical surface areas, 33 cortical thickness values, and six subcortical volumes), in which edge weights were proportional to the similarity between two brain morphological features in terms of deviation from healthy controls (i.e. z-score transformed). Global networks were characterized using measures of network segregation (clustering and modularity), network integration (global efficiency), and their balance (small-worldness), and their community membership was assessed. Hub profiling of regional networks was undertaken using measures of betweenness, closeness, and eigenvector centrality. Individually calculated network measures were integrated across the 37 datasets using a meta-analytical approach. These network measures were summated across the network density range of K = 0.10-0.25 per participant, and were integrated across the 37 datasets using a meta-analytical approach. Compared with healthy controls, at a global level, the structural covariance networks of OCD showed lower clustering (P < 0.0001), lower modularity (P < 0.0001), and lower small-worldness (P = 0.017). Detection of community membership emphasized lower network segregation in OCD compared to healthy controls. At the regional level, there were lower (rank-transformed) centrality values in OCD for volume of caudate nucleus and thalamus, and surface area of paracentral cortex, indicative of altered distribution of brain hubs. Centrality of cingulate and orbito-frontal as well as other brain areas was associated with OCD illness duration, suggesting greater involvement of these brain areas with illness chronicity. In summary, the findings of this study, the largest brain structural covariance study of OCD to date, point to a less segregated organization of structural covariance networks in OCD, and reorganization of brain hubs. The segregation findings suggest a possible signature of altered brain morphometry in OCD, while the hub findings point to OCD-related alterations in trajectories of brain development and maturation, particularly in cingulate and orbitofrontal regions.

Basal ganglia volume and shape in anorexia nervosa

Background

Reward-centred models have proposed that anomalies in the basal ganglia circuitry that underlies reward learning and habit formation perpetuate anorexia nervosa (AN). The present study aimed to investigate the volume and shape of key basal ganglia regions, including the bilateral caudate, putamen, nucleus accumbens (NAcc), and globus pallidus in AN.

Methods

The present study combined data from two existing studies resulting in a sample size of 46 women with AN and 56 age-matched healthy comparison (HC) women. Group differences in volume and shape of the regions of interest were examined. Within the AN group, the impact of eating disorder characteristics on volume and shape of the basal ganglia regions were also explored.

Results

The shape analyses revealed inward deformations in the left caudate, right NAcc, and bilateral ventral and internus globus pallidus, and outward deformations in the right middle and posterior globus pallidus in the AN group.

Conclusions

The present findings appear to fit with the theoretical models suggesting that there are alterations in the basal ganglia regions associated with habit formation and reward processing in AN. Further investigation of structural and functional connectivity of these regions in AN as well as their role in recovery would be of interest.

Interactive effects of age and recent substance use on striatal shape morphology at substance use disorder treatment entry

BACKGROUND

Striatal neuroadaptations are regarded to play an important role in the progression from voluntary to compulsive use of addictive substances and provide a promising target for the identification of neuroimaging biomarkers. Recent advances in surface-based computational analysis enable morphological assessment linking variations in global and local striatal shape to duration and magnitude of substance use with a degree of sensitivity that exceeds standard volumetric analysis.

METHODS

This study used a new segmentation methodology coupled with local surface-based indices of surface area and displacement to provide a comprehensive structural characterization of the striatum in 34 patients entering treatment for substance use disorder (SUD) and 49 controls, and to examine the influence of recent substance use on abnormal age-related striatal deformation in SUD patients.

RESULTS

Patients showed a small reduction in striatal volume and no difference in surface area or shape in comparison to controls. Between-group differences in shape were likely neutralized by the bidirectional influence of recent substance use on striatal shape in SUD patients. Specifically, there was an interaction between age and substance such that among older patients more drug use was associated with greater inward striatal contraction but more alcohol use was associated with greater outward expansion.

CONCLUSIONS

This study builds on previous work and advances our understanding of the nature of striatal neuroadaptations as a potential biomarker of disease progression in addiction.

Brain Morphological Dynamics of Procrastination: The Crucial Role of the Self-Control, Emotional, and Episodic Prospection Network

Globally, about 17% individuals are suffering from the maladaptive procrastination until now, which impacts individual's financial status, mental health, and even public policy. However, the comprehensive understanding of neuroanatomical understructure of procrastination still remains gap. 688 participants including 3 independent samples were recruited for this study. Brain morphological dynamics referred to the idiosyncrasies of both brain size and brain shape. Multilinear regression analysis was utilized to delineate brain morphological dynamics of procrastination in Sample 1. In the Sample 2, cross-validation was yielded. Finally, prediction models of machine learning were conducted in Sample 3. Procrastination had a significantly positive correlation with the gray matter volume (GMV) in the left insula, anterior cingulate gyrus (ACC), and parahippocampal gyrus (PHC) but was negatively correlated with GMV of dorsolateral prefrontal cortex (dlPFC) and gray matter density of ACC. Furthermore, procrastination was positively correlated to the cortical thickness and cortical complexity of bilateral orbital frontal cortex (OFC). In Sample 2, all the results were cross-validated highly. Predication analysis demonstrated that these brain morphological dynamic can predict procrastination with high accuracy. This study ascertained the brain morphological dynamics involving in self-control, emotion, and episodic prospection brain network for procrastination, which advanced promising aspects of the biomarkers for it.

MR-based age-related effects on the striatum, globus pallidus, and thalamus in healthy individuals across the adult lifespan

While numerous studies have used magnetic resonance imaging (MRI) to elucidate normative age-related trajectories in subcortical structures across the human lifespan, there exists substantial heterogeneity among different studies. Here, we investigated the normative relationships between age and morphology (i.e., volume and shape), and microstructure (using the T1-weighted/T2-weighted [T1w/T2w] signal ratio as a putative index of myelin and microstructure) of the striatum, globus pallidus, and thalamus across the adult lifespan using a dataset carefully quality controlled, yielding a final sample of 178 for the morphological analyses, and 162 for the T1w/T2w analyses from an initial dataset of 253 healthy subjects, aged 18-83. In accordance with previous cross-sectional studies of adults, we observed age-related volume decrease that followed a quadratic relationship between age and bilateral striatal and thalamic volumes, and a linear relationship in the globus pallidus. Our shape indices consistently demonstrated age-related posterior and medial areal contraction bilaterally across all three structures. Beyond morphology, we observed a quadratic inverted U-shaped relationship between T1w/T2w signal ratio and age, with a peak value occurring in middle age (at around 50 years old). After permutation testing, the Akaike information criterion determined age relationships remained significant for the bilateral globus pallidus and thalamus, for both the volumetric and T1w/T2w analyses. Our findings serve to strengthen and expand upon previous volumetric analyses by providing a normative baseline of morphology and microstructure of these structures to which future studies investigating patients with various disorders can be compared.

Caudate volume differences among treatment responders, non-responders and controls in children with obsessive-compulsive disorder

Treatment response in obsessive-compulsive disorder (OCD) is heterogeneous and the neurobiological underpinnings of such variability are unknown. To investigate this issue, we looked for differences in brain structures possibly associated with treatment response in children with OCD. 29 children with OCD (7-17 years) and 28 age-matched controls underwent structural magnetic resonance imaging. Patients then received treatment with fluoxetine or group cognitive-behavioral therapy during 14 weeks, and were classified as treatment responders or non-responders. The caudate nucleus, thalamus and orbitofrontal cortex were selected a priori, according to previous evidence of their association with OCD and its treatment. Gray matter (GM) volume comparisons between responders, non-responders and controls were performed, controlling for total GM volume. 17 patients were classified as responders. Differences among responders, non-responders and controls were found in both caudate nuclei (both p-values = 0.041), but after Bonferroni correction for multiple comparisons, these findings were non-significant. However, after excluding the effect of an outlier, findings were significant for the right caudate (p = 0.004). Pairwise comparisons showed larger caudate GM volume in responders versus non-responders and controls, bilaterally. The right caudate accounted for 20.2% of the variance in Y-BOCS changes after treatment in a linear regression model, with a positive correlation (p = 0.016). We present a possible neural substrate for treatment response in pediatric OCD, which is in line with previous evidence regarding the caudate nucleus. Considering the limitations, further research is needed to replicate this finding and elucidate the heterogeneity of treatment response in children with OCD (National Clinical Trials Registration Number: NCT01148316).

Characteristic alteration of subcortical nuclei shape in medication-free patients with obsessive-compulsive disorder

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The study established a subregional-level anatomic alteration profile of subcortical structures in patients with obsessive-compulsive disorder (OCD).

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The OCD patients showed an expansion of the lateral amygdala (right hemisphere) and right pallidum.

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Deformities in pallidum were associated with illness duration and symptom severity of OCD.

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Gender difference in OCD-related morphometric alterations were found in amygdala and caudate.

Background

Subcortical nuclei are important components in the pathology model of obsessive-compulsive disorder (OCD), and subregions of these structures subserve different functions that may distinctively contribute to OCD symptoms. Exploration of the subregional-level profile of structural abnormalities of these nuclei is needed to develop a better understanding of the neural mechanism of OCD.

Methods

A total of 83 medication-free, non-comorbid OCD patients and 93 age- and sex-matched healthy controls were recruited, and high-resolution T1-weighted MR images were obtained for all participants. The volume and shape of the subcortical nuclei (including the nucleus accumbens, amygdala, caudate, pallidum, putamen and thalamus) were quantified and compared with an automated parcellation approach and vertex-wise shape analysis using FSL-FIRST software. Sex differences in these measurements were also explored with an exploratory subgroup analysis.

Results

Volumetric analysis showed no significant differences between patients and healthy control subjects. Relative to healthy control subjects, the OCD patients showed an expansion of the lateral amygdala (right hemisphere) and right pallidum. These deformities were associated with illness duration and symptom severity of OCD. Exploratory subgroup analysis by sex revealed amygdala deformity in male patients and caudate deformity in female patients.

Conclusions

The lateral amygdala and the dorsal pallidum were associated with OCD. Neuroanatomic evidence of sexual dimorphism was also found in OCD. Our study not only provides deeper insight into how these structures contribute to OCD symptoms by revealing these subregional-level deformities but also suggests that gender effects may be important in OCD studies.

Multivariate classification of drug-naive obsessive-compulsive disorder patients and healthy controls by applying an SVM to resting-state functional MRI data

BACKGROUND

Previous resting-state functional magnetic resonance imaging (rs-fMRI) studies have revealed intrinsic regional activity alterations in obsessive-compulsive disorder (OCD), but those results were based on group analyses, which limits their applicability to clinical diagnosis and treatment at the level of the individual.

METHODS

We examined fractional amplitude low-frequency fluctuation (fALFF) and applied support vector machine (SVM) to discriminate OCD patients from healthy controls on the basis of rs-fMRI data. Values of fALFF, calculated from 68 drug-naive OCD patients and 68 demographically matched healthy controls, served as input features for the classification procedure.

RESULTS

The classifier achieved 72% accuracy (p ≤ 0.001). This discrimination was based on regions that included the left superior temporal gyrus, the right middle temporal gyrus, the left supramarginal gyrus and the superior parietal lobule.

CONCLUSIONS

These results indicate that OCD-related abnormalities in temporal and parietal lobe activation have predictive power for group membership; furthermore, the findings suggest that machine learning techniques can be used to aid in the identification of individuals with OCD in clinical diagnosis.

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.

Significant concordance of genetic variation that increases both the risk for obsessive-compulsive disorder and the volumes of the nucleus accumbens and putamen

BACKGROUND

Many studies have identified changes in the brain associated with obsessive-compulsive disorder (OCD), but few have examined the relationship between genetic determinants of OCD and brain variation.AimsWe present the first genome-wide investigation of overlapping genetic risk for OCD and genetic influences on subcortical brain structures.

METHOD

Using single nucleotide polymorphism effect concordance analysis, we measured genetic overlap between the first genome-wide association study (GWAS) of OCD (1465 participants with OCD, 5557 controls) and recent GWASs of eight subcortical brain volumes (13 171 participants).

RESULTS

We found evidence of significant positive concordance between OCD risk variants and variants associated with greater nucleus accumbens and putamen volumes. When conditioning OCD risk variants on brain volume, variants influencing putamen, amygdala and thalamus volumes were associated with risk for OCD.

CONCLUSIONS

These results are consistent with current OCD neurocircuitry models. Further evidence will clarify the relationship between putamen volume and OCD risk, and the roles of the detected variants in this disorder.Declaration of interestThe authors have declared that no competing interests exist.

Altered grey matter volume and cortical thickness in patients with schizo-obsessive comorbidity

Recent findings suggest that schizo-obsessive comorbidity (SOC) may be a unique diagnostic entity. We examined grey matter (GM) volume and cortical thickness in 22 patients with SOC, and compared them with 21 schizophrenia (SCZ) patients, 22 obsessive-compulsive disorder (OCD) patients and 22 healthy controls (HCs). We found that patients with SOC exhibited reduced GM volume in the left thalamus, the left inferior semi-lunar lobule of the cerebellum, the bilateral medial orbitofrontal cortex (medial oFC), the medial superior frontal gyrus (medial sFG), the rectus gyrus and the anterior cingulate cortex (aCC) compared with HCs. Patients with SOC also exhibited reduced cortical thickness in the right superior temporal gyrus (sTG), the right angular gyrus, the right supplementary motor area (SMA), the right middle cingulate cortex (mCC) and the right middle occipital gyrus (mOG) compared with HCs. Together with the differences in GM volume and cortical thickness between patients with SOC and patients with only SCZ or only OCD, these findings highlight the GM changes specific to patients with SOC.

Impaired planning in patients with obsessive-compulsive disorder and unaffected first-degree relatives: Evidence for a cognitive endophenotype

Patients with obsessive-compulsive disorder (OCD) show deficient planning capacity in the Tower of London (TOL) problem solving task. Preliminary evidence for similar deficits in unaffected first-degree relatives suggests that impaired planning may constitute an endophenotype of OCD. However, results on this issue are inconsistent, possibly owing to small sample sizes and variability in problem structure across TOL tasks. Here, we adopted a computerized version of the TOL task featuring a 2 × 2 factorial design (high/low search depth × full/partial tower goal state) and examined a well-characterized sample of n = 72 OCD patients, n = 76 unaffected first-degree relatives and n = 102 healthy comparison subjects. Both OCD patients and relatives exhibited significantly less accurate problem solving than controls. Search depth, goal hierarchy, or the number of minimum moves did not moderate these group differences. Medication, OCD symptoms, and depressive comorbidity did not affect TOL performance in patients, suggesting a state-independent effect. In conclusion, we found that OCD patients as well as unaffected first-degree relatives show deficient TOL performance across a range of task conditions, strongly supporting the role of impaired planning as an endophenotype of OCD, and contributing to the growing evidence for fronto-striatal dysfunctions in OCD.

Emotion Regulation in Obsessive-Compulsive Disorder, Unaffected Siblings, and Unrelated Healthy Control Participants

BACKGROUND

Functional neuroimaging endophenotypes of obsessive-compulsive disorder (OCD) have been suggested during executive tasks. The purpose of this study was to investigate whether behavioral and neural responses during emotion processing and regulation also represent an endophenotype of OCD.

METHODS

Forty-three unmedicated adult OCD patients, 19 of their unaffected siblings, and 38 healthy control participants underwent 3T functional magnetic resonance imaging during an emotion regulation task including neutral, fear-inducing, and OCD-related visual stimuli. Stimuli were processed during natural appraisal and during cognitive reappraisal, and distress ratings were collected after each picture. We performed between-group comparisons on task behavior and brain activation in regions of interest during emotion provocation and regulation.

RESULTS

Siblings reported similar distress as healthy control participants during provocation, and significantly less than patients. There was no significant three-group difference in activation during fear provocation or regulation. Three-group comparisons showed that patients had higher amygdala and dorsomedial prefrontal cortex activation during OCD-related emotion provocation and regulation, respectively, while siblings were intermediate between patients and control participants but not significantly different from either. Siblings showed higher left temporo-occipital activation (compared with both healthy control participants and patients) and higher frontolimbic connectivity (compared with patients) during OCD-related regulation.

CONCLUSIONS

Unaffected siblings do not show the same distress and amygdala activation during emotional provocation as OCD patients. Siblings show distinct activation in a temporo-occipital region, possibly related to compensatory cognitive control. This suggests that emotion regulation is not a strong endophenotype for OCD. When replicated, this contributes to our understanding of familial risk and resilience for OCD.

Increased Attentional Bias Toward Visual Cues in Internet Gaming Disorder and Obsessive-Compulsive Disorder: An Event-Related Potential Study

Internet gaming disorder (IGD) is a newly identified potential addiction disorder associated with compulsive internet-game playing behavior and attentional bias toward online gaming- related cues. Attentional bias toward addiction-related cues is the core feature of addiction that is associated with craving, but the pathophysiology of attentional bias in IGD is not well-understood, such as its relationship to compulsivity. In this study, we used the electrophysiological marker of late positive potential (LPP) to compare attentional bias in IGD and obsessive compulsive disorder (OCD). Twenty patients with IGD, 20 patients with OCD, and 23 healthy control (HC) subjects viewed a series of game-related, OCD-related, and neutral pictures while their event-related potentials (ERPs) were recorded. The game-related cues included in-game screen captures of popular internet games. The OCD-related cues included pictures which provokes obsessive and compulsive symptoms of contamination/washing or checking. LPPs were calculated as the mean value of amplitudes between 350 and 750 ms at the centro-parietal (CP1, CPz, CP2) and parietal (P1, Pz, P2) electrode sites. Higher LPP amplitudes were found for game-related cues in the IGD group than in the HCs, and higher LPP amplitudes were observed in the OCD group for OCD-related cues. The IGD group did not exhibit LPP changes in response to OCD-related cues. Subjective scales demonstrated increased arousal to game-related cues and OCD-related cues in both the IGD and OCD groups compared with the HC group. Increased LPPs in response to disorder-specific cues (game-related and OCD-related) were found in both IGD and OCD groups respectively, although the groups showed overlapping arousal on subjective scales. Our results indicate that LPP is a candidate neurophysiological marker for cue-related craving in IGD.

Imaging and Genetic Approaches to Inform Biomarkers for Anxiety Disorders, Obsessive-Compulsive Disorders, and PSTD

Anxiety disorders are the most common mental health problem in the world and also claim the highest health care cost among various neuropsychiatric disorders. Anxiety disorders have a chronic and recurrent course and cause significantly negative impacts on patients' social, personal, and occupational functioning as well as quality of life. Despite their high prevalence rates, anxiety disorders have often been under-diagnosed or misdiagnosed, and consequently under-treated. Even with the correct diagnosis, anxiety disorders are known to be difficult to treat successfully. In order to implement better strategies in diagnosis, prognosis, treatment decision, and early prevention for anxiety disorders, tremendous efforts have been put into studies using genetic and neuroimaging techniques to advance our understandings of the underlying biological mechanisms. In addition to anxiety disorders including panic disorder, generalised anxiety disorder (GAD), specific phobias, social anxiety disorders (SAD), due to overlapping symptom dimensions, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD) (which were removed from the anxiety disorder category in DSM-5 to become separate categories) are also included for review of relevant genetic and neuroimaging findings. Although the number of genetic or neuroimaging studies focusing on anxiety disorders is relatively small compare to other psychiatric disorders such as psychotic disorders or mood disorders, various structural abnormalities in the grey or white matter, functional alterations of activity during resting-state or task conditions, molecular changes of neurotransmitter receptors or transporters, and genetic associations have all been reported. With continuing effort, further genetic and neuroimaging research may potentially lead to clinically useful biomarkers for the prevention, diagnosis, and management of these disorders.

Association between hippocampus volume and symptom profiles in obsessive-compulsive disorder

Background

The hippocampus has recently been identified to play a key role in the pathophysiology of adult obsessive-compulsive disorder (OCD). Surprisingly, there is only limited evidence regarding the potential relationships with symptom dimensions. Due to the heterogeneity of symptoms in OCD, we aimed at further examining, whether hippocampal volume differences might be related to symptom profiles instead of single symptom dimensions.

Methods

In order to find out more about the potential association between clinical symptom profiles and alterations in hippocampal volume we categorized a large sample of OCD patients (N = 66) into distinct symptom profile groups using K-means clustering. In addition, hippocampal volumes of the different symptom profile groups were compared with hippocampal volumes in a sample of 66 healthy controls.

Results

We found significant differences in hippocampal volume between the different symptom profile groups which remained significant after correcting for age, sex, total intracranial volume, OCI-total score, depression, medication, disease duration and scanner. The patient group characterized by overall lower symptom scores and without high symptom severity in any specific domain showed the highest hippocampal volume. Finally, the comparison with healthy controls demonstrated significantly lower hippocampal volumes in those patients whose symptom profile was characterized by a high severity of ordering and checking symptoms.

Conclusions

Present results provide further confirmation for alterations in hippocampus structure in OCD and suggest that symptom profiles which take into account the multi-symptomatic character of the disorder should be given greater attention in this context.

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Different symptom profiles are associated with differences in hippocampus volume.

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This effect seems to be independent of other clinical parameters.

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Symptom interrelations seem to link structural alterations and psychopathology.

Structural alterations in patients with obsessive-compulsive disorder: a surface-based analysis of cortical volume, surface area and thickness

BACKGROUND

Mounting evidence indicates the presence of structural brain alterations in individuals with obsessive-compulsive disorder (OCD). Findings are, however, rather heterogeneous, which may be partly because of differences in methodological approaches or clinical sample characteristics. The aim of the present study was to analyze the whole brain cortical volume, surface area and thickness in a large sample of patients with OCD compared with age- and sex-matched healthy controls.

METHODS

We conducted whole brain surface-based analyses of grey matter measures using the automated FreeSurfer software in patients with OCD and matched controls. Group analyses were performed and corrected for multiple testing using Monte Carlo simulations (p < 0.05). Altered brain regions and their average morphological values were associated to symptom severity and type (Yale-Brown Obsessive Compulsive Scale scores).

RESULTS

We included 75 patients and 75 controls in our analyses. Patients with OCD showed decreases in both volume and surface area compared with healthy controls in inferior-superior parieto-occipital regions. In addition, the precuneus, posterior cingulate areas, middle frontal and orbitofrontal areas, and middle inferior temporal areas extending to the fusiform gyrus were characterized by a reduced surface area only. There were no differences in grey matter thickness between the groups.

LIMITATIONS

The presence of comorbidities, medication usage and the multisymptomatic feature of OCD could have influenced our results to a certain degree.

CONCLUSION

Our results suggest decreased grey matter volume and surface area in several key regions in patients with OCD. Parietal regions showed reductions in both volume and surface area, which underlines the potential relevance of these regions for the pathophysiology of the disorder.

Linking persistent negative symptoms to amygdala-hippocampus structure in first-episode psychosis

Early persistent negative symptoms (PNS) following a first episode of psychosis (FEP) are linked to poor functional outcome. Reports of reduced amygdalar and hippocampal volumes in early psychosis have not accounted for heterogeneity of symptoms. Age is also seldom considered in this population, a factor that has the potential to uncover symptom-specific maturational biomarkers pertaining to volume and shape changes within the hippocampus and amygdala. T1-weighted volumes were acquired for early (N=21), secondary (N=30), non-(N=44) PNS patients with a FEP, and controls (N=44). Amygdalar-hippocampal volumes and surface area (SA) metrics were extracted with the Multiple Automatically Generated Templates (MAGeT)-Brain algorithm. Linear mixed models were applied to test for a main effect of group and age × group interactions. Early PNS patients had significantly reduced left amygdalar and right hippocampal volumes, as well as similarly lateralized negative age × group interactions compared to secondary PNS patients (P<0.017, corrected). Morphometry revealed decreased SA in early PNS compared with other patient groups in left central amygdala, and in a posterior region when compared with controls. Early and secondary PNS patients had significantly decreased SA as a function of age compared with patients without such symptoms within the right hippocampal tail (P<0.05, corrected). Significant amygdalar-hippocampal changes with age are linked to PNS after a FEP, with converging results from volumetric and morphometric analyses. Differential age trajectories suggest an aberrant maturational process within FEP patients presenting with PNS, which could represent dynamic endophenotypes setting these patients apart from their non-symptomatic peers. Studies are encouraged to parse apart such symptom constructs when examining neuroanatomical changes emerging after a FEP.

Meta-analytic investigations of common and distinct grey matter alterations in youths and adults with obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a disabling illness with onset generally in childhood. OCD-youths differ from OCD-adults with regard to gender distribution, comorbidity patterns and treatment options. However, little is known about the neural correlate differences underpin those two populations. The current meta-analysis summarizes voxel based morphometry findings to elucidate whether differences of neural correlates exist between these two populations. Both OCD-youths and OCD-adults demonstrated greater striatal volume and smaller prefrontal grey matter volume (GMV). However, smaller GMV in left visual cortex was observed in OCD-youths only, while smaller GMV in anterior cingulate gyrus and greater GMV in cerebellum were demonstrated only in OCD-adults. Meta-regression showed greater GMV in left putamen was most prominent in samples with higher percentages of medicated OCD-adults. Our findings confirmed the most consistent GMV alterations in OCD were in prefrontal-striatal circuitry. Besides, other regions may involve at different developmental stages including deficits of visual cortex in OCD-youths and abnormalities of limbic-cerebellar circuit in OCD-adults. Medication effect may be more pronounced in the striatum, especially the putamen.