1,721,348 research outputs found
Voxel-based meta-analysis of regional white-matter volume differences in autism spectrum disorder versus healthy controls
No full textBackground We conducted a meta-analysis of voxel-based morphometry (VBM) studies in autism spectrum disorder (ASD) to clarify the changes in regional white-matter volume underpinning this condition, and generated an online database to facilitate replication and further analyses by other researchers.Method PubMed, ScienceDirect, Web of Knowledge and Scopus databases were searched between 2002 (the date of the first white-matter VBM study in ASD) and 2010. Manual searches were also conducted. Authors were contacted to obtain additional data. Coordinates were extracted from clusters of significant white-matter difference between patients and controls. A new template for white matter was created for the signed differential mapping (SDM) meta-analytic method. A diffusion tensor imaging (DTI)-derived atlas was used to optimally localize the changes in white-matter volume.Results Thirteen datasets comprising 246 patients with ASD and 237 healthy controls met inclusion criteria. No between-group differences were found in global white-matter volumes. ASD patients showed increases of white-matter volume in the right arcuate fasciculus and also in the left inferior fronto-occipital and uncinate fasciculi. These findings remained unchanged in quartile and jackknife sensitivity analyses and also in subgroup analyses (pediatric versus adult samples).Conclusions Patients with ASD display increases of white-matter volume in tracts known to be important for language and social cognition. Whether the results apply to individuals with lower IQ or younger age and whether there are meaningful neurobiological differences between the subtypes of ASD remain to be investigated. © 2011 Cambridge University Press
A general approach for combining voxel-based meta-analyses conducted in different neuroimaging modalities
No full textMeta-analyses are useful to summarize the exponential amount of inconsistent and conflicting neuroimaging data. However, they are usually separately conducted for each different neuroimaging modality, preventing the multimodal integration of different imaging findings in a given neuropsychiatric disorder. Here, we describe an innovative method to meta-analytically combine the results of different imaging modalities, such as structural and functional paradigms. The method accounts for the presence of noise in the estimation of the p-values, and can be easily applied to any meta-analytical software. We hope that with this advanced imaging tool, researchers will be able to provide more complete multimodal pictures of the brain regions affected in different neuropsychiatric disorders
The use of a nonimmersive virtual reality programme in Anorexia nervosa: A single case-report
No full textObjective: People with anorexia nervosa (AN) experience high levels of fear and anxiety related to eating. The aim of this case report was to describe the use of a virtual reality (VR) programme developed to facilitate exposure to food as a supplement to treatment for a person with AN. Method: A 21-year-old patient with AN was given the VR module in addition to the Maudsley Model of Treatment for Adults with Anorexia Nervosa. Weight, eating disorder symptomatology (EDE-Q) and general psychopathology (DASS) were assessed before and after the module was delivered. Results: At the end of the module, the patient reported lower levels of anxiety, safety behaviours and fears related to food. Both eating disorder symptoms and distress were reduced. Body mass index increased from 15 to 16.8kg/m 2 during the module. Conclusion: The VR exposure module was associated with a beneficial change in the relationship to food and was perceived to be helpful by the individual. Copyright © 2011 John Wiley & Sons, Ltd and Eating Disorders Association
Family accomodation in obsessive-compulsive disorder: relation to symptom dimensions, clinical and family charcateristics
No full textAbstract
Family accommodation is the term used to indicate the process whereby family members of patients with obsessive-compulsive disorder (OCD) assist or participate in the patients' rituals. Family accommodation is a relatively under-researched phenomenon in OCD but an important one because it may be predictive of poor treatment outcome. This study systematically examined several socio-demographic and clinical variables that are associated with family accommodation in a well-characterized sample of adult patients and their healthy family members. Experienced clinicians administered the Family Accommodation Scale (FAS) to 141 psychopathology-free family members cohabiting with 97 patients with OCD. The items of the FAS were first subjected to principal component analysis (PCA) and the resulting domains of family accommodation (Participation, Modification, and Distress and Consequences) introduced as dependent variables in a series of multiple regression models assessing the relationship between family accommodation domains and a wide range of clinical variables, including Axis I and II psychopathology and symptom dimensions derived from the Yale-Brown Obsessive-Compulsive Scale (YBOCS) Symptom Checklist. The results showed that family accommodation was common, with the provision of reassurance, participation in rituals and assisting the patient in avoidance being the most frequent practices (occurring on a daily basis in 47%, 35%, and 43% of family members, respectively). The PCA of the YBOCS Symptom Checklist yielded four symptom dimensions, which were identical to those previously identified in the international literature. Multiple linear regression analyses showed that a higher score on the contamination/washing symptom dimension and a positive family history for an anxiety disorder other than OCD (referring to a family member other than the participant in this study) predicted greater scores on several domains of family accommodation. Our study confirms that family accommodation is frequent and distressing in psychopathology-free family members cohabiting with adult OCD patients. Family accommodation is particularly frequent and distressing when the patient has prominent contamination/washing symptoms and/or when another family member has a history of an anxiety disorder. Such families may be more likely to benefit from family-based interventions but this remains to be tested in controlled trials
Multimodal meta-analysis of structural and functional brain changes in first episode psychosis and the effects of antipsychotic medication
No full textAbstractStructure and function in the human brain are closely related. At the onset of psychosis, brain imaging studies have identified robust changes in brain function and structure, but no data are available relating these two domains. After systematic literature searches, we included all available studies reporting whole-brain structural or cognitive functional imaging findings in first-episode (FEP) subjects in multimodal Signed Differential Mapping (SDM). Forty-three studies met the inclusion criteria. The structural database comprised 965 FEP subjects matched with 1040 controls whilst the functional cohort included 362 FEP subjects matched with 403 controls. The analysis identified conjoint structural and functional differences in the insula/superior temporal gyrus and the medial frontal/anterior cingulate cortex bilaterally. In these regions, large and robust decreases in grey matter volume were found with either reduced or enhanced activation. Meta-regression analyses indicated that grey matter volume in the anterior cingulate and left insular clusters was influenced by exposure to antipsychotics: patients receiving medication were more likely to show structural abnormalities in these regions
A case series to investigate food-related fear learning and extinction using in vivo food exposure in anorexia nervosa: A clinical application of the inhibitory learning framework
Full text linkObjective: Anorexia nervosa is characterized by severe malnutrition. This study tested the hypothesis that fear of food is a learned behaviour and evaluated the feasibility and effectiveness of gradual exposure to food to improve eating behaviour in people with anorexia nervosa. Methods: Eighteen women were recruited and completed baseline self-reports. They were interviewed regarding early experiences of eating and the development of food-related anxiety. Participants received eight sessions of in vivo food exposure. Results: Findings indicated that fear of food is a learned behaviour, associated with catastrophic thoughts around the consequences of eating and safety behaviours. Patients consumed at least half of the food item selected in all but one session. Body mass index increased, and food restriction, eating concern, eating disorder-related preoccupations, and overall anxiety reduced (medium/large ES). Conclusion: Findings corroborate an anxiety-based model of anorexia nervosa and support the relevance of targeting food-related fears using exposure-based protocols
Hoarding disorder: A new obsessive-compulsive related disorder in DSM-5
Full text linkObsessive-compulsive disorder (OCD) and related disorders have been the subject of significant revisions in the fifth edition of the Diagnostic and Statistical Manual (DSM-5). One of these major changes has been the removal of OCD from the 'Anxiety Disorders' section and its instalment in a new and distinct Obsessive-Compulsive and Related Disorders (OCRDs) chapter. However, it is the instatement of hoarding disorder (HD) as a new OCRD that marks the most significant change. Previously considered a symptom of OCPD, and subsequently linked to OCD, it is now acknowledged that hoarding can emerge independently from any alternative condition. The present paper provides an updated review of recent investigations supporting the status of HD as an independent nosological entity. Specifically, we will present the new DSM-5 diagnostic criteria and examine the literature pertaining to the psychopathological and phenomenological aspects of the disorder, with particular attention to practical strategies that can help clinicians to recognise and differentiate HD from OCD. Finally, the available assessment and treatment strategies for HD are summarised
Anisotropic Kernels for Coordinate-Based Meta-Analyses of Neuroimaging Studies
No full textPeak-based meta-analyses of neuroimaging studies create, for each study, a brain map of effect size or peak likelihood by convolving a kernel with each reported peak. A kernel is a small matrix applied in order that voxels surrounding the peak have a value similar to, but slightly lower than that of the peak. Current kernels are isotropic, i.e., the value of a voxel close to a peak only depends on the Euclidean distance between the voxel and the peak. However, such perfect spheres of effect size or likelihood around the peak are rather implausible: a voxel that correlates with the peak across individuals is more likely to be part of the cluster of significant activation or difference than voxels uncorrelated with the peak. This paper introduces anisotropic kernels, which assign different values to the different neighboring voxels based on the spatial correlation between them. They are specifically developed for effect-size signed differential mapping (ES-SDM), though might be easily implemented in other meta-analysis packages such as activation likelihood estimation (ALE). The paper also describes the creation of the required correlation templates for gray matter/BOLD response, white matter, cerebrospinal fluid, and fractional anisotropy. Finally, the new method is validated by quantifying the accuracy of the recreation of effect size maps from peak information. This empirical validation showed that the optimal degree of anisotropy and full-width at half-maximum (FWHM) might vary largely depending on the specific data meta-analyzed. However, it also showed that the recreation substantially improved and did not depend on the FWHM when full anisotropy was used. Based on these results, we recommend the use of fully anisotropic kernels in ES-SDM and ALE, unless optimal meta-analysis-specific parameters can be estimated based on the recreation of available statistical maps. The new method and templates are freely available at http://www.sdmproject.com/. © 2014 Radua, Rubia, Canales-Rodríguez, Pomarol-Clotet, Fusar-Poli and Mataix-Cols
Exposure to food in anorexia nervosa and brain correlates of food-related anxiety: findings from a pilot study
No full textBackground: Although the primary target of treatment for anorexia nervosa (AN) is weight gain, established psychological interventions focus on maintaining factors of AN, and do not specifically address eating behaviours. We have previously reported results of a case series investigating in-vivo food exposure in AN, demonstrating the feasibility and acceptability of this treatment together with evidence of significant clinical change (Cardi, Leppanen, Mataix‐Cols, Campbell, & Treasure, 2019). The current study examined the neural circuitry of food-related anxiety. Methods: We examined neural reactivity (fMRI) to food images pre- and post-food exposure therapy (n=16), and compared it to a group of healthy control participants (HC n=21) who were scanned on two occasions. Results: Prior to treatment, the AN group (compared to HC) showed less reactivity in the anterior cingulate cortex (ACC). Following exposure treatment, patients (compared to HC), show increased activity in the dorsolateral prefrontal cortex, decreased activity in the superior parietal lobe and no differences in the ACC. The level of activation of the insula (pre-treatment) predicted the degree of post-treatment reduction in self-reported food anxiety in AN. Changes in food-related anxiety were also associated with changes in neural activation in a cluster located in the middle temporal gyrus/lateral parietal cortex. Limitations: The primary limitations of this work are the small sample size and lack of patient comparison group. Conclusions: Exposure to food in AN may be associated with changes in neural circuitries implicated in emotion regulation and attentional processes. However, these findings need replication in larger and controlled studies
Declarative and procedural learning in individuals with subclinical obsessive-compulsive symptoms
No full textPrevious neuropsychological research suggests that psychometrically defined subclinical obsessive-compulsive (OC) individuals perform worse than non-OC controls on specific tests of executive functioning. This study aimed to extend these findings by comparing the performance of 25 subclinical OC and 28 non-OC control subjects on measures of declarative learning (Rey Auditory Verbal Leaming Test), motor procedural learning (star maze), spatial problem solving (single administration of the 3-disk version of the Tower of Hanoi; TH3), and "cognitive" procedural leaming (repeated administrations of the 4-disk version of the Tower of Hanoi; TH4). In addition, the subjects were administered measures of general intelligence, anxiety and depression. No between-group differences were observed on measures of declarative and motor procedural leaming. Subclinical OC subjects needed significantly more moves than controls to solve TH3, suggesting poorer spatial problem solving ability. A significant group x trial interaction on the TH4 suggested reduced cognitive skill acquisition in the subclinical OC group. However, performance on TH3 and TH4 was significantly correlated in the OC group but not in the control group, suggesting that the suboptimal acquisition of cognitive skills among subclinical OC subjects is more likely to be related to inefficient spatial problem solving strategies than to a cognitive procedural learning deficit per se. These results replicate and expand upon previous findings and support a dimensional model of Obsessive-Compulsive Disorder
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