A differential neural response in obsessive-compulsive disorder patients with washing compared with checking symptoms to disgust

BACKGROUND: Patients with obsessive-compulsive disorder (OCD) have symptoms that predominantly concern washing (washers) or checking (checkers), or both. Functional neuroimaging has been used to identify the neural correlates of the urge to ritualize but has not distinguished between washing and checking symptoms in OCD. We used functional magnetic resonance imaging to compare the neural response to emotive pictures in washers and checkers. METHODS: In one of two 5-minute experiments, washers (N = 7), checkers (N = 7) and age-matched normal controls (N = 14) were scanned while viewing alternating blocks of normally disgusting (rated as disgusting by all subjects) and neutral pictures. In the other experiment, all patients and a normal subgroup (N = 8) viewed alternating blocks of washer-relevant (rated as more disgusting by washers than normal controls or checkers) and neutral pictures. RESULTS: In all subjects, normally disgusting pictures activated visual regions implicated in perception of aversive stimuli and the insula, important in disgust perception. Only in washers were similar regions activated by washer-relevant pictures. In checkers, these pictures activated fronto-striatal regions associated with the urge to ritualize in OCD. Normal controls were more similar in neural response to checkers than washers to these pictures. Both normal controls and checkers had frontal regions activated significantly more by washer-relevant than normally disgusting pictures, and had these regions activated significantly more than washers by washer-relevant pictures. CONCLUSIONS: We demonstrate a differential neural response to washer-relevant disgust in washers and checkers: only washers demonstrate a neural response to washer-relevant disgust associated with emotion perception rather than attention to non-emotive visual detail.     

Kinematical analysis of emotionally induced facial expressions in patients with obsessive-compulsive disorder

BACKGROUND; Motor function is deficient in many patients with obsessive-compulsive disorder (OCD), especially in the face. To investigate subtle motor dysfunction, kinematical analysis of emotional facial expressions can be used. Our aim was to investigate facial movements in response to humorous film stimuli in OCD patients. METHOD: Kinematical analysis of facial movements was performed. Ultrasound markers at defined points of the face provided exact measurement of facial movements, while subjects watched a humorous movie ('Mr Bean'). Thirty-four OCD patients (19 male, 15 female; mean (S.D.) age: 35.8 (11.5) years; mean (S.D.) total Y-BOCS score: 25.5 (5.9)) were studied in unmedicated state and after a 10-week treatment with the SSRI sertraline. Thirty-four healthy controls (19 male, 15 female; mean (S.D.) age: 37.5 (13.1) years) were also investigated. RESULTS: At baseline, OCD patients showed significantly slower velocity at the beginning of laughing than healthy controls and a reduced laughing frequency. There was a significant negative correlation between laughing frequency and severity of OCD symptoms. Ten weeks later a significant increase of laughing frequency and initial velocity during laughing was found. CONCLUSIONS: Execution of adequate facial reactions to humour is abnormally slow in OCD patients. Susceptibility of OCD patients with regard to emotional stimuli is less pronounced than in healthy subjects. This phenomenon is closely correlated to OCD symptoms and is state-dependent.     

Factor analysis of obsessive-compulsive disorder YBOCS-SC symptoms and association with 5-HTTLPR SERT polymorphism.

Symptoms defining obsessive-compulsive disorder (OCD) are diverse. Factor analyses of OCD symptoms have been used to evaluate obsessive-compulsive phenotypes that are thought to be more homogenous than the macro phenotype. There is evidence that three factors (symmetry/ordering, obsessions/checking, and hoarding) are familial and preliminary evidence that repetitive rituals are associated with a functional polymorphism in the promotor region of the serotonin transporter gene (5-HTTLPR). The goal of this study was to examine relationships between OCD symptom dimensions and 5-HTTLPR. We genotyped 153 subjects who met DSM-IV criteria for OCD. We used the Yale-Brown obsessive-compulsive scale symptom checklist (YBOCS-SC) to assess OCD symptoms. Using principle components analysis, we derived four factors from the 13 symptom categories of the YBOCS-SC in this patient sample, which replicated previous factor analyses of this scale. The frequencies of the S allele and the SS genotype were associated with the second factor including obsessions regarding symmetry and compulsions involving repeating, counting, and ordering/arranging. This study may contribute to understanding of molecular genetic features underlying the appearance of symptom clusters in OCD.     

Gray matter differences between pediatric obsessive-compulsive disorder patients and high-risk siblings: A preliminary voxel-based morphometry study

Neuroimaging studies have identified alterations in frontostriatal circuitry in obsessive-compulsive disorder (OCD). Voxel-based morphometry (VBM) allows for the assessment of differences in gray matter density across the whole brain. VBM has not previously been used to examine regional gray matter density in pediatric OCD patients and the siblings of pediatric OCD patients. Volumetric magnetic resonance imaging (MRI) studies were conducted in 10 psychotropic naïve pediatric patients with OCD, 10 unaffected siblings of pediatric patients with OCD, and 10 healthy controls. VBM analysis was conducted using SPM2. Statistical comparisons were performed with the general linear model, implementing small volume random field corrections for a priori regions of interest (anterior cingulate cortex or ACC, striatum and thalamus). VBM analysis revealed significantly lower gray matter density in OCD patients compared to healthy in the left ACC and bilateral medial superior frontal gyrus (SFG). Furthermore, a small volume correction was used to identify a significantly greater gray matter density in the right putamen in OCD patients as compared to unaffected siblings of OCD patients. These findings in patients, siblings, and healthy controls, although preliminary, suggest the presence of gray matter structural differences between affected subjects and healthy controls as well as between affected subjects and individuals at risk for OCD.     

Nonclinical populations in research on obsessive-compulsive disorder: A critical review

This article provides a review of the literature on nonclinical obsessive-compulsives (NCOCs). The main areas of focus include: (a) prevalence of obsessive-compulsive symptoms in nonclinical populations, (b) symptom profile, (c) associated psychopathology, (d) personality and psychological characteristics, (e) cognitive dysfunction, and (f) coping styles. For all six areas, findings on NCOCs are compared with research on clinical samples. Results suggest that: (a) lowlevel obsessive compulsive symptoms, as well as OCD, occur frequently in the general population; (b) a comparison of the symptom profile of NCOCs and OCD patients reveals both similarities and differences; (c) levels of associated anxiety, depression, and personality traits are consistent across studies and indicate that the scores of NCOCs fall between those of normal controls and OCD patients; (d) basic research on personality and psychological aspects of NCOCs has identified potential etiological factors in the development of OCD, including inflated responsibility and guilt, obsessive-compulsive personality traits, excessive need for control over the environment, and exaggerated responsiveness to emotional provocation; (e) NCOCs perform significantly worse on measures of executive functioning, memory, and information processing in comparison to control subjects, but unlike their OCD counterparts, their scores lie within the normal range; (f) the most common types of strategies employed by NCOCs and OCD patients in an effort to cope with obsessive-compulsive symptoms are qualitatively similar but less effective for OCD patients. The nature of the relationship between nonclinical obsessive-compulsive symptomatology and OCD is discussed with these findings in mind. In addition, critical commentary regarding methodological issues, as well as unanswered research questions which await empirical research, are addressed.     

Gender in obsessive-compulsive disorder and obsessive-compulsive spectrum disorders

Summary Background: There is increasing recognition that obsessive-compulsive disorder (OCD) and putative OCD spectrum disorders (OCSDs) are not homogenous entities. Gender may provide an important window onto the heterogeneity of these various disorders. Methods: A MEDLINE review of gender issues in OCD and putative OCD spectrum disorders (excluding eating disorders) was undertaken (1965–2000). These included demographic variables, clinical phenomenology, etiological factors, and treatment implications. Results: OCD differs from other anxiety disorders in having an approximately equal male:female gender ratio. OCSDs (e.g. body dysmorphic disorder) may have an equal gender ratio, may be more common in women (e.g. trichotillomania, hypochondriasis) or may be more common in men (e.g. Tourette's disorder). Etiological factors may differ across gender; an association between perinatal or early brain injury and OCD or Tourette's appears particularly important in males, while OCD and trichotillomania may also begin during pregnancy or shortly after childbirth with exacerbation of symptoms during menstruation. It is not clear that anti-androgens are effective in OCD, nor that gender predicts response to serotonin reuptake inhibitors in this disorder. Conclusion: There is a relative scarcity of literature addressing gender issues in OCD and putative OCSDs. That literature which does exist is not entirely conclusive, but raises a number of interesting questions for future research.     

Obsessive-compulsive disorder in patients with velocardiofacial (22q11 deletion) syndrome.

The study of neurogenetic microdeletion syndromes provides an insight into the developmental psychopathology of psychiatric disorders. The aim of the study was to evaluate the prevalence of psychiatric disorders, especially obsessive-compulsive disorder (OCD), in patients with velocardiofacial syndrome (VCFS), a 22q11 microdeletion syndrome. Forty-three subjects with VCFS of mean age 18.3 +/- 10.6 years were comprehensively assessed using semi-structured psychiatric interview and the Yale-Brown obsessive compulsive scale (Y-BOCS). Best estimate diagnoses were made on the basis of information gathered from subjects, parents, teachers, and social workers. Fourteen VCFS subjects (32.6%) met the DSM-IV criteria for OCD. OCD had an early age of onset and generally responded to fluoxetine treatment. It was not related to mental retardation. The most common obsessive-compulsive symptoms were contamination, aggression, somatic worries, hoarding, repetitive questions, and cleaning. Sixteen of the 43 patients (37.2%) had attention-deficit/hyperactivity disorder (ADHD), and 7 (16.2%) had psychotic disorder. The results of our study suggest that there is a strong association between VCFS and early-onset OCD. This finding may be significant in the understanding of the underlying genetic basis of OCD.     

Voxel-based morphometry study of gray matter abnormalities in obsessive-compulsive disorder

To examine regional abnormalities in the brains of patients with obsessive-compulsive disorder (OCD), we assessed the gray matter (GM) density using voxel-based morphometry (VBM). We compared magnetic resonance images (MRIs) acquired from 71 OCD patients and 71 age- and gender-matched normal controls and examined the relationship between GM density and various clinical variables in OCD patients. We also investigated whether GM density differs among the subtypes of OCD compared to healthy controls. We detected significant reduction of GM in the inferior frontal gyrus, the medial frontal gyrus, the insula, the cingulate gyrus, and the superior temporal gyrus of OCD patients. A significant increase in GM density was observed in the postcentral gyrus, the thalamus, and the putamen. Some of these regions, including the insular and postcentral gyrus, were also associated with the severity of obsessive- compulsive symptoms. These findings indicate that the frontal-subcortical circuitry is dysfunctional in OCD, and suggest that the parietal cortex may play a role in the pathophysiology of this disease.     

Obsessive-compulsive disorder in pregnancy and the postpartum period: course of illness and obstetrical outcome

The study aimed to examine the course of obsessive-compulsive disorder (OCD) across pregnancy and its impact on obstetric and neonatal outcomes. Women enrolled prior to 20-week gestation in a prospective, observational study. The Structured Clinical Interview for DSM-IV was completed to obtain lifetime Axis I diagnoses. A total of 56 women with OCD were followed at 1 to 3-month intervals through 52 weeks postpartum. Each visit, the Yale-Brown Obsessive Compulsive Scale (YBOCS), clinical assessment, and medication/exposure tracking were performed. Obstetric and neonatal data were abstracted from the medical record. In subjects with OCD, associations between perinatal obsessive-compulsive symptoms (OCSs) and outcomes were examined. Additionally, outcomes were compared to 156 matched psychiatric patients without OCD. Maternal age inversely correlated with the YBOCS scores across the study period (β?=??0.5161, p?=?.0378). Cesarean section was associated with increased OCSs in the postpartum period compared to vaginal delivery (β?=?5.3632, p?=?0.043). No associations were found between severity of perinatal obsessions or compulsions and any specific obstetric or neonatal complications. Subjects without OCD had higher frequency of fetal loss compared to mothers with OCD (χ ²?=?4.03, p?=?0.043). These novel prospective data fail to identify an association of OCSs with adverse outcomes. In contrast, there is an association of delivery method and younger maternal age with increased postnatal symptoms of OCD. Psychiatric subjects without OCD may have a higher risk of miscarriage and intrauterine fetal demise compared to subjects with OCD.     

Neuropsychological performance of OCD patients before and after treatment with fluoxetine: evidence for persistent cognitive deficits

BACKGROUND: There is an ongoing debate about the nature of executive dysfunction that accompanies obsessive-compulsive disorder (OCD). One reason for this may be that state-related factors, such as use of medication or co-morbid symptoms, confound with task performance. This study tried to isolate trait- from state-dependent cognitive impairments by examining variability of cognition following treatment. METHOD: Nineteen OCD patients were tested on the Cambridge Neuropsychological Test Automated Battery (CANTAB) before and after treatment with fluoxetine. Their pattern of performance was compared to the one observed in healthy volunteers (N = 24). RESULTS: OCD patients displayed impairments in planning ability, spatial memory and motor speed that persisted after clinical improvement. With treatment, OCD performance diverged from that of controls on measures of focused attention and strategic ability. However, these effects were rather mild as they did not entail a significant deterioration of performance within the OCD sample. CONCLUSIONS: Our data suggest that cognitive impairments in OCD are not secondary to symptoms and therefore form a trait feature of the disorder. The nature of the deficits refers to a chronic dysfunction of the dorsolateral-striatal circuit. The minor effects of treatment on task performance is in line with recent evidence that serotonin mediates cognitive functions of orbitofrontal cortex to a greater extent than those associated with dorsolateral prefrontal regions.     

Harm avoidance in subjects with obsessive-compulsive disorder and their families

INTRODUCTION: This study investigates the role of harm avoidance (HA) as a possible risk factor in the familiality of obsessive-compulsive disorder (OCD). HA is considered to be a genetically influenced personality trait with an increasingly understood neuroanatomical basis. METHOD: 75 subjects with OCD from hospital sites and a community sample and their 152 first degree relatives and 75 age and sex matched controls with their 143 first degree relatives were evaluated with structured clinical interviews (DSM-IV). HA was assessed with Cloninger's Tridimensional Personality Questionnaire (TPQ). RESULTS: Subjects with OCD had higher scores of HA than controls (p相似文献   

A Self-Rated Scale for Obsessive-Compulsive Disorder

The Self-Rated Scale for Obsessive-Compulsive Disorder is an objective 35-item questionnaire that measures the severity of obsessive-compulsive disorder (OCD). Scale construction employed both rational and empirical item-selection procedures and utilized the responses of 127 diagnosed obsessive-compulsive subjects. A cross-validation study that used 40 obsessive-compulsive subjects found high internal consistency and significant correlations between the new scale and two clinician-rated measures of OCD. Principal components analysis of the combined subject sample (167 obsessive-compulsive subjects) identified four orthogonal components: distressing thoughts, rituals, perfection, and fear of contamination. In conclusion, the Self-Rated Scale for Obsessive-Compulsive Disorder appears to be a comprehensive, easy-to-use, and psychometrically sound instrument for measuring severity of OCD.     

Altered brain activation in ventral frontal-striatal regions following a 16-week pharmacotherapy in unmedicated obsessive-compulsive disorder

Recent studies have reported that cognitive inflexibility associated with impairments in a frontal-striatal circuit and parietal region is a core cognitive deficit of obsessive-compulsive disorder (OCD). However, few studies have examined progressive changes in these regions following clinical improvement in obsessive-compulsive symptoms. To determine if treatment changes the aberrant activation pattern associated with task switching in OCD, we examined the activation patterns in brain areas after treatment. The study was conducted on 10 unmedicated OCD patients and 20 matched controls using event-related functional magnetic resonance imaging. Treatment improved the clinical symptoms measured by the Yale-Brown Obsessive Compulsive Scale and behavioral flexibility indicated by the switching cost. At baseline, OCD showed significantly less activation in the dorsal and ventral frontal-striatal circuit and parietal regions under the task-switch minus task-repeat condition compared with controls. After treatment, the neural responses in the ventral frontal-striatal circuit in OCD were partially normalized, whereas the activation deficit in dorsal frontoparietal regions that mediate shifting attention or behavioral flexibility persisted. It is suggested that altered brain activation in ventral frontal-striatal regions in OCD patients is associated with their cognitive flexibility and changes in these regions may underlie the pathophysiology of OCD.     

The OCD collaborative genetics study: methods and sample description.

Results from twin and family studies suggest that obsessive-compulsive disorder (OCD) may be transmitted in families but, to date, genes for the disorder have not been identified. The OCD Collaborative Genetics Study (OCGS) is a six-site collaborative genetic linkage study of OCD. Specimens and blinded clinical data will be made available through the National Institute of Mental Health (NIMH) cell repository. In this initial report, we describe the methods of the study and present clinical characteristics of affected individuals for researchers interested in this valuable resource for genetic studies of OCD. The project clinically evaluated and collected blood specimens from 238 families containing 299 OCD-affected sibling pairs and their parents, and additional affected relative pairs, for a genome-wide linkage study. Of the 999 individuals interviewed to date, 624 were diagnosed with "definite" OCD. The mean age of subjects was 36 years (range 7-95). The majority of affected individuals (66%) were female. The mean age at onset of obsessive-compulsive symptoms was 9.5 years. Specific mood disorders, anxiety disorders, eating disorders, and skin picking were more prevalent in female cases, whereas tics, Tourette disorder, and alcohol dependence were more prevalent in male cases. Compared to "definite" cases of OCD, "probable" cases (n = 82) had, on average, later age at onset of obsessive-compulsive symptoms, lower severity score, and fewer numbers of different categories of obsessions and compulsions, and they were less likely to have received treatment for their symptoms.     

Attention-Deficit Hyperactivity and Obsessive-Compulsive Symptoms in Adult Patients With Primary Restless Legs Syndrome: Different Phenotypes of the Same Disease?

Objectives: To investigate the prevalence of attention deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD) symptoms in adult patients with primary restless legs syndrome (RLS) and to determine the iron biological correlates of these comorbidities. Participants and Methods: We obtained demographic and clinical data from consecutive 105 outpatients with idiopathic RLS who answered validated questionnaires designed to assess the presence of ADHD and OCD symptoms. In these patients, iron blood parameters were routinely checked. Results: Of the total sample, 42.86% of the patients with RLS showed symptoms reminiscent either of ADHD or OCD. Prevalence of ADHD and OCD symptoms was 27.62% and 7.62%, respectively. Compared to other groups, a significantly higher percentage of RLS patients with ADHD symptoms was on antidepressant (p = 0.012); and women with ADHD symptoms, either alone or combined with OCD symptoms, showed significant reduced ferritin concentrations compared to men with either isolated ADHD symptoms or with combined ADHD and OCD symptoms (p = 0.028 and p = 0.025, respectively). Conclusions: Our findings highlight the high prevalence of ADHD and OCD symptoms in adult patients with primary RLS and independently of serum iron stores decrease, except for women with ADHD symptoms either alone or in combination with OCD symptoms. This may suggest an overlapping neurobiological dopaminergic and serotoninergic dysfunction in ADHD, OCD, and RLS, and question the expression of different RLS phenotypes. The efficacy of dopamine agonists in these groups of patients should be questioned in future studies.     

Functional connectivity in fronto-subcortical circuitry during the resting state in obsessive-compulsive disorder

Obsessions and compulsions mediated by cognitive inflexibility might be associated with abnormal resting state functional connectivity in the default mode network (DMN) that represents intrinsically generated neuronal activity. It was hypothesized that decreased functional connectivity in the DMN would occur in components of fronto-subcortical circuits in patients with obsessive-compulsive disorder (OCD). Twenty-two unmedicated OCD patients and 22 age- and sex-matched healthy controls received resting state functional scanning runs. The posterior cingulate cortex (PCC) region was chosen as the seed region for the connectivity analysis. Correlations between temporal connectivity with the seed region and scores on clinical measures and obsessive-compulsive symptom dimensions were also assessed. OCD patients demonstrated less functional connectivity within the DMN in the anterior cingulate cortex, middle frontal gyrus, and putamen compared to controls. The functional connectivity to the PCC seed region in OCD patients was in the direction opposite to that in the prefrontal areas with regard to scores on cleaning and obsessions/checking dimensions of OCD. These data provide evidence for fronto-subcortical dysfunction in OCD. Results from this study also support the notion that OCD is a heterogeneous disorder mediated by distinct circuits.     

Comparative cognitive profiles of obsessive-compulsive disorder and schizophrenia

A body of neuropsychological research revealed cognitive impairments in patients suffering from obsessive-compulsive disorder (OCD). Only few investigations addressed the question of how specific these impairments are. The present study compared the performances of 19 subjects with OCD to 19 subjects with schizophrenia and 19 healthy controls on neuropsychological tasks across the main cognitive domains (memory, attention, visual spatial and executive functioning). For purposes of data-reduction, single test measures of the test battery applied were aggregated into eight cognitive domain scores. Contrary to our expectation we found comparable performance profiles of obsessive-compulsive (OC) and schizophrenia subjects across domains with impairments primarily affecting simple attentional skills and memory skills. However, deficits of subjects with schizophrenia were greater in magnitude than those of subjects with OCD on all domains assessed. Elevated depression scores exerted a relevant impact on performance deficits in the OC but not in the schizophrenia sample.     

Clinical features associated to refractory obsessive-compulsive disorder

Some patients with obsessive-compulsive disorder (OCD) exhibit an unsatisfactory reduction in symptom severity despite being treated with all the available therapeutic alternatives. The clinical variables associated with treatment-refractoriness in OCD are inconsistently described in the literature. METHODS: To investigate factors associated with treatment-refractoriness of patients with OCD, we conducted a case-control study, comparing 23 patients with treatment-refractory OCD to 26 patients with treatment-responding OCD. RESULTS: The factors associated with refractoriness of OCD were higher severity of symptoms since the onset of OCD (p<0.001), chronic course (p=0.003), lack of a partner (p=0.037), unemployment (p=0.025), low economic status (p=0.015), presence of obsessive-compulsive symptoms of sexual/religious content (p=0.043), and higher scores on family accommodation (p<0.001). Only the three latter variables remained significantly associated with treatment-refractoriness after regression analyses. Limitations: small sample size, the biases and drawbacks inherent to a case-control study, and the inclusion criteria used to define the study groups may have limited the generalisation of the results. CONCLUSION: A major strength of this study is the systematic and structured evaluation of a vast array of variables related to the clinical expression of OCD, including epigenetic factors and ratings derived from instruments evaluating family accommodation. The presence of sexual/religious symptoms, low economic status and high modification on family function due to OCD were independently associated with treatment-refractoriness. Future longitudinal studies are warranted to verify if these variables represent predictive factors of treatment non-response.     

Brain-derived neurotrophic factor gene Val66Met polymorphism and cognitive function in obsessive-compulsive disorder

In the present study, we have tested the hypothesis that brain-derived neurotrophic factor (BDNF) gene Val66Met polymorphism is associated with obsessive-compulsive disorder (OCD) and also investigated the association between the BDNF Val66Met polymorphism and the performance on tests measuring executive functions in a sample of patients with OCD. A total of 100 patients diagnosed with OCD according to DSM-IV criteria and 110 control subjects were included in this study. Single nucleotide polymorphism (G/A) leading to Val to Met substitution at codon 66 in BDNF was screened in the DNA samples of all participants. The genotype frequencies of BDNF Val66Met polymorphism were compared in OCD patients and healthy controls. The four subgroups of OCD and healthy control subjects, determined according to being Val homozygous or carrying a Met allele, were also compared according to their performance in a battery of neuropsychological tests of executive functions and verbal memory. There was no significant difference for the allele and genotype distributions of BDNF Val66Met polymorphism between the OCD and healthy control groups. Compared to the other three subgroups, OCD-Met carriers were slower on Trail-Making Test part A (TMT A), part B (TMT B) score and its speed-corrected score (TMT B-A). OCD-Met carriers had also poor performance on verbal fluency tasks and several CVLT measures compared only to the healthy control-Met carriers. These results demonstrate that the BDNF Val66Met polymorphism does not appear to be a risk factor for OCD. However, the presence of a BDNF Met allele, which is a known attenuator of BDNF activity, may be associated with a poorer executive functioning in OCD. ? 2012 Wiley Periodicals, Inc.     

Association between symptom severity and internal capsule volume in obsessive-compulsive disorder

Neurobiological models support an involvement of white matter tracts in the pathophysiology of obsessive-compulsive disorder (OCD), but there has been little systematic evaluation of white matter volumes in OCD using magnetic resonance imaging (MRI). We investigated potential differences in the volume of the cingulum bundle (CB) and anterior limb of internal capsule (ALIC) in OCD patients (n = 19) relative to asymptomatic control subjects (n = 15). White matter volumes were assessed using a 1.5T MRI scanner. Between-group comparisons were carried out after spatial normalization and image segmentation using optimized voxel-based morphometry. Correlations between regional white matter volumes in OCD subjects and symptom severity ratings were also investigated. We found significant global white matter reductions in OCD patients compared to control subjects. The voxel-based search for regional abnormalities (with covariance for total white matter volumes) showed no specific white matter volume deficits in brain portions predicted a priori to be affected in OCD (CB and ALIC). However, large clusters of significant positive correlation with OCD severity scores were found bilaterally on the ALIC. These findings provide evidence of OCD-related ALIC abnormalities and suggest a connectivity dysfunction within frontal-striatal-thalamic-cortical circuits. Further studies are warranted to better define the role of such white matter alterations in the pathophysiology of OCD, and may provide clues for a more effectively targeting of neurosurgical treatments for OCD.