The interaction between Comt and Bdnf variants influences obsessive–compulsive-related dysfunctional beliefs

Cognitive models emphasize the importance of dysfunctional beliefs as overimportance/need to control thoughts, perfectionism, intolerance of uncertainty, responsibility, and overestimation of threat in obsessive–compulsive disorder (OCD). Twin studies suggest that these beliefs are significantly heritable, but candidate genes associated with them have not been analyzed. We genotyped the Val158Met in the COMT gene and Val66Met variant in the BDNF gene in 141 OCD patients and analyzed their single and interactive effects on the obsessive beliefs questionnaire (OBQ-44). Variability in dysfunctional beliefs was not affected by the COMT or BDNF genotype in isolation, but we detected a significant COMT × BDNF interaction effect on responsibility/overestimation of threat and overimportance/need to control thoughts scores. Subjects with the BDNF Met-present and the COMT Met-present genotype showed higher scores on responsibility/overestimation of threat. An interaction between dopaminergic and neurotrophic functional gene variants may influence dysfunctional beliefs hypothesized to contribute to the development of OCD.     

Psychometric properties of the Brazilian version of the Obsessive Beliefs Questionnaire (OBQ-44)

The present study was designed to assess the psychometric properties of the Brazilian version of the Obsessive Beliefs Questionnaire (OBQ-44) in 104 patients with obsessive compulsive disorder (OCD) at the Hospital de Clínicas de Porto Alegre. The secondary objective was to ascertain whether a decline in OBQ-44 scores occurs after cognitive-behavioral group therapy (CBGT). Factor analysis identified three dysfunctional belief domains from the original scale. Internal consistency and reproducibility were very good and good, respectively. Sensitivity to treatment change (cognitive-behavioral group therapy) was good, and pre-post intervention standardized effect sizes (Cohen's d) were strong. The OBQ-44 plays an important role in this setting; as a user-friendly, self-administered instrument that lists the most common dysfunctional beliefs of OCD patients, it enables healthcare providers to assess whether their patients' beliefs change after treatment.     

Reduced cortical thickness in non-medicated patients with obsessive-compulsive disorder

Increasing evidence suggests the presence of grey matter volume abnormalities in patients with obsessive-compulsive disorder (OCD) and the mediation of the expression of different OCD symptoms by discrete neural systems of the brain. However, limited studies have investigated the abnormalities of cortical thickness, and their results are comparatively inconsistent, possibly owing to the inclusion of medicated patients. Therefore, this study investigated cortical thickness abnormalities using surface-based analysis to identify distinct neural correlates of each symptom dimension in non-medicated patients with OCD. Thirty non-medicated patients with OCD and 30 age- and gender-matched healthy controls underwent magnetic resonance imaging. Group comparison of cortical thickness was performed using surface-based analysis. We also conducted correlation analysis between cortical thickness and each symptom dimension score. Compared to the healthy controls, the OCD patients had statistically significant reduction in cortical thickness in the cluster that contained the left superior temporal gyrus and posterior insular cortex (p<.05, corrected); no areas of the brain had significantly greater cortical thickness. Negative correlation was also found between cortical thickness and "cleaning" dimension scores in the left postcentral and right superior parietal gyri. The present results suggest that cortical thinning in the region that contains the left superior temporal gyrus and posterior insula may underlie pathophysiology of OCD and that discrete neural systems may mediate the "cleaning" symptom dimension.     

Cognitive dysfunctions in patients with obsessive-compulsive disorder compared to the patients with schizophrenia patients: relation to overvalued ideas

OBJECTIVE: The clinical overlaps between schizophrenia and obsessive-compulsive disorder (OCD) seem to be related to thought disorders involving obsessions, overvalued ideas, and delusions. Overvalued ideas are beliefs falling in between obsessions and delusions and are stronger than obsessions but weaker than delusions. The goal of the present study was to compare patients with OCD to those with schizophrenia in terms of cognitive functions and to relate cognition and overvalued ideas in OCD. METHODS: Twenty three patients with OCD (free of depression), 24 patients with schizophrenia, and 22 healthy subjects matched to patients in age, gender, education, and hand dominance were included in the study. All subjects were administered neurocognitive tests assessing verbal learning-memory, executive functions, verbal fluency, attention and verbal working memory. RESULTS: Patients with schizophrenia showed worse performance on cognitive tests than the OCD and control groups. The severity of overvalued ideas was significantly correlated to cognitive functions in the OCD group. There were no significant differences in cognitive functions between schizophrenia group and the OCD patients who had higher scores on the Overvalued Ideas Scale (OVIS). CONCLUSION: Overvalued ideas in OCD may be related to cognitive dysfunctions in OCD and this subtype of OCD may have similar characteristics to schizophrenia in terms of cognition.     

Relationship between symptom dimensions and brain morphology in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is known as a clinically heterogeneous disorder characterized by symptom dimensions. Although substantial numbers of neuroimaging studies have demonstrated the presence of brain abnormalities in OCD, their results are controversial. The clinical heterogeneity of OCD could be one of the reasons for this. It has been hypothesized that certain brain regions contributed to the respective obsessive-compulsive dimensions. In this study, we investigated the relationship between symptom dimensions of OCD and brain morphology using voxel-based morphometry to discover the specific regions showing alterations in the respective dimensions of obsessive-compulsive symptoms. The severities of symptom dimensions in thirty-three patients with OCD were assessed using Obsessive-Compulsive Inventory-Revised (OCI-R). Along with numerous MRI studies pointing out brain abnormalities in autistic spectrum disorder (ASD) patients, a previous study reported a positive correlation between ASD traits and regional gray matter volume in the left dorsolateral prefrontal cortex and amygdala in OCD patients. We investigated the correlation between gray and white matter volumes at the whole brain level and each symptom dimension score, treating all remaining dimension scores, age, gender, and ASD traits as confounding covariates. Our results revealed a significant negative correlation between washing symptom dimension score and gray matter volume in the right thalamus and a significant negative correlation between hoarding symptom dimension score and white matter volume in the left angular gyrus. Although our result was preliminary, our findings indicated that there were specific brain regions in gray and white matter that contributed to symptom dimensions in OCD patients.     

Volumetric MRI study of key brain regions implicated in obsessive-compulsive disorder

Neuroanatomic abnormalities have been implicated in the pathophysiology of obsessive-compulsive disorder (OCD). To date, no study has measured the orbito-frontal cortex (OFC), anterior cingulate, caudate nucleus, and thalamus concurrently in first-episode patients. Thus, we performed a volumetric MRI study in patients who were treatment-naive and healthy controls focusing on the in vivo neuroanatomy of the whole brain, total gray and white matter volume, thalamus, caudate nucleus, anterior cingulate cortex, and OFC concurrently. The volumes of thalamus, caudate nucleus, anterior cingulate cortex, and OFC were measured in 12 OCD patients who were treatment-naive and 12 healthy control subjects. Anterior cingulate and OFC volumes included both white and gray matters. Volumetric measurements were made with T1-weighted coronal MRI images, with 1.5-mm-thick slices, at 1.5 T. The patients had increased white matter volume than healthy controls. The patient group had significantly smaller left and right OFC volumes and significantly greater left and right thalamus volumes compared with healthy controls. Anterior cingulate exhibited a near-significant difference between the patients and healthy controls on left side. Significant correlations were found between Y-BOCS scores and left OFC, and right OFC, and between Y-BOCS and left thalamus volumes in the patient group. In conclusion, our findings suggest that abnormalities in these areas may play an important role in the pathophysiology of OCD.     

帕罗西汀联合认知行为疗法治疗强迫症的临床对照研究

目的比较单用帕罗西汀与帕罗西汀联合认知行为疗法对强迫症的临床疗效。方法采用半随机法将符合《中国精神障碍分类与诊断标准(第3版)》(CCMD-3)强迫症诊断标准的86例患者分为研究组和对照组各43例,两组均给予帕罗西汀治疗,研究组在此基础上给予每周1次的认知行为治疗,均观察12周。于治疗前和治疗后第4、8、12周分别采用耶鲁-布朗强迫量表(Y-BOCS)、汉密尔顿焦虑量表(HAMA)评定临床疗效,于治疗第4、8、12周采用副反应量表(TESS)评定不良反应。结果治疗4周末起两组Y-BOCS总评分均较治疗前低(P均0.01),研究组HAMA评分低于对照组(P0.01),第8周末起研究组Y-BOCS评分低于对照组(P0.05);治疗12周末,研究组强迫行为因子评分低于对照组(P0.05),且研究组总有效率高于对照组(86.05%vs.62.79%,P0.05),研究组和对照组不良反应发生率差异无统计学意义(16.28%vs.20.93%,P0.05)。结论单用帕罗西汀与帕罗西汀联合认知行为疗法均可缓解强迫障碍患者症状,但帕罗西汀联合认知行为疗法的效果优于单用帕罗西汀治疗,尤其对强迫行为的改善更为突出。     

Hippocampus and amygdalar volumes in patients with refractory obsessive-compulsive disorder

Functional and structural neuroimaging studies have implicated the hippocampus-amygdala complex in the pathophysiology of obsessive-compulsive disorder (OCD), although no consensus has been established. These brain regions have not been investigated in refractory OCD patients. Volumes of the hippocampus, and amygdala were measured by magnetic resonance imaging (MRI) in a sample of 14 refractory OCD patients and 14 healthy comparison subjects. The mean left and right hippocampal and amygdala volumes of the patients were smaller than those of the healthy controls. OCD severity was not correlated with amygdala volumes but was related to the left hippocampus. Duration of illness was correlated with both hippocampus and left amygdala. Our findings suggest that hippocampus and amygdalar abnormalities can be considered in refractoriness to OCD.     

Hippocampus and amygdalar volumes in patients with somatization disorder

In regard to somatization disorder which covers an important section of our patient population, there is no systematic structural magnetic resonance imaging (MRI) study in the literature. Therefore, we aimed to use structural MRI to evaluate the hippocampus amygdalar complex which is associated with both stress and regulation of emotion that are main basis clinical presentation of somatization disorder in the patients with somatization disorder. Totally 40 subjects (20 patients with somatization disorder and 20 healthy controls) were enrolled. Intracranial volume (ICV), whole brain volume, gray and white matter volumes, and hippocampus and amygdalar volumes of the subjects were measured. In regard to unadjusted mean volumes of measured structures, the patients had significantly smaller mean volumes of the left and right amygdala. However, two groups did not differ significantly in terms of whole brain, total gray and white matter or hippocampus volumes. The repeated measures ANCOVA predicting left and right amygdala volumes demonstrated a significant main effect of diagnostic group. In conclusion, the findings of the present study revealed that the patients with somatization disorder had significantly smaller mean volumes of the left and right amygdala without any differences in regard to whole brain, total gray and white matter or hippocampus volumes. On the basis of the current findings, it seems reasonable to evaluate that abnormalities in connectivity and/or metabolism dimensions and to examine the effects of drugs or psychotherapeutic approaches could be especially informative.     

Specificity of belief domains in OCD: validation of the French version of the Obsessive Beliefs Questionnaire and a comparison across samples

This paper assesses the psychometric properties of the French version of the Obsessive Beliefs Questionnaire (OBQ-44) and investigates whether the questionnaire discriminates between obsessive-compulsive disorder (OCD), anxious control (AC), and non-clinical control (NCC) participants. A confirmatory factor analysis suggested a poor fit of the model. An exploratory factor analysis replicated the original factor structure. The subscales were moderately intercorrelated and highly correlated with the total score. There was partial support for convergent/divergent validity of the OBQ-44. In analyses of variance comparing the three samples, the participants in the OCD sample scored significantly higher than the participants in the AC and NCC samples on all of the OBQ-44 scores. In analyses of covariance comparing the OCD and NCC samples while controlling for general distress and age, the participants with OCD scored significantly higher than the NCC participants on all of the OBQ-44 scores. Implications of the current study are discussed.