Gray matter volume reduction in obsessive-compulsive disorder with schizotypal personality trait

Schizotypal personality disorder in clinical obsessive-compulsive disorder samples: a brief overview

Obsessive-compulsive disorder (OCD) is a chronic and disabling mental disorder characterized by the presence of obsessions and/or compulsions that cause major distress and impair important areas of functioning. About 9 out of 10 patients with OCD have comorbid psychiatric diagnoses. A high proportion of clinically diagnosed OCD patients fulfill diagnostic criteria of a schizophrenia spectrum disorder, to the point that significant evidence in the literature supports the existence and the clinical relevance of a schizo-obsessive spectrum of disorders, including schizotypal personality disorder (SPD) with OCD (schizotypal OCD). In this paper, we provide a brief but comprehensive analysis of the literature on the clinical coexistence between OCD and SPD. The clinical validity of the so-called schizotypal OCD is analyzed through a comprehensive investigation of the relationship between SPD features and obsessive-compulsive phenomena in clinical OCD samples. This review describes the potential connections between OCD and SPD on the epidemiological, sociodemographic, psychopathological, and clinical levels. SPD is commonly observed in OCD patients: about 10% of OCD patients have a full categorical diagnosis of SPD. Early clinical identification of SPD features-and, more generally, of psychotic features and personality disorders-in OCD patients is strongly recommended. In fact, a proper and early diagnosis with early treatment may have benefits for prognosis. However, although schizotypal OCD seems to have clinical and predictive validity, further neurobiological and genetic studies on etiological specificity are warranted.

Identifying Schizo-Obsessive Comorbidity by Tract-Based Spatial Statistics and Probabilistic Tractography

A phenomenon in schizophrenia patients that deserves attention is the high comorbidity rate with obsessive-compulsive disorder (OCD). Little is known about the neurobiological basis of schizo-obsessive comorbidity (SOC). We aimed to investigate whether specific changes in white matter exist in patients with SOC and the relationship between such abnormalities and clinical parameters. Twenty-eight patients with SOC, 28 schizophrenia patients, 30 OCD patients, and 30 demographically matched healthy controls were recruited. Using Tract-based Spatial Statistics and Probabilistic Tractography, we examined the pattern of white matter abnormalities in these participants. We also used ANOVA and Support Vector Classification of various white matter indices and structural connection probability to further examine white matter changes among the 4 groups. We found that patients with SOC had decreased fractional anisotropy (FA) and increased radial diffusivity in the right sagittal stratum and the left crescent of the fornix/stria terminalis compared with healthy controls. We also found changed connection probability in the Default Mode Network, the Subcortical Network, the Attention Network, the Task Control Network, the Visual Network, the Somatosensory Network, and the cerebellum in the SOC group compared with the other 3 groups. The classification results further revealed that FA features could differentiate the SOC group from the other 3 groups with an accuracy of .78. These findings highlight the specific white matter abnormalities found in patients with SOC.

Schizotypy and smooth pursuit eye movements as potential endophenotypes of obsessive-compulsive disorder

Patients with obsessive-compulsive disorder (OCD) show dysfunctions of the fronto-striatal circuitry, which imply corresponding oculomotor deficits including smooth pursuit eye movements (SPEM). However, evidence for a deficit in SPEM is inconclusive, with some studies reporting reduced velocity gain while others did not find any SPEM dysfunctions in OCD patients. Interestingly, psychosis-like traits have repeatedly been linked to both OCD and impaired SPEM. Here, we examined a large sample of n = 168 patients with OCD, n = 93 unaffected first-degree relatives and n = 171 healthy control subjects to investigate whether elevated levels of schizotypy and SPEM deficits represent potential endophenotypes of OCD. We applied a SPEM task with high demands on predictive pursuit that is more sensitive to assess executive dysfunctions than a standard task with continuous visual feedback, as episodes of target blanking put increased demands on basal ganglia and prefrontal involvement. Additionally, we examined the relation between schizotypy and SPEM performance in OCD patients and their relatives. Results indicate that OCD patients and unaffected relatives do not show deficient performance in either standard or predictive SPEM. Yet, both patients and relatives exhibited elevated levels of schizotypy, and schizotypy was significantly correlated with velocity gain during standard trials in unmedicated and depression-free OCD patients. These findings highlight the role of schizotypy as a candidate endophenotype of OCD and add to the growing evidence for predisposing personality traits in OCD. Furthermore, intact gain may represent a key characteristic that distinguishes the OCD and schizophrenia patient populations.

Altered Functional Connectivity of the Default Mode Network in Patients With Schizo-obsessive Comorbidity: A Comparison Between Schizophrenia and Obsessive-compulsive Disorder

Clinical and neuroimaging data support the idea that schizo-obsessive comorbidity (SOC), similar to obsessive-compulsive disorder (OCD) and schizophrenia (SCZ), may be a distinct brain disorder. In this study, we examined the strength of resting-state functional connectivity (rsFC) between 19 subregions of the default mode network (DMN) and whole brain voxels in 22 patients with SOC features, 20 patients with SCZ alone, 22 patients with OCD, and 22 healthy controls (HC). The main results demonstrated that patients with SOC exhibited the highest rsFC strength within subregions of the DMN and the lowest rsFC strength between the DMN and subregions of the salience network (SN) compared with the other 3 groups. In addition, compared with HCs, all 3 patient groups exhibited increased rsFC between subregions of the DMN and the executive control network (ECN). The SOC and SCZ group both exhibited increased rsFC between subregions of the DMN and the middle temporal gyrus, but the OCD group exhibited decreased rsFC between them. These findings highlight a specific alteration in functional connectivity in the DMN in patients with SOC, and provide new insights into the dysfunctional brain organization of different mental disorders.

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.

Relationship between social-cognitive and social-perceptual aspects of theory of mind and neurocognitive deficits, insight level and schizotypal traits in obsessive-compulsive disorder

OBJECTIVE

The primary aim of the current study was to investigate different aspects of theory of mind (ToM), including social-cognitive (ToM-reasoning) and social-perceptual (ToM-decoding) in obsessive-compulsive disorder (OCD). We also aimed to investigate the relationship between ToM, neurocognition and a number of clinical variables including overvalued ideas, schizotypal personality traits, level of insight, and disease severity.

METHOD

Thirty-four patients who have been diagnosed with OCD according to DSM-IV and 30 healthy controls were included in the study. All participants were given a neuropsychological battery including tasks measuring ToM-reasoning, ToM-decoding and other neurocognitive functions. Schizotypal Personality Questionnaire (SPQ), Yale Brown Obsession and Compulsion Scale (YBOC-S) and Overvalued Ideas Scale (OVIS) were also administered to the participants.

RESULTS

Patients with OCD showed significant deficits in both aspects of ToM. ToM performances of patients showed a significant positive correlation with neurocognitive functions. When controlled for general cognition factor, patient-control difference for ToM-reasoning (F = 3,917; p = 0,05), but not ToM-decoding, remained statistically significant. ToM-reasoning impairment of patients was significantly related to the severity of OCD symptoms and poor insight (p = 0,026 and p = 0,045, respectively). On the other hand, general cognitive factor (β = 0,778; t = 3,146; p = 0,04) was found to be the only significant predictor of ToM-reasoning in OCD patients in the multiple linear regression model.

CONCLUSION

OCD is associated with ToM impairment, which is related to schizotypal traits, disease severity and poor insight, yet neurocognitive deficits also significantly contribute to this finding. However, ToM-reasoning impairment could be considered as a relatively distinct feature of OCD, which is partly separate from general cognitive deficits.

Whole-brain volume alteration and its correlation with anxiety severity in patients with obsessive-compulsive disorder and generalized anxiety disorder

PURPOSE

To evaluate the differential gray matter (GM) and white matter volume alterations between healthy controls and patients with obsessive-compulsive disorder (OCD) and generalized anxiety disorder (GAD) using voxel-based morphometry (VBM).

METHOD

Patients with OCD and GAD, and healthy controls underwent MR.

RESULTS

Patients with GAD showed significantly decreased GM volume in the medial prefrontal cortex (mPFC) compared with patients with OCD (p < 0.001). The GM volumes of the mPFC in patients with GAD were negatively correlated with Hamilton Anxiety Rating Scales.

CONCLUSION

Our findings indicate that the mPFC volume abnormality may be associated with anxiety disorder in patients with GAD rather than OCD.

The clinical characteristics of obsessive compulsive disorder associated with high levels of schizotypy

OBJECTIVES

This study aims to examine the characteristics of obsessive compulsive disorder (OCD) associated with high levels of schizotypy.

METHODS

Using the Schizotypal Personality Questionnaire (SPQ) with 177 individuals with OCD, patients with OCD and high levels of schizotypy (OCD-HS) were compared to patients with OCD and low levels of schizotypy (OCD-LS) on a range of clinical characteristics. Self-report and clinician-administered instruments were used. Results were adjusted for the severity of OCD symptoms, age, marital status and comorbidity using logistic regression.

RESULTS

Patients with OCD-HS were younger and less likely to have been married. OCD-HS was associated with higher rates of symmetry/order obsessions, ordering/arranging compulsions, checking compulsions, co-occurring major depression, post-traumatic stress disorder, substance use disorders and greater general psychopathology. Previously reported associations, such as higher total scores on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) were not significant when adjusted for differences in demographic variables and comorbidity.

CONCLUSIONS

Patients with OCD-HS were associated with specific OCD symptoms and comorbid conditions and may warrant a specific treatment approach.

Clinical and neurocognitive profiles of subjects at high risk for psychosis with and without obsessive-compulsive symptoms

OBJECTIVE

Obsessive-compulsive symptoms (OCS), which are common in psychotic-spectrum illnesses, are of clinical interest because of their association with poor prognosis or cognitive dysfunction. However, few studies on the clinical and neurocognitive implications of OCS in individuals at ultra-high risk for psychosis (UHR) have been conducted.

METHOD

Sixty-five UHR subjects [24 with OCS (UHR+OCS), 41 without OCS (UHR-OCS)], and 40 healthy controls were assessed using clinical scales and neurocognitive tests.

RESULTS

Those with UHR+OCS showed more severe clinical symptoms and poorer global functioning as compared to both healthy controls and the UHR-OCS group, according to the results of the Global Assessment of Functioning, the Comprehensive Assessment of At-Risk Mental States, and the Positive and Negative Syndrome Scale (total, negative, and general scores). In the neurocognitive domain, those in the UHR-OCS group showed notably greater latency in the Stroop task and more confabulation errors in immediate recall in the Rey-Osterrieth Complex Figure Test compared with those in UHR+OCS group, whose performance levels were similar to those of the healthy control group.

CONCLUSIONS

The OCS manifested in UHR individuals was associated with a more severe clinical symptomatic presentation, including lower global functioning and more psychotic symptoms. On the other hand, those with UHR-OCS performed more poorly on some cognitive tests. The features that distinguish the groups can be used for developing prognoses and intervention strategies for the heterogeneous UHR group.

Early versus late onset obsessive-compulsive disorder: evidence for distinct subtypes

The distinction between early versus late onset is important for understanding many different kinds of disorders. In an effort to identify etiologically homogeneous subtypes of obsessive-compulsive disorder (OCD), numerous studies have investigated whether early onset OCD (EO) can be reliably distinguished from a comparatively later onset form of the disorder (LO). The present article presents a systematic review and evaluation of this subtyping scheme, including meta-analyses and re-analyses of raw data. Regarding the latter, latent class analyses of nine datasets, including clinical and community samples, consistently indicated that age-of-onset is not a unimodal phenomena. Evidence suggests that there are two distinguishable groups; EO (mean onset 11 years) and LO (mean onset 23 years). Approximately three-quarters of cases of OCD (76%) were classified as EO. Meta-analyses indicated that EO, compared to LO, is (a) more likely to occur in males, (b) associated with greater OCD global severity and higher prevalence of most types of OC symptoms, (c) more likely to be comorbid with tics and possibly with other putative obsessive-compulsive spectrum disorders, and (d) associated with a greater prevalence of OCD in first-degree relatives. EO and LO were also distinguishable on other psychosocial and biological variables. Overall, results support the view that EO and LO are distinct subtypes of OCD. Comparisons with other, potentially overlapping OCD subtyping schemes are discussed, implications for DSM-V are considered, and important directions for future investigation are proposed.

Outcome of severe obsessive-compulsive disorder with schizotypal features: a pilot study

BACKGROUND/PURPOSE

Long-term outcome of patients with severe obsessive-compulsive disorder (OCD) and schizotypal features has been rarely studied. We investigated this issue in this retrospective pilot study.

METHODS

Twenty-two patients with severe OCD and schizotypal features were identified by chart review. Another 22 OCD patients without schizotypal features (OCD-NS) served as the comparison group. Those with schizotypal features must not fulfill a diagnosis of schizophrenia or schizotypal disorder. After an average follow-up of 6.6 years, each patient received a re-diagnosis clinical interview. Relevant demographic and clinical data were collected. Patients with schizotypal features were classified into two groups after re-diagnosis: those with schizophrenia or schizotypal disorder (OCD-SS group, n = 9) and those with only schizotypal traits (OCD-ST group, n = 13) that did not fulfill a well-formed schizophrenia-spectrum disorder. Demographic data, family history, clinical symptoms, and OCD course were compared among the three patient groups.

RESULTS

Compared with the OCD-NS group, the OCD-SS group was significantly less educated, less likely to be married or female, and had earlier onset of illness and poorer OCD course (p<0.05). There was no significant difference in any demographic and clinical variables between the OCD-SS and OCD-ST groups except that the OCD-ST group had a significantly better OCD course (p < 0.01).

CONCLUSION

The findings suggest that a substantial proportion of the patients with severe OCD and schizotypal features evolve into schizophrenia spectrum disorder and are associated with a poor long-term outcome, whereas the OCD-NS group might stay with limited manifestations of schizotypal features and have a better outcome.

Is there evidence of brain white-matter abnormalities in obsessive-compulsive disorder?: a narrative review

OBJECTIVE

Although several studies have confirmed the occurrence of gray-matter abnormalities in obsessive-compulsive disorder (OCD), the literature on white matter in OCD is more limited. In this study, we reviewed the role of white-matter abnormalities in the pathophysiology of OCD.

METHOD

We reviewed the PubMed studies investigating white-matter integrity in patients with OCD between 1980 and 2010.

RESULTS

Case studies of patients who developed obsessive-compulsive symptoms secondary to multiple sclerosis, cerebrovascular diseases, and paraneoplastic leucoencephalopathy and controlled studies of patients with OCD examined with neuroimaging techniques (eg, structural, diffusion, and spectroscopic magnetic resonance imaging) were all consistent with the existence of abnormalities in specific white-matter tracts (eg, internal capsule, cingulate bundle, and corpus callosum) of individuals with OCD.

CONCLUSIONS

Our review emphasizes that the reported white-matter alterations in OCD complement the broader gray-matter abnormalities identified and may well suggest that OCD is associated with large-scale disruption in brain systems or networks, as opposed to being a consequence of disturbances in isolated brain regions.

Cognitive event-related potentials differentiate schizophrenia with obsessive-compulsive disorder (schizo-OCD) from OCD and schizophrenia without OC symptoms

Clinical and neurobiological evidence suggests that concurrent presentation of schizophrenia and obsessive-compulsive (schizo-OCD) symptoms represents a distinct clinical entity. Given that obsessive-compulsive disorder (OCD) and schizophrenia have been modeled as having different neurofunctional profiles, the overlap between them represents a heuristic challenge for cognitive and endophenotype research. Event-related potentials (ERPs) may be used to probe neurophysiological correlates of the cognitive, emotional and behavioral disturbances found in neuropsychiatric entities such as schizo-OCD. Here we measure ERPs during a discriminative response task (DRT) in patients presenting with the DSM-IV criteria for both schizophrenia and OCD. We also performed these measurements in patients with OCD without psychotic features, as well as in patients with schizophrenia without OC symptoms. Schizo-OCD patients showed a distinct ERP pattern, with abnormally increased target activation (akin to OCD patients, but unlike the pattern observed in schizophrenic patients) and reduced P300 amplitudes (akin to schizophrenic patients, but unlike OCD patients). Similar to the control subjects, schizo-OCD patients showed larger amplitudes in the non-target condition than in the target condition. These results suggest that schizo-OCD may not only be a distinct clinical entity from pure OCD and schizophrenia, but it may also be characterized by a distinguishable neurophysiologic pattern. Neurobiological underpinnings deserve further considerations and might drive to a definition of a distinctive endophenotype for schizo-OCD in the de-construction of the schizophrenia endophenotype.

Neuroimaging in obsessive-compulsive disorder

Many neuroimaging studies have investigated the pathophysiology of obsessive-compulsive disorder. These studies have contributed greatly to the development of contemporary neurocircuitry models of obsessive-compulsive disorder, which emphasize the dysfunction of fronto-striato-thalamocortical circuitry in obsessive-compulsive disorder patients. Specifically, dysfunctions of the orbitofrontal cortex, anterior cingulate cortex, thalamus and caudate nucleus have been revealed through resting state or symptom provocation studies. In addition, dysfunctional activations in the dorsolateral prefrontal cortex and parietal regions have been reported. Recently, these findings have led to the suggestion that the pathogenesis of obsessive-compulsive disorder involves an imbalance between dorsal and ventral fronto-striatal circuits. In this review, we provide updated findings on structural and functional neuroimaging studies performed with obsessive-compulsive disorder patients. The limitations of traditional imaging techniques and recent developments to overcome them will also be discussed.

Meta-analysis of brain volume changes in obsessive-compulsive disorder

BACKGROUND

Many neuroimaging studies exploring the volumes of brain structures in obsessive-compulsive disorder (OCD) have been published in the past 2 decades. In this study, we attempted to provide a complete overview of structural alterations in OCD by meta-analyzing magnetic resonance imaging (MRI) data.

METHODS

We conducted a systematic search of MRI studies that reported volumetric measurements in both OCD patients and healthy subjects. Data were entered into the meta-analysis through calculation of the standardized mean differences (SMDs) between the volumes of cerebral regions in OCD patients and the corresponding volumes in control subjects. We then performed a meta-regression to explore the influence of clinical covariates on effect sizes.

RESULTS

Although no volumetric differences were found for the whole brain, intracranial region, gray matter, or prefrontal cortex, OCD patients did show a reduced volume of the left anterior cingulate cortex (ACC) and the left and right orbitofrontal cortex (OFC). No significant volumetric differences within the basal ganglia were observed, although the left and right thalamic volumes were significantly increased in OCD patients. The severity of obsessive or compulsive symptoms correlated significantly with the effect sizes for the left and right thalamus.

CONCLUSIONS

Our findings indicate volumetric differences between OCD patients and control subjects in the cortical and thalamic regions, suggesting that structural alteration of the thalamocortical pathways may contribute to the functional disruptions of frontosubcortical circuits observed in OCD.

Morphometric magnetic resonance imaging in psychiatry

Although advances in the clinical criteria of various axis I psychiatric disorders are continually being made, there is still considerable overlap in the clinical features, and diagnosis is often challenging. As a result, there has been substantial interest in using morphometric magnetic resonance imaging to better characterize these diseases and inform diagnosis. Region of interest and voxel-based morphometry studies are reviewed herein to examine the extent to which these goals are being met across various psychiatric disorders. It is concluded based on the studies reviewed that specific patterns of regional loss, although present in certain axis I disorders, are not, as yet, diagnostically useful. However, advances in outcome and treatment monitoring show considerably more promise for rapid application in psychiatry.

Impact of coexistent schizotypal personality traits on frontal lobe function in obsessive-compulsive disorder

OBJECTIVE

This study was a post-hoc analysis of the results from a neuropsychological battery which was conducted to investigate the frontal lobe difference between obsessive-compulsive disorder (OCD) patients with and without schizotypal personality trait (SPT), especially dorsolateral prefrontal and medial frontal functions.

METHODS

Fifty-five OCD patients were divided into two groups according to their Personality Disorder Questionnaire-4+ scores. Patients with OCD with SPT (n=17) and OCD without SPT (n=38) were compared to 52 schizophrenia patients and 67 healthy subjects. Two neuropsychological tasks, the Wisconsin Card Sorting Test (WCST) and verbal fluency tests which are considered to reflect dorsolateral and medial frontal functions, were selected for an analysis.

RESULTS

OCD with SPT patients and patients with schizophrenia performed significantly worse than controls in both the WCST and verbal fluency tasks, whereas OCD without SPT patients showed no deficits in the same tasks. Moreover, we found no statistically significant difference in either task between patients having OCD with SPT and patients with schizophrenia.

CONCLUSION

This study indicate that OCD with SPT may have distinct patterns of neurocognitive deficit that differ from those of OCD without SPT, especially in terms of frontal lobe function.