The MATRICS consensus cognitive battery for the assessment of cognitive impairment in schizotypal personality disorder

Cognitive deficits are a core impairment across the range of schizophrenia (SZ) spectrum disorders, including schizotypal personality disorder (SPD). The MATRICS Consensus Cognitive Battery (MCCB) was developed to be a robust, specific, and valid cognitive assessment battery to assess cognition in clinical trials for treating cognitive impairments in SZ. Despite the similarity of cognitive impairments shown in SPD and SZ and the clear relevance of uniform assessment across a diagnostic spectrum, the MCCB has yet to be validated in SPD. As such, this is the first study to evaluate the sensitivity of the MCCB for the assessment of cognitive function in individuals with SPD. Participants were 30 individuals with SPD and 54 healthy controls (HC) assessed with the MCCB and supplemental neurocognitive assessments (Trails B, DOT test, Paced Auditory Serial Addition Test (PASAT), AX Continuous Performance Task (AX-CPT), and N-back). Individuals with SPD performed worse than HC participants on all MCCB subtests, as well as on converging supplemental tasks including Trails B, DOT test, PASAT, AX-CPT, and N-back. These results indicate that the MCCB was sensitive to cognitive impairment in SPD compared to controls. SPD participants demonstrate impairments similar to data of SZ participants within the literature, although to a slightly lesser degree of severity. Taken together, these results highlight the generalizability of using the MCCB across SZ spectrum diagnostic groups to assess cognition. Such findings allow for further comparison across disorders, greater understanding of the cognitive characteristics in the spectrum, and use of uniform assessment within cognitive intervention research.

The genetic epidemiology of schizotypal personality disorder

BACKGROUND

The concept of schizotypal personality disorder (SPD) emerged from observations of personality characteristics common in relatives of schizophrenic patients. While often studied in family designs, few studies and none with genetic measures, have examined SPD in epidemiological samples.

METHODS

We studied individuals born in Sweden 1940-2000 with an ICD-10 diagnosis of SPD with no prior schizophrenia (SZ) diagnosis (n = 2292). Demographic features, patterns of comorbidity, and Family Genetic Risk Scores (FGRS) were assessed from multiple Swedish registries. Prediction of progression to SZ was assessed by Cox models.

RESULTS

SPD was rare, with a prevalence of 0.044%, and had high levels of comorbidity with autism spectrum disorder (ASD), OCD, ADHD, and major depression (MD), and increased rates of being single, unemployed and in receipt of welfare. Affected individuals had elevated levels of FGRS for SZ (+0.42), ASD (+0.30), MD (+0.29), and ADHD (+0.20). Compared to cases of schizophrenia, they had significantly lower rates of FGRSSZ, but significantly elevated rates of genetic risk for ASD, MD, and ADHD. Over a mean follow-up of 8.7 years, 14.6% of SPD cases received a first diagnosis of SZ, the risk for which was significantly increased by levels of FGRSSZ, male sex, young age at SPD diagnosis and an in-patient SPD diagnosis and significantly decreased by comorbidity with MD, ASD, and ADHD.

CONCLUSIONS

Our results not only support the designation of SPD as a schizophrenia spectrum disorder but also suggest potentially important etiologic links between SPD and ASD and, to a lesser extent, ADHD, OCD, and MD.

Clinical features of individuals with schizotypal personality disorder with and without suicidal ideation

This study compared demographic and clinical features in a sample of 384 participants: healthy controls (HC; n = 166) and individuals with schizotypal personality disorder (SPD) with (n = 50) and without (n = 168) suicidal ideation (SI) to examine specific risk factors for suicidality in SPD. Compared to the non-SI group, the SI group showed significantly greater severity of depression, aggression, impulsivity, affective lability, schizotypal features, poorer social adjustment, and had fewer social contacts. Individuals in the SI group were also more likely to have a history of a suicide attempt and comorbid borderline personality disorder in comparison to the non-SI group. Logistic regression analysis indicated that severity of depression and the number of social contacts drove the difference between the SI and non-SI groups. Compared with both SPD subgroups, the HC group was significantly less depressed, aggressive, impulsive, affectively labile, had fewer schizotypal features, was better socially adjusted, and had more social contacts. This study indicates that overall, the SI group is a more severely impaired group of individuals with SPD compared to the non-SI group. Better educating medical professionals about the diagnosis and management of SPD and its associations with suicidality is warranted.

A pilot randomized controlled trial comparing a novel compassion and metacognition approach for schizotypal personality disorder with a combination of cognitive therapy and psychopharmacological treatment

BACKGROUND

Schizotypal personality disorder is characterized by a pervasive pattern of maladaptive behavior that has been associated with the liability for schizophrenia. Little is known about effective psychosocial interventions. This pilot non-inferiority randomized controlled trial aimed to compare a novel form of psychotherapy tailored for this disorder and a combination of cognitive therapy and psychopharmacological treatment. The former treatment - namely, Evolutionary Systems Therapy for Schizotypy-integrated evolutionary, metacognitively oriented, and compassion focused approaches.

METHODS

Thirty-three participants were assessed for eligibility, twenty-four randomized on a 1:1 ratio, nineteen included in the final analysis. The treatments lasted 6 months (24 sessions). The primary outcome was change across nine measurements in personality pathology, the secondary outcomes were remission from diagnosis and pre-post changes in general symptomatology and metacognition.

RESULTS

Primary outcome suggested a non-inferiority of the experimental treatment in respect to control condition. Secondary outcomes reported mixed results. There was no significant difference in terms of remission, but experimental treatment showed a larger reduction of general symptomatology (η² = 0.558) and a larger increase in metacognition (η² = 0.734).

CONCLUSIONS

This pilot study reported promising results about the effectiveness of the proposed novel approach. A confirmatory trial on large sample size is needed to provide evidence about relative effectiveness of the two treatment conditions.

TRIAL REGISTRATION

ClinicalTrials.gov; NCT04764708; Registration day 21/02/2021.

Pseudoneurotic symptoms in the schizophrenia spectrum: An empirical study

BACKGROUND

Nonpsychotic symptoms (depression, anxiety, obsessions etc.) are frequent in schizophrenia-spectrum disorders. Twentieth century foundational psychopathological literature claimed that certain nonpsychotic symptoms (here termed pseudoneurotic symptoms) are relatively closely linked with the schizophrenia-spectrum, despite descriptive overlap with symptoms of other diagnoses. In this study, we investigated the association of pseudoneurotic and other nonpsychotic symptoms with the schizophrenia-spectrum as well as a hypothesis about an association of pseudoneurotic symptoms with disorder of basic self.

METHODS

The sample (N = 226) comprised patients with non-affective psychosis (N = 119), schizotypal personality disorder (N = 51) and other mental illness (N = 56), who were examined with a comprehensive assessment of lifetime psychopathology. Informed by the literature, we constructed scales targeting pseudoneurotic symptoms and other, more general, nonpsychotic symptoms.

RESULTS

Pseudoneurotic symptoms aggregated significantly in schizophrenia-spectrum disorders with an Area under the receiver operating characteristic curve of 0.84 (SE 0.03) for classifying patients with schizophrenia-spectrum disorders versus other mental illness. Patients with non-affective psychosis scored slightly, but significantly, higher on the scale targeting general nonpsychotic symptomatology than the other groups. In multiple regression analysis, pseudoneurotic symptoms were predicted by general nonpsychotic symptoms, disorders of basic self, and negative symptoms but not positive symptoms.

CONCLUSION

The study supports that certain neurotic-like symptoms with specific descriptive features (pseudoneurotic symptoms) are associated with schizophrenia-spectrum disorders. It suggests that pseudoneurotic symptoms are linked with temporally stable schizophrenia psychopathology (disorder of basic self and negative symptoms).

Hyperreactivity and Impaired Habituation of Startle Amplitude During Unpleasant Pictures in Borderline but Not Schizotypal Personality Disorder: Quantifying Emotion Dysregulation

BACKGROUND

Borderline personality disorder (BPD) is characterized by greater intensity of reactions to unpleasant emotional cues and a slower-than-normal return of these responses to baseline. Habituation is defined as decreased response to repeated stimulation. Affect-modulated startle (AMS), a translational psychophysiological approach, is mediated by the amygdala and used to study emotion processing in both humans and animals. This is the first study to examine the specificity of habituation anomalies in BPD during passive emotional and neutral picture processing.

METHODS

A total of 90 participants were studied: patients with BPD (n = 35), patients with schizotypal personality disorder (n = 26; included as a psychopathological comparison group), and healthy control subjects (n = 29). Participants received rigorous clinical assessments, and patients were unmedicated. AMS was examined during a series of intermixed unpleasant, neutral, and pleasant pictures.

RESULTS

Compared with the other groups, patients with BPD showed greater overall AMS during unpleasant pictures and prolonged habituation of startle amplitude during unpleasant pictures from early to later trials. The groups did not differ in AMS during neutral or pleasant pictures or self-reported picture valence. Among the patients with BPD, prolonged habituation to unpleasant pictures was associated with greater symptom severity and suicidal/self-harming behavior.

CONCLUSIONS

These findings 1) indicate that abnormal processing of and habituation to unpleasant pictures is observed in BPD but not schizotypal personality disorder, suggesting that these deficits are not simply characteristics of personality disorders in general; 2) are consistent with studies showing deficient amygdala habituation to unpleasant pictures in BPD; and 3) have significant implications for clinical assessment and treatment of BPD, e.g., alternative therapies for BPD such as gradual exposure to unpleasant emotional stimuli or amygdala neurofeedback may aid habituation deficits.

Frontotemporal thalamic connectivity in schizophrenia and schizotypal personality disorder

Schizotypal personality disorder (SPD) resembles schizophrenia, but with attenuated brain abnormalities and the absence of psychosis. The thalamus is integral for processing and transmitting information across cortical regions and widely implicated in the neurobiology of schizophrenia. Comparing thalamic connectivity in SPD and schizophrenia could reveal an intermediate schizophrenia-spectrum phenotype to elucidate neurobiological risk and protective factors in psychosis. We used rsfMRI to investigate functional connectivity between the mediodorsal nucleus (MDN) and pulvinar, and their connectivity with frontal and temporal cortical regions, respectively in 43 healthy controls (HCs), and individuals in the schizophrenia-spectrum including 45 psychotropic drug-free individuals with SPD, and 20 individuals with schizophrenia-related disorders [(schizophrenia (n = 10), schizoaffective disorder (n = 8), schizophreniform disorder (n = 1) and psychosis NOS (n = 1)]. Individuals with SPD had greater functional connectivity between the MDN and pulvinar compared to individuals with schizophrenia. Thalamo-frontal (i.e., between the MDN and rostral middle frontal cortex) connectivity was comparable in SPD and HCs; in SPD greater connectivity was associated with less symptom severity. Individuals with schizophrenia had less thalamo-frontal connectivity and thalamo-temporal (i.e., pulvinar to the transverse temporal cortex) connectivity compared with HCs. Thalamo-frontal functional connectivity may be comparable in SPD and HCs, but abnormal in schizophrenia, and that this may be protective against psychosis in SPD.

The impact of schizotypy on quality of life among adults with autism spectrum disorder

BACKGROUND

Autism spectrum disorder (ASD) and schizotypal personality disorder can be difficult to distinguish. Deficits in social relationships and social interaction, present in both conditions, are known to impair quality of life. The aim of the present study was to investigate if schizotypal symptoms affect quality of life among adults diagnosed with autism spectrum disorder and to study the association between schizotypy and autistic traits among them.

METHODS

Participants diagnosed with autism spectrum disorder (n = 110) completed questionnaires exploring schizotypy (Schizotypal Personality Questionnaire - Brief Revised (SPQ-BR)), autistic traits (The Ritvo Autism, Asperger Diagnostic Scale-Revised Screen 14 items), anxiety and depression (The Hospital Anxiety and Depression scale) and quality of life (Brunnsviken Brief Quality of Life Scale and the European quality of life index version 5D).

RESULTS

Schizotypy was found to be associated with anxiety, depressive and autistic symptoms, and poor quality of life. Although schizotypy was a predictor for impaired quality of life, this relationship was mediated by symptoms of anxiety and depression, plausibly inherent to autism. Autistic traits were positively associated with all higher order constructs of the SPQ-BR, i.e. positive and negative schizotypy, disorganization and social anxiety, as well as with poor quality of life.

CONCLUSIONS

There is considerable overlap between schizotypy and autism that needs to be considered in research. Prominent schizotypal traits in people with ASD may constitute an endophenotype coinciding with a particularly poor quality of life.

TRIAL REGISTRATION

ClinicalTrials.gov identifier:  NCT03570372 : Internet-based Treatment for Adults with Autism Spectrum Disorder (MILAS).

When No Diagnosis "Fits": Diagnostically Homeless and Emotionally Dysregulated Children and Adolescents

Clinical experience supports the concept of children with severe disturbances in most areas of functioning, with psychiatric symptom onset before age 6. They are emotionally dysregulated and extremely anxious and have developmental difficulties. Given the absence of an appropriate diagnostic category, it is best to consider clinical phenomenology and then categorize each dysfunction domain (mood/anxiety problems, possible psychosis, language impairment/thought disorder, and relationship/social problems).

Exploring Identity Disturbance and Psychotic Spectrum Symptoms as Predictors of Borderline and Schizotypal Personality Disorders

INTRODUCTION

Borderline personality disorder (BPD) and schizotypal personality disorder (SPD) were introduced in DSM-III and retained in DSM-5 Section II. They often co-occur and some aspects of the clinical differentiation between the 2 diagnoses remain unclear (e.g., psychotic-like features and identity disturbance).

METHODS

The present study explored if self-reported identity disturbance and psychosis proneness could discriminate between the BPD and SPD DSM-5 diagnoses. All patients were interviewed with the Schedules for Clinical Assessment in Neuropsychiatry and the Structured Clinical Interview for DSM-5 Personality Disorders, and administered the Inventory of Personality Organization, Self-Concept and Identity Measure, Schizotypal Personality Questionnaire, Perceptual Aberration Scale, and the Magical Ideation Scale.

RESULTS

A total of 105 patients were initially assessed, 26 were excluded, and the final sample (N = 79) was composed of 34 BPD patients, 25 SPD patients, and 20 patients with co-occurring SPD and BPD. The BPD group (n = 34) was first compared with the pure SPD group (n = 25), and secondly with the total group of patients diagnosed with SPD (n = 25 + 20). Logistic regression analyses indicated that primitive defenses and disorganization best differentiated the BPD and the pure SPD group, while primitive defenses and interpersonal factor along with perceptual aberrations best differentiated the BPD and the total SPD group.

CONCLUSION

Identity disturbance did not predict the diagnostic groups, but BPD patients were characterized by primitive defenses, which are closely related to identity disturbance. Pure SPD was characterized by oddness/eccentricity, while the lack of specificity for cognitive-perceptual symptoms suggests that the positive symptoms do not differentiate BPD from SPD.

Schizotypy and psychopathic tendencies interactively improve misattribution of affect in boys with conduct problems

Psychopathic tendencies are associated with difficulties in affective theory of mind (ToM), that is, in recognizing others affective mental states. In clinical and non-clinical adult samples, it has been shown that where psychopathic tendencies co-occur with schizophrenia spectrum disorders, the impairing effects of psychopathic tendencies on ToM are attenuated. These effects are yet to be examined in adolescents. We examined if the impairing effect of psychopathic tendencies on affective ToM was attenuated with increasing severity of schizotypal personality disorder (PD) in a sample of 80 incarcerated adolescent boys. We showed that the impairing effect of psychopathic tendencies on the recognition of neutral mental states, but not positive or negative mental states, was evident when the relative severity of schizotypal PD was low. However, with higher scores on both measures, we observed better performance in judging neutral mental states. The preservation of affective ToM in adolescents who show elevations in psychopathic tendencies and schizotypal PD may enable them to manipulate and extort their victims for personal gain. Our results emphasize the need to consider comorbidity in clinical case formulation when working with adolescents with conduct problems and psychopathic tendencies. More broadly, our results also suggest that the pattern of social cognitive abilities associated with co-occurring psychopathology does not always conform to an often-theorized double-dose of deficit hypothesis.

Amphetamine-induced striatal dopamine release in schizotypal personality disorder

RATIONALE

Previous research has suggested that schizotypal personality disorder (SPD), a condition that shares clinical and cognitive features with schizophrenia, may be associated with elevated striatal dopamine functioning; however, there are no published studies of dopamine release within subregions of the striatum in SPD.

OBJECTIVES

To characterize dopamine release capacity in striatal subregions and its relation to clinical and cognitive features in SPD.

METHODS

We used positron emission tomography with [¹¹C]raclopride and an amphetamine challenge to measure dopamine D2-receptor availability (binding potential, BP_ND), and its percent change post-amphetamine (∆BP_ND) to index amphetamine-induced dopamine release, in subregions of the striatum in 16 SPD and 16 healthy control participants. SPD participants were evaluated with measures of schizotypal symptom severity and working memory.

RESULTS

There were no significant group differences in BP_ND or ∆BP_ND in any striatal subregion or whole striatum. Among SPD participants, cognitive-perceptual symptoms were associated at trend level with ∆BP_ND in the ventral striatum, and disorganized symptoms were significantly negatively related to ∆BP_ND in several striatal subregions.

CONCLUSIONS

In contrast to previous findings, SPD was not associated with elevated striatal dopamine release. However, in SPD, there was a moderate positive association between ventral striatal dopamine release and severity of cognitive-perceptual symptoms, and negative associations between striatal dopamine release and severity of disorganized symptoms. Future larger scale investigations that allow for the separate examination of subgroups of participants based on clinical presentation will be valuable in further elucidating striatal DA functioning in SPD.

Schizophrenia-spectrum psychopathology in obsessive-compulsive disorder: an empirical study

The differential diagnosis of obsessive-compulsive disorder (OCD) and schizophrenia-spectrum disorders can be difficult. In the current diagnostic criteria, basic concepts such as obsession and delusion overlap. This study examined lifetime schizophrenia-spectrum psychopathology, including subtle schizotypal symptomatology and subjective anomalies such as self-disorders, in a sample diagnosed with OCD in a specialized setting. The study also examined the differential diagnostic potential of the classic psychopathological notions of true obsession ('with resistance') and pseudo-obsession. The study involved 42 outpatients diagnosed with OCD at two clinics specialized in the treatment of OCD. The patients underwent semi-structured, narrative interviews assessing a comprehensive battery of psychopathological instruments. The final lifetime research-diagnosis was based on a consensus between a senior clinical psychiatrist and an experienced research clinician. The study found that 29% of the patients fulfilled criteria of schizophrenia or another non-affective psychosis as main, lifetime DSM-5 research-diagnosis. Another 33% received a research-diagnosis of schizotypal personality disorder, 10% a research-diagnosis of major depression and 29% a main research-diagnosis of OCD. Self-disorders aggregated in the schizophrenia-spectrum groups. True obsessions had a specificity of 93% and a sensitivity of 58% for a main diagnosis of OCD. In conclusion, a high proportion of clinically diagnosed OCD patients fulfilled diagnostic criteria of a schizophrenia-spectrum disorder. The conspicuous obsessive-compulsive symptomatology may have resulted in a disregard of psychotic symptoms and other psychopathology. Furthermore, the differentiation of obsessions from related psychopathological phenomena is insufficient and a conceptual and empirical effort in this domain is required in the future.

Short communication: Diffusion tensor anisotropy in the cingulate in borderline and schizotypal personality disorder

Despite considerable phenomentological differences between borderline personality disorder (BPD) and schizotypal personality disorder (SPD), research increasingly provides evidence that some BPD symptoms overlap with SPD symptoms (e.g., disturbed cognitions). We examined the cingulate, a brain region implicated in the pathophysiology of both disorders, to determine similarities/differences between the groups, and similarities/differences from healthy controls (HC's). 3T structural and diffusion tensor magnetic resonance imaging scans were acquired in BPD (n = 27), SPD (n = 32), HC's (n = 34). Results revealed that BPD patients exhibited significantly lower FA in posterior cingulate white matter compared to HC's (p = 0.04), but SPD patients did not.

Reprint of: F-18Fluorodeoxyglucose positron emission tomography studies of the schizophrenia spectrum: The legacy of Monte S. Buchsbaum, M.D

This is a selective review of the work of Buchsbaum and colleagues. It revisits and pays tribute to four decades of publications employing positron emission tomography (PET) with ^F-18fluorodeoxyglucose (FDG) to examine the neurobiology of schizophrenia-spectrum disorders (including schizotypal personality disorder (SPD) and schizophrenia). Beginning with a landmark FDG-PET study in 1982 reporting hypofrontality in unmedicated schizophrenia patients, Buchsbaum and colleagues published high-impact work on regional glucose metabolic rate (GMR) abnormalities in the spectrum. Several key discoveries were made, including the delineation of schizophrenia-spectrum abnormalities in frontal and temporal lobe, cingulate, thalamus, and striatal regions using three-dimensional mapping with coregistered MRI and PET. These findings indicated that SPD patients have less marked frontal lobe and striatal dysfunction compared with schizophrenia patients, possibly mitigating frank psychosis. Additionally, these investigations were among the first to conduct early seed-based functional connectivity analyses with FDG-PET, showing aberrant cortical-subcortical circuitry and, in particular, revealing a thalamocortical circuitry abnormality in schizophrenia. Finally, pioneering work employing the first double-blind randomized antipsychotic (haloperidol) vs. placebo FDG-PET study design in schizophrenia indicated that GMR in the striatum, more than in any other region, was related to clinical response.

Schizotypal personality disorder in individuals with the Attenuated Psychosis Syndrome: Frequent co-occurrence without an increased risk for conversion to threshold psychosis

The Attenuated Psychosis Syndrome (APS), proposed as a condition warranting further study in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), is a controversial diagnostic construct originally developed to identify individuals at clinical high-risk for psychosis. The relationship of APS and Schizotypal Personality Disorder (SPD) remains unclear with respect to their potential co-occurrence and the effect of SPD on risk for conversion to threshold psychosis. We examined the prevalence and effect on conversion of SPD in a cohort of 218 individuals whose symptoms met APS criteria. Results indicated that SPD was highly prevalent (68%), and that SPD did not influence risk for conversion. Rather, total positive symptom burden measured by the Structured Interview for Psychosis-Risk Syndromes (SIPS; OR 1.12, p = 0.02) emerged as the strongest predictor of conversion. These data suggest that when encountering a patient whose presentation meets SPD criteria, the clinician should assess whether APS criteria are also met and, for 1-2 years, carefully monitor positive symptoms for possible conversion to threshold psychosis.

The Schizotypal Personality Questionnaire - Child (SPQ-C): Psychometric properties and relations to behavioral problems with multi-informant ratings

The Schizotypal Personality Questionnaire (SPQ) is one of the most widely used screening tools for schizotypy in adults. The Schizotypal Personality Questionnaire-Child version (SPQ-C) was recently developed to assess schizotypy in children and has a similar three-factor structure to the adult SPQ (i.e., Cognitive-Perceptual, Interpersonal-Affective, and Disorganization). However, few studies to date have reported on the psychometric properties and the usefulness of the SPQ-C in Eastern populations, including Mainland China. This study presents the first psychometric assessment of the Chinese SPQ-C in Mainland China. Exploratory factor analysis and confirmatory factor analysis were used to assess the factor structure of the SPQ-C in 1668 children (M = 12.10, SD = 0.60 years) from the China Jintan Child Cohort Study. Our findings document a three-factor structure and partial measurement invariance across residential location and gender, replicating the psychometric properties of the SPQ-C in English. The Chinese SPQ-C further correlates with standard behavioral problems (i.e., Child Behavior Checklist, Youth Self-Report and Teacher Report Form), demonstrating construct validity and utility as a child psychopathology assessment tool. Our findings provide the first robust psychometric evidence for a three-factor structure of the Chinese SPQ-C in a large Mainland Chinese sample, and suggest that the SPQ-C is suitable as a screening tool for schizotypy in community children who may be at risk for behavioral problems and later psychosis.

F-18Fluorodeoxyglucose positron emission tomography studies of the schizophrenia spectrum: The legacy of Monte S. Buchsbaum, M.D

This is a selective review of the work of Buchsbaum and colleagues. It revisits and pays tribute to four decades of publications employing positron emission tomography (PET) with ^F-18fluorodeoxyglucose (FDG) to examine the neurobiology of schizophrenia-spectrum disorders (including schizotypal personality disorder (SPD) and schizophrenia). Beginning with a landmark FDG-PET study in 1982 reporting hypofrontality in unmedicated schizophrenia patients, Buchsbaum and colleagues published high-impact work on regional glucose metabolic rate (GMR) abnormalities in the spectrum. Several key discoveries were made, including the delineation of schizophrenia-spectrum abnormalities in frontal and temporal lobe, cingulate, thalamus, and striatal regions using three-dimensional mapping with coregistered MRI and PET. These findings indicated that SPD patients have less marked frontal lobe and striatal dysfunction compared with schizophrenia patients, possibly mitigating frank psychosis. Additionally, these investigations were among the first to conduct early seed-based functional connectivity analyses with FDG-PET, showing aberrant cortical-subcortical circuitry and, in particular, revealing a thalamocortical circuitry abnormality in schizophrenia. Finally, pioneering work employing the first double-blind randomized antipsychotic (haloperidol) vs. placebo FDG-PET study design in schizophrenia indicated that GMR in the striatum, more than in any other region, was related to clinical response.

Frontal and temporal cortical volume, white matter tract integrity, and hemispheric asymmetry in schizotypal personality disorder

Abnormalities in temporal and frontal cortical volume, white matter tract integrity, and hemispheric asymmetry have been implicated in schizophrenia-spectrum disorders. Schizotypal personality disorder can provide insight into vulnerability and protective factors in these disorders without the confounds associated with chronic psychosis. However, multimodal imaging and asymmetry studies in SPD are sparse. Thirty-seven individuals with SPD and 29 healthy controls (HC) received clinical interviews and 3T magnetic resonance T1-weighted and diffusion tensor imaging scans. Mixed ANOVAs were performed on gray matter volumes of the lateral temporal regions involved in auditory and language processing and dorsolateral prefrontal cortex involved in executive functioning, as well as fractional anisotropy (FA) of prominent white matter tracts that connect frontal and temporal lobes. In the temporal lobe regions, there were no group differences in volume, but SPD had reduced right>left middle temporal gyrus volume asymmetry compared to HC and lacked the right>left asymmetry in the inferior temporal gyrus volume seen in HC. In the frontal regions, there were no differences between groups on volume or asymmetry. In the white matter tracts, SPD had reduced FA in the left sagittal stratum and superior longitudinal fasciculus, and increased right>left asymmetry in sagittal stratum FA compared to HC. In the SPD group, lower left superior longitudinal fasciculus FA was associated with greater severity of disorganization symptoms. Findings suggest that abnormities in structure and asymmetry of temporal regions and frontotemporal white matter tract integrity are implicated in SPD pathology.

Developmental Aspects of Schizotypy and Suspiciousness: a Review

Purpose of the Review

This review identifies the early developmental processes that contribute to schizotypy and suspiciousness in adolescence and adulthood. It includes the most recent literature on these phenomena in childhood.

Recent Findings

The early developmental processes that affect schizotypy and paranoia in later life are complex. In contrast to existing studies of psychiatric patients and clinical/nonclinical adult populations, the study of schizotypy and suspiciousness in young children and adolescents is possible due to new child-appropriate dimensional assessments. New assessments and the advancement of technology (e.g., virtual reality in mental health) as well as statistical modeling (e.g., mediation and latent-class analyses) in large data have helped identified the developmental aspects (e.g., psychosocial, neurocognitive and brain factors, nutrition, and childhood correlates) that predict schizotypy and suspiciousness in later life.

Summary

Prospective longitudinal designs in community youths can enhance our understanding of the etiology of schizophrenia-spectrum disorders and, in the future, the development of preventive interventions by extending adult theories and interventions to younger populations.

Enhanced mental imagery and intact perceptual organization in schizotypal personality disorder

According to a widely held view, psychotic disorders such as schizophrenia are characterized by a vague boundary between the perception of the external world and the inner imagery of persons, objects, and events. In this study, we addressed the perception-imagery debate in schizotypal personality disorder (SPD). Thirty individuals with SPD and 30 matched healthy subjects completed a lateral masking task. Participants were asked to detect a low-contrast Gabor patch flanked by two collinear Gabor masks. In the perceptual task, the masks were physically present, whereas in the imagery task, participants only imagined the masks. By applying a binocular rivalry paradigm, we also measured the imagery priming effect. Results revealed that, in the perceptual task, collinear masks similarly decreased contrast threshold in SPD and controls. In the imagery task, contrast threshold reduction (facilitation by the imagined masks) was more pronounced in SPD relative to the controls. In the binocular rivalry paradigm, individuals with SPD showed higher imagery priming effects as compared to healthy controls. Enhanced imagery was not related to schizotypal traits. These results indicate intact early visual perception and heightened imagery in SPD, which may be a trait marker of unusual experiences without psychotic disorganization.

Anomalous Self-Experiences: Markers of Schizophrenia Vulnerability or Symptoms of Depersonalization Disorder? A Phenomenological Investigation of Two Cases

BACKGROUND

Basic self-disturbance (BSD) is proposed to constitute the clinical core of schizophrenia spectrum disorders, including prodromal states and schizotypy. Anomalous self-experiences (ASEs) are suggested as phenotypic variants of BSD, representing markers of schizophrenia vulnerability. However, ASEs are not restricted to the schizophrenia spectrum, but may also occur in non-psychotic states like depersonalization disorder (DPD). It is unclear to what extent the prevalence and nature of ASEs are differing between the two conditions. The main aim of this paper is to assess and compare ASEs in both conditions, based on literature and two illustrating cases. This might expand the understanding of these phenomena, and strengthen the basis for clinical differentiation.

METHODS

One patient with schizotypal personality disorder (SPD) and one with DPD were selected from an ongoing clinical high-risk (CHR) for psychosis study. ASEs were assessed with the Examination of Anomalous Self-Experience (EASE) and analyzed according to the two central dimensions of BSD: diminished self-affection and hyperreflexivity, as well as according to prototypical aspects of depersonalization. The cases were also analyzed and compared with respect to chronology, other symptomatology, and psychopathological pathways.

RESULTS

Both cases revealed ASEs reflecting the central dimensions of BSD as well as prototypical aspects of depersonalization. Only the SPD case however, linked ASEs to psychotic-like ideas of external influence and control. The symptoms had an insidious early childhood onset with no obvious triggers in the SPD case, and an abrupt adolescence onset triggered by second-time cannabis use and panic anxiety in the DPD case.

CONCLUSIONS

The similarities and differences in ASEs, symptomatology and developmental pathways of the two cases might be accounted for by an updated model of self-disorders. The model proposes that schizophrenia manifests as a result of a combination of early "primary"-onset ASEs, reflecting dis-turbances in early neurodevelopment, and later occurring, "secondary" ASEs of a more defensive-protective character. In line with this, the DPD case may be characterized only by secondary ASEs and thus better protected against psychotic decompensation than the SPD case, tentatively affected by a combination of primary and secondary ASEs.

Reduced functional connectivity between bilateral precuneus and contralateral parahippocampus in schizotypal personality disorder

BACKGROUND

Schizotypal personality disorder (SPD) is linked to schizophrenia in terms of shared genetics, biological markers and phenomenological characteristics. In the current study, we aimed to determine whether the previously reported altered functional connectivity (FC) with precuneus in patients with schizophrenia could be extended to individuals with SPD.

METHODS

Twenty subjects with SPD and 19 healthy controls were recruited from 4461 freshmen at a university in Shanghai and received a resting-state scan of MRI. All participants were evaluated by the Chinese version of Schizotypal Personality Questionnaire (SPQ) and the Chinese version of Symptom Checklist (SCL-90). The imaging data were analysed using the seed-based functional connectivity method.

RESULTS

Compared with the controls, SPD subjects exhibited reduced FC between bilateral precuneus and contralateral parahippocampus. In SPD group, SPQ total score was negatively correlated with FC between right precuneus and left parahippocampus (r = -0.603, p = 0.006); there was a negative trend between SPQ subscale score of suspiciousness and FC between left precuneus and right parahippocampus (r = -0.553, p = 0.014); and a positive trend was found between SPQ subscale score of odd or eccentric behaviour and FC between left precuneus and right superior temporal gyrus (r = 0.543, p = 0.016). As for the SCL-90 score, a similar negative trend was found between SCL-90 subscale score of suspiciousness and FC between right precuneus and left parahippocampus (r = -0.535, p = 0.018) in SPD group.

CONCLUSIONS

Our findings suggest that the decreased functional connectivity between precuneus and contralateral parahippocampus might play a key role in the pathophysiology of schizophrenia spectrum disorder.

Structural alterations of the pyramidal pathway in schizoid and schizotypal cluster A personality disorders

AIM

Schizoid (ScPD) and Schizotypal (SPD) personality disorders are rare and severe disorders. They are associated with high liability to schizophrenia and present an attenuated form of its negative symptoms, which are considered a putative endophenotype for schizophrenia. The trans-diagnostic study of negative symptoms in non-psychotic populations such as ScPD/SPD might provide useful markers of a negative-symptom domain; however, little is known about their neurobiological substrates. The aim of the study was to investigate differences in gray and white matter volumes in subjects with ScPD/SPD compared to a group of healthy controls.

METHODS

Structural magnetic resonance images were obtained from 20 never-psychotic subjects with ScPD/SPD and 28 healthy controls. Resulting values from clusters of differences were correlated in patients with relevant clinical variables (O-LIFE scale).

RESULTS

ScPD/SPD presented greater bilateral white matter volume compared to healthy controls in the superior part of the corona radiata, close to motor/premotor regions, which correlated with the O-LIFE subtest of cognitive disorganization. No differences were found in regional gray matter or global gray/white matter volumes.

CONCLUSION

Greater volumes in motor pathways might relate to cognitive symptoms and motor alterations commonly present in schizophrenia-related disorders. Given the established link between motor signs and psychosis, structural alterations in motor pathways are suggested as a putative biomarker of a negative-symptom domain in psychosis subject to further testing.

Neurological soft signs in Chinese adolescents with schizophrenia and schizotypal personality traits

OBJECTIVE

Neurological soft signs (NSSs) may reflect neurodevelopmental anomalies in association with the spectrum of schizophrenia disorders. We examined NSSs in Chinese adolescents with schizophrenia and schizotypal personality traits.

METHODS

Eighty-seven schizophrenic adolescents (SCH group), 85 adolescents with only schizotypal personality traits (SPT group), and 88 healthy controls (HC group) were enrolled. The NSS subscales of the Cambridge Neurological Inventory (CNI) were administered to all 260 participants.

RESULTS

The NSS prevalence rates were higher in the SCH group than in the other two groups for both hands in the fist-edge-palm, Oseretsky, and graphesthesia tests. Relative to HCs, the SCH group also showed higher NSS prevalence rates in the right finger agnosia and right mirror movement of finger opposition tests. SCH>SPT>HC trends were observed for all NSS subscale scores and for the left, right, and total NSS scores.

CONCLUSIONS

To our knowledge, the present study is the first to examine NSSs in adolescents with schizophrenia and adolescents with schizotypal personality traits. These results provide preliminary findings suggesting that schizophrenia spectrum disorders may be characterized by developmental abnormalities in the central nervous system, and support the notion that NSSs may be schizophrenia spectrum disorder biomarkers.

Co-morbidity of personality disorder in schizophrenia among psychiatric outpatients in China: data from epidemiologic survey in a clinical population

BACKGROUND

The reported rates of personality disorder (PD) in subjects with schizophrenia (SZ) are quite varied across different countries, and less is known about the heterogeneity of PD among subjects with SZ. We examined the co-morbidity of PD among patients who are in the stable phase of SZ.

METHOD

850 subjects were randomly sampled from patients diagnosed with SZ in psychiatric and psycho-counseling clinics at Shanghai Mental Health Center. Co-morbidity of PDs was assessed through preliminary screening and patients were administered several modules of the SCID-II. Evidence of heterogeneity was evaluated by comparing patients diagnosed with SZ with those who presented with either affective disorder or neurosis (ADN).

RESULTS

204 outpatients (24.0 %) in the stable phase of SZ met criteria for at least one type of DSM-IV PD. There was a higher prevalence of Cluster-A (odd and eccentric PD) and C (anxious and panic PD) PDs in SZ (around 12.0 %). The most prevalent PD was the paranoid subtype (7.65 %). Subjects with SZ were significantly more likely to have schizotypal PD (4.4 % vs. 2.1 %, p = 0.003) and paranoid PD (7.6 % vs. 5.4 %, p = 0.034), but much less likely to have borderline, obsessive-compulsive, depressive, narcissistic and histrionic PD.

CONCLUSIONS

These findings suggest that DSM-IV PD is common in patients with SZ than in the general population. Patterns of co-morbidity with PDs in SZ are different from ADN.

Neurophysiological evidence of impaired self-monitoring in schizotypal personality disorder and its reversal by dopaminergic antagonism

Background

Schizotypal personality disorder (SPD) is a schizophrenia-spectrum disorder characterized by odd or bizarre behavior, strange speech, magical thinking, unusual perceptual experiences, and social anhedonia. Schizophrenia proper has been associated with anomalies in dopaminergic neurotransmission and deficits in neurophysiological markers of self-monitoring, such as low amplitude in cognitive event-related brain potentials (ERPs) like the error-related negativity (ERN), and the error positivity (Pe). These components occur after performance errors, rely on adequate fronto-striatal function, and are sensitive to dopaminergic modulation. Here we postulated that analogous to observations in schizophrenia, SPD individuals would show deficits in self-monitoring, as measured by the ERN and the Pe. We also assessed the capacity of dopaminergic antagonists to reverse these postulated deficits.

Methods

We recorded the electroencephalogram (EEG) from 9 SPD individuals and 12 healthy controls in two separate experimental sessions while they performed the Eriksen Flanker Task, a classical task recruiting behavioral monitoring. Participants received a placebo or 1 mg risperidone according to a double-blind randomized design.

Results

After placebo, SPD individuals showed slower reaction times to hits, longer correction times following errors and reduced ERN and Pe amplitudes. While risperidone impaired performance and decreased ERN and Pe in the control group, it led to behavioral improvements and ERN amplitude increases in the SPD individuals.

Conclusions

These results indicate that SPD individuals show deficits in self-monitoring analogous to those in schizophrenia. These deficits can be evidenced by neurophysiological measures, suggest a dopaminergic imbalance, and can be reverted by dopaminergic antagonists.

Screening schizotypal personality disorder for detection of clinical high risk of psychosis in Chinese mental health services

Schizotypal personality disorder (SPD) is viewed as a marker of prodromal psychosis. However, information regarding genetic risk (e.g. SPD) is often overlooked in the identification process. This study assessed whether SPD screening questionnaire help the prodromal psychosis (also widely applied "clinical high risk" (CHR) for clinical sample) detection in Chinese mental health service. This work also examined whether SPD had higher frequency in genetic risk population and CHR subjects. Two wave studies concerning the SPD identification was used for analysis. Wave 1 survey: 3075 subjects were assessed by Personality Diagnostic Questionnaire for SPD (PDQ-SPD) and Structured Clinical Interview for DSM-IV Axis II (SCID-II). Wave 2 survey: 2113 subjects screened with the prodromal questionnaire -brief version (PQ-B), PDQ-SPD, and interviewed by Structured Interview for Prodromal Symptoms (SIPS). Subjects with family history of mental disorders or with psychosis reported significantly higher scores in SPD. Receiver operating characteristic curves suggested that PDQ-SPD had moderate sensitivity and specificity for identifying CHR subjects. There was significant higher on SPD features in subjects with early stage (Course less than 1 year) of psychosis. Identifying SPD may be useful in early detection of psychosis especially in detecting the genetic risk syndromes and can be integrated with existing prodromal screen tools to improve its efficiency.

The correlates of obsessive-compulsive, schizotypal, and borderline personality disorders in obsessive-compulsive disorder

We assessed correlates of obsessive-compulsive (OCPD), schizotypal (SPD) and borderline (BPD) personality disorders in 110 obsessive-compulsive disorder (OCD) patients. We found OCD patients with OCPD (20.9%) to exhibit higher rates of hoarding and bipolar disorders, increased severity of hoarding and symmetry, lower prevalence of unacceptable thoughts involving sex and religion and less non-planning impulsivity. Conversely, OCD patients with SPD (13.6%) displayed more frequently bipolar disorder, increased severity of depression and OCD neutralization, greater prevalence of "low-order" behaviors (i.e., touching), lower low-planning impulsivity and greater "behavioral" compulsivity. Finally, in exploratory analyses, OCD patients with BPD (21.8%) exhibited lower education, higher rates of several comorbid psychiatric disorders, greater frequency of compulsions involving interpersonal domains (e.g. reassurance seeking), increased severity of depression, anxiety and OCD dimensions other than symmetry and hoarding, more motor and non-planning impulsivity, and greater "cognitive" compulsivity. These findings highlight the importance of assessing personality disorders in OCD samples.

Sensory gating disturbances in the spectrum: similarities and differences in schizotypal personality disorder and schizophrenia

BACKGROUND

DSM-5 places schizophrenia on a continuum from severe, chronic schizophrenia to the attenuated schizophrenia-like traits of schizotypal personality disorder (SPD), the prototypic schizophrenia-related personality disorder. SPD shares common genetic and neurobiological substrates with schizophrenia, including information processing abnormalities, although they are less marked. This is the first study to directly compare the P50 evoked electroencephalographic response-a measure of sensory gating and a neurophysiological endophenotype-between schizophrenia-spectrum groups. Two hypotheses were tested: (1) Compared with healthy controls (HCs), schizophrenia patients show reduced P50 suppression and SPD patients resemble schizophrenia but exhibit less marked deficits; and (2) Deficient P50 suppression in SPD is associated with greater clinical symptom severity.

METHODS

P50 was assessed in 32 schizophrenia-spectrum disorder patients (12 SPD, 20 schizophrenia patients) and 25 demographically-matched HCs. The standard conditioning (C)-testing (T) paradigm was used and P50 suppression was quantified using the T-C difference and the T/C ratio.

RESULTS

All P50 measures showed a linear, stepwise pattern with the SPD group intermediate between the HC and schizophrenia groups. Compared with HCs, both patient groups had lower conditioning and T-C difference values. Among the SPD group, greater clinical symptom severity was associated with greater conditioning-response amplitude deficits.

CONCLUSION

These findings: (1) are novel in showing that P50 deficits in SPD resemble those observed in schizophrenia, albeit less marked; (2) support the concept that the phenomenological link between SPD and schizophrenia lies in shared neurocognitive/neurophysiological pathologies; and (3) provide evidence that P50 is a neurophysiological endophenotype for schizophrenia-spectrum disorders.

Altered default mode network functional connectivity in schizotypal personality disorder

The default mode network (DMN) has been identified to play a critical role in many mental disorders, but such abnormalities have not yet been determined in patients with schizotypal personality disorder (SPD). The purpose of this study was to analyze the alteration of the DMN functional connectivity in subjects with (SPD) and compared it to healthy control subjects. Eighteen DSM-IV diagnosed SPD subjects (all male, average age: 19.7±0.9) from a pool of 3000 first year college students, and eighteen age and gender matched healthy control subjects were recruited (all male, average age: 20.3±0.9). Independent component analysis (ICA) was used to analyze the DMN functional connectivity alteration. Compared to the healthy control group, SPD subjects had significantly decreased functional connectivity in the frontal areas, including the superior and medial frontal gyrus, and greater functional connectivity in the bilateral superior temporal gyrus and sub-lobar regions, including the bilateral putamen and caudate. Compared to subjects with SPD, the healthy control group showed decreased functional connectivity in the bilateral posterior cingulate gyrus, but showed greater functional connectivity in the right transverse temporal gyrus and left middle temporal gyrus. The healthy control group also showed greater activation in the cerebellum compared to the SPD group. These findings suggest that DMN functional connectivity, particularly that involving cognitive or emotional regulation, is altered in SPD subjects, and thus may be helpful in studying schizophrenia.

DSM-IV schizotypal personality disorder: a taxometric analysis among individuals with and without substance use disorders in the general population

This study examined the underlying structure of DSM-IV schizotypal personality disorder (SPD) among individuals with and without a substance use disorder. Using a nationally representative sample of U.S. adults, taxometric analyses were conducted on SPD in the total sample and among individuals with and without a substance use disorder. The structure of SPD in the total sample and among individuals without substance use disorders was dimensional (comparison curve fit indices (CCFI): 0.440, 0.365) whereas a taxonic structure was demonstrated among individuals with a substance use disorder (CCFI: 0.679). Taxonicity underlying schizotypy and SPD in prior taxometric research may have been the result of sampling high risk subsamples of the population. Taxometric research on SPD and other personality psychopathology among high risk subgroups of the population can help elucidate the complex etiology of SPD and the role played by comorbid substance use disorders in the expressivity of these disorders.

Vocational functioning in schizotypal and paranoid personality disorders

Impaired vocational functioning is a hallmark of schizophrenia, but limited research has evaluated the relationships between work and schizophrenia-spectrum personality disorders, including schizotypal (SPD) and paranoid personality disorder (PPD). This study compared employment history and job characteristics of 174 individuals drawn from the community or clinic, based on four personality disorder groups: SPD Only, PPD Only, SPD+PPD, and No SPD or PPD. Symptoms and cognitive functioning were also assessed. Both PPD and/or SPD were associated with lower rates of current employment, and a history of having worked at less cognitively complex jobs than people without these disorders. Participants with PPD were less likely to have a history of competitive work for one year, whereas those with SPD tended to have worked at jobs involving lower levels of social contact, compared with those without these disorders. When the effects of symptoms and cognitive functioning were statistically controlled, PPD remained a significant predictor of work history, and SPD remained a significant predictor of social contact on the job. The findings suggest that impaired vocational functioning is an important characteristic of SPD and PPD.

Working memory in schizotypal personality disorder: fMRI activation and deactivation differences

BACKGROUND

Schizotypal personality disorder (SPD) is considered a schizophrenia spectrum disorder, sharing with schizophrenia cognitive, neuropsychological, epidemiological, and biological characteristics. Working memory may be one area of shared deficit, although to date, this is only the second study to investigate working memory in SPD using fMRI.

METHODS

In a block-design fMRI study, fifteen antipsychotic-naïve SPD and sixteen healthy control subjects performed blocks of a 2back visual working memory task and 0back continuous performance task while undergoing whole-brain fMRI at 3T. Whole-brain analyses were performed for the 0back>rest (fixation baseline) and the 2back>0back contrasts (isolating the working memory component from the visual perception and attention component). Parameter estimates were extracted to determine whether observed differences were due to task-induced activation and/or deactivation.

RESULTS

Activation differences emerged between the two groups, without differences in task performance. In the 0back task, SPD showed decreased task-induced activation of the left postcentral gyrus. In the 2back>0back contrast, HC showed greater task-induced activation of the left posterior cingulate gyrus, superior temporal gyrus, insula, and middle frontal gyrus. These differences were due to SPD subjects' decreased task-induced activation in the left posterior cingulate gyrus, and task-induced deactivation in the remaining regions.

CONCLUSIONS

These findings suggest that compared to HC subjects, individuals with SPD may achieve comparable working memory performance. However, differences emerge at the level of functional neural activation, attributable to different task-induced activation and deactivation patterns. Such differential recruitment of neural resources may be beneficial, contributing to SPD subjects' ability to perform these tasks comparably to HC subjects.

Empathic accuracy and cognition in schizotypal personality disorder

Interpersonal dysfunction contributes to significant disability in the schizophrenia spectrum. Schizotypal Personality Disorder (SPD) is a schizophrenia-related personality demonstrating social cognitive impairment in the absence of frank psychosis. Past research indicates that cognitive dysfunction or schizotypy may account for social cognitive dysfunction in this population. We tested SPD subjects and healthy controls on the Empathic Accuracy (EA) paradigm and the Reading of the Mind in the Eyes Test (RMET), assessing the impact of EA on social support. We also explored whether EA differences could be explained by intelligence, working memory, trait empathy, or attachment avoidance. SPD subjects did not differ from controls in RMET, but demonstrated lower EA during negative valence videos, associated with lower social support. Dynamic, multimodal EA paradigms may be more effective at capturing interpersonal dysfunction than static image tasks such as RMET. Schizotypal severity, trait empathy, and cognitive dysfunction did not account for empathic dysfunction in SPD, although attachment avoidance is related to empathic differences. Empathic dysfunction for negative affect contributes to decreased social support in the schizophrenia spectrum. Future research may shed further light on potential links between attachment avoidance, empathic dysfunction, and social support.

Laplace-Beltrami Eigenvalues and Topological Features of Eigenfunctions for Statistical Shape Analysis

This paper proposes the use of the surface based Laplace-Beltrami and the volumetric Laplace eigenvalues and -functions as shape descriptors for the comparison and analysis of shapes. These spectral measures are isometry invariant and therefore allow for shape comparisons with minimal shape pre-processing. In particular, no registration, mapping, or remeshing is necessary. The discriminatory power of the 2D surface and 3D solid methods is demonstrated on a population of female caudate nuclei (a subcortical gray matter structure of the brain, involved in memory function, emotion processing, and learning) of normal control subjects and of subjects with schizotypal personality disorder. The behavior and properties of the Laplace-Beltrami eigenvalues and -functions are discussed extensively for both the Dirichlet and Neumann boundary condition showing advantages of the Neumann vs. the Dirichlet spectra in 3D. Furthermore, topological analyses employing the Morse-Smale complex (on the surfaces) and the Reeb graph (in the solids) are performed on selected eigenfunctions, yielding shape descriptors, that are capable of localizing geometric properties and detecting shape differences by indirectly registering topological features such as critical points, level sets and integral lines of the gradient field across subjects. The use of these topological features of the Laplace-Beltrami eigenfunctions in 2D and 3D for statistical shape analysis is novel.