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.

Co-occurrence of borderline and schizotypal personality disorders: a scoping review.

BACKGROUND: The historical concept of borderline conditions refers to the pathology on the border between neurosis and psychosis. In DSM-III the conditions were divided into specific but also somewhat overlapping diagnostic criteria for Borderline Personality Disorder (BPD) and Schizotypal Personality Disorder (SPD). This phenomenological overlap, which results in co-occurrence of the two diagnoses, remains a clinical challenge to this day. METHODS: To address this issue we examined the co-occurrence of SPD and BPD according to the established DSM-IV/-5 diagnostic criteria. A literature search was conducted including studies that employed a structured interview with defined BPD and SPD criteria. RESULTS: Studies from 20 samples were included (i.e. 15 patients, 3 community and 2 forensic samples). For patients diagnosed primarily with BPD, 1-27% also met the criteria for SPD and for patients diagnosed primarily with SPD, 5 - 33% showed co-occurrence with BPD. In the forensic samples, co-occurrence for primary BPD was 10% and 67 - 82% for primary SPD. In the community samples, co-occurrence for primary BPD was 29% and 50% for primary SPD. The pattern of co-occurrence across community samples was particularly heterogeneous. CONCLUSION: The identified co-occurrences for BPD and SPD were considerably sample-dependent, and samples and measurements were generally too heterogeneous for a precise meta-analysis. Forensic and community samples generally showed higher co-occurrences, but these findings were characterized by potential methodological limitations.

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.

Psychotherapy for patients with schizotypal personality disorder: A scoping review.

BACKGROUND: Treatment of schizotypal personality disorder is complex. Currently, there are no clear evidence-based recommendations for use of psychotherapy for individuals suffering from this mental illness, and studies are sparse. Our aim in this review is to map and describe the existing research and to answer the research question: What do we know about the use of psychotherapy for people with schizotypal personality disorder? METHODS: We conducted a scoping review using systematic searches in the Embase, MEDLINE and PsycINFO databases. Two reviewers screened possible studies and extracted data on subject samples, type of psychotherapy, outcomes and suggested mechanisms of change. The review is based on the PRISMA checklist for scoping reviews. RESULTS: Twenty-three papers were included, and we found a wide variety of study types, psychotherapeutic orientations and outcomes. Few studies emerged that focused solely on schizotypal personality disorder. CONCLUSION: Psychotherapy as a treatment for schizotypal personality disorder is understudied compared with diagnoses such as schizophrenia and borderline personality disorder. Our results included two randomized controlled studies, as well as mainly smaller studies with different approaches to diagnostic criteria, psychotherapeutic orientation and outcome measures. The findings are too sparse and too diverse to make any evidence-based recommendations. We found some indications that psychotherapy may support and assist individuals with schizotypal personality disorder.

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).

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.

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.

Clinical features of scrupulosity: Associated symptoms and comorbidity.

OBJECTIVE: Scrupulosity is a manifestation of obsessive-compulsive disorder (OCD) characterized by religious or moral core fears. Clinicians often struggle to treat scrupulosity, which may be associated with several features known to predict poor treatment outcome. The purpose of this study was to examine these features in participants with scrupulous OCD, contamination OCD, and healthy controls. METHOD: A total of 68 participants (57.4% women, agemean = 34.01) completed diagnostic interviews, and measures of symptoms and quality-of-life. RESULTS: Relative to comparison groups, scrupulous participants had higher rates of obsessive-compulsive personality disorder, more severe schizotypal symptoms, and more severe symptoms of depression. In addition, OCD severity was strongly associated with poor insight in the scrupulous group. Both OCD groups reported poorer quality of life than did healthy controls. CONCLUSIONS: Clinicians working with scrupulous individuals may enhance the efficacy of treatment in this challenging population by assessing carefully for these features, and incorporating treatment elements that address them.

Utilizing MERIT to promote recovery in schizotypal personality disorder: An illustrative case study.

INTRODUCTION: Difficulties forming an integrated sense of oneself, others, and one's place in the community have been observed to pose a barrier to recovery from schizophrenia spectrum disorders (SSD). This has promoted the development of metacognitive approaches to psychotherapy that seek to assist persons in making sense of and managing their psychosocial challenges. One of these approaches, Metacognitive Reflection Insight Therapy (MERIT), has begun to be more broadly explored among adults with schizophrenia. Persons with other forms of SSD, including schizotypal personality disorder (SPD), also experience difficulties forming an integrated sense of themselves and others and could potentially be amenable to MERIT. METHODS: To explore this possibility, this study reports the application of MERIT to an adult with SPD in a unique cultural context. RESULTS: Evidence of acceptability and meaningful resultant clinical gains are described. CONCLUSIONS: Taken as a whole, this study provides a rich illustration of how metacognition can be successfully targeted by MERIT in forms of SSD potentially less severe than schizophrenia, including SPD in a unique cultural setting.

Schizotypal personality disorder and suicide: problems and perspectives.

Schizotypal personality disorder (SPD) is classified in DSM-V as a cluster A personality disorder. Cluster A personality disorders are described as odd or eccentric conditions. SPD is associated with significant disability and many psychiatric comorbidities. Several studies have shown that SPD and schizotypal traits are associated with suicidal ideation and behaviour. Suicide prevention interventions in individuals with SPD are impeded because (1) SPD is frequently not diagnosed; (2) SPD is difficult to treat; and (3) there are no guidelines for suicide screening or suicide prevention interventions in individuals with SPD. Suicide prevention in persons with SPD consists of (1) diagnosing SPD; (2) providing appropriate treatment for SPD; and (3) providing suicide screening and suicide prevention. Interventions aiming at reduction of depressive symptoms, improvement of self-esteem, and interpersonal skills may be effective at reducing suicide risk amongst individuals with SPD. Studies of suicidality in persons with SPD are needed and may be an important area of suicide research. It is to be hoped that future studies of the pathophysiology of suicidality in individuals with SPD will help to develop strategies for suicide screening and suicide prevention interventions in persons with SPD and improve suicide prevention in this challenging patient population.

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.

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.

Harnessing Reddit to Understand the Written-Communication Challenges Experienced by Individuals With Mental Health Disorders: Analysis of Texts From Mental Health Communities.

BACKGROUND: Mental disorders such as depression, bipolar disorder, and schizophrenia are common, incapacitating, and have the potential to be fatal. Despite the prevalence and gravity of mental disorders, our knowledge concerning everyday challenges associated with them is relatively limited. One of the most studied deficits related to everyday challenges is language impairment, yet we do not know how mental disorders can impact common forms of written communication, for example, social media. OBJECTIVE: The aims of this study were to investigate written communication challenges manifest in online mental health communities focusing on depression, bipolar disorder, and schizophrenia, as well as the impact of participating in these online mental health communities on written communication. As the control, we selected three online health communities focusing on positive emotion, exercising, and weight management. METHODS: We examined lexical diversity and readability, both important features for measuring the quality of writing. We used four well-established readability metrics that consider word frequencies and syntactic complexity to measure writers' written communication ability. We then measured the lexical diversity by calculating the percentage of unique words in posts. To compare lexical diversity and readability among communities, we first applied pairwise independent sample t tests, followed by P value adjustments using the prespecified Hommel procedure to adjust for multiple comparison. To measure the changes, we applied linear least squares regression to the readability and lexical diversity scores against the interaction sequence for each member, followed by pairwise independent sample t tests and P value adjustments. Given the large sample of members, we also report effect sizes and 95% CIs for the pairwise comparisons. RESULTS: On average, members of depression, bipolar disorder, and schizophrenia communities showed indications of difficulty expressing their ideas compared with three other online health communities. Our results also suggest that participating in these platforms has the potential to improve members' written communication. For example, members of all three mental health communities showed statistically significant improvement in both lexical diversity and readability compared with members of the OHC focusing on positive emotion. CONCLUSIONS: We provide new insights into the written communication challenges faced by individuals suffering from depression, bipolar disorder, and schizophrenia. A comparison with three other online health communities suggests that written communication in mental health communities is significantly more difficult to read, while also consisting of a significantly less diverse lexicon. We contribute practical suggestions for utilizing our findings in Web-based communication settings to enhance members' communicative experience. We consider these findings to be an important step toward understanding and addressing everyday written communication challenges among individuals suffering from mental disorders.

Supervoxel-based statistical analysis of diffusion tensor imaging in schizotypal personality disorder.

To study white matter changes in schizotypal personality disorder (SPD), we developed a new statistical analysis method based on supervoxels for diffusion tensor imaging. Twenty patients with SPD and eighteen healthy controls were recruited from a pool of 3000 first-year university undergraduates, and underwent MRI using a 3T scanner. Diffusion tensors were first normalized into ICBM-152 space followed by a supervoxel segmentation based on graph clustering to segment white matter tensors into diffusion homogeneous supervoxels. Fractional anisotropy (FA) values in supervoxels were compared between SPD and healthy controls using permutation test. Suprathreshold cluster size test was used to correct multiple comparison. At last, fibers with significant differences were extracted from supervoxel clusters with significance level P < 0.05. Results showed that FA values in genu of corpus callosum were significantly reduced (P = 0.012) in patients with SPD (FA = 0.565) compared with healthy controls (FA = 0.593). In summary, this study proposed a novel supervoxel segmentation method for diffusion tensor imaging using graph-based clustering, and extended permutation test and suprathreshold cluster size test to supervoxels for detection of white matter changes.

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.

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.

A longitudinal twin study of cluster A personality disorders.

BACKGROUND: While cluster A personality disorders (PDs) have been shown to be moderately heritable, we know little about the temporal stability of these genetic risk factors. METHOD: Paranoid PD (PPD) and schizotypal PD (STPD) were assessed using the Structured Interview for DSM-IV Personality in 2793 young adult twins from the Norwegian Institute of Public Health Twin Panel at wave 1 and 2282 twins on average 10 years later at wave 2. Using the program Mx, we fitted a longitudinal latent factor model using the number of endorsed criteria for PPD and STPD. RESULTS: The stability over time of the criteria counts for PPD and STPD, estimated as polychoric correlations, were +0.34 and +0.40, respectively. The best-fit longitudinal model included only additive genetic and individual-specific environmental factors with parameter estimates constrained to equality across the two waves. The cross-wave genetic and individual-specific environmental correlations for a latent cluster A factor were estimated to equal +1.00 and +0.13, respectively. The cross-time correlations for genetic and environmental effects specific to the individual PDs were estimated at +1.00 and +0.16-0.20, respectively. We found that 68% and 71% of the temporal stability of PPD and STPD derived, respectively, from the effect of genetic factors. CONCLUSION: Shared genetic risk factors for two of the cluster A PDs are highly stable in adults over a 10-year period while environmental risk factors are relatively transient. Over two-thirds of the long-term stability of the common cluster A PD liability can be attributed to genetic influences.

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.

[French validation of the Revised Paranormal Belief Scale]. / Validation française de la Revised Paranormal Belief Scale.

INTRODUCTION: For the last decades, many researchers have focused on paranormal beliefs. Beliefs in the existence of paranormal phenomena would be common and studies conducted in westernized countries have highlighted a high prevalence of individuals believing in the existence of such phenomena. Tobacyk and Milford (1984) developed the Revised Paranormal Belief Scale (RPBS) for assessing beliefs in paranormal phenomena. This 26-item self-reported questionnaire, measuring beliefs in phenomena such as witchcraft or superstition, is one of the most widely used questionnaires to assess such beliefs. While studies focusing on paranormal beliefs tend to develop, there is no French self-report instrument to assess this construct. Researchers have tried to identify specific variables that might be linked to such beliefs, and some have focused on personalities of individuals who believe in the paranormal. Schizotypy has been reported to be significantly and positively correlated with paranormal beliefs. OBJECTIVES: The aim of this study was a) to validate the French version of the RPBS and b) to explore the relationship between Schizotypal Personality Disorder traits and paranormal beliefs. METHODS: After being recruited using the Internet and social networks (e.g. facebook), a sample of 313 participants (mean [SD] age=31.12 [11.62]; range 18-58years) completed the Schizotypal Personality Questionnaire (SPQ-B), assessing Schizotypal Personality Disorder traits and the Revised Paranormal Belief Scale assessing paranormal beliefs. RESULTS: Confirmatory factor analysis (CFA) was conducted to test the proposed 7-factor structure of the RPB developed by Tobacyk. Several adjustment indices were used to evaluate the model. As the first model did not fit the original one, others models were tested. Our findings indicated that a seven-factor solution, excluding 2 items, best described the item structure: (1) spiritualism, (2) superstition, (3) witchcraft, (4) precognition, (5) traditional religious belief, (6) psi, (7) and extraordinary life forms. Relationships between paranormal beliefs and Schizotypal Personality Disorder traits were also explored. Correlations between some subscales of the SPQ-B and some dimensions of the RPBS were found. The "cognition-perception" subscale was strongly correlated with the "witchcraft", "spirituality", "precognition" and "psi" subscales. Nevertheless, this subscale was lightly correlated with the "traditional religious belief" and "extraordinary life forms" dimensions. No correlation was found between the others dimensions of schizotypy as "disorganized" and "interpersonal" and dimensions of paranormal beliefs. DISCUSSION: The initial model developed by Tobacyk and Milford did not fit the data from the French population. The low internal consistencies regarding both superstition and extraordinary life forms dimensions highlighted some cultural differences that have to be acknowledged. This result emphasizes that beliefs in some extraordinary life forms as Loch Ness monster are not an important dimension to take into account in a French population. Our findings also indicate that the RPBS is a valid and reliable instrument for assessing paranormal beliefs in a French population. Our findings also highlight that such beliefs are associated with Schizotypal Personality Disorder traits. Developing research on the association between Schizotypal Personality Disorder traits and such beliefs appears of prime importance. Future studies focusing on features associated with paranormal beliefs are also warranted.