Oxford-Liverpool Inventory Research Articles

Cue-Reactive Phenomenology Mediates the Relationship Between Positive Schizotypy and Cue-Reactive Urge to Gamble in Poker-Machine Gamblers

Although ubiquitous in numerous nightlife cultures, poker-machines present a high risk for problematic use and addiction. Previous research has demonstrated that gambling cues (e.g., flashing lights) can activate gambling urges in poker-machine gamblers. However, the processes that contribute to the maintenance of cue-reactive urges to gamble remain unclear. Consequently, the present study explored whether positive schizotypy predicted gambling urge, and whether cue-reactive altered state of awareness, cue-reactive altered time sense, and cue-reactive absorption mediated this relationship. Seventy adults aged between 19 and 68 (M = 48.86, SD = 12.82) participated in an online cue-reactivity experiment. Participants first completed the Problem Gambling Severity Index and the Unusual Experiences subscale of the Short Oxford-Liverpool Inventory of Feelings and Experiences. Subsequently, at three time points (i.e., baseline, directly after a neutral cue, and directly after a gambling cue) participants completed the Altered State of Awareness, Altered Time Sense, and Absorption subscales of the Phenomenology of Consciousness Inventory and a visual analogue scale measuring cue-reactive urge to gamble. It was found that positive schizotypy was significantly positively correlated with cue-reactive urge to gamble. Additionally, cue-reactive altered state of awareness, cue-reactive altered time sense, and cue-reactive absorption mediated this relationship. The theoretical, clinical and practical implications are discussed.

Schizotypy, affective temperaments and anhedonia in bipolar depression.

"Schizotypy" is a term describing personality traits reflected in emotional, perceptual and cognitive styles. Affective temperaments are trait-like features which were observed to be stable in time and predispose to mood disorders. The purpose of this study was to examine relationship between schizotypal features, affective temperaments and anhedonia in patients with bipolar depression. 54 patients with bipolar depression were included in the study. Participant were administered the following psychometric tools: Dimensional Anhedonia Rating Scale (DARS), Snaith-Hamilton Pleasure Scale (SHAPS), Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE), Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A), and Quick Inventory of Depressive Symptomatology - Self-Report (QIDS-SR). Correlations between the variables were calculated and linear regression models were built. Only hyperthymia (affective temperament) and introvertive anhedonia (schizotypal domain) were statistically significantly correlated with anhedonia. In regression models, introvertive anhedonia predicted higher whereas hyperthymic features lower severity of anhedonia (measured by the SHAPS scale). Hyperthymic features are protective and introvertive anhedonia is a risk factor for consummatory anhedonia.

Psychotic and autistic traits among magicians and their relationship with creative beliefs.

There is a common perception that creativity is associated with psychopathology. Previous studies have shown that members of creative groups such as comedians, artists and scientists scores higher than the norm on psychotic traits, and scientists in STEM (science, technology, engineering and mathematics) fields score highly on autistic traits. To test whether magicians, a creative group that has not been studied before, also score highly on psychopathological traits and autism, and to test the associations of creative self-efficacy and creative identity with schizotypal and autistic traits among magicians. A sample of 195 magicians and 233 people from the general population completed measures of schizotypal traits (Oxford-Liverpool Inventory of Feelings and Experiences) and autism (Abridged Version of the Autism-Spectrum Quotient), as well as the Short Scale of Creative Self. Magicians were also compared with other creative groups with respect to schizotypal traits, based on previously published data. Magicians scored lower than the general population sample on three of the four schizophrenia measures (cognitive disorganisation, introvertive anhedonia and impulsive nonconformity) but did not differ with respect to unusual experiences or autism scores. Magicians scored higher on creative self-efficacy and creative personal identity than the general sample. Magicians' scores on schizotypal traits were largely lower than those of other creative groups. Originality of magic was positively correlated with unusual experiences (r = 0.208), creative self-efficacy (r = 0.251) and creative identity (r = 0.362). This is the first study to show a creative group with lower scores than norms on psychotic traits. The results highlight the unique characteristics of magicians and the possible myriad associations between creativity and mental disorders among creative groups.

Interoceptive and Affective Alterations in Body Integrity Dysphoria: An Online Self-Reporting Study

Introduction: Body integrity dysphoria (BID) is a rare condition in which individuals experience a long-lasting desire to achieve a specific physical disability. In this study, we tested the hypothesis of interoceptive and affective abnormalities in BID, in line with the evidence of structural and functional alteration of the interoceptive-affective neural system in these individuals. Method: Our study involved 68 participants with BID (mean age: 35.6, SD: 16.4). Among these participants, 47 expressed a desire for amputation, 14 desired paralysis, 3 sought sensory deprivation, and 3 desired a combination of these forms. For comparisons, we recruited a control group of 79 participants (mean age: 35.2, SD: 15.8). We administered assessment measures to investigate alexithymia level (TAS-20), disgust sensitivity (DS-R), interoceptive awareness (MAIA-2), and (affective and cognitive) empathy (QCAE). We also administered the Short Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) to identify psychiatric comorbidities. Subgroups with low O-LIFE scores (BID = 31; controls = 43) and subgroups with high O-LIFE scores (BID = 37; controls = 36) were derived through a median-split procedure. Results: Within the BID low O-LIFE group, we found reduced interoceptive sensibility, reduced disgust sensitivity, and increased difficulty in identifying feelings, which refers to a dimension of the alexithymia trait. Within the BID high O-LIFE group, we observed a reduced disgust sensitivity and interoceptive sensibility, accompanied by a diminished score in cognitive empathy. Conclusion: Our study suggests that BID can be associated with altered interoceptive and affective processing.

Psychological variables associated with resistance to treatment with serotonin and noradrenaline reuptake inhibitors in fibromyalgia

ObjectiveThe treatment of fibromyalgia (FM) often offers only partial pain relief. Among the most effective drugs for FM pain are serotonin and noradrenalin reuptake inhibitors (SNRI). Few studies investigated the affective temperaments and personality features in FM. Our objective was to explore the associations between the affective temperaments, personality traits, schizotypy and response to SNRI treatment in FM. Methods60 FM patients: 30 responsive to SNRI (FM T[+]), 30 non-responsive to SNRI (FM T[−] and 30 healthy controls were recruited. Resistance to SNRI was defined as <30% pain reduction during at least 8-week treatment. Subjects were assessed by physician and filled self-report questionnaires: Temperament Scale of Memphis, Pisa and San Diego- autoquestionnaire, Ten Item Personality Inventory, Oxford-Liverpool Inventory of Feelings and Experiences and Fibromyalgia Impact Questionnaire (FIQ). ANOVA analysis and simple logistic regressions were used to examine the links between psychological variables and lack of response to SNRI. ResultsFM T[−] presented higher scores in total FIQ and in physical, work, well-being, pain, fatigue/sleep, stiffness domains than FM T[+]. FM T[−] showed higher levels of: irritable and anxious temperaments, neuroticism, schizotypy than FM T[+]. The levels of depressive, irritable and anxious temperaments, introversion, neuroticism and schizotypy were linked to lack of response to SNRI. ConclusionsFM T[+] and FM T[−] differ in clinical presentation and psychological features. The levels of affective temperaments, personality and schizotypal traits are associated with lack response to SNRI in FM.

Schizotypy dimensions do not predict overshadowing

When two cues are presented together and reliably predict an outcome (AB-O1) an “overshadowing” effect is typically observed. That is, the relationship between these cues and the outcome is learned about less well than a cue presented on its own with an outcome (e.g., C – O1). The current study sought to explore the relationship between overshadowing and the positive and negative dimensions of schizotypy. A total of 256 participants completed an overshadowing procedure embedded within a causal judgement task and the Short Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) which measured the different dimensions of schizotypy. A unilateral overshadowing effect was observed, however, none of the dimensions of schizotypy predicted the magnitude of this effect. These results are the first to demonstrate this finding using an appropriately powered sample and reveal that a tendency to experience symptoms of schizophrenia does not impact upon the overshadowing effect.

Non-dynamism and temporal disturbances

Philosophical accounts denying that temporal passage is an objective feature of reality face an explanatory challenge with respect to why it appears to us as though time passes. Recently, two solutions have surfaced. Cognitive illusionism claims that people experience the passage of time due to their belief that time passes. Cognitive error theory claims that we do not experience the passage of time, but hold the belief that we do, which we have acquired through making an inference from the prior belief that time passes. These approaches suppose that belief and passage experience are explanatorily connected, and they depend on the claims that people who experience the passage of time or at least believe that they do also believe that time passes. To test these claims, we probed the beliefs of populations of individuals with depression and schizotypy, thus conditions that are strongly associated with alterations in temporal phenomenology. Depression was assessed with the Beck Depression Inventory (BDI) and schizotypy with the short Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE). While cognitive illusionism and inferentialist cognitive error theory would predict a strong association between BDI and O-LIFE scores and beliefs about time passage, our study found no such association. The experience of passage does not seem to be explanatorily connected to beliefs about the passage of time.

Validation of the Korean Version of the Community Assessment of Psychic Experiences in General Population.

The Community Assessment of Psychic Experiences has been widely translated and commonly used as a measure for psychotic experiences and psychosis proneness in clinical and research environments worldwide. This study aimed to establish the psychometric properties (reliability and validity) and factor structure of a Korean version of the Community Assessment of Psychic Experiences (K-CAPE) in the general population. A total of 1,467 healthy participants completed K-CAPE and other psychiatric symptom-related scales (Paranoia scale, Patient Health Questionnaire-9, Dissociative Experiences Scale-II, and Oxford-Liverpool Inventory of Feelings and Experiences) via online survey. K-CAPE's internal reliability was analyzed using Cronbach's alpha coefficient. Confirmatory factor analysis (CFA) was performed to investigate whether the original three-factor model (positive, negative, and depressive) and other hypothesized multidimensional models (including positive and negative subfactors) were suitable for our data. Exploratory factor analysis (EFA) was conducted to explore better alternative factor solutions with a follow-up CFA. To assess convergent and discriminant validity, we examined correlations between K-CAPE subscales with other established measures of psychiatric symptoms. K-CAPE showed good internal consistency in all original three subscales (all greater than α=0.827). The CFA demonstrated that the multidimensional models exhibited relatively better quality than the original three-dimensional model. Although the model fit indices did not reach their respective optimal thresholds, they were within an acceptable range. Results from the EFA indicated 3-5 factor solutions. In 3-factor solution, "negative-avolition" items were founded to be loaded more consistently with depressive items than with the negative dimension. In 4-factor solution, positive items were divided into two subfactors: "positive-bizarre experiences" and "positive-delusional thoughts," while negative symptoms were separated into two distinct subfactors in 5-factor solution: "negative-avolition (expressive)," and "negative-social (experiential)." The correlation coefficients between K-CAPE subscales and corresponding measurements were significant (p<0.001), confirming the convergent and discriminant validity. Our study provides evidence to support the reliability and validity of the K-CAPE and its use as a measure of psychotic symptoms in the Korean population. Although alternative factor structures did not improve the model fit, our EFA findings implicate the use of subfactors to investigate more specific domains of positive and negative symptoms. Given the heterogeneous nature of psychotic symptoms, this may be useful in capturing their different underlying mechanisms.

Trait schizotypy and the psychosis prodrome: Current standard assessment of extended psychosis spectrum phenotypes

Schizotypy has become an increasingly important construct for elaborating psychotic disorders that vary along the schizophrenic spectrum. However, different schizotypy inventories vary in conceptual approach and measurement. In addition, commonly used schizotypy scales have been seen as qualitatively different from screening instruments for prodromal schizophrenia like the Prodromal Questionnaire-16 (PQ-16). Our study investigated the psychometric properties of three schizotypy questionnaires (the Schizotypal Personality Questionnaire-Brief, Oxford-Liverpool Inventory of Feelings and Experiences, and the Multidimensional Schizotypy Scale) as well as the PQ-16 in a cohort of 383 non-clinical subjects. We initially evaluated their factor structure using Principal Component Analysis (PCA) and used Confirmatory Factor Analysis (CFA) to test a newly proposed composition of factors. PCA results support a three-factor structure of schizotypy that accounts for 71% of the total variance, but also shows cross-loadings of some schizotypy subscales. CFA of the newly composed schizotypy factors (together with an added neuroticism factor) shows good fit. Analyses including the PQ-16 indicate considerable overlap with measures of trait schizotypy, suggesting that the PQ-16 might not be quantitatively or qualitatively different from schizotypy measurements. Taken together, results indicate that there is good support for a three-factor structure of schizotypy but also that different schizotypy measurements grasp facets of schizotypy differently. This points towards the need for an integrative approach for assessing the construct of schizotypy.

Rumination and schizotypal personality traits

<p>Although ru&shy;mination and schizotypal traits can be considered transdiagnostic phenomena and can occur within non-clinical population as well, a relatively small number of research has been carried out on the topic involving both patient and non clinical participants. The aim of this study is to examine the rela&shy;tionship between schizotypal traits and rumination using a transdiagnostic approach, involving participants living with psychotic disorders and sine morbo individuals.</p>. <p>We recruited participants living with psychotic disorders (paranoid schizophrenia, hebephrenia, schizoaffective disorder, etc.) (n = 30) and controls who had not been diagnosed with any mental illnesses (n = 67). The connection between rumination and schizotypal traits was examined by self-report questionnaire method in a cross-sectional arrangement. The Oxford-Liverpool Inventory was used to measure schizotypal traits, and the Ruminative Thought Style Questionnaire was used to determine the level of rumination.&nbsp;</p>. <p>Schizotypal symptoms (&beta; = 0.575; p &lt; 0.001), especially cognitive disorganization (&beta; = 0.459; p &lt; 0.001) and unusual experiences (&beta; = 0.221; p = 0.029) significantly explained the degree of rumination.&nbsp;</p>. <p>Our results support the hypothesis that the association between rumination and schizotypic traits is due to decreased cognitive inhibitory functions.</p>.

Structural Relationships Among Mental Boundaries, Childhood Imaginary Companions, Creative Experiences, and Entity Encounters.

This study investigated relationships between thin mental boundary functioning, creativity, imaginary companions (ICs), and anomalous '(entity) encounter experiences.' A convenience sample of 389 respondents completed the Revised Transliminality Scale, Oxford-Liverpool Inventory of Feelings and Experiences, Creative Experiences Questionnaire, Survey of Strange Events, and a measure of Childhood Imaginary Companions. Competing testing with path analysis found that the best-fitting model was consistent with the causal chain of 'Thin Boundaries (transliminality and schizotypy) → Creative Experiences → ICs → (Entity) Encounter Experiences.' These results suggest that deep-types of ICs (i.e., showing apparent independent agency) are perhaps most accurately characterized as syncretic cognitions versus hallucination-like experiences. The authors examine these findings relative to study limitations, as well as discussing the need for future research that approaches ICs as a special mental state that can facilitate allied altered-anomalous experiences. In this context, this study furthered understanding of relationships between conscious states related to mental boundaries, childhood imaginary companions, creative experiences, and entity encounters.

The effect of schizotypy on spatial learning in an environment with a distinctive shape.

In two experiments, participants completed the Oxford-Liverpool Inventory of Feelings and Experiences measuring schizotypal traits across four dimensions (unusual experiences, cognitive disorganization, introvertive anhedonia, and impulsive non-conformity). They then took part in a virtual navigation task where they were required to learn about the position of a hidden goal with reference to geometric cues of a rectangular arena or rely on colored wall panels to find the hidden goal in a square-shaped arena. Unusual experience and cognitive disorganization were significant predictors of the use of geometric cues, but no significant predictors were found for the use of wall panels. Implications to hippocampal function and the clinical domain are considered.

Childhood Imaginary Companion and Schizotypy in Adolescents and Adults

Objective: This study evaluated the association of Childhood Imaginary Companion (CIC) status and schizotypy levels of adolescents and adults within the framework of the Hierarchical Taxonomy of Psychopathology (HiTOP). Method: The sample included 255 Iranian adolescents and adults, grouped according to their CIC status, who responded mostly via e-questionnaires on a website. Schizotypy dimensions were compared between these two groups. Two measures compatible with the HiTOP model were also evaluated both in relation to the short scale of the Oxford-Liverpool Inventory of Feelings and Experiences (sO-LIFE) schizotypy dimensions and the CIC status of participants; one scale used exclusively with adolescents (i.e., the Achenbach System of Empirically-Based Assessment-Youth Self-Report [ASEBA-YSR]), and another with adults (i.e., the NEO-Five Factor Inventory [NEO-FFI]). Results: Scores on the unusual experiences (UnEx) the impulsive nonconformity (ImpNon) dimensions, and the total score of the sO-LIFE were higher for the CIC group. For adolescents, the UnEx dimension and the Thought Problems subscale of the ASEBA-YSR correlated. Scores on three subscales of the ASEBA-YSR (i.e., Thought Problems, Obsessive-Compulsive Problems, and PTSD Problems) were significantly higher for the CIC group. For adults, the neuroticism domain of the NEO-FFI correlated strongly with total score of the sO-LIFE and the cognitive disorganization (CogDis) dimension. This domain of the NEO-FFI was the only one in which CIC adults scored higher than the NIC group. Conclusion: CIC in adolescents and adults is associated with a set of schizotypy dimensions in line with the concept of the “happy schizotype.”

Distinct neural signatures of schizotypy and psychopathy during visual word‐nonword recognition

Previous behavioural data indicate lower word‐nonword recognition accuracy in association with a high level of positive schizotypy, psychopathy, or motor impulsivity traits, each with some unique contribution, in the general population. This study aimed to examine the neural underpinnings of these associations using functional magnetic resonance imaging (fMRI) in a volunteer sample. Twenty‐two healthy English‐speaking adults completed self‐report measures of schizotypy (Oxford‐Liverpool Inventory of Feelings and Experiences [O‐LIFE]), psychopathy (Triarchic Psychopathy Measure [TriPM]), and impulsivity (Barratt Impulsiveness Scale [BIS‐11]) and underwent whole‐brain fMRI while performing a lexical decision task (LDT) featuring high and low‐frequency words, real nonwords, and pseudohomophones. Higher positive schizotypy (Unusual Experiences) was associated with lower cerebellum activity during identification of low‐frequency words (over real nonwords). Higher Boldness (fearless dominance) and Meanness (callous aggression) facets of psychopathy were associated with lower striatal and posterior cingulate activity when identifying nonwords over words. Higher Motor Impulsivity was associated with lower activity in the fusiform (bilaterally), inferior frontal (right‐sided), and temporal gyri (bilaterally) across all stimuli‐types over resting baseline. Positive schizotypy, psychopathy, and impulsivity traits influence word‐nonword recognition through distinct neurocognitive mechanisms. Positive schizotypy and psychopathy appear to influence LDT performance through brain areas that play only a supportive (cerebellum) or indirect role in reading‐related skills. The negative association between Motor Impulsivity and activations typically found for phonological processing and automatic word identification indicates a reduced bilateral integration of the meaning and sound of mental word representations, and inability to select the appropriate outputs, in impulsive individuals.

No influence of sex on the relationship between schizotypy factors and executive control across the schizophrenia spectrum

Sex differences in symptoms and executive control across schizophrenia spectrum disorders (SSD) are consistently reported. Similarly, these findings of sex differences are also observed in schizotypy, that is, schizophrenia-like features occurring in healthy individuals in the absence of a clinical diagnosis. This study aimed to examine the relationships between performance on three major domains of executive control: performance monitoring, response inhibition, and cognitive set-shifting, and schizotypy factor scores in both SSD patients and healthy controls (HCs), and whether sex moderated any relationships observed. A total of 111 (67 males and 44 females) patients with SSD and 258 (129 males and 129 females) HCs were included in this study. Schizotypal personality traits (in both SSD and HC) was assessed using the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE). Executive control performance was assessed using seven tasks. Stepwise linear regressions revealed that performance on cognitive set-shifting tasks was significantly associated with the introvertive anhedonia, cognitive disorganisation, and unusual experiences subscales of the O-LIFE. When sex was examined as a moderator, it was not a significant moderator of any of the relationships between cognitive set-shifting tasks and schizotypy factors. The results suggest that independent of sex, cognitive set-shifting ability is associated to an increased vulnerability to schizotypal personality traits, although performance monitoring and response inhibition did not.

Examining relationships between state and trait psychotic symptoms and quality of life in schizophrenia spectrum disorders

Positive and negative symptoms are core aspects of schizophrenia and have been shown to influence patient quality of life (QOL). Previous studies have largely focused on current or state symptoms, with limited work on the contributions of trait symptoms to QOL. This study sought to examine the relationship between both state and trait symptoms and objective and subjective QOL. Fifty-three schizophrenia spectrum disorder patients and 47 healthy controls were recruited. State symptomatology was assessed using the Positive and Negative Syndrome Scale in the patients only. In all participants, trait symptoms were assessed using the Oxford-Liverpool Inventory of Feelings and Experiences, and QOL using Lehman's QOL Interview. Hierarchical linear regression analyses, controlling for depression and neurocognition, revealed that negative state symptoms were related to objective QOL within the patients, while negative trait symptoms were associated with both objective and subjective QOL in patients and healthy controls. No relationships were observed with positive state or trait symptoms and either QOL measure. The findings suggest a degree of complexity in the associations between symptoms and QOL, with primacy for negative symptoms at both state and trait levels. A greater appreciation of trait symptoms may help explain non-complementary QOL changes following symptom remission.

Clarifying the roles of schizotypy and psychopathic traits in lexical decision performance

IntroductionSome studies suggest that lexical recognition is impaired in people with schizophrenia, psychopathy and/or antisocial personality disorders, but not affective disorders. We examined the extent to which various traits dimensionally linked to one or more of these disorders are associated with lexical recognition performance in the general population. MethodsSeventy-eight healthy English-speaking participants completed self-report measures of schizotypy, psychopathy, impulsivity, depression, anxiety and stress. All participants were assessed on a one-choice variant of a lexical decision task (LDT). ResultsMeanness and Boldness traits of psychopathy (Triarchic Psychopathy Measure), and positive schizotypy (Unusual Experiences, Oxford-Liverpool Inventory of Feelings and Experiences) were associated with poor word-nonword accuracy, and predicted a significant amount of unique variance (Meanness, 12%; Boldness, 4.8%; Positive Schizotypy, 4.4%; total 21%) in performance. Higher motor impulsivity predicted 30% of the variance in low-frequency words recognition accuracy, but only in non-native English speakers. Affective traits were not associated with LDT performance. ConclusionPsychopathic traits show stronger negative associations with lexical recognition performance than schizotypal traits, and impulsivity may differently influence lexical decision performance in native and non-native speakers. Further studies are needed to replicate these findings, especially the influence of language familiarity in the impulsivity-performance relationship, and to clarify the influence of corresponding symptom dimensions in lexical recognition abilities, taking language familiarity, migration status, and comorbidity into account, in people with schizophrenia, psychopathy, and/or antisocial personality disorders.

Nonclinical psychotic-like experiences and schizotypy dimensions: Associations with hippocampal subfield and amygdala volumes.

Schizotypy and psychotic‐like experiences (PLE) form part of the wider psychosis continuum and may have brain structural correlates in nonclinical cohorts. This study aimed to compare the effects of differential schizotypy dimensions, PLE, and their interaction on hippocampal subfields and amygdala volumes in the absence of clinical psychopathology. In a cohort of 367 psychiatrically healthy individuals, we assessed schizotypal traits using the Oxford‐Liverpool Inventory of Life Experiences (O‐LIFE) and PLE using the short form of the Prodromal Questionnaire (PQ‐16). Based on high‐resolution structural MRI scans, we used automated segmentation to estimate volumes of limbic structures. Sex and total intracranial volume (Step 1), PLE and schizotypy dimensions (Step 2), and their interaction terms (Step 3) were entered as regressors for bilateral amygdala and hippocampal subfield volumes in hierarchical multiple linear regression models. Positive schizotypy, but not PLE, was negatively associated with left amygdala and subiculum volumes. O‐LIFE Impulsive Nonconformity, as well as the two‐way interaction between positive schizotypy and PLE, were associated with larger left subiculum volumes. None of the estimators for right hemispheric hippocampal subfield volumes survived correction for multiple comparisons. Our findings support differential associations of hippocampus subfield volumes with trait dimensions rather than PLE, and support overlap and interactions between psychometric positive schizotypy and PLE. In a healthy cohort without current psychosis risk syndromes, the positive association between PLE and hippocampal subfield volume occurred at a high expression of positive schizotypy. Further studies combining stable, transient, and genetic parameters are required.

Subclinical schizotypal vs. autistic traits show overlapping and diametrically opposed facets in a non-clinical population

BackgroundThe overlap of autism spectrum disorder (ASD) and psychosis or schizophrenia spectrum disorders (SSD) has exposed problems central to conceptualising and understanding co-morbidity in psychiatric disorders. MethodsIn the present study, we demonstrate that a deep phenotyping approach aids clarification of both overlapping and diametrically opposed features of ASD and SSD on the level of trait facets. ResultsWe first show overlap of negative and disorganised (but not positive) features of schizotypy with autistic traits in a sample of n = 376 German non-clinical subjects using multiple psychometric measures of schizotypy (MSS multidimensional schizotypy scale, OLIFE Oxford-Liverpool Inventory of Feelings and Experiences, and SPQ-B schizotypal personality questionnaire – brief) and the AQ autism spectrum quotient, with control measures for affective spectrum pathology (BDI). Findings were then replicated in a French-Swiss sample (n = 264) using MSS, OLIFE, AQ, and in addition the Community Assessment of Psychic Experiences (CAPE). Additional principal component analysis confirmed our finding of the co-existence of both overlapping (loss of function, social communication deficit, and negative schizotypy) as well as diametrically opposed features (AQ attention to detail, positive schizotypy) across the two spectra. Results were validated with Horn's parallel analyses, affirming two component solutions, and PCA using sample-specific, factor-analysis-derived schizotypy scores. ConclusionsProviding a framework for multi-dimensional transdiagnostic characterisation of ASD vs. SSD phenotypes we point out overlapping vs. discriminating facets. In addition to the use of novel multidimensional schizotypy scales, it also shows transcultural consistency of findings, and highlights a particular role for the attention to detail AQ subscale.

Schizotypy in Parkinson\u2019s disease predicts dopamine-associated psychosis

Psychosis is the most common neuropsychiatric side-effect of dopaminergic therapy in Parkinson’s disease (PD). It is still unknown which factors determine individual proneness to psychotic symptoms. Schizotypy is a multifaceted personality trait related to psychosis-proneness and dopaminergic neurotransmission in healthy subjects. We investigated whether (1) PD patients exhibit lower schizotypy than controls and (2) dopamine-related neuropsychiatric side-effects can be predicted by higher schizotypy. In this cross-sectional study, we used the Oxford-Liverpool Inventory of Feelings and Experiences in 56 PD patients (12 women, mean ± sd age: 61 ± 11 years) receiving their usual dopaminergic medication and 32 age-matched healthy controls (n = 32; 18 women, mean ± sd age: 57 ± 6 years). We further compared schizotypy scores of patients with (n = 18, 32.1%) and without previously experienced psychosis. We found that patients exhibited lower schizotypy than controls. Further, patients with a history of psychosis exhibited higher schizotypy than patients without these symptoms. Using an information theoretic measure and a machine learning approach, we show that schizotypy yields the greatest predictive value for dopamine-associated hallucinations compared to other patient characteristics and disease related factors. Our results indicate an overlap between neural networks associated with schizotypy and the pathophysiology of PD and a relationship between schizotypy and psychotic side-effects of dopaminergic medication.