Predicting schizophrenia: findings from the Edinburgh High-Risk Study

Social functioning and frontal alpha asymmetry in schizophrenia

BACKGROUND

Schizophrenia (SZ) is a psychiatric disorder that often involves reduced social functioning. Frontal alpha asymmetry (FAA) is a neurophysiological marker extracted from electroencephalogram (EEG) data that is likely related to motivational and emotional tendencies, such as reduced motivation across various psychiatric disorders, including SZ. Therefore, it may offer a neurophysiological marker for social functioning.

OBJECTIVES

The present study aimed to examine whether FAA is related to social functioning in schizophrenia. Additionally, a group of people with autism spectrum disorder (ASD) was included to explore whether findings are unique to schizophrenia, or whether they are found in another diagnostic group with atypical social behaviors.

METHODS

Analysis of variance and regression models were used to evaluate data from resting-state EEG, clinical interviews, and self-report measures. Data from 33 participants with SZ were compared to 38 healthy controls and 30 individuals with ASD.

RESULTS

Although people with SZ showed differences in FAA compared to healthy controls, the altered neurophysiology was not related to reduced social functioning in SZ. However, FAA was related to social functioning in people without a psychiatric diagnosis. Additionally, comparisons between the SZ and ASD group revealed few differences in patterns of FAA and social functioning, suggesting commonalities between the disorders in these areas.

CONCLUSIONS

FAA likely does not present a neurophysiological marker for reduced social functioning in schizophrenia, though future work should examine its role in other possible clinical manifestations shared between schizophrenia and ASD.

The association between discourse production and schizotypal personality traits

Discourse abnormalities are a prominent feature in schizophrenia spectrum disorders, including poor lexical diversity, and have been found to differentiate patients from healthy subjects. However, discourse processing in individuals with high schizotypal personality traits is less understood and is often overshadowed by research on clinical psychotic symptoms. In the present study, we examined schizotypal traits at a non-clinical threshold and their association with lexical diversity and discourse coherence using two automated Natural Language Processing (NLP) tools - Type-Token-Ratio (TTR) measures from the Tool for the Automatic Analysis of Lexical Diversity (TAALED) and discourse coherence using sentence-level average cosign similarity with FastText to assess sentence similarity. 276 college students completed the full assessment including the Schizotypal Personality Questionnaire- Brief Revised (SPQ-BR) and recorded a speech sample describing a detailed painting. Results revealed that high schizotypal traits, specifically positive traits, were associated with lower lexical diversity and higher sentence similarity. Our findings suggest that even when clinically significant symptoms are not present, discourse abnormalities are present in healthy populations with high ST. The stronger association with positive traits suggests that theories of perseveration and top-down processing may warrant further investigation in schizophrenia-spectrum disorders.

Neuropsychology and Neurobiology of Negative Schizotypy: A Selective Review

Schizotypy refers to a latent personality organization that reflects liability to schizophrenia. Because schizotypy is a multidimensional construct, people with schizotypy vary in behavioral and neurobiological features. In this article, we selectively review the neuropsychological and neurobiological profiles of people with schizotypy, with a focus on negative schizotypy. Empirical evidence is presented for alterations of neuropsychological performance in negative schizotypy. We also cover the Research Domain Criteria domains of positive valence, social process, and sensorimotor systems. Moreover, we systematically summarize the neurobiological correlates of negative schizotypy at the structural, resting-state, and task-based neural levels, as well as the neurochemical level. The convergence and inconsistency of the evidence are critically reviewed. Regarding theoretical and clinical implications, we argue that negative schizotypy represents a useful organizational framework for studying neuropsychology and neurobiology across different psychiatric disorders.

Early Childhood Neurocognition in Relation to Middle Childhood Psychotic Experiences in Children at Familial High Risk of Schizophrenia or Bipolar Disorder and Population-Based Controls: The Danish High Risk and Resilience Study

BACKGROUND AND HYPOTHESIS

Familial high-risk (FHR) studies examining longitudinal associations between neurocognition and psychotic experiences are currently lacking. We hypothesized neurocognitive impairments at age 7 to be associated with increased risk of psychotic experiences from age 7 to 11 in children at familial high risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) and population-based controls (PBC), and further, impaired functioning in some neurocognitive functions to be associated with greater risk of psychotic experiences in children at FHR-SZ or FHR-BP relative to PBC.

STUDY DESIGN

Neurocognition was assessed at age 7 (early childhood) and psychotic experiences from age 7 to 11 (middle childhood) in 449 children from the Danish High Risk and Resilience Study. The neurocognitive assessment covered intelligence, processing speed, attention, visuospatial and verbal memory, working memory, and set-shifting. Psychotic experiences were assessed through face-to-face interviews with the primary caregiver and the child.

STUDY RESULTS

Set-shifting impairments at age 7 were associated with greater risk of psychotic experiences from age 7 to 11 in children at FHR-SZ. Children at FHR-BP and PBC showed no differential associations. Working memory and visuospatial memory impairments were related to increased risk of psychotic experiences across the cohort. However, adjusting for concurrent psychopathology attenuated these findings.

CONCLUSIONS

Early childhood neurocognitive impairments are risk markers of middle childhood psychotic experiences, of which impaired set-shifting appears to further increase the risk of psychotic experiences in children at FHR-SZ. More research is needed to examine longitudinal associations between neurocognitive impairments and psychotic experiences in FHR samples.

Reduced willingness to expend effort for rewards is associated with risk for conversion and negative symptom severity in youth at clinical high-risk for psychosis

BACKGROUND

Schizophrenia (SZ) is typically preceded by a prodromal (i.e. pre-illness) period characterized by attenuated positive symptoms and declining functional outcome. Negative symptoms are prominent among individuals at clinical high-risk (CHR) for psychosis (i.e. those with prodromal syndromes) and predictive of conversion to illness. Mechanisms underlying negative symptoms are unclear in the CHR population.

METHODS

The current study evaluated whether CHR participants demonstrated deficits in the willingness to expend effort for rewards and whether these impairments are associated with negative symptoms and greater risk for conversion. Participants included 44 CHR participants and 32 healthy controls (CN) who completed the Effort Expenditure for Reward Task (EEfRT).

RESULTS

Compared to CN, CHR participants displayed reduced likelihood of exerting high effort for high probability and magnitude rewards. Among CHR participants, reduced effort expenditure was associated with greater negative symptom severity and greater probability of conversion to a psychotic disorder on a cross-sectional risk calculator.

CONCLUSIONS

Findings suggest that effort-cost computation is a marker of illness liability and a transphasic mechanism underlying negative symptoms in the SZ spectrum.

Neurocognitive Subgroups in Children at Familial High-risk of Schizophrenia or Bipolar disorder: Subgroup Membership Stability or Change From Age 7 to 11-The Danish High Risk and Resilience Study

BACKGROUND AND HYPOTHESIS

Subgroups with distinct levels of neurocognitive functioning exist in children of parents with schizophrenia or bipolar disorder. However, studies investigating the temporal stability of subgroup membership are currently lacking. We hypothesized that a minority of children at familial high-risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) would transition to a different neurocognitive subgroup from age 7 to 11 and that most transitions would be to a more impaired subgroup.

STUDY DESIGN

Latent profile analysis was used to identify subgroups at two assessments (age 7 and 11) based on the performance of 320 children at FHR-SZ or FHR-BP across eight neurocognitive functions. Temporal stability in subgroup membership was evaluated with latent profile transition analysis. Population-based controls (age 7, n = 199; age 11, n = 178) were included as a reference group. Children transitioning to a more impaired subgroup were compared with nontransitioning children on sex, FHR-status, global functioning, and psychopathology.

STUDY RESULTS

At both assessment points, we identified three subgroups based on neurocognitive performance: a moderately-severely impaired, a mildly impaired, and an above-average subgroup. A total of 12.8% of children transitioned to a different subgroup, of which the majority (85.2%) moved to a more impaired subgroup. Parental diagnosis of schizophrenia, but neither parental diagnosis of bipolar disorder, global functioning at age 7, psychopathology, nor sex significantly differentiated children transitioning to a more impaired subgroup from nontransitioning children.

CONCLUSIONS

During pre-adolescence, neurocognitive developmental lag is associated with being at FHR-SZ. Close attention to these children's neurocognitive development is indicated.

Animal Models of Relevance to the Schizophrenia Prodrome

Patients with schizophrenia often undergo a prodromal phase prior to diagnosis. Given the absence of significant therapeutic improvements, attention has recently shifted to the possibility of intervention during this early stage to delay or diminish symptom severity or even prevent onset. Unfortunately, the 20 or so trials of intervention to date have not been successful in either preventing onset or improving long-term outcomes in subjects who are at risk of developing schizophrenia. One reason may be that the biological pathways an effective intervention must target are not static. The prodromal phase typically occurs during late adolescence, a period during which a number of brain circuits and structures are still maturing. We propose that developing a deeper understanding of which circuits/processes and brain structures are still maturing at this time and which processes drive the transition to schizophrenia will take us a step closer to developing better prophylactic interventions. Fortunately, such knowledge is now emerging from clinical studies, complemented by work in animal models. Our task here is to describe what would constitute an appropriate animal model to study and to potentially intervene in such processes. Such a model would allow invasive analysis of the cellular and molecular substrates of the progressive neurobiology that defines the schizophrenia prodrome and hopefully offer valuable insights into potential prophylactic targets.

The stress-vulnerability model on the path to schizophrenia: Interaction between BDNF methylation and schizotypy on the resting-state brain network

The interplay between schizophrenia liability and environmental influences has been considered to be responsible for the development of schizophrenia. Recent neuroimaging studies have linked aberrant functional connectivity (FC) between the default-mode network (DMN) and the frontoparietal network (FPN) in the resting-state to the underlying neural mechanism of schizophrenia. By using schizotypy as the proxy for genetic-based liability to schizophrenia and methylation of brain-derived neurotrophic factor (BDNF) to represent environmental exposure, this study investigated the impact of the interaction between vulnerability and the environment on the neurobiological substrates of schizophrenia. Participants in this study included 101 healthy adults (HC) and 46 individuals with ultra-high risk for psychosis (UHR). All participants were tested at resting-state by functional magnetic resonance imaging, and group-independent component analysis was used to identify the DMN and the FPN. The Perceptual Aberration Scale (PAS) was used to evaluate the schizotypy level. The methylation status of BDNF was measured by pyrosequencing. For moderation analysis, the final sample consisted of 83 HC and 32 UHR individuals. UHR individuals showed reduced DMN-FPN network FC compared to healthy controls. PAS scores significantly moderated the relationship between the percentage of BDNF methylation and DMN-FPN network FC. The strength of the positive relationship between BDNF methylation and the network FC was reduced when the schizotypy level increased. These findings support the moderating role of schizotypy on the neurobiological mechanism of schizophrenia in conjunction with epigenetic changes.

Evaluating the Social Functioning Scale modified for use in individuals at clinical high-risk for psychosis

BACKGROUND

Social functioning deficits occur prior to the onset of psychosis and predict conversion to psychosis in clinical high-risk (CHR) populations. The Social Functioning Scale (SFS), a self-report measure of social functioning, is widely used in adults with psychosis but has not been tailored to CHR individuals. CHR syndromes overlap with the adolescent/young-adult developmental period, a time with unique social demands and contexts. The current study evaluates a modified version of the SFS in CHR individuals.

METHODS

Two independent samples of CHR participants (n = 84 and n = 45) and non-CHR participants (n = 312 and n = 42) completed the SFS and a psychosis-risk interview. Resulting factors were compared across diagnostic categories (CHR, Major Depressive Disorder, Generalized Anxiety Disorder) and community controls (CC) who were not excluded for any psychopathology except psychosis, depression, and anxiety. CHR participants completed scales of negative symptoms, global social and role functioning, cognition, and finger tapping as measures of convergent and divergent validity.

RESULTS

Exploratory factor analysis identified three SFS factors (RMSEA = 0.05) which demonstrated reliability in a confirmatory analysis in an independent sample: Recreation (α = 0.82), Nightlife (α = 0.85), and Interpersonal (α = 0.69). Factors and their composite score demonstrated increased social deficits in CHR compared to CC and depression groups and showed expected convergent (r's = 0.30-0.54) and divergent (r's = -0.004-0.26) validity with appropriate measures.

CONCLUSIONS

These findings suggest that there are reliable, valid, and developmentally relevant categories of social behavior within the SFS that differentiate between CHR and MDD or CC individuals. Recommendations for future work with CHR populations are included.

Mental disorders in preadolescent children at familial high-risk of schizophrenia or bipolar disorder - a four-year follow-up study: The Danish High Risk and Resilience Study, VIA 11: The Danish High Risk and Resilience Study, VIA 11

BACKGROUND

Children at familial high-risk of schizophrenia and bipolar disorder have an elevated prevalence of mental disorders but studies of children within a narrow age range are lacking and there are few conjoint studies of these two groups. Knowledge on their mental health is important for prevention and early intervention.

METHODS

The authors examined mental disorders and global functioning in children at familial high-risk of schizophrenia (FHR-SZ) and bipolar disorder (FHR-BP) compared with population-based controls. In a longitudinal cohort study, 450 children (FHR-SZ, n = 171; FHR-BP, n = 104; controls, n = 175), were assessed for Axis I disorders at baseline and four-year follow-up (mean age 11.9, SD 0.2) with the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children and for global functioning with Children's Global Assessment Scale.

RESULTS

Cumulative incidence of Any Axis I disorder was elevated by age 11 in children at FHR-SZ (54.4%, OR 3.0, 95% CI 1.9-4.7, p < .001) and children at FHR-BP (52.9%, OR 2.8, 95% CI 1.7-4.7, p < .001) compared with controls (28.6%). Children at FHR-SZ and FHR-BP had higher rates of affective disorders (OR 4.4, 95% CI 1.4-13.5, p = .009; OR 5.1, 95% CI 1.6-16.4, p = .007), anxiety disorders (OR 2.1, 95% CI 1.1-4.0, p = .02; OR 3.0, 95% CI 1.5-6.1, p = .002), and stress and adjustment disorders (OR 3.3, 95% CI 1.4-7.5, p = .006; OR 5.3, 95% CI 2.2-12.4, p < .001). Disruptive behavior disorders (OR 2.8, 95% CI 1.0-7.3, p = .04) and ADHD (OR 2.9, 95% CI 1.6-5.3, p < .001) were elevated in children at FHR-SZ. Both FHR groups had lower global functioning than controls. Cumulative incidence of disorders increased equally across the three groups from early childhood to preadolescence and level of functioning did not change differentially.

CONCLUSIONS

Children at FHR-SZ and FHR-BP have an elevated prevalence of mental disorders and poorer functioning than controls. Vulnerability in children at FHR manifests early and remains stable throughout childhood. Early attention toward their mental health and identification of those in need of intervention is warranted.

Treatments for Social Interaction Impairment in Animal Models of Schizophrenia: A Critical Review and Meta-analysis

BACKGROUND

While pharmacological treatments for positive symptoms of schizophrenia are widely used, their beneficial effect on negative symptoms, particularly social impairment, is insufficiently studied. Therefore, there is an increasing interest in preclinical research of potentially beneficial treatments, with mixed results. The current review aims to evaluate the efficacy of available treatments for social deficits in different animal models of schizophrenia.

STUDY DESIGN

A systematic literature search generated 145 outcomes for the measures "total time" and "number" of social interactions. Standardized mean differences (SMD) and 95% confidence interval (CI) were calculated, and heterogeneity was tested using Q statistics in a random-effect meta-analytic model. Given the vast heterogeneity in effect sizes, the animal model, treatment group, and sample size were all examined as potential moderators.

STUDY RESULTS

The results showed that in almost all models, treatment significantly improved social deficit (total time: SMD = 1.24; number: SMD = 1.1). The moderator analyses discovered significant subgroup differences across models and treatment subgroups. Perinatal and adult pharmacological models showed the most substantial influence of treatments on social deficits, reflecting relative pharmacological validity. Furthermore, atypical antipsychotic drugs had the highest SMD within each model subgroup.

CONCLUSIONS

Our findings indicate that the improvement in social interaction behaviors is dependent on the animal model and treatment family used. Implications for the preclinical and clinical fields are discussed.

Factors Related to Passive Social Withdrawal and Active Social Avoidance in Schizophrenia

ABSTRACT

Social withdrawal in schizophrenia may be a result of "passive" motivation (reduced drive to engage) or "active" motivation (increased drive to avoid). We conducted a cross-sectional, between-subjects study using self-report measures and social cognition tasks to evaluate the relationships between motivational subtypes, social abilities, and social functioning in schizophrenia spectrum (n = 52, ages 19-34). Regression models showed significant differences in passive and active withdrawal. Passive, but not active, motivation predicted social functioning as measured by a clinical interview. This suggests that motivation, especially passive type, plays an important role in social withdrawal in schizophrenia. However, on a self-report measure of social functioning, neither passive nor active motivation predicted outcomes, suggesting a potential disconnect between observer versus self-report measures when assessing social motivation. Furthermore, performance on tasks of social abilities did not predict motivation, which supports the idea that motivation is distinct from social ability and should be specifically addressed in treatment.

Episodic memory impairment in children and adolescents at risk for schizophrenia: A role for context processing

People with schizophrenia experience episodic memory impairments that have been theorized to reflect deficits in processing context (e.g., spatio-temporal features tied to a specific event). Although past research has reported episodic memory impairments in young people at-risk for schizophrenia, the extent to which these impairments reflect context processing deficits remains unknown. We addressed this gap in the literature by examining whether children and adolescents at risk for schizophrenia exhibit context processing deficits during free recall, a memory task with high contextual demands. Our sample included three groups (N = 58, 9–16 years old) varying in risk for schizophrenia:16 high-risk, unaffected first-degree relatives of patients with schizophrenia, bipolar disorder, and/or schizoaffective disorder, 22 clinical control participants with a comorbid disorder (ADHD and/or an anxiety disorder), and 20 healthy control participants. Participants first completed a free recall task and then completed a recognition memory task. Based on established theories of episodic memory, we assumed that context processing played a more pivotal role in free recall than recognition memory. Consequently, if schizophrenia risk is associated with context processing deficits, then memory impairment should be present in free recall measures that are most sensitive to context processing (i.e., recall accuracy and temporal contiguity). Consistent with this prediction, free recall accuracy and temporal contiguity were lower for the high-risk group than the healthy controls, whereas recognition memory was comparable across groups. These findings suggest that episodic memory impairments associated with schizophrenia in unaffected, first-degree relatives may reflect context processing deficits.

A systematic review of premorbid cognitive functioning and its timing of onset in schizophrenia spectrum disorders

Cognitive impairments are core features of established schizophrenia spectrum disorders (SSD). However, it remains unclear whether specific cognitive functions are differentially impaired pre-onset and at what age these impairments can be detected. The purpose of this review was to elucidate these issues through a systematic summary of results from longitudinal studies investigating impairment in specific cognitive domains as antecedents of SSD. Relevant studies were identified by electronic and manual literature searches and included any original study of cognitive domains any time pre-onset of SSDs that included a control group. Effect sizes were calculated by domain for studies comparing high-risk participants who developed SSD with those who did not. The strongest evidence for impairment pre-onset was for mental processing speed, verbal learning and memory, executive function, and social cognition. Some verbal impairments, like language abilities at age 3 and verbal learning and memory at age 7, may develop as static deficits. Conversely, some non-verbal impairments, like mental processing speed, visuospatial abilities, and visual working memory manifest as developmental lag and become significant later in life. Most effect sizes were small to moderate, except for verbal fluency (d' = 0,85), implying this impairment as central in high-risk participants who develop SSD. The present review documents extensive cognitive impairments pre-onset of SSD, and that these impairments start early in life, in line with the neurodevelopmental hypothesis of schizophrenia. Increased knowledge about cognitive impairments preonset can provide a better basis for understanding the complex pathogenesis of SSD as well as informing cognitive remediation programs.

Delay discounting in youth at clinical high-risk for psychosis and adults with schizophrenia

BACKGROUND

Schizophrenia (SZ) is typically preceded by a prodromal (i.e. pre-illness) period characterized by attenuated positive symptoms and declining functional outcome. Negative symptoms are prominent among individuals at clinical high-risk (CHR) for psychosis (i.e. those with prodromal syndromes) and highly predictive of conversion to illness. Mechanisms underlying negative symptoms in the CHR population are unclear. Two studies were conducted to evaluate whether abnormalities in a reward processing mechanism thought to be core to negative symptoms in SZ, value representation, also exist in CHR individuals and whether they are associated with negative symptoms transphasically.

METHODS

Study 1 included 33 individuals in the chronic phase of illness who have been diagnosed with schizophrenia or schizoaffective disorder (SZ) and 40 healthy controls (CN). Study 2 included 37 CHR participants and 45 CN. In both studies, participants completed the delay discounting (DD) task as a measure of value representation and the Brief Negative Symptom Scale was rated to measure negative symptoms.

RESULTS

Results indicated that patients with SZ had steeper discounting rates than CN, indicating impairments in value representation. However, CHR participants were unimpaired on the DD task. In both studies, steeper discounting was associated with greater severity of negative symptoms.

CONCLUSIONS

These findings suggest that deficits in value representation are associated with negative symptoms transphasically.

Preventive psychiatry: a blueprint for improving the mental health of young people

Preventive approaches have latterly gained traction for improving mental health in young people. In this paper, we first appraise the conceptual foundations of preventive psychiatry, encompassing the public health, Gordon's, US Institute of Medicine, World Health Organization, and good mental health frameworks, and neurodevelopmentally-sensitive clinical staging models. We then review the evidence supporting primary prevention of psychotic, bipolar and common mental disorders and promotion of good mental health as potential transformative strategies to reduce the incidence of these disorders in young people. Within indicated approaches, the clinical high-risk for psychosis paradigm has received the most empirical validation, while clinical high-risk states for bipolar and common mental disorders are increasingly becoming a focus of attention. Selective approaches have mostly targeted familial vulnerability and non-genetic risk exposures. Selective screening and psychological/psychoeducational interventions in vulnerable subgroups may improve anxiety/depressive symptoms, but their efficacy in reducing the incidence of psychotic/bipolar/common mental disorders is unproven. Selective physical exercise may reduce the incidence of anxiety disorders. Universal psychological/psychoeducational interventions may improve anxiety symptoms but not prevent depressive/anxiety disorders, while universal physical exercise may reduce the incidence of anxiety disorders. Universal public health approaches targeting school climate or social determinants (demographic, economic, neighbourhood, environmental, social/cultural) of mental disorders hold the greatest potential for reducing the risk profile of the population as a whole. The approach to promotion of good mental health is currently fragmented. We leverage the knowledge gained from the review to develop a blueprint for future research and practice of preventive psychiatry in young people: integrating universal and targeted frameworks; advancing multivariable, transdiagnostic, multi-endpoint epidemiological knowledge; synergically preventing common and infrequent mental disorders; preventing physical and mental health burden together; implementing stratified/personalized prognosis; establishing evidence-based preventive interventions; developing an ethical framework, improving prevention through education/training; consolidating the cost-effectiveness of preventive psychiatry; and decreasing inequalities. These goals can only be achieved through an urgent individual, societal, and global level response, which promotes a vigorous collaboration across scientific, health care, societal and governmental sectors for implementing preventive psychiatry, as much is at stake for young people with or at risk for emerging mental disorders.

Theory of mind in schizotypy: A behavioral and event-related potential (ERP) study

Background

Schizophrenia is known for their theory of mind (ToM) impairment. However, this impairment in schizotypy (schizotypal traits) lacks investigation.

Aims

The present study investigated: (1) whether ToM ability was impaired in schizotypy; (2) whether the ERP amplitudes in nine brain regions of interest associated with ToM (e.g., frontal region) in schizotypy and healthy controls differed; and (3) whether the relationship between ToM performances and ERP amplitudes in schizotypy differed from that in healthy controls.

Method

Forty eight adolescents and young adults (16 schizotypy) with the mean age of 18 years were tested. The Reading the Mind in the Eyes Test (RMET) was used to assess their ToM during which ERP amplitudes were recorded.

Results

The schizotypy group showed significantly lower ERP amplitudes in all conditions of RMET in frontal, frontal-central, central, occipital and temporal regions when compared to those in healthy controls. Also, schizotypy's ERP amplitudes in the frontal, frontal-central, central, occipital, and temporal regions were different from those in the healthy individuals in responding to different types of ToM stimuli (positive, negative and neutral). In schizotypy group, reaction time responding to emotional stimuli was negatively related to ERP amplitudes in the frontal, central-parietal, parietal, occipital, and occipito-temporal regions during RMET while no significant correlations were found in healthy controls.

Conclusion

The present findings inform us with the knowledge regarding the neural and behavioral abnormality of ToM in schizotypy, suggesting that brain activity can be an alternative to detect ToM impairment in schizotypy.

Prepubertal Environmental Enrichment Prevents Dopamine Dysregulation and Hippocampal Hyperactivity in MAM Schizophrenia Model Rats

BACKGROUND

Schizophrenia (SCZ) is a neurodevelopmental disorder with a progressive, prolonged course. Early prevention for SCZ is promising but overall lacks support from preclinical evidence. Previous studies have tested environmental enrichment (EE) in certain models of SCZ and discovered a broadly beneficial effect in preventing behavioral abnormalities relevant, yet not specific, to the disorder. Nonetheless, whether EE can prevent dopamine (DA) dysregulation, a hallmark of psychosis and SCZ, had not been tested.

METHODS

Using the MAM (methylazoxymethanol acetate) rat model of schizophrenia and saline-treated control animals, we investigated the long-term electrophysiological effects of prepubertal (postnatal day 21-40) EE on DA neurons, pyramidal neurons in the ventral hippocampus, and projection neurons in the basolateral amygdala. Anxiety-related behaviors in the elevated plus maze and locomotor responses to amphetamine were also analyzed.

RESULTS

Prepubertal EE prevented the increased population activity of DA neurons and the associated increase in locomotor response to amphetamine. Prepubertal EE also prevented hyperactivity in the ventral hippocampus but did not prevent hyperactivity in the basolateral amygdala. Anxiety-like behaviors in MAM rats were not ameliorated by prepubertal exposure to EE.

CONCLUSIONS

Twenty-day prepubertal EE is sufficient to prevent DA hyperresponsivity in the MAM model, measured by electrophysiological recordings and locomotor response to amphetamine. This effect is potentially mediated by normalizing excessive firing in the ventral hippocampus without affecting anxiety-like behaviors and basolateral amygdala firing. This study identified EE as a useful preventative approach that may protect against the pathophysiological development of SCZ.

Sex-Related Differences in White Matter Asymmetry and Its Implications for Verbal Working Memory in Psychosis High-Risk State

Objective: Sexual dimorphism has been investigated in schizophrenia, although sex-specific differences among individuals who are at clinical high-risk (CHR) for developing psychosis have been inconclusive. This study aims to characterize sexual dimorphism of language areas in the brain by investigating the asymmetry of four white matter tracts relevant to verbal working memory in CHR patients compared to healthy controls (HC). HC typically show a leftward asymmetry of these tracts. Moreover, structural abnormalities in asymmetry and verbal working memory dysfunctions have been associated with neurodevelopmental abnormalities and are considered core features of schizophrenia. Methods: Twenty-nine subjects with CHR (17 female/12 male) for developing psychosis and twenty-one HC (11 female/10 male) matched for age, sex, and education were included in the study. Two-tensor unscented Kalman filter tractography, followed by an automated, atlas-guided fiber clustering approach, were used to identify four fiber tracts related to verbal working memory: the superior longitudinal fasciculi (SLF) I, II and III, and the superior occipitofrontal fasciculus (SOFF). Using fractional anisotropy (FA) of tissue as the primary measure, we calculated the laterality index for each tract. Results: There was a significantly greater right>left asymmetry of the SLF-III in CHR females compared to HC females, but no hemispheric difference between CHR vs. HC males. Moreover, the laterality index of SLF-III for CHR females correlated negatively with Backward Digit Span performance, suggesting a greater rightward asymmetry was associated with poorer working memory functioning. Conclusion: This study suggests increased rightward asymmetry of the SLF-III in CHR females. This finding of sexual dimorphism in white matter asymmetry in a language-related area of the brain in CHR highlights the need for a deeper understanding of the role of sex in the high-risk state. Future work investigating early sex-specific pathophysiological mechanisms, may lead to the development of novel personalized treatment strategies aimed at preventing transition to a more chronic and difficult-to-treat disorder.

Metabolite abnormalities in psychosis risk: A meta-analysis of proton magnetic resonance spectroscopy studies

Accumulating evidence implicates that individuals at high-risk of psychosis have already exhibited pathophysiological changes in brain metabolites including glutamate, gamma-Aminobutyric Acid (GABA), N-Acetylaspartate (NAA), creatine (Cr), myo-inositol (MI) and choline (Cho). These changes may contribute to the development of schizophrenia and associate with psychotic genes. However, specific metabolic changes of brain sub-regions in individuals at risk have still been controversial. Thus, the current study aimed to investigate the brain metabolic changes including glutamate, Glx, GABA, GABA/Glx, NAA, Cr, MI and Cho levels in individuals at risk by conducting a case-control meta-analysis and meta-regression of proton magnetic resonance spectroscopy studies. Primary outcomes revealed that individuals at risk exhibited increased Cr levels at the rostral medial prefrontal cortex (rmPFC), decreased NAA and Cr levels at the thalamus, and increased MI levels at the dorsolateral prefrontal cortex. Sub-group analyses further indicated that individuals with clinical high-risk (CHR) exhibited increased Cr levels at the medial prefrontal cortex (mPFC) and decreased Glx levels at the thalamus, while individuals with genetic risk (siblings of psychiatric patients) exhibited significant increased Glx and MI levels at the mPFC. However, GABA, GABA/Glx and Cho levels showed no significant result. These findings suggest that the dysfunctional metabolites at the mPFC and the thalamus may be an essential neurobiological basis at the early stage of psychosis.

Do psychosis prodrome onset negative symptoms predict first presentation negative symptoms?

Background:

Negative symptoms have been previously reported during the psychosis prodrome, however our understanding of their relationship with treatment-phase negative symptoms remains unclear.

Objectives:

We report the prevalence of psychosis prodrome onset negative symptoms (PONS) and ascertain whether these predict negative symptoms at first presentation for treatment.

Methods:

Presence of expressivity or experiential negative symptom domains was established at first presentation for treatment using the Scale for Assessment of Negative Symptoms (SANS) in 373 individuals with a first episode psychosis. PONS were established using the Beiser Scale. The relationship between PONS and negative symptoms at first presentation was ascertained and regression analyses determined the relationship independent of confounding.

Results:

PONS prevalence was 50.3% in the schizophrenia spectrum group (n = 155) and 31.2% in the non-schizophrenia spectrum group (n = 218). In the schizophrenia spectrum group, PONS had a significant unadjusted (χ2 = 10.41, P < 0.001) and adjusted (OR = 2.40, 95% CI = 1.11–5.22, P = 0.027) association with first presentation experiential symptoms, however this relationship was not evident in the non-schizophrenia spectrum group. PONS did not predict expressivity symptoms in either diagnostic group.

Conclusion:

PONS are common in schizophrenia spectrum diagnoses, and predict experiential symptoms at first presentation. Further prospective research is needed to examine whether negative symptoms commence during the psychosis prodrome.

Categorical and Dimensional Approaches to Examining the Joint Effect of Autism and Schizotypal Personality Disorder on Sustained Attention

INTRODUCTION

Accumulating evidence for the co-occurrence autism spectrum disorder (ASD) and schizotypal personality disorder (SPD) at both the diagnostic and symptom levels raises important questions about the nature of their association and the effect of their co-occurrence on the individual's phenotype and functional outcome. Research comparing adults with ASD and SPD, as well as the impact of their co-occurrence on outcomes is extremely limited. We investigated executive functioning in terms of response inhibition and sustained attention, candidate endophenotypes of both conditions, in adults with ASD, SPD, comorbid ASD and SPD, and neurotypical adults using both categorical and dimensional approaches.

METHODS

A total of 88 adults (Mean Age = 37.54; SD = 10.17): ASD (n = 26; M/F = 20/6); SPD (n = 20; M/F = 14/6); comorbid ASD and SPD (n=9; M/F=6/3) and neurotypicals (n=33; M/F=23/10) completed the Sustained Attention to Response Task (SART) in both its fixed and random forms. Positive and autistic symptom severity was assessed with the positive subscale of the Positive and Negative Syndrome Scale (PANSSpos) and the PANSS Autism Severity Score (PAUSS), respectively.

RESULTS

Controlling for full scale IQ, working memory and medication dosage, group analyses revealed that the comorbid group committed fewer omission errors than the ASD group on the fixed SART, and fewer omission errors than the ASD and SPD groups on the random SART. The individual difference analyses of the entire sample revealed that the PANSSpos and PAUSS interactively reduced omission errors in both the fixed and random SARTs, as well as increased d' scores, indicative of improved overall performance. We observed no significant results for commission errors or reaction time.

CONCLUSIONS

Concurrent elevated levels of autistic and positive psychotic symptoms seem to be associated with improved sustained attention abilities (reduced omission errors) but not inhibition (commission errors). Our findings highlight the importance of investigating the concurrent effect of ASD and SPD at both the symptom and diagnostic levels, and raise important questions for future research regarding the clinical and behavioral phenotypes of adults with dual diagnosis and, more generally, about the nature of the relationship between ASD and SPD.

Evidence for Specific Associations Between Depressive Symptoms, Psychotic Experiences, and Suicidal Ideation in Chilean Adolescents From the General Population

Associations between psychotic experiences and suicidal ideation are not yet fully understood, and the potential role of depressive symptoms in this relationship remains unclear. The current study examined relationships between depressive symptoms (DS), psychotic experiences (PE) and suicidal ideation (SI) using two complementary approaches on cross-sectional data from a community sample of adolescents aged 13-19 years (N = 1,591). First, we investigated the association between the three domains using mediation analysis, showing that depressive symptoms partly mediate the relationship between psychotic experiences and suicidal ideation. Second, we looked at associations between the three domains at item level using network analysis. Specific associations between symptoms of the three domains were found, indicating depressive symptoms of sadness, avolition, pessimism, and self-criticalness/worthlessness as the most central symptoms in the network. Suicidal ideation was associated with the depressive symptoms pessimism and worthlessness, to social anxiety, and to perceptual anomalies. Our results show that the mediating effect of depressive symptoms between psychotic experiences and suicidal ideation may be due to associations between specific aspects of SI, depressive symptoms and psychotic experiences. These findings can contribute to the planning of health services and programs aimed at the timely detection of psychopathology and suicidal risk in young people.

Anxiety Mediates the Relationship between Psychotic-Like Experiences and Social Functioning in the General Population

INTRODUCTION

Within the psychosis continuum that includes schizophrenia (SZ) at the severe end and the general population at the mild end, anxiety may negatively impact social functioning more than psychosis or psychotic-like experiences (PLE). This claim is supported by previous reports that show anxiety mediates the relationship between psychosis and social functioning in SZ, suggesting anxiety is critical to social functioning in SZ. Yet no studies have examined a similar relationship in the general population, and this is important because people with PLE are at a significantly higher risk for developing full-blown psychosis.

METHODS

Similar to those with SZ, we predicted heightened anxiety would mediate the relationship between PLE, as measured by The -Oxford-Liverpool Inventory of Feelings and Experiences, and social functioning, as measured by Social Adjustment Scale - Self-Report, in the general population.

RESULTS

Indeed, the current study showed that the relationship between PLE and social functioning was mediated by anxiety (z = 7.81, p < 0.001) within an unselected crowdsourcing sample representative of the general population (Amazon M-Turk; n = 197, mean age 32.38 years).

CONCLUSION

Taken together with previous reports, the current findings suggest that anxiety is a functionally relevant dimension across the psychosis continuum and improving anxiety may improve social functioning across this continuum.

Characterization of children and adolescents with psychosis risk syndrome: The Children and Adolescents Psychosis Risk Syndrome (CAPRIS) study

AIM

Despite the interest in psychosis risk syndrome (PRS) in children and adolescents, information on the syndrome in this population is scarce.

METHODS

Prospective naturalistic multi-site study in which 10- to 17-year-old help-seeking subjects who met PRS criteria (positive or negative attenuated symptoms; brief limited intermittent psychotic symptoms; genetic risk or schizotypal personality disorder plus impairment in functioning) were included, along with 45 age and sex-matched healthy controls (HC). All subjects were clinically and functionally assessed.

RESULTS

Ninety-one PRS subjects (PRSS) with a mean age of 15.5 ± 1.4 met inclusion criteria (IC). Compared with HC, PRSS presented worse global and academic functioning in the previous year, had experienced more psychiatric and psychological problems, and presented gestational ages outside the normal range. More than 80% of PRSS met ≥2 IC, with 65.9% having one Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Text Revision diagnosis, and 61.7% of those having ≥2 diagnoses. Some 49.5% of PRSS had a first- or second-degree family history (FH) of psychosis. Patients with first- and second-degree FH do not differ in their clinical expression.

CONCLUSIONS

Children and adolescents with PRS are a patient group with a pattern of neurodevelopmental impairment and clinical complexity similar to patients with schizophrenia spectrum disorders, highlighting the importance of assessing these variables in child and adolescent samples. PRSS with first- and second-degree relatives with FH do not present differences in their clinical presentation, suggesting that including these two groups of patients in the genetic risk criteria would enrich knowledge of these criteria.

Longitudinal Cognitive Performance in Individuals at Ultrahigh Risk for Psychosis: A 10-year Follow-up

It remains unclear whether the onset of psychosis is associated with deterioration in cognitive performance. The aim of this study was to examine the course of cognitive performance in an ultrahigh risk (UHR) cohort, and whether change in cognition is associated with transition to psychosis and change in functioning. Consecutive admissions to Personal Assessment and Crisis Evaluation (PACE) Clinic between May 1994 and July 2000 who had completed a comprehensive cognitive assessment at baseline and follow-up were eligible (N = 80). Follow-up ranged from 7.3 to 13.4 years (M = 10.4 years; SD = 1.5). In the whole sample, significant improvements were observed on the Similarities (P = .03), Information (P < .01), Digit Symbol Coding (P < .01), and Trail Making Test-B (P = .01) tasks, whereas performance on the Rey Auditory Verbal Learning Test (Trials 1-3) declined significantly (P < .01) over the follow-up period. Change in performance on cognitive measures was not significantly associated with transition status. Taking time to transition into account, those who transitioned after 1 year showed significant decline on Digit Symbol Coding, whereas those who did not transition improved on this measure (P = .01; effect size [ES] = 0.85). Small positive correlations were observed between improvements in functioning and improvements in performance on Digit Symbol Coding and Arithmetic (0.24, P = .03 and 0.28, P = .01, respectively). In summary, the onset of psychosis was not associated with deterioration in cognitive ability. However, specific findings suggest that immediate verbal learning and memory, and processing speed may be relevant domains for future risk models and early intervention research in UHR individuals.

Predictors of psychotic symptoms among young people with special educational needs

BACKGROUND

Psychotic symptoms and psychotic disorders occur at increased rates in adults with intellectual disability, including borderline intellectual functioning, compared with the general population. Little is known about the development of such symptoms in this population.AimsTo examine whether clinical factors predictive of psychotic disorder in a familial study of schizophrenia also apply to those with intellectual disability.

METHOD

Adolescents with special educational needs (SEN) were assessed with the Structured Interview for Schizotypy (SIS) and Childhood Behavioural Checklist (CBCL). These scores were used to prospectively divide participants based on their anticipated risk for psychotic disorder. A subsample were reassessed three times over 6 years, using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

The SEN group were more symptomatic than controls throughout (Cohen's d range for PANSS subscale scores: 0.54-1.4, all P &lt; 0.007). Over 6 years of follow-up, those above the SIS and CBCL cut-off values at baseline were more likely than those below to display morbid positive psychotic symptoms (odds ratio, 3.5; 95% CI 1.3-9.0) and develop psychotic disorder (odds ratio, 11.4; 95% CI 2.6-50.1). Baseline SIS and CBCL cut-off values predicted psychotic disorder with sensitivity of 0.67, specificity of 0.85, positive predictive value of 0.26 and negative predictive value of 0.97.

CONCLUSIONS

Adolescents with SEN have increased psychotic and non-psychotic symptoms. The personality and behavioural features associated with later psychotic disorder in this group are similar to those in people with familial loading. Relatively simple screening measures may help identify those in this vulnerable group who do and do not require monitoring for psychotic symptoms.Declaration of interestNone.

FRONTAL ALPHA ASYMMETRY IN YOUTH AT CLINICAL HIGH-RISK FOR PSYCHOSIS

PURPOSE OF THE REVIEW

Negative symptoms are highly predictive of whether individuals at clinical high-risk (CHR) develop a psychotic disorder. However, little is known about pathophysiological mechanisms underlying negative symptoms during this period. The current study examined neurophysiological mechanisms underlying negative symptoms in CHR individuals using electroencephalography frontal alpha asymmetry power, a biomarker of approach and avoidance motivation.

RECENT FINDINGS

People with schizophrenia display abnormal patterns of frontal alpha asymmetry indicative of reduced approach motivation. However, It is unknown whether similar abnormalities occur in CHR youth that predict negative symptoms.

SUMMARY

Results indicated that CHR and healthy controls did not differ in frontal alpha asymmetry scores. However, in CHR youth, frontal alpha asymmetry was inversely correlated with the motivation and pleasure dimension of negative symptoms, which was accounted for by mood symptoms. Findings suggest that depression contributes to reduced approach motivation in CHR youth that manifests clinically as negative symptoms.

Clinical psychopathology in youth at familial high risk for psychosis

AIM

While the course of psychopathology has been explored from an index mental health diagnosis onwards, there are few detailed, prospective studies of the occurrence of clinical psychopathology in youth with familial risk for severe mental illnesses such as psychosis. We sought to describe the appearance of Axis I psychopathology in a unique sample of adolescents with a family history of schizophrenia (FHR).

METHODS

One hundred and sixty two first- and second-degree relatives (mean age 15.7 ± 3.6; range 8-25) of probands with schizophrenia or schizoaffective disorder were assessed at baseline and annual intervals for up to 3 years, focusing on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) Axis I psychopathology.

RESULTS

Fourteen individuals (8.6%) developed a psychotic disorder. One hundred and five subjects (65%) met criteria for an Axis I disorder over the course of the study, the most common of which was a depressive episode (40 subjects; 25%). Of the 148 individuals who did not develop psychosis, 91 (61%) had one or more Axis I disorders compared with 10/14 converters who had a comorbid Axis I disorder (71%). Ordered by increasing age of onset, diagnoses included cognitive and externalizing disorders, anxiety disorders, affective disorders, substance use disorders and psychotic disorders.

CONCLUSIONS

In addition to an elevated risk of psychosis, young FHR relatives manifest a broad range of non-psychotic Axis I psychopathology in childhood and adolescence. This breadth of diagnoses has implications for the structure and function of mental health services for young people.

At-risk studies and clinical antecedents of psychosis, bipolar disorder and depression: a scoping review in the context of clinical staging

Identifying young people at risk of developing serious mental illness and identifying predictors of onset of illness has been a focus of psychiatric prediction research, particularly in the field of psychosis. Work in this area has facilitated the adoption of the clinical staging model of early clinical phenotypes, ranging from at-risk mental states to chronic and severe mental illness. It has been a topic of debate if these staging models should be conceptualised as disorder-specific or transdiagnostic. In order to inform this debate and facilitate cross-diagnostic discourse, the present scoping review provides a broad overview of the body of literature of (a) longitudinal at-risk approaches and (b) identified antecedents of (homotypic) illness progression across three major mental disorders [psychosis, bipolar disorder (BD) and depression], and places these in the context of clinical staging. Stage 0 at-risk conceptualisations (i.e. familial high-risk approaches) were identified in all three disorders. However, formalised stage 1b conceptualisations (i.e. ultra-high-risk approaches) were only present in psychosis and marginally in BD. The presence of non-specific and overlapping antecedents in the three disorders may support a general staging model, at least in the early stages of severe psychotic or mood disorders.

Social aversive conditioning in youth at clinical high risk for psychosis and with psychosis: An ERP study

BACKGROUND

Social cognition and emotion processing are compromised in schizophrenia. Disruptions in these domains may also be present during the psychosis-risk state. Aversive conditioning is an established translational research paradigm to investigate affective reactivity and learning. Using an aversive conditioning ERP paradigm with social cues, we examined whether psychosis patients and at-risk youths differentially respond to aversively conditioned faces.

METHODS

Participants (ages 10-30) were enrolled into three demographically-matched groups: clinical risk for psychosis (CR, n = 32), psychosis (PS, n = 26), and healthy control (HC, n = 33). EEGs were recorded during a delay aversive conditioning task in which three neutral faces were paired with an aversive tone at 100%, 50% and 0% contingencies. Analysis focused on group differences in ERP peaks representing visual processing (occipital P120), emotional valence (frontal VPP), and directed attention (parietal-occipital P300), for dimensions of aversiveness (100% vs. 0%) and unpredictability (50% vs. 100% + 0%).

RESULTS

HC, but not CR or PS, showed increased P300 amplitude to aversive vs. non-aversive conditioned stimuli. CR, but not PS or HC, showed increased VPP amplitude to unpredictable vs. predictable stimuli.

CONCLUSIONS

PS and CR both fail to allocate appropriate salience to social cues that are predictably aversive. CR, but not PS exhibit heightened emotional reactivity to social cues that are of uncertain salience. Clinical risk for schizophrenia may involve neural abnormalities distinct from both healthy and fully-established disease states.

Impact of rurality and substance use on young people at ultra high risk for psychosis

BACKGROUND

Longitudinal research into early intervention for youth at ultra high risk (UHR) for psychosis demonstrates beneficial outcomes including increased treatment compliance and greater participation in education and the workforce. Despite known barriers for rural youth accessing mental health services, research comparing urban and rural UHR youth is lacking. The study included an examination of the impact of substance use on functioning of UHR youth.

METHODS

Youth aged 12 to 25 years were recruited from the urban area of Newcastle or the rural area of Orange, New South Wales, Australia, and identified as UHR by the Comprehensive Assessment of At Risk Mental States. Rural and urban youth were compared on clinical profiles, social and occupational functioning and substance use.

RESULTS

The rural youth showed different help-seeking behaviours and had greater functional impairment than urban youth. Substance use was common across the sample of 57 youth (mean age 16.5 years, 56% female) and a history of hazardous substance use was associated with higher levels of depression. Rural youth (n = 32) were more likely than urban youth to be taking antidepressants at baseline (44% compared with 16%).

CONCLUSION

Different patterns of help seeking by rural UHR youth suggest a need for greater access to psychosis informed primary care early intervention services. Interventions should target functional decline to prevent adverse outcomes such as reduced community participation and unemployment. In addition, interventions for substance use should be a priority for UHR youth, who should also be screened and monitored for depressive symptoms and treated for depression if indicated.

Examining relationships between psychotic experiences and suicidal ideation in adolescents using a network approach

BACKGROUND

Suicide is one of the leading causes of death in young individuals. Timely and adequate identification of individuals with suicidal ideation could prevent from suicidal behavior. Psychotic experiences (PE) have been shown to increase levels of suicidal ideation (SI) in the general population. Therefore, detailed investigation of the relationship of PE and SI is relevant. However, the exact nature of the relationship between these two phenomena remains unclear. Understanding psychopathology as a complex network of interacting symptoms could be helpful to elucidate specific associations existing between PE and SI.

METHOD

A specific type of network analysis, the Ising model, was used to examine connections between dichotomized questions on psychotic experiences and suicidal ideation in a cross-sectional study with 1685 adolescents from the general population aged 13-18 years.

RESULTS

SI was mostly connected to the PE domains perceptual anomalies (PA) and bizarre experiences (BE), which have higher strength values in the network. Central nodes within these domains, as indexed by higher centrality measures (strength and betweenness) were: auditory experiences (PA1: hearing voices when you are alone), persecutory ideation (BE1: feelings of being persecuted; BE2: conspiracy against you), and social anxiety (SANX) (SANX1: I cannot get close to people).

CONCLUSIONS

Suicidal ideation is differentially connected to specific psychotic experiences. Auditory PE, persecutory ideation, and social anxiety symptoms could play a central role in the interconnectedness of the two constructs.

Negative symptoms of psychosis: A life course approach and implications for prevention and treatment

AIM

Negative symptoms are a cause of enduring disability in serious mental illness. In spite of this, the development of effective treatments for negative symptoms has remained slow. The challenge of improving negative symptom outcomes is compounded by our limited understanding of their aetiology and longitudinal development.

METHODS

A literature search was conducted for life course approach of negative symptoms using PubMed. Further articles were included following manual checking of reference lists and other search strategies. The paper contains a theoretical synthesis of the literature, summarized using conceptual models.

RESULTS

Negative symptom definitions are compared and considered within a context of the life course. Previous studies suggest that several illness phases may contribute to negative symptoms, highlighting our uncertainty in relation to the origin of negative symptoms.

CONCLUSIONS

Similar to other aspects of schizophrenia, negative symptoms likely involve a complex interplay of several risk and protective factors at different life phases. Concepts suggested in this article, such as "negative symptom reserve" theory, require further research, which may inform future prevention and treatment strategies.

Delusional disorder: The role of personality and emotions on delusional ideation

The relationship between personality and Delusional Disorder in still debated. The present study aimed to evaluate the role of personality features and emotional dispositions on the proneness to delusional beliefs, through the lens of a dimensional approach. 91 outpatients were administered the Structured Interview for DSM-IV Personality Disorders, the Pathological Narcissism Inventory, the Positive and Negative Affect Schedule and the Peters et al. Delusions Inventory. Delusion proneness was positively related to the "Hiding the Self" domain of narcissistic vulnerability and to paranoid traits and negatively related to "Positive Affect". Paranoid traits and "Hiding the Self" significantly interacted in influencing delusion ideation. These data suggest that proneness to delusion depends, at least in part, on a complex interplay between specific emotional and paranoid dispositions within personality.

Polygenic risk for schizophrenia, transition and cortical gyrification: a high-risk study

BACKGROUND

Schizophrenia is a highly heritable disorder, linked to several structural abnormalities of the brain. More specifically, previous findings have suggested that increased gyrification in frontal and temporal regions are implicated in the pathogenesis of schizophrenia.

METHODS

The current study included participants at high familial risk of schizophrenia who remained well (n = 31), who developed sub-diagnostic symptoms (n = 28) and who developed schizophrenia (n = 9) as well as healthy controls (HC) (n = 16). We first tested whether individuals at high familial risk of schizophrenia carried an increased burden of trait-associated alleles using polygenic risk score analysis. We then assessed the extent to which polygenic risk was associated with gyral folding in the frontal and temporal lobes.

RESULTS

We found that individuals at high familial risk of schizophrenia who developed schizophrenia carried a significantly greater burden of risk-conferring variants for the disorder compared to those at high risk (HR) who developed sub-diagnostic symptoms or remained well and HC. Furthermore, within the HR cohort, there was a significant and positive association between schizophrenia polygenic risk score and bilateral frontal gyrification.

CONCLUSIONS

These results suggest that polygenic risk for schizophrenia impacts upon early neurodevelopment to confer greater gyral folding in adulthood and an increased risk of developing the disorder.

Associations between psychosis endophenotypes across brain functional, structural, and cognitive domains

BACKGROUND

A range of endophenotypes characterise psychosis, however there has been limited work understanding if and how they are inter-related.

METHODS

This multi-centre study includes 8754 participants: 2212 people with a psychotic disorder, 1487 unaffected relatives of probands, and 5055 healthy controls. We investigated cognition [digit span (N = 3127), block design (N = 5491), and the Rey Auditory Verbal Learning Test (N = 3543)], electrophysiology [P300 amplitude and latency (N = 1102)], and neuroanatomy [lateral ventricular volume (N = 1721)]. We used linear regression to assess the interrelationships between endophenotypes.

RESULTS

The P300 amplitude and latency were not associated (regression coef. -0.06, 95% CI -0.12 to 0.01, p = 0.060), and P300 amplitude was positively associated with block design (coef. 0.19, 95% CI 0.10-0.28, p 0.38). All the cognitive endophenotypes were associated with each other in the expected directions (all p < 0.001). Lastly, the relationships between pairs of endophenotypes were consistent in all three participant groups, differing for some of the cognitive pairings only in the strengths of the relationships.

CONCLUSIONS

The P300 amplitude and latency are independent endophenotypes; the former indexing spatial visualisation and working memory, and the latter is hypothesised to index basic processing speed. Individuals with psychotic illnesses, their unaffected relatives, and healthy controls all show similar patterns of associations between endophenotypes, endorsing the theory of a continuum of psychosis liability across the population.

Decomposing P300 into correlates of genetic risk and current symptoms in schizophrenia: An inter-trial variability analysis

BACKGROUND

The P300 event-related potential (ERP) component, which reflects cognitive processing, is a candidate biomarker for schizophrenia. However, the role of P300 in the pathophysiology of schizophrenia remains unclear because averaged P300 amplitudes reflect both genetic predisposition and current clinical status. Thus, we sought to identify which aspects of P300 are associated with genetic risk versus symptomatic status via an inter-trial variability analysis.

METHODS

Auditory P300, clinical symptoms, and neurocognitive function assessments were obtained from forty-five patients with schizophrenia, thirty-two subjects at genetic high risk (GHR), thirty-two subjects at clinical high risk (CHR), and fifty-two healthy control (HC) participants. Both conventional averaging and inter-trial variability analyses were conducted for P300, and results were compared across groups using analysis of variance (ANOVA). Pearson's correlation was utilized to determine associations among inter-trial variability for P300, current symptoms and neurocognitive status.

RESULTS

Average P300 amplitude was reduced in the GHR, CHR, and schizophrenia groups compared with that in the HC group. P300 inter-trial variability was elevated in the CHR and schizophrenia groups but relatively normal in the GHR and HC groups. Furthermore, P300 inter-trial variability was significantly related to negative symptom severity and neurocognitive performance results in schizophrenia patients.

CONCLUSIONS

These results suggest that P300 amplitude is an endophenotype for schizophrenia and that greater inter-trial variability of P300 is associated with more severe negative and cognitive symptoms in schizophrenia patients.

Social affective context reveals altered network dynamics in schizophrenia patients

Impairments in social cognition and interactions are core psychopathologies in schizophrenia, often manifesting as an inability to appropriately relate to the intentions and feelings of others. Neuroimaging has helped to demarcate the dynamics of two distinct functional connectivity circuits underlying the social-affective processes related to mentalization (known as Theory of Mind, ToM) and somatic-affiliation (known as Embodied Simulation, ES). While evidence points to abnormal activation patterns within these networks among those suffering from schizophrenia, it is yet unclear however, if these patients exhibit this abnormal functional connectivity in the context of social-affective experiences. The current fMRI study, investigated functional connectivity dynamics within ToM and ES networks as subjects experienced evolving cinematic portrayals of fear. During scanning, schizophrenia patients and healthy controls passively watched a cinematic scene in which a mother and her son face various threatening events. Participants then provided a continuous and retrospective report of their fear intensity during a second viewing outside the scanner. Using network cohesion index (NCI) analysis, we examined modulations of ES-related and ToM-related functional connectivity dynamics and their relation to symptom severity and the continuous emotional ratings of the induced cinematic fear. Compared to patients, healthy controls showed higher ES-NCI and marginally lower ToM-NCI during emotional peaks. Cross-correlation analysis revealed an intriguing dynamic between NCI and the inter-group difference of reported fear. Schizophrenia patients rated their fear as lower relative to healthy controls, shortly after exhibiting lower ES connectivity. This increased difference in rating was also followed by higher ToM connectivity among schizophrenia patients. The clinical relevance of these findings is further highlighted by the following two results: (a) ToM-NCI was found to have a strong correlation with the severity of general symptoms during one of the two main emotional peaks (Spearman R = 0.77); and (b) k-mean clustering demonstrated that the networks' NCI dynamic during the social-affective context reliably differentiated between patients and controls. Together, these findings point to a possible neural marker for abnormal social-affective processing in schizophrenia, manifested as the disturbed balance between two functional networks involved in social-affective affiliation. This in turn suggests that exaggerated mentalization over somatic-affiliative processing, in response to another's' distress may underlie social-affective deficits in schizophrenia.

Developmental aspects of schizophrenia and related disorders: possible implications for treatment strategies

Schizophrenia and other schizophrenia-spectrum disorders are neurodevelopmental disorders which may share genetic susceptibility factors and represent differential expressions of an underlying vulnerability. Schizophrenia may have its onset in childhood and can be reliably diagnosed. However, developmental factors modulate disease expression in children. Although the prevalence of schizophrenia in childhood is low, children who develop schizophrenia in adult life may show subtle and non-specific developmental abnormalities, consistent with the neurodevelopmental hypothesis. Studies of the schizophrenia prodrome also demonstrate that abnormalities may be apparent years before the onset of positive symptoms. Such evidence raises the possibility of using preventive approaches in the treatment of schizophrenia. Further advances in our knowledge of the aetiopathology of schizophrenia (and the identification of endophenotypes within the group of schizophrenia and related disorders) may further improve our ability to predict disease development, making implementation of preventive interventions more achievable.

IQ tests as aids to diagnosis and management in early schizophrenia

Intellectual and other more specific neurocognitive impairments in schizophrenia are important for understanding the aetiology of the condition and its likely outcome. However, these impairments are not usually considered important for supporting a diagnosis in suspected early schizophrenia. IQ testing is widely available and probably acceptable to most people likely to be experiencing the early stages of psychosis and who might be unable or unwilling to disclose details of their history and mental state or to cooperate with more comprehensive neuropsychological assessment. Although in general IQ tests have only limited diagnostic value in schizophrenia, the finding of a substantial decline in IQ score from the estimated premorbid level may be helpful in supporting a provisional diagnosis of early schizophrenia in cases without organic signs in which the clinical picture is unclear or incomplete. More important, the results of IQ tests may contribute to a better understanding of patients' impairments and assist clinical management in a number of ways, as illustrated here by three fictional case studies.

Imaging and Genetic Biomarkers Predicting Transition to Psychosis

The search for diagnostic and prognostic biomarkers in schizophrenia care and treatment is the focus of many within the research community. Longitudinal cohorts of patients presenting at elevated genetic and clinical risk have provided a wealth of data that has informed our understanding of the development of schizophrenia and related psychotic disorders.Imaging follow-up of high-risk cohorts has demonstrated changes in cerebral grey matter of those that eventually transition to schizophrenia that predate the onset of symptoms and evolve over the course of illness. Longitudinal follow-up studies demonstrate that observed grey matter changes can be employed to differentiate those who will transition to schizophrenia from those who will not prior to the onset of the disorder.In recent years our understanding of the genetic makeup of schizophrenia has advanced significantly. The development of modern analysis techniques offers researchers the ability to objectively quantify genetic risk; these have been successfully applied within a high-risk paradigm to assist in differentiating between high-risk individuals who will subsequently become unwell and those who will not.This chapter will discuss the application of imaging and genetic biomarkers within high-risk groups to predict future transition to schizophrenia and related psychotic disorders. We aim to provide an overview of current approaches focussing on grey matter changes that are predictive of future transition to illness, the developing field of genetic risk scores and other methods being developed to aid clinicians in diagnosis and prognosis.

A Possible Link between Anxiety and Schizophrenia and a Possible Role of Anhedonia

In the prodromal phase of schizophrenia, severe alterations of the visual appearance of the environment have been found, accompanied by a state of intense anxiety. The present study considers the possibility that these alterations really exist in the appearance of objects, but that healthy people do not see them. The image of the world that we see is continuously deformed and fragmented by foreshortenings, partial overlapping, and so on and must be constantly reassembled and interpreted; otherwise, it could change so much that we would hardly recognize it. Since pleasure has been found to be involved in visual and cognitive information processing, the possibility is considered that anhedonia (the reduction of the ability to feel pleasure) might interfere with the correct reconstruction and interpretation of the image of the environment and alter its appearance. The possibility is also considered that these alterations might make the environment hostile, might at times evoke the sensation of being trapped by a predator, and might be the cause of the anxiety that accompanies them. According to some authors, they might also induce delusional ideas, in an attempt to restore meaning in a world that has become chaotic and frightening.

A polygenic risk score analysis of psychosis endophenotypes across brain functional, structural, and cognitive domains

This large multi-center study investigates the relationships between genetic risk for schizophrenia and bipolar disorder, and multi-modal endophenotypes for psychosis. The sample included 4,242 individuals; 1,087 patients with psychosis, 822 unaffected first-degree relatives of patients, and 2,333 controls. Endophenotypes included the P300 event-related potential (N = 515), lateral ventricular volume (N = 798), and the cognitive measures block design (N = 3,089), digit span (N = 1,437), and the Ray Auditory Verbal Learning Task (N = 2,406). Data were collected across 11 sites in Europe and Australia; all genotyping and genetic analyses were done at the same laboratory in the United Kingdom. We calculated polygenic risk scores for schizophrenia and bipolar disorder separately, and used linear regression to test whether polygenic scores influenced the endophenotypes. Results showed that higher polygenic scores for schizophrenia were associated with poorer performance on the block design task and explained 0.2% (p = 0.009) of the variance. Associations in the same direction were found for bipolar disorder scores, but this was not statistically significant at the 1% level (p = 0.02). The schizophrenia score explained 0.4% of variance in lateral ventricular volumes, the largest across all phenotypes examined, although this was not significant (p = 0.063). None of the remaining associations reached significance after correction for multiple testing (with alpha at 1%). These results indicate that common genetic variants associated with schizophrenia predict performance in spatial visualization, providing additional evidence that this measure is an endophenotype for the disorder with shared genetic risk variants. The use of endophenotypes such as this will help to characterize the effects of common genetic variation in psychosis.

Two-Year Clinical and Functional Outcomes of an Asian Cohort at Ultra-High Risk of Psychosis

Background: To determine the 2-year clinical and functional outcomes of an Asian cohort at ultra-high risk (UHR) of psychosis. Method: This was a longitudinal study with a follow-up period of 2 years on 255 help-seeking adolescents and young adults at UHR of psychosis managed by a multi-disciplinary mental health team in Singapore. Clients received case management, psychosocial, and pharmacological treatment as appropriate. Data comprising symptom and functional outcomes were collected over the observation period by trained clinicians and psychiatrists. Results: The 2-year psychosis transition rate was 16.9%, with a median time to transition of 168 days. After 2 years, 14.5% of the subjects had persistent at-risk symptoms while 7.5% developed other non-psychotic psychiatric disorders. 38.4% of the cohort had recovered and was discharged from mental health services. The entire cohort's functioning improved as reflected by an increase in the score of the Social and Occupational Functioning Assessment Scale during the follow-up period. Predictors to psychosis transition included low education level, baseline unemployment, a history of violence, and brief limited intermittent psychotic symptoms, while male gender predicted the persistence of UHR state, or the development of non-psychotic disorders. Conclusion: Use of the current UHR criteria allows us to identify individuals who are at imminent risk of developing not just psychosis, but also those who may develop other mental health disorders. Future research should include identifying the needs of those who do not transition to psychosis, while continuing to refine on ways to improve the UHR prediction algorithm for psychosis.

Initial development and preliminary psychometric properties of the Prodromal Inventory of Negative Symptoms (PINS)

In the psychosis prodrome, sub-threshold positive symptoms are often preceded by negative symptoms. Individuals exhibiting these attenuated symptoms are primarily adolescents and young adults at clinical high-risk (CHR) for developing a psychotic disorder. In the CHR state, negative symptoms are highly predictive of the transition to diagnosable illness, making the assessment of these symptoms very important. Existing scales used to evaluate negative symptoms in this critical population are informative but have conceptual and psychometric limitations and/or were not designed according to modern conceptions delineated in the 2005 NIMH Negative Symptom Consensus Conference. The current study reports the development of the Prodromal Interview of Negative Symptoms (PINS) - a next-generation scale designed in accordance with the consensus conference recommendations. Preliminary data on the psychometric properties of the PINS is reported as part of ongoing scale development that will use a data-driven, iterative process to generate a final scale. Analysis of data from 53 CHR cases, 30 of whom were re-evaluated at 12months, indicated that the beta version of the PINS demonstrated good internal consistency, inter-rater reliability, convergent validity, and discriminant validity. These preliminary findings provide direction for a revision of this measure, which resulted in the PINS-2, a promising new measure for the assessment of negative symptoms in CHR populations. This manuscript presents both the initial scale and resulting untested instrument, as well as a series of plans and recommendations for future development.