"Schizotaxia": clinical implications and new directions for research

The concept of schizotypy - A computational anatomy perspective

Despite major progress in diagnostic accuracy and symptomatic treatment of mental disorders, there is an ongoing debate about their classification aiming to follow current advances in neurobiology. The main goal of this review is to provide a comprehensive summary of the put forward schizotypy concept that follows the needs for objective assessment of schizophrenia-like personality traits in the general population. We focus on major achievements in the field from the perspective of magnetic resonance imaging-based computational anatomy of the brain. Particular interest is devoted to overlapping brain structure findings in schizotypy and schizophrenia to promote a dimensional view on schizophrenia as extension of phenotype traits in the non-clinical general population.

Neurocognitive performance in family-based and case-control studies of schizophrenia

BACKGROUND

Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures.

METHODS

The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS.

RESULTS

Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms.

CONCLUSIONS

Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs.

Self-disorders and the schizophrenia spectrum: a study of 100 first hospital admissions

INTRODUCTION

Self-disorders (SD) have been described as a core feature of schizophrenia both in classical and recent psychopathological literature. However, the specificity of SD for the schizophrenia spectrum disorders has never been demonstrated in a diagnostically heterogeneous sample, nor has the concurrent validity of SD been examined.

AIM

(1) To examine the specificity of Examination of Anomalous Self-Experiences (EASE) measured SD to the schizophrenia spectrum disorder in first contact inpatients, (2) to explore the internal consistency and factorial structure of the EASE, (3) to assess the concurrent validity of SD by exploring correlations between SD and the canonical psychopathological dimensions of schizophrenia, (4) to explore relations of SD to intelligence, sociodemographic, and extrinsic illness characteristics.

METHODS

A total of 100 consecutive first admission patients underwent a comprehensive psychopathological examination and an assessment of SD with the EASE scale. The diagnostic distribution of the EASE scores was tested with ANOVA, whereas the relations between the EASE scores and other symptomatic dimensions of schizophrenia were tested with Spearman's rho. A potential factorial structure and the internal consistency of the EASE scale were also examined.

RESULTS

SD aggregated significantly in the schizophrenia spectrum disorders, with no differences between schizophrenia and schizotypal disorders. EASE scores correlated moderately with canonical psychopathological dimensions of schizophrenia. Factor analysis of the EASE disclosed only one factor and the internal consistency of the EASE was excellent.

CONCLUSIONS

SD aggregate selectively in the schizophrenia spectrum disorders, with similar levels in schizophrenia and schizotypy. The study lends validity to the view of SD as an experiential vulnerability phenotype of the schizophrenia spectrum disorders.

Genetic and environmental bases of the interplay between magical ideation and personality

Sub-threshold psychotic symptoms are quite commonly present in general population. Among these, Magical Ideation (MI) has been proved to be a valid predictor of psychosis. However, the genetic and environmental influences on the interplay between MI and personality have not fully been explored. A total of 534 adult twins from the population-based Italian Twin Register were assessed for MI using the MI Scale (MIS) and for personality with the temperament and character inventory (TCI). A Multivariate Cholesky model was applied with Mx statistical program. The best-fitting model showed that additive genetic and unshared environmental factors explain approximately the same proportion of variance in MI, whereas a less strong genetic influence on personality traits emerged. Relevant correlations between MI and specific personality traits (novelty seeking, cooperativeness, self-directedness, self-transcendence) were found, suggesting shared influences for MI and these traits. Both genetic and environmental factors explained these correlations, with genetic factors playing a predominant role. Moderate-to-substantial genetic effects on MI and personality were found. Shared genetic and environmental effects underlie the phenotypic correlation between MI (psychosis-proneness) and personality traits, i.e. self-directedness (negative association) and self-transcendence (positive association), potentially representing predictive markers of psychosis liability related to schizotypy and personality.

A review of neuroimaging studies of young relatives of individuals with schizophrenia: a developmental perspective from schizotaxia to schizophrenia

In an effort to identify the developing abnormalities preceding psychosis, Dr. Ming T. Tsuang and colleagues at Harvard expanded Meehl's concept of "schizotaxia," and examined brain structure and function in families affected by schizophrenia (SZ). Here, we systematically review genetic (familial) high-risk (HR) studies of SZ using magnetic resonance imaging (MRI), examine how findings inform models of SZ etiology, and suggest directions for future research. Neuroimaging studies of youth at HR for SZ through the age of 30 were identified through a MEDLINE (PubMed) search. There is substantial evidence of gray matter volume abnormalities in youth at HR compared to controls, with an accelerated volume reduction over time in association with symptoms and cognitive deficits. In structural neuroimaging studies, prefrontal cortex (PFC) alterations were the most consistently reported finding in HR. There was also consistent evidence of smaller hippocampal volume. In functional studies, hyperactivity of the right PFC during performance of diverse tasks with common executive demands was consistently reported. The only longitudinal fMRI study to date revealed increasing left middle temporal activity in association with the emergence of psychotic symptoms. There was preliminary evidence of cerebellar and default mode network alterations in association with symptoms. Brain abnormalities in structure, function and neurochemistry are observed in the premorbid period in youth at HR for SZ. Future research should focus on the genetic and environmental contributions to these alterations, determine how early they emerge, and determine whether they can be partially or fully remediated by innovative treatments.

Schizotypal personality disorder

Early phenomenological descriptions of schizophrenia have acknowledged the existence of milder schizophrenia spectrum disorders characterized by the presence of attenuated symptoms typically present in chronic schizophrenia. The investigation of the schizophrenia spectrum disorders offers an opportunity to elucidate the pathophysiological mechanisms giving rise to schizophrenia. Differences and similarities between subjects with schizotypal personality disorder (SPD), the prototypical schizophrenia personality disorder, and chronic schizophrenia have been investigated with genetic, neurochemical, imaging, and pharmacological techniques. Patients with SPD and the more severely ill patients with chronic schizophrenia share cognitive, social, and attentional deficits hypothesized to result from common neurodevelopmentally based cortical temporal and prefrontal pathology. However, these deficits are milder in SPD patients due to their capacity to recruit other related brain regions to compensate for dysfunctional areas. Individuals with SPD are also less vulnerable to psychosis due to the presence of protective factors mitigating subcortical DA hyperactivity. Given the documented close relationship to other schizophrenic disorders, SPD will be included in the psychosis section of DSM-5 as a schizophrenia spectrum disorder as well as in the personality disorder section.

Development of liability syndromes for schizophrenia: where did they come from and where are they going?

Three decades after Paul Meehl proposed the term "schizotaxia" to describe a conceptual framework for understanding the liability to schizophrenia, Ming Tsuang et al. at Harvard University reformulated the concept as a clinical syndrome with provisional research criteria. The reformulated view relied heavily on more recent data showing that many non-psychotic, un-medicated biological relatives of individuals with schizophrenia showed difficulties in cognitive and other clinical functions that resembled those seen in their ill relatives. The reformulation raised questions about both whether and when liability could be assessed validly in the absence of psychosis, and about the extent to which symptoms of liability are reversible. Both questions bear on the larger issue of early intervention in schizophrenia. This article reviews the efforts of Tsuang et al. to conceptualize and validate schizotaxia as one such syndrome of liability. Towards this end, liability is considered first more generally as an outcome of interactive genetic and environmental factors. Liability is then considered in the context of endophenotypes as a concept that is both broader and is potentially more specific (and predictive) than many DSM or ICD diagnostic symptoms. Liability syndromes are then considered in the context of their proximity to illness, first by reviewing prodromal syndromes (which are more proximal), and then by considering schizotaxia, which, as it is currently formulated, is pre-prodromal and, therefore, less proximal. Finally, challenges to validation and future directions for research are considered.

Prevention and recovery in early psychosis (PREP(®)): building a public-academic partnership program in Massachusetts, United States

Recently, there has been increasing emphasis on early intervention (EI) for psychotic disorders. EI programs in public mental health settings have been established in countries such as Australia, the United Kingdom, and Canada. However, there are relatively few EI programs in the United States (U.S.). Here we describe the conceptual origins and practical development of the PREP program, i.e., Prevention and Recovery in Early Psychosis, as it evolved in a public academic psychiatry setting in Boston, Massachusetts, U.S. PREP developed over a decade through a partnership between the Massachusetts Department of Mental Health and academic institutions within the Harvard Department of Psychiatry. We discuss the evolution, programmatic features, funding mechanisms, staffing, and the role of clinical training in PREP. The key principles in developing the PREP Program include the focus on early, evidence based, person-centered and phase-specific, integrated and continuous, comprehensive care. This program has served as a foundation for the emergence of related services at our institution, including a research clinic treating those at clinical high risk or within the putative "prodromal" period preceding frank psychosis. This account offers one possible blueprint for the development of EI programs despite the lack in the U.S. of a national mandate for EI or prevention-based mental health programs.

Neurocognition in youth and young adults under age 30 at familial risk for schizophrenia: a quantitative and qualitative review

INTRODUCTION

Neurocognitive dysfunction is a central feature of schizophrenia and is observed during all phases of the illness. Because schizophrenia is known to run in families, studying neurocognitive function in first-degree, nonpsychotic relatives has been a widely utilised strategy for almost 50 years for understanding presumed "genetic risk". Studying nonpsychotic relatives ("familial high-risk", or FHR) allows for identification of cognitive vulnerability markers independent of confounds associated with psychosis.

METHODS

Prior meta-analyses have elucidated the level and pattern of cognitive deficits in the premorbid, prodromal, and postonset periods of psychosis, and in relatives regardless of age. However, no prior quantitative analyses have specifically focused on studies of young first-degree relatives of individuals with schizophrenia who have not passed through the peak age illness risk (<age 30). The English language literature of neuropsychological studies of first-degree relatives for schizophrenia was identified up to 15 May 2011.

RESULTS

From 33 studies, 28 studies met our criteria for quantitative review, utilising >70 individual tests and 250 variables.

CONCLUSIONS

In general, young FHR individuals demonstrated deficits with a moderate level of severity compared with healthy controls. The largest average effect sizes (ESs), based on tests given in at least three independent studies, were on estimates of Full Scale IQ (d= -0.777), followed by Vocabulary (d= -0.749) and single word reading tests (d= -0.698) (often used as estimates of IQ). Measures of declarative memory, sustained attention, working memory and others had more modest ESs. Deficits were milder than in established schizophrenia, but often as severe as in clinical high-risk or putatively prodromal participants and in older relatives examined in prior meta-analyses. Additionally, while assessed from a more limited literature, youth at FHR for schizophrenia tended to show worse neurocognitive functioning than those at FHR for affective psychosis. This suggests that genetic risk for schizophrenia as reflected in a positive FHR carries an especially heavy impact on cognitive ability.

Neurocognitive profile and its association with psychopathology in first-degree relatives of patients with schizophrenia. a case-control study

BACKGROUND

People with schizophrenia show a broad range of neurocognitive deficits, which are considered as core features of the disorder and are thought to be partly heritable. Similar deficits, albeit at a lesser degree, have been also found in their healthy biological relatives. These deficits, if better characterized, might represent underlying vulnerable traits for psychosis.

METHODS

This case-control study compared neurocognitive functioning of adult first-degree relatives of patients with schizophrenia (SCZ-RELs) (n=55) with healthy control subjects (n=55) and explored its association with the negative symptoms. Subjects in both study and control group were assessed with an extensive neurocognitive test battery (Trail Making test, Phonemic Verbal fluency, Wisconsin Card Sorting Test, Bushke Fuld Test, Stroop Test, n-Back and Digit span) and a set of clinical measures (SANS, GAF and DAS).

RESULTS

SCZ-RELs were more significantly impaired on executive function tasks (i.e. Wisconsin Card Sorting Test and the Phonemic Verbal fluency) and displayed significantly more severe negative symptoms and poorer social functioning than control subjects. Significant correlations between neurocognitive measures and negative symptoms were found in the study group, whereas no significant correlations were detected among the controls.

DISCUSSION

Subtle executive impairments, associated with negative symptoms, are shown to be evident in healthy relatives of patients with schizophrenia. These deficits, which reflect subtle dysfunction in concept formation, flexibility and mental shifting, may be seen as potential phenotypic markers of vulnerability for schizophrenia. This raises the question of underlying prefrontal dysfunction as core feature of the disorder.

The relationship between personality disorders and Axis I psychopathology: deconstructing comorbidity

The purpose of this review is (a) to study and systematically review the recent literature examining the co-occurrence and relationships between Axis I psychiatric disorders and Axis II personality disorders, specifically the six originally proposed for the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5, and (b) to consider the clinical utility of the current Axis I and Axis II approach in the DSM-IV-TR and apply findings to state a position on the issue of collapsing together Axis I and Axis II. Community surveys or prospective cohort studies were reviewed as a priority. Our review indicates that the associations between clinical disorders and personality disorders clearly varied within each disorder and across the six personality disorders. Our understanding has advanced, particularly related to the clinical utility of comorbidity, and there may be sufficient evidence to support moving borderline personality disorder to Axis I. However, it seems premature to conclude that comorbidity is best conceptualized by having all disorders in a single category or by deleting disorders so that comorbidity is reduced. Our review suggests some priorities for future research into comorbidity, such as including personality disorders in future multivariate comorbidity models.

Auditory working memory impairments in individuals at familial high risk for schizophrenia

OBJECTIVES

The search for predictors of schizophrenia has accelerated with a growing focus on early intervention and prevention of psychotic illness. Studying nonpsychotic relatives of individuals with schizophrenia enables identification of markers of vulnerability for the illness independent of confounds associated with psychosis. The goal of these studies was to develop new auditory continuous performance tests (ACPTs) and evaluate their effects in individuals with schizophrenia and their relatives.

METHODS

We carried out two studies of auditory vigilance with tasks involving working memory (WM) and interference control with increasing levels of cognitive load to discern the information-processing vulnerabilities in a sample of schizophrenia patients, and two samples of nonpsychotic relatives of individuals with schizophrenia and controls. Study 1 assessed adults (mean age = 41), and Study 2 assessed teenagers and young adults age 13-25 (M = 19).

RESULTS

Patients with schizophrenia were impaired on all five versions of the ACPTs, whereas relatives were impaired only on WM tasks, particularly the two interference tasks that maximize cognitive load. Across all groups, the interference tasks were more difficult to perform than the other tasks. Schizophrenia patients performed worse than relatives, who performed worse than controls. For patients, the effect sizes were large (Cohen's d = 1.5), whereas for relatives they were moderate (d = ~0.40-0.50). There was no age by group interaction in the relatives-control comparison except for participants <31 years of age.

CONCLUSIONS

Novel WM tasks that manipulate cognitive load and interference control index an important component of the vulnerability to schizophrenia.

A plausible model of schizophrenia must incorporate psychological and social, as well as neuro developmental, risk factors

Subtle alterations in brain development caused by genes or early environmental hazards, such as obstetric complications, play a role in projecting some individuals on a trajectory toward schizophrenia. High-risk and cohort studies demonstrate that children destined to develop schizophrenia tend to have delayed milestones and subtle neuromotor and cognitive impairments (particularly in coordination and language). These neurocognitive problems lead to difficulties in interpersonal relations, and their progressive alienation makes these at-risk children more likely to harbor odd or paranoid ideas. This cascade of increasingly deviant development may then be compounded by brain maturational changes during adolescence with a resultant lability of the dopaminergic response to stress. As a result, the individual is more susceptible to the effects of the abuse of dopamine-releasing drugs, and to other risk factors such as migration or stressful life events; social isolation may be a common pathway underlying several of the social risk factors.

Conceptualization of the liability for schizophrenia: clinical implications

Historically, the Diagnostic and Statistical Manual of Mental Disorders (DSM) diagnostic criteria for schizophrenia have emphasized several features, including symptoms of psychosis, a dissociation of symptoms from their etiology, a reliance on clinical symptoms, and a categorical approach to classifying the disorder. Although these emphases are quite useful, they have limitations. We review these here, and stress the importance of incorporating recent data on the genetic /biological and neurodevelopmental origins of schizophrenia into current conceptions of the disorder. We also review “schizotaxia, ” which is a concept thai embodies this point of view, occurs before the onset of psychosis, and is hypothesized to represent the liability for schizophrenia. If our hypothesis on this point is correct, the identification of schizotaxic individuals will eventually facilitate the development of prevention strategies by identifying a premorbid (but clinically significant) condition for schizophrenia. Moreover, the identification of biological or neuropsychological components of schizotaxia will provide more specific bases for developing novel treatment interventions. Our initial attempts to develop protocols for the assessment and treatment of schizotaxia are encouraging, and will be reviewed.

Cognitive and prepulse inhibition deficits in psychometrically high schizotypal subjects in the general population: relevance to schizophrenia research

Schizophrenia and schizotypal personality disorder share common clinical profiles, neurobiological and genetic substrates along with Prepulse Inhibition and cognitive deficits; among those, executive, attention, and memory dysfunctions are more consistent. Schizotypy is considered to be a non-specific "psychosis-proneness," and understanding the relationship between schizotypal traits and cognitive function in the general population is a promising approach for endophenotypic research in schizophrenia spectrum disorders. In this review, findings for executive function, attention, memory, and Prepulse Inhibition impairments in psychometrically defined schizotypal subjects have been summarized and compared to schizophrenia patients and their unaffected first-degree relatives. Cognitive flexibility, sustained attention, working memory, and Prepulse Inhibition impairments were consistently reported in high schizotypal subjects in accordance to schizophrenia patients. Genetic studies assessing the effects of various candidate gene polymorphisms in schizotypal traits and cognitive function are promising, further supporting a polygenic mode of inheritance. The implications of the findings, methodological issues, and suggestions for future research are discussed.

A study of trait anhedonia in non-clinical Chinese samples: evidence from the Chapman Scales for Physical and Social Anhedonia

Background

Recent studies suggest that anhedonia, an inability to experience pleasure, can be measured as an enduring trait in non-clinical samples. In order to examine trait anhedonia in a non-clinical sample, we examined the properties of a range of widely used questionnaires capturing anhedonia.

Methods

887 young adults were recruited from colleges. All of them were administered a set of checklists, including Chapman Scale for Social Anhedonia (CRSAS) and the Chapman Scale for Physical Anhedonia Scale (CPAS), The Temporal Experience of Pleasure Scale(TEPS), and The Schizotypal Personality Questionnaire (SPQ).

Results

Males showed significantly higher level of physical (F = 5.09, p<0.001) and social (F = 4.38, p<0.005) anhedonia than females. As expected, individuals with schizotypal personality features also demonstrated significantly higher scores of physical (t = 3.81, p<0.001) and social (t = 7.33, p<0.001) trait anhedonia than individuals without SPD features, but no difference on self-report anticipatory and consummatory pleasure experience.

Conclusions

Concerning the comparison on each item of physical and social anhedonia, the results indicated that individuals with SPD feature exhibited higher than individuals without SPD features on more items of social anhedonia than physical anhedonia scale. These preliminary findings suggested that trait anhedonia can be identified a non-clinical sample. Exploring the demographic and clinical correlates of trait anhedonia in the general population may provide clues to the pathogenesis of psychotic disorder.

Neurocognitive and clinical dysfunction in adult Chinese, nonpsychotic relatives of patients with schizophrenia: Findings from the Changsha study and evidence for schizotaxia

Many first-degree relatives of patients with schizophrenia demonstrate deficits in neurocognitive, social, clinical and other dimensions, in the absence of psychosis. Based on a reformulation of Meehl's concept of "schizotaxia" as a clinically meaningful syndrome reflecting liability to schizophrenia, we proposed research criteria in relatives focused on negative symptoms and neurocognitive deficits. Here we assess validity of the syndrome in a sample of Chinese adult relatives by assessing measures of concurrent validity, and by using cluster analysis to test the hypothesis that relatives could be grouped into distinct schizotaxic and non-schizotaxic subgroups based on our diagnostic criteria. Thirty community comparison subjects (CCS) and 189 relatives were evaluated with measures of clinical, cognitive, medical and social function at the Mental Health Institute, Second Xiangya Hospital of Central South University, Changsha (Hunan, China), as part of a larger study to identify and ameliorate symptoms of schizotaxia. Using modified research criteria based on negative symptoms and neurocognitive deficits, 103 relatives did not meet criteria for schizotaxia, and 86 did. The cluster analysis confirmed a two-group solution that corresponded to our non-schizotaxic and schizotaxic groups, but it increased the non-schizotaxic group to 135, and reduced the schizotaxic group to 53. Both schizotaxic groups, but especially the cluster-derived group, showed significant impairment in a variety of independent (i.e. non-criterion related) measures of clinical and social function. These findings provide additional validity for a liability syndrome, and for its utility as an intervention target for strategies aimed at ameliorating both its core and its associated symptoms.

Are neurocognitive, clinical and social dysfunctions in schizotaxia reversible pharmacologically?: Results from the Changsha study

The Changsha study identifies adult, non-psychotic relatives of patients with schizophrenia who show deficits in neurocognitive, social, clinical and other dimensions, and who meet provisional criteria for a liability syndrome for schizophrenia ('schizotaxia'). In this study, we investigated whether negative symptoms, neurocognitive deficits, or other measures of clinical and social function in subjects who met our research criteria for schizotaxia were amenable to pharmacological remediation with a low dose (2.0 mg) of risperidone, a second generation antipsychotic medication. One hundred eighty nine relatives were assessed at the Mental Health Institute, Second Xiangya Hospital of Central South University, Changsha (Hunan Province, China), between 12/06 - 12/08. Eighty six of these individuals met modified criteria for schizotaxia, and 36 agreed to enter a 6-week, double-blind, placebo-controlled protocol. ANCOVAs using age and gender as covariates showed significant improvement in the risperidone group (n=20) on neurocognitive function (Wisconsin Card Sorting Test Total Errors and Perseverative Errors) and on a self-report measure of social function (Social Adjustment Scale), compared to the placebo-control group (n=16). Effect sizes were small to medium. Notably, risperidone effect sizes were larger (medium to large) in a subset of subjects (risperidone=15; placebo=10) whose membership in the schizotaxic group was supported empirically by cluster analysis. Negative symptoms did not change significantly in either analysis. The results are generally consistent with previous open-label investigations of risperidone administration in subjects with schizotaxia, and provide evidence that some neurocognitive and clinical problems are amenable to remediation in non-psychotic relatives of people with schizophrenia.

Neurocognitive predictors of functional outcome two to 13 years after identification as ultra-high risk for psychosis

BACKGROUND AND AIM

Little is known about the relationship between neurocognitive performance and functional outcome before the onset of frank psychosis. This longitudinal study aimed to investigate neurocognitive predictors of poor functional outcome in a group identified as ultra-high risk (UHR) for psychosis between two and 13 years prior.

METHOD

Individuals (N=230) identified as UHR for psychosis at the PACE Clinic in Melbourne completed assessment of psychopathology, functioning and neurocognition at baseline and follow-up. The mean length of follow-up was 7.26 years (SD 3.05).

RESULTS

Forty-one individuals with the poorest functional outcome were identified. Only 48.8% of this group had transitioned to psychosis. Poor functional outcome was associated with reduced performance at baseline in the specific neurocognitive domains of verbal learning and memory, processing speed and attention, and verbal fluency, but not global cognitive impairment. Reduced performance on a verbal story recall task, in combination with higher negative symptoms at baseline, was the best predictor of later poor outcome. Baseline positive psychotic symptoms and GAF scores were not associated with later poor outcome.

DISCUSSION

To date, this is the longest follow-up study of an UHR sample. Poor functional outcome was associated with specific neurocognitive decrements, regardless of transition to psychosis. The detection of individuals with poor functioning at follow-up, against a background of previously identified risk factors for psychotic disorder, may yield a valid group in which to study biomarkers and treatment of schizophrenia.

The silent side of the spectrum: schizotypy and the schizotaxic self

The identification of individuals carrying unexpressed genetic liability to schizophrenia is crucial for both etiological research and clinical risk stratification. Subclinical psychopathological features detectable in the nonpsychotic part of the schizophrenia spectrum could improve the delineation of informative vulnerability phenotypes. Inspired by Meehl's schizotaxia-schizotypy heuristic model, we tested anomalous subjective experiences (self-disorders, SDs) as a candidate vulnerability phenotype in a sample of nonpsychotic, genetically high-risk subjects. A total of 218 unaffected members of 6 extended multiplex families (assessed between 1989 and 1999 during the Copenhagen Schizophrenia Linkage Study) were stratified into 4 groups of increasing psychopathological expressivity: no mental illness (NMI), no mental illness with schizotypal traits (NMI-ST), personality disorders not fulfilling other personality disorders (OPDs), and schizotypal personality disorder (SPD). We tested the distribution of SDs among the subgroups, the effect of SDs on the risk of belonging to the different subgroups, and the effect of experimental grouping and concomitant psychopathology (ie, negative symptoms (NSs) and subpsychotic formal thought disorder [FTD]) on the chances of experiencing SDs. SDs distribution followed an incremental pattern from NMI to SPD. SDs were associated with a markedly increased risk of NMI-ST, OPDs, or SPD. The odds of SDs increased as a function of the diagnostic category assignment, independently of sociodemographics and concomitant subclinical psychopathology (NSs and FTD). The results support SDs as an expression of schizotaxic vulnerability and indicate a multidimensional model of schizotypy--characterized by SDs, NSs, FTD--as a promising heuristic construct to address liability phenotypes in genetically high-risk studies.

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

BACKGROUND/PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Early and broadly defined psychosis risk mental states

Current definitions of the prodromal (or at-risk mental state) phase of schizophrenia include attenuated and/or transient psychotic symptoms as well as a combination of different risk indicators and a recent significant deterioration in global functioning. Data accumulated to date suggest rates of conversion to frank psychosis within two years in 25 to 40% of cases supporting the validity of these criteria. However, at this late phase of illness, functional deterioration is often already pronounced, highlighting the need for earlier identification. Moreover, negative symptoms and social impairments, cognitive deficits, other non-psychotic psychopathology and/or functional decline and non-specific biological indicators, often can be detected well before the at-risk mental state as currently defined; indicating that a broad characterization of an earlier stage may be possible. Identifying specific criteria to define this group of individuals, starting from the framework of familial high-risk, can help define a broader group of people, including earlier at-risk mental states, for future research. The hope is that this research will help facilitate intervention at earlier stages that may in turn minimize functional deterioration, and delay, attenuate or even prevent transition to psychosis. The disadvantages as well as the potential benefits of this approach are discussed.

Reduced intra-amygdala activity to positively valenced faces in adolescent schizophrenia offspring

Studies suggest that the affective response is impaired in both schizophrenia and adolescent offspring of schizophrenia patients. Adolescent offspring of patients are developmentally vulnerable to impairments in several domains, including affective responding, yet the bases of these impairments and their relation to neuronal responses within the limbic system are poorly understood. The amygdala is the central region devoted to the processing of emotional valence and its sub-nuclei including the baso-lateral and centro-medial are organized in a relative hierarchy of affective processing. Outputs from the centro-medial nucleus converge on regions involved in the autonomous regulation of behavior, and outputs from the baso-lateral nucleus modulate the response of reward processing regions. Here using fMRI we assessed the intra-amygdala response to positive, negative, and neutral valenced faces in a group of controls (with no family history of psychosis) and offspring of schizophrenia parents (n=44 subjects in total). Subjects performed an affective continuous performance task during which they continually appraised whether the affect signaled by a face on a given trial was the same or different from the previous trial (regardless of facial identity). Relative to controls, offspring showed reduced activity in the left centro-medial nucleus to positively (but not negatively or neutral) valenced faces. These results were independent of behavioral/cognitive performance (equal across groups) suggesting that an impaired affective substrate in the intra-amygdala response may lie at the core of deficits of social behavior that have been documented in this population.

Children of parents with affective and nonaffective psychoses: a longitudinal study of behavior problems

OBJECTIVE

It is generally accepted that children of parents with schizophrenia or other forms of psychosis are at heightened risk for a range of behavioral problems. However, it remains unclear whether offspring of parents with different forms of psychosis (e.g., schizophrenia, other nonaffective psychoses, and affective psychoses) have distinct forms of behavioral problems (i.e., internalizing and externalizing).

METHOD

Behavioral observations of children of parents with psychosis (N=281) and parents without psychosis (N=185) were conducted at ages 4 and 7 years.

RESULTS

There were no significant differences between groups in behavior observed at age 4 years. At age 7 years, compared with children of unaffected parents, children of parents with psychosis had an adjusted odds ratio of 2.8 (95% CI=1.5-5.6) for externalizing problems, in particular for children of parents with schizophrenia (adjusted odds ratio=4.4; 95% CI=1.7-12.5). This increase in risk for externalizing problems was observed for female children only (adjusted odds ratio=8.1; 95% CI=2.5-26.3). In contrast, male children were at increased risk for internalizing problems (adjusted odds ratio=3.6; 95% CI=1.6-8.3).

CONCLUSIONS

Children of parents with various forms of psychosis are at risk for internalizing and externalizing problems by age 7 years. This risk varies by gender of the offspring. Implications for treatment of parents with psychotic disorders and high-risk children are discussed.

The Social Cognition and Interaction Training (SCIT): an extension to individuals with schizotypal personality features

The current study aimed to extend the clinical utility of the Social Cognition and Interaction Training (SCIT) to individuals with schizotypal personality features. It provided preliminary findings on the suitability and efficacy of the SCIT for these individuals in mainland China.

Imaging genetic liability to schizophrenia: systematic review of FMRI studies of patients' nonpsychotic relatives

There is a growing literature on brain activity in the nonpsychotic first-degree relatives of patients with schizophrenia as measured using functional imaging. This systematic review examined 20 studies in 4 domains of cognition, including cognitive control (7 samples), working memory (5 samples), long-term memory (4 samples), and language (4 samples). While the literature was widely divergent, these studies did consistently find activation differences between patients' relatives and controls. The most consistent increases in activation within hemisphere were found in right ventral prefrontal cortex (PFC) and right parietal cortex. Abnormal activity, defined as significant increases or decreases in activation relative to controls irrespective of hemisphere, was found in about two-thirds of contrasts in the cerebellum, dorsal prefrontal, lateral temporal, and parietal cortices, and thalamus, with basal ganglia and ventral PFC showing abnormalities in approximately half of those contrasts. Anterior cingulate was generally spared in patients' relatives. The diversity of findings in studies of patients' relatives may derive from differences between the cognitive demands across studies. We identify avenues for building a more accurate and cumulative literature, including symmetrical inclusion criteria for relatives and controls, recording in-scanner responses, using both a priori and whole-brain tests, explicitly reporting threshold values, reporting main effects of task, reporting effect sizes, and quantifying the risk of false negatives. While functional imaging in the relatives of schizophrenia patients remains a promising methodology for understanding the impact of the unexpressed genetic liability to schizophrenia, no single region or mechanism of abnormalities has yet emerged.

Sustained attention deficit along the psychosis proneness continuum: a study on the Sustained Attention to Response Task (SART)

BACKGROUND

Sustained attention deficits have been associated with schizophrenia. However, these findings were limited to patients with schizophrenia and cannot be generalized to a wider nonclinical sample with schizotypal personality features.

OBJECTIVES

This study aimed to examine the sensitivity of a theory-driven test, the Sustained Attention Response to Task (SART), in individuals with schizotypal personality features. We also investigated the relationships between different parameters of SART and different dimensions of schizotypal features.

METHODS

One hundred and ninety-nine participants (74 individuals with schizophrenia, 69 individuals with psychometrically determined schizotypal features, and 56 healthy controls) took part in this study. Participants scoring in the top 10% of the Schizotypal Personality Questionnaire (SPQ) score were identified as having schizotypal features, and those scoring in the bottom 10% were recruited as healthy controls. All participants were administered the SART in an experimental cubicle.

RESULTS

The findings indicated that: (1) significant differences were found in SART commission error and sensitivity between the 3 experimental groups, with patients with schizophrenia and individuals with schizotypal features performing worse than healthy controls; (2) there was a trend toward statistical significance for SART efficiency score and d', with controls performing better than patients with schizophrenia and individuals with schizotypal features; (3) some associations between some SART indices and schizotypal traits were found; and (4) there was no significant relationship between SART indices and clinical symptoms in patients with schizophrenia in this study.

CONCLUSIONS

: This investigation demonstrated the potential value of a relatively new sustained attention paradigm for research in schizophrenia spectrum disorders.

Toward a better identification and treatment of schizophrenia prodrome

The prodromal period leading to schizophrenia has been the focus of significant interest in recent years. This is due not only to the possibility of identification of preschizophrenic states but also to the potential for improving prognosis as a result of early intervention. There are many approaches to the identification of the schizophrenia prodrome. Interventions in the prodromal period have met with various degrees of success. In this article, the authors present an overview of the literature reflecting the development of the prodromal concept and its implications for early identification. They also discuss various interventions proposed for this period and some ethical considerations related to these interventions. Despite the growing body of knowledge in this field, there is a need for more research data to support the establishment of treatment guidelines. Future directions of research are also discussed.

Emotion processing in persons at risk for schizophrenia

Evidence suggests that individuals with schizophrenia demonstrate emotion-processing deficits. However, the nature and extent of emotion abnormalities in individuals considered at risk for schizophrenia have not been previously summarized. This article provides a review of the recent literature pertaining to emotion processing in 3 at-risk populations: those at familial high risk, those with schizotypal characteristics, and those in the putative prodrome to psychosis. Studies are reviewed across the components of emotion perception, experience, and expression. Further, we discuss investigations into psychophysiology, brain structure, and brain function that employ emotion probes. Review of the literature suggests that individuals at high risk demonstrate similar abnormalities to those with schizophrenia but at an attenuated level. The most robust findings in at-risk groups are in the areas of reduced emotion perception, self-reported anhedonia, and increased negative affect. We conclude with an agenda for future research.

Social functioning deficits in young people at risk for schizophrenia

OBJECTIVE

Impairment in social functioning is a central feature of schizophrenia and is known to be evident before the onset of psychosis, acting as a potential vulnerability marker. The aim of the present study was to test the hypothesis that social impairment is simultaneously a state and trait marker of risk for schizophrenia and schizophrenia-related disorder.

METHOD

Social functioning was examined in three groups: ultra-high-risk subjects (UHR, n =32), genetic high-risk subjects (GHR, n =32), and age- and IQ-matched healthy controls (HC, n =30). Social functioning was assessed using the Social Functioning Scale (SFS), and prodromal symptoms were assessed in high-risk subjects using the Comprehensive Assessment of At-Risk Mental States (CAARMS).

RESULTS

Both the UHR and GHR groups exhibited significantly impaired social functioning compared with the HC group, and the UHR group was more impaired than the GHR group. In the UHR group, duration of prodromal symptoms was related to impaired 'interpersonal behaviour'. Positive and negative symptoms were not significantly associated with social functioning, whereas disorganized and general symptoms were significantly correlated with poor 'independence-competence' in UHR individuals.

CONCLUSION

The findings support the hypothesis that impairment in social functioning is both a trait and state marker of risk for schizophrenia and other psychotic disorders, implying that social impairment constitutes a mediating vulnerability indicator of psychotic disorders including schizophrenia.

The schizotypal ambivalence scale as a marker of schizotypy

The present study examined the psychometric properties of the Schizotypal Ambivalence Scale (SAS) in a sample of 1798 young adults. The study also investigated the concurrent validity of the measure for identifying schizophrenic-like symptoms in a sample of 43 high scorers on the scale and 43 control participants. Previous findings indicated that high scores on the SAS were associated with schizophrenia-spectrum pathology in a sample of schizotypic young adults selected with other measures. However, this is the first study to assess schizophrenic-like psychopathology in a sample selected using the SAS. The SAS has good internal consistency (coefficient alpha = 0.84) and test-retest reliability (intraclass correlation = 0.74 across 9 weeks). As hypothesized, the ambivalence group exceeded the control group on interview ratings of schizotypal, schizoid, paranoid, psychotic-like, and negative symptoms, as well as exhibiting poorer overall functioning. The SAS seems to be a promising measure of schizotypy in young adults.

Competing definitions of schizophrenia: what can be learned from polydiagnostic studies?

The contemporary diagnoses of schizophrenia (sz)-Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition(DSM-IV) and International Classification of Diseases, 10th Revision(ICD-10)-are widely considered as important scientific achievements. However, these algorithms were not a product of explicit conceptual analyses and empirical studies but defined through consensus with the purpose of improving reliability. The validity status of current definitions and of their predecessors remains unclear. The so-called "polydiagnostic approach" applies different definitions of a disorder to the same patient sample in order to compare these definitions on potential validity indicators. We reviewed 92 polydiagnostic sz studies published since the early 1970s. Different sz definitions show a considerable variation concerning frequency, concordance, reliability, outcome, and other validity measures. The DSM-IV and the ICD-10 show moderate reliability but both definitions appear weak in terms of concurrent validity, eg, with respect to an aggregation of a priori important features. The first-rank symptoms of Schneider are not associated with family history of sz or with prediction of poor outcome. The introduction of long duration criteria and exclusion of affective syndromes tend to restrict the diagnosis to chronic stable patients. Patients fulfilling the majority of definitions (core sz patients) do not seem to constitute a strongly valid subgroup but rather a severely ill subgroup. Paradoxically, it seems that a century after the introduction of the sz concept, research is still badly needed, concerning conceptual and construct validity of sz, its essential psychopathological features, and phenotypic boundaries.

Taxonic structure of schizotypal personality in nonclinical subjects: Issues of replicability and age consistency

To assess the replicability and age consistency of the taxonic structure and base-rate of schizotypy, 803 university students (21.9 years) and 929 high school students (16.4 years) were administered three self-report measures of schizotypal personality. The two groups came from the same town and were matched on gender. MAXCOV analyses were consistent with a low base-rate taxon of approximately 10% only in the university student group; in the younger group, the three schizotypal personality measures did not show clear evidence of taxonicity. These findings support the hypothesis of the taxonic structure of schizotypal personality in adult subjects, but they raise questions concerning the identification of schizotypy in younger samples.

Long-term administration of the low-dose risperidone in schizotaxia subjects

The term schizotaxia is currently defined as a syndrome of neuropsychological deficits and negative symptoms found in relatives of schizophrenic patients. The aim of this study was to assess the effect of long-term treatment with the low-dose risperidone on cognitive and social functioning in seven schizotaxia patients. There were four males and three females, aged between 17 and 44 years, first-degree (four patients) or second-degree (three patients) relatives of schizophrenic patients. Schizotaxia was recognized in them on account of neuropsychological and social function impairment. They all consented to risperidone administration, 1-2 mg/day. Duration of risperidone treatment has ranged between 3-7 years. In all subjects, the continuous treatment with risperidone brought about a marked improvement in their cognitive, social, and vocational functioning. Neuropsychological testing after 6-24 months showed significant improvement on such tests as Wisconsin Card Sorting Test (WCST), Trail Making Test (TMT), and Stroop Test. Discontinuation of treatment after 3-4 years did not cause deterioration of functioning.

Plasma homovanillic acid levels in schizophrenic patients: correlation with negative symptoms

The relation between changes in the levels of plasma homovanillic acid (pHVA) and clinical evolution during neuroleptic treatment of schizophrenic patients has not been satisfactorily characterized, as a number of conflicting findings have been reported. Significant correlations have generally been found using the assessment of positive symptoms as an index of clinical outcome. Nevertheless, attempts to correlate pHVA concentrations with negative symptoms have yielded contradictory results. With a view to evaluating if different responses in negative symptoms are associated with distinct pHVA profiles, we examined the levels of pHVA in 46 neuroleptic-free schizophrenic patients and in these patients after neuroleptic treatment. Negative and positive symptoms were also addressed before and after treatment. Our results reveal that at least two classes of negative symptoms exist; the clinical evolution of the first class of negative symptoms parallels that of positive symptoms, and clinical improvement correlates with reduced dopaminergic activity. In contrast, in the second class, reduced dopaminergic activity is associated with a further deterioration of negative symptoms. These findings corroborate the heterogeneity of negative symptoms and may contribute to a better definition of endophenotypes in the schizophrenic syndrome.

Neuropsychological functioning in adolescents and young adults at genetic risk for schizophrenia and affective psychoses: results from the Harvard and Hillside Adolescent High Risk Studies

Siblings and offspring of persons with schizophrenia carry elevated genetic risk for the illness and manifest attentional and memory impairments. Because less is known about other neuropsychological functions and their specificity in adolescents, we conducted a genetic high-risk (HR) study of schizophrenia (HR-SCZ) and affective psychosis (HR-AFF). Participants (ages 12-25) were from the Harvard Adolescent High-Risk and Hillside Family studies, including 73 HR-SCZ, 18 HR-AFF, and 84 community controls (CCs) recruited in metropolitan Boston and New York. Groups were compared on overall neurocognitive functioning, 6 domains, and 13 test scores, controlling for age, parental education, and correlated data within families. The HR-SCZ group was significantly impaired overall, while the HR-AFF group demonstrated a trend toward overall impairment. HR-SCZ subjects showed significantly lower Verbal Ability (d = .73) and Executive Functioning/Working Memory (d = .47) than CCs. HR-AFF subjects showed reduced Verbal Ability (d = .64) compared to CCs. Excluding 12 CCs with a parental history of depression (without psychosis) led to larger differences between HR and CC groups across domains. Moreover, HR-SCZ and CC group differences in Verbal Memory (d = .39) and Visual-Spatial (d = .34) became statistically significant. There were no significant differences between HR-SCZ and HR-AFF groups. Data support a modest neuropsychological deficit in persons at genetic HR for psychosis, with a broader range of deficits in HR-SCZ. Future work should assess the relationship of neurocognition to adaptive functioning and possible onset of psychosis in HR samples. Ascertainment criteria for controls may markedly influence results and interpretation of group differences.

Early symptoms of mania and the role of parental risk

OBJECTIVES

The objectives of this study were to: (i) describe the phenomenology of youths diagnosed with subsyndromal bipolar disorders; (ii) describe the phenomenology of youngsters who are the children of bipolar parents, who are also experiencing subsyndromal symptoms of bipolar disorder (patients with 'cyclotaxia'); and (iii) explore which symptoms may be most useful in identifying youths with cyclotaxia.

METHODS

Four hundred outpatients between the ages of 5 and 17 years received a diagnostic assessment and psychometric questionnaires pertaining to mood symptomatology and psychosocial functioning. Parental diagnostic information was also obtained. Children and adolescents were assigned to one of three diagnostic groups: a 'syndromal bipolar disorder (BP)' group (n = 118), a 'sub-syndromal bipolar (SUB-BP)' group (n = 75), or a 'non-bipolar (NON-BP)' group (n = 207). In addition, based on parental diagnoses, youths were assigned to either a high genetic risk group (n = 167) or a low genetic risk group (n = 233).

RESULTS

Youths with subsyndromal bipolar disorders were found to have intermediate degrees of manic symptoms than youths with bipolar disorder and youths without a bipolar diagnosis. Offspring of parents having a bipolar disorder were more likely to show symptoms of hypomania and mania than youths without a bipolar parent. Youths at genetic risk for developing a bipolar disorder were not found to be at higher risk for having a diagnosis of attention-deficit hyperactivity disorder or a disruptive behavior disorder. Finally, results suggest that elevated mood with irritability and rapid mood fluctuations are the key distinguishing characteristics of 'cyclotaxia'.

CONCLUSIONS

There exists a group of youngsters who are the offspring of a parent/parents with a bipolar disorder who do not suffer from BP 1 or BP 2, yet have elevated mood symptoms and psychosocial dysfunction. As a result of these observations, treatment studies are needed for youths with 'cyclotaxia'.

Taxonic structure of schizotypal personality disorder: a multiple-instrument, multi-sample study based on mixture models

This study used a multi-sample, multiple-instrument strategy to evaluate the hypothesis that schizotypal personality disorder (SPD) is taxonic. In Study 1, 721 consecutively admitted inpatients and outpatients were evaluated with the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II) and the Personality Diagnostic Questionnaire-4+ (PDQ-4+). The data from both questionnaire types were submitted to multivariate normal mixture analysis, which was carried out on factor scores obtained from a three-factor model of SPD criteria; these results supported the hypothesis that SPD is taxonic. The same was true of Study 2, which administered the Semi-structured Interview for DSM-III-R Personality Disorders (SIDP-R) to an independent sample of 537 consecutively admitted outpatients. Similar findings were observed in Study 3, in which the SIDP-R was administered to 225 non-clinical subjects. The results show that the typology of DSM III-R and -IV SPD diagnosis is consistent with the latent structure of SPD features.

Pathways to schizophrenic psychosis: a LISREL-tested model of the unfolding of the schizophrenic prodrome

In this article a literature-based model (the Schizotypic Syndrome Questionnaire [SSQ] model) is presented that gives a description of the temporal unfolding of the schizophrenic prodrome. As a guiding principle for the selection of the symptoms in the model, the hypothesis was held that the main prodromal features determine each other in terms of cause and effect. Furthermore, the developmental pathways between the symptoms were not allowed to be in conflict with the usual observation that negative symptoms precede psychotic-like ones nor--at least in broad outline--with J.P. Docherty, D.P. van Kammen, S.G. Siris, and S.R. Marder's (1978) description of the various onset stages in the development of a schizophrenic psychosis. For the definitive version of the SSQ model, 12 symptoms were selected (e.g., affective flattening, suspicion, and delusional thinking). After specifying the paths to be estimated, the model was examined in two randomly drawn samples from a total community-based sample of 771 normal subjects and in the total sample itself, in each case resulting in adequate fit values. Moreover, all postulated pathways were found to be significantly different from zero. The use of a normal sample was based on the continuum hypothesis. Given the present-day discussions concerning the tenability of the schizophrenia concept, the model's implications with respect to that issue are particularly emphasized. Furthermore, the concept of the schizophrenia prodrome itself is critically discussed.

Development from birth to adolescence of children at-risk for schizophrenia

OBJECTIVE

Offspring of patients with schizophrenia are at-risk for developing schizophrenia in adult life. The aim of this paper is to describe the development from infancy through adolescence of a sample of Israeli young people at-risk for schizophrenia.

METHODS

The Jerusalem Infant Development Study (JIDS) has followed prospectively from birth through adolescence 15 young people who have a parent with schizophrenia. Neurobehavioral data were gathered at infancy, middle childhood, and adolescence. Mental disorder was assessed at adolescence.

RESULTS

Data suggest that some children whose parents have schizophrenia are at increased risk for a variety of neuromotor, cognitive, and attentional problems during infancy and childhood, compared to children whose parents had no mental disorder or nonschizophrenia mental disorder. Those high-risk children with neurobehavioral signs are also more likely to have poorer social adjustment, greater social withdrawal, and more symptoms within the schizophrenia spectrum. Case studies are presented of two children with early neurobehavioral impairment who, as adolescents, developed disorders within the schizophrenia spectrum.

CONCLUSION

Because neurobehavioral impairment may be marking genetic vulnerability to schizophrenia spectrum disorders, clinicians treating children whose parents have schizophrenia need to thoroughly evaluate symptoms of mental disorder--but also neuromotor and neuropsychological functioning.

Searching for the liability to schizophrenia: concepts and methods underlying genetic high-risk studies of adolescents

Conceptualizations of the liability for schizophrenia help guide the development of research protocols, which, in turn, provide empirical confirmations or disconfirmations of the conceptualization's tenets. This paper focuses on a conception of liability and its relationships to genetic adolescent high-risk studies. Specifically, the derivation and nature of a proposed multidimensional syndrome of liability to schizophrenia ("schizotaxia") are outlined, followed by a representative review of features reported in previous high-risk studies that may be related to schizotaxia, and a perspective on future high-risk investigations. Overall, genetic high-risk studies generally confirm the concept of liability in the offspring of parents with schizophrenia, as expressed by deficits or abnormalities in multiple dimensions. It is concluded that high-risk studies on the liability to schizophrenia provide an important tool with which to explore the etiology and development of schizophrenia, in part by contributing to the identification and validation of specific liability syndromes.

Temperament types are associated with weak self-construct, elevated distress and emotion-oriented coping in schizophrenia: evidence for a complex vulnerability marker?

Knowledge concerning temperament factors involved in vulnerability to schizophrenia is limited. We hypothesized that temperament and self-variables (emotional distress, coping styles, self-efficacy and self-esteem) might present a complex trait marker for underlying vulnerability to schizophrenia. We sought to (1) assess temperament dimensions and types in schizophrenia patients and healthy controls using the Tridimensional Personality Questionnaire (TPQ), and (2) explore their association with symptom dimensions, emotional distress, coping styles, self-constructs, demographic and background variables. We evaluated 90 consecutively recruited DSM-IV schizophrenia patients and 136 healthy controls matched for gender and age. We found that the harm avoidance (HA) factor was higher, while reward dependence (RD) was lower in schizophrenia patients than in healthy controls. Relationships of negative symptoms to novelty seeking (NS) and general psychopathology with both NS and HA show a confounding relation to self-variables. TPQ temperament types were defined by dichotomization into high and low according to medians of the three TPQ temperament dimensions. The odds ratios for the HA and HA/NS temperament types were significantly higher, while the NS/RD type was lower in schizophrenia patients than in healthy controls. HA/NS, HA/RD and high-HA/NS/RD types revealed higher scores for emotional distress, emotion-oriented coping and lower scores on self-constructs. No links were found between temperament types and schizophrenia symptom dimensions, task and avoidance oriented coping, or demographic and background variables. Thus, our findings strengthen the hypothesis that temperament types, when associated with elevated emotional distress, emotion-oriented coping and weak self-constructs, might represent a complex trait marker for underlying vulnerability to schizophrenia.

Functional magnetic resonance imaging during auditory verbal working memory in nonpsychotic relatives of persons with schizophrenia: a pilot study

BACKGROUND

First-degree relatives of persons with schizophrenia carry elevated genetic risk for the illness and show deficits on high-load information processing tasks. We used functional magnetic resonance imaging (fMRI) to test whether nonpsychotic relatives show altered functional activation in the prefrontal cortex (PFC), thalamus, hippocampus, and anterior cingulate during a working memory task requiring interference resolution.

METHODS

Twelve nonpsychotic relatives of persons with schizophrenia and 12 healthy control subjects were administered an auditory, verbal working memory version of the Continuous Performance Test during fMRI. An asymmetric, spin-echo, T2*-weighted sequence (15 contiguous, 7-mm axial slices) was acquired on a full-body MR scanner. Data were analyzed by Statistical Parametric Mapping (SPM).

RESULTS

Compared with control subjects, relatives showed greater task-elicited activation in the PFC and the anterior and dorsomedial thalamus. When task performance was controlled, relatives showed significantly greater activation in the anterior cingulate. When effects of other potentially confounding variables were controlled, relatives generally showed significantly greater activation in the dorsomedial thalamus and anterior cingulate.

CONCLUSIONS

This pilot study suggests that relatives of persons with schizophrenia have subtle differences in brain function in the absence of psychosis. These differences add to the growing literature identifying neurobiological vulnerabilities to schizophrenia.

Considering schizophrenia from a prevention perspective

Schizophrenia is a serious mental illness that causes major disability and psychosocial impairment. Recent advances in the neurosciences are prompting considerations of schizophrenia from a preventive perspective. An overview of the literature is provided on two important aspects of the development of a prevention orientation in schizophrenia research: elucidation of potential causal risk factors for schizophrenia and research on risk markers. Risk factors for schizophrenia include, but are not limited to, family history, older paternal age, velo-cardio-facial syndrome, maternal infections during pregnancy, pregnancy and delivery complications, and social adjustment difficulties in childhood and adolescence. Potential risk markers include structural brain pathology, minor physical anomalies and dermatoglyphic abnormalities, neurocognitive deficits, eye-tracking dysfunction, certain electrophysiologic findings, and olfactory identification deficits. Several early efforts at indicated preventive interventions targeting individuals at particularly high risk for developing the disorder are discussed. The preventive medicine and public health disciplines may have a role in future research and interventions that apply a preventive perspective to schizophrenia and other mental illnesses. Like any other chronic medical condition, schizophrenia can be considered from a preventive perspective.