Treatment of nonpsychotic relatives of patients with schizophrenia: four case studies

Pathways to functional outcome in subjects with schizophrenia living in the community and their unaffected first-degree relatives

RATIONALE

Variables influencing real-life functioning have repeatedly been modeled in schizophrenia subjects but not systematically investigated in their unaffected first-degree relatives (SRs), in whom milder forms of deficits reported in schizophrenia have been observed, but confounders of clinical cohorts are not in play. Demonstrating that pathways to functional outcome are similar between patients and SRs would validate structural models developed in schizophrenia subjects. The present multicenter study aimed to explore whether variables associated with real-life functioning are similar in schizophrenia patients and their unaffected relatives.

METHODS

The study sample included 921 schizophrenia patients, 379 SRs and 780 healthy controls. Structural Equation Models (SEMs) were used in patients and SRs to test associations of psychopathological dimensions, neurocognition, social cognition, resilience, perceived stigma and functional capacity with real-life functioning domains, impaired in both patients and SRs.

RESULTS

Interpersonal Relationships and Work Skills were the only functional domains impaired in both patients and SRs. For both domains, functional impairment in patients was found to predict impairment in unaffected relatives, suggesting the involvement of similar illness-related vulnerability factors. In both groups variables significantly associated with Interpersonal Relationships included Social Cognition, Neurocognition, Avolition, Resilience, Disorganization, Perceived Stigma and Gender, and those significantly associated with Work Skills included Social Cognition, Neurocognition and Disorganization.

CONCLUSIONS

Pathways to functional outcome for Interpersonal relationships and Work skills are similar between schizophrenia patients and their unaffected first-degree relatives. These findings validate, in the absence of confounders of clinical cohorts, structural models of determinants of functional outcome in people with schizophrenia.

Experimental Medicine in Psychiatry New Approaches in Schizophrenia, Depression and Cognition

The use of experimental medicine studies to bridge the gap between Phase 1 and 2 drug trials and so to enhance translation of basic neuroscience studies using experimental animals to the clinic is proposed. Illustrative examples are provided for affective disorders and schizophrenia in relation also to cognitive dysfunction.

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.

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.

'At-risk' for psychosis research: where are we heading?

The 'at-risk' criteria are a useful paradigm for investigating the psychological, neurocognitive, neurobiological and genetic risk factors for psychosis, specifically schizophrenia. To date, the primary outcome of interest in at-risk research has been the development of psychotic disorder, whereby patients are categorized as either having 'transitioned' or 'not transitioned'. Despite the acceptance of this dichotomy, it is important to consider that the threshold at which psychotic symptoms progress from attenuated to frank 'psychotic disorder' is arbitrary and may be incorrect or meaningless in terms of neurobiological and functional changes associated with psychosis. This has implications for clinical care and the search for markers of schizophrenia. We present recent research suggesting that the term 'outcome' needs to be broadened to incorporate non-psychotic diagnoses, functioning and negative symptoms. Shifting the traditional notion of outcome is the future challenge for at-risk research, but the inclusion of outcomes other than psychosis is likely to result in better aetiological models of psychotic illness.

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.

How many genes are involved in schizophrenia? A simple simulation

We attempted to estimate how many genes are involved in schizophrenia using a simulation based on the polygenic threshold model. The basic assumptions were as follows: (1) All genes involved are transmitted independently; (2) every locus is composed of two alleles - one pathogenic and the other non-pathogenic; (3) all pathogenic alleles are dominant; (4) the two alleles at any locus are in Hardy-Weinberg Equilibrium (HWE) in the general population (GP) but not within the patient (PP) or non-patient (NP) subpopulations; (5) the number of affected loci determines the disease genetically; and (6) only a fraction of genetically determined individuals actually becomes ill. A range of the total number of disease-related genes (N) and threshold genetic load (T) was set for the simulation. Assuming that the number of affected loci follows a binomial distribution, the mean gene frequencies satisfying a disease prevalence of 1.12% in the GP were sought for various N and T combinations. Based on these gene frequencies, the odds ratio and the incidence rate in relatives under random mating were calculated. These results were then compared with real genetic epidemiologic data to obtain best-fit estimates for N and T. The results indicated that a polygenic threshold model with an N greater than 100 and a T in the range of 0.3-0.8 fits the empirical data. It was estimated that at least several hundreds of study subjects are required to yield a statistically significant frequency difference for a single gene between the patient and the control groups.

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.

Evaluation of state and trait biomarkers in healthy volunteers for the development of novel drug treatments in schizophrenia

Antipsychotic drugs are the mainstay of treatment for schizophrenia but they have little effect on core negative symptoms or cognitive impairment. To meet the deficiencies of current treatments, novel potential compounds are emerging from preclinical research but translation to clinical success has been poor. This article evaluates the possibility that cognitive and physiological abnormalities in schizophrenia can be used as central nervous system biomarkers to predict, in healthy volunteers, the likely efficacy of entirely new pharmacological approaches to treatment. Early detection of efficacy would focus resource on rapidly developing, effective drugs. We review the relevance of selected cognitive and physiological abnormalities as biomarkers in schizophrenia and three of its surrogate populations: (i) healthy volunteers with high trait schizotypy; (ii) unaffected relatives of patients; and (iii) healthy volunteers in a state of cortical glutamate disinhibition induced by low-dose ketamine. Several biomarkers are abnormal in these groups and in some instances there has been exploratory work to determine their sensitivity to drug action. They are generally insensitive to current antipsychotics and therefore their predictive validity cannot be established until novel, therapeutically useful drugs are discovered. Until then such biomarker studies can provide evidence of drugs engaging with the mechanism of interest and encouragement of the concept.

The borders of mental disorder in psychiatry and the DSM: past, present, and future

Over the past 60 years, the Diagnostic and Statistical Manual of Mental Disorders (DSM) has evolved from early efforts to collect statistical information to a modern compendium of mental disorders that can be reliably diagnosed, but have not been validated. Throughout this history, DSM architects have struggled with the seemingly fundamental, but complex question of how to define a mental disorder. Current proposals indicate that a spectrum model of mental illness will be embraced in DSM-5, prompting renewed concern and debate about pathologizing normal existence. While a spectrum view of mental illness may reflect biologic reality and help pave the path towards validated models of psychiatric disorder, diagnostic expansion does have important practical implications and could give rise to problems in clinical work and society at large, including the further sanctioning of a shift from psychiatric treatment to neuroenhancement. Debates about what should or should not be considered a mental illness in DSM-5 are likely to remain unresolved and, in the future, must be framed according to contextual utility. Diagnosis and thresholds of pathology are ultimately value-based so that careful analysis and perhaps even different definitions of disorder may be required to guide decision-making in research, clinical work, and public policy.

Coping flexibility in young adults: comparison between subjects with and without schizotypal personality features

The current study examined characteristics of coping patterns adopted by college students in mainland China. In particular, it examined the coping strategies adopted by subjects with schizotypal personality (SPD) features compared to those without SPD features, and compared the relative effectiveness of their coping. Four types of coping flexibility were identified among the college sample (n=427), including active-inflexible, passive-inflexible, active-inconsistent, and passive-inconsistent styles. The passive-inconsistent style was related to the worst outcomes. When comparing subjects with SPD features with those without SPD features, subjects with SPD features endorsed significantly more emotion-focused strategies in uncontrollable situations than those without SPD features. The SPD group experienced higher levels of trait anxiety, depression, paranoid ideation and general health problems. The SPD group also generally perceived more, less controllable stress than the non-SPD group and randomly used all four categories of coping strategies.

Genetics and intermediate phenotypes of the schizophrenia--bipolar disorder boundary

Categorization of psychotic illnesses into schizophrenic and affective psychoses remains an ongoing controversy. Although Kraepelinian subtyping of psychosis was historically beneficial, modern genetic and neurophysiological studies do not support dichotomous conceptualization of psychosis. Evidence suggests that schizophrenia and bipolar disorder rather present a clinical continuum with partially overlapping symptom dimensions, neurophysiology, genetics and treatment responses. Recent large scale genetic studies have produced inconsistent findings and exposed an urgent need for re-thinking phenomenology-based approach in psychiatric research. Epidemiological, linkage and molecular genetic studies, as well as studies in intermediate phenotypes (neurocognitive, neurophysiological and anatomical imaging) in schizophrenia and bipolar disorders are reviewed in order to support a dimensional conceptualization of psychosis. Overlapping and unique genetic and intermediate phenotypic signatures of the two psychoses are comprehensively recapitulated. Alternative strategies which may be implicated into genetic research are discussed.

Premorbid cognitive deficits in young relatives of schizophrenia patients

Neurocognitive deficits in schizophrenia (SZ) are thought to be stable trait markers that predate the illness and manifest in relatives of patients. Adolescence is the age of maximum vulnerability to the onset of SZ and may be an opportune "window" to observe neurocognitive impairments close to but prior to the onset of psychosis. We reviewed the extant studies assessing neurocognitive deficits in young relatives at high risk (HR) for SZ and their relation to brain structural alterations. We also provide some additional data pertaining to the relation of these deficits to psychopathology and brain structural alterations from the Pittsburgh Risk Evaluation Program (PREP). Cognitive deficits are noted in the HR population, which are more severe in first-degree relatives compared to second-degree relatives and primarily involve psychomotor speed, memory, attention, reasoning, and social-cognition. Reduced general intelligence is also noted, although its relationship to these specific domains is underexplored. Premorbid cognitive deficits may be related to brain structural and functional abnormalities, underlining the neurobiological basis of this illness. Cognitive impairments might predict later emergence of psychopathology in at-risk subjects and may be targets of early remediation and preventive strategies. Although evidence for neurocognitive deficits in young relatives abounds, further studies on their structural underpinnings and on their candidate status as endophenotypes are needed.

Psychopathology and personality traits in psychotic patients and their first-degree relatives

Personality dimensions have been associated with symptoms dimensions in schizophrenic patients (SP). In this paper we study the relationships between symptoms of functional psychoses and personality dimensions in SP and their first-degree relatives (SR), in other psychotic patients (PP) and their first-degree relatives (PR), and in healthy controls in order to evaluate the possible clinical dimensionality of these disorders. Twenty-nine SP, 29 SR, 18 PP, 18 PR and 188 controls were assessed using the temperament and character inventory (TCI-R). Current symptoms were evaluated with positive and negative syndrome scale (PANSS) using the five-factor model described previously (positive [PF], negative [NF], disorganized [DF], excitement [EF] and anxiety/depression [ADF]). Our TCI-R results showed that patients had different personality dimensions from the control group, but in relatives, these scores were not different from controls. With regard to symptomatology, we highlight the relations observed between harm avoidance (HA) and PANSS NF, and between self-transcendence (ST) and PANSS PF. From a personality traits-genetic factors point of view, schizophrenia and other psychosis may be initially differentiated by temperamental traits such as HA. The so-called characterial traits like ST would be associated with the appearance of psychotic symptoms.

Epidemiology of schizophrenia: review of findings and myths

By describing patterns of disease distribution within populations, identifying risk factors, and finding associations, epidemiologic studies have contributed to the current understanding of schizophrenia. Advanced paternal age and the association with autoimmune diseases are some of the newly described epidemiologic findings shaping the current definition of schizophrenia. Although early intervention strategies have gained momentum, primary prevention of schizophrenia still seems a very distant aspiration. This article reviews the major epidemiological features of schizophrenia, with particular attention to the recent advances using population-based data. It also discusses some pervasive misconceptions about schizophrenia epidemiology, such as universal distribution and gender equality.

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.

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'.

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.

Prodromal interventions for schizophrenia vulnerability: the risks of being "at risk"

Given the morbidity and difficulty of treating psychotic disorders, including schizophrenia, there has been a move toward identifying and treating adolescents and young adults who appear to be clinically at risk or "prodromal" to psychosis. The field now has greater specificity in identification, with rates of 40-50% conversion to frank psychosis within 1-2 years. There is further evidence that medications and other treatments may have some efficacy for "prodromal" patients, though with variable side effects. However, controversy remains about some of the inherent risks in prodromal research, such as medication exposure and stigma among false-positives. In this paper, we add to this discussion through an analysis of ethics in prodromal research from the more established field of predictive genetic testing. Issues are raised about the effects of information on patients, families, and institutions, as well as future insurability, the limits of confidentiality (as it relies on discretion of patients and families), the autonomy of minors with psychiatric symptoms, and even the risks for the true-positive patient.

The use of pharmacotherapy in the prodrome of schizophrenia

In treating schizophrenia there has been a shift in focus, with more attention being paid to early intervention based on the notion that effective treatment at this point can improve outcome. Most of this work has centred on pharmacotherapeutic interventions during the first psychotic break. More recently, attention has turned to the potential value of intervening even earlier, that is during the so-called "prodrome" that has been identified as predating the first psychotic break by as much as 4-5 years. We now have a limited number of published reports addressing this topic and these are reviewed here.

Schizotaxia: current status and future directions

Schizophrenia is a biologic disorder whose etiology involves a combination of genetic and environmental risk factors. In this review, the authors update the conceptual basis of schizotaxia, consider evidence for its validity, and look toward its likely evolution in the future.

Genetically mediated brain abnormalities in schizophrenia

Schizophrenia is a highly heritable, neurobehavioral disorder; however, the mode of inheritance is complex, and linkage findings have been difficult to replicate. Some consistent linkage findings have emerged on chromosomes 1, 6, 8, 11, 13, 15, and 22. New methods are being developed for candidate gene identification, including the use of neurobiologic phenotypes observed in relatives of persons with schizophrenia. Neuroimaging studies of relatives implicate abnormal hippocampal structure and inefficient prefrontal network functioning, probably representing mild variants of the abnormalities observed in schizophrenia. These characteristics may represent stable markers of vulnerability to schizophrenia, because they are not confounded by effects of antipsychotic drugs or psychosis. Recent studies provide evidence for a small role of the catechol-O-methyltransferase gene on 22q, and the serotonin receptor transporter gene on 17q11-q12 in the development of schizophrenia. Linking genes and brain regions or networks is an important step in identification of the pathophysiology of schizophrenia.

Vulnerability markers in the schizophrenia spectrum: implications for phenomenology, genetics, and the identification of the schizophrenia prodrome

A continuum of symptoms between "normality" and overt psychosis has been documented in relatives of schizophrenia patients, SPD, and individuals who may be in the early stages of a psychotic illness with "subsyndromal" symptoms. The empirically derived criteria for SPD have been refined to define a clinical phenotype that is linked to schizophrenia. The clinical SPD symptoms define a heterogeneous group of individuals who are often comorbid for Axis I and II disorders, may or may not have a family history of schizophrenia, and are at risk for developing schizophrenia themselves. SPD subjects have similar abnormalities to those observed in schizophrenia patients on various psychophysiologic paradigms designed to study central inhibition, including P50 event-related potential suppression, PPI of the startle response, and the antisaccade task. Because SPD subjects do not have many of the confounding variables observed in schizophrenia patients (i.e., medication effects), these paradigms might represent vulnerability markers that are possible endophenotypes for schizophrenia spectrum illness. Questions still remain as to whether SPD is genotypically linked to schizophrenia but has genes of lesser penetrance, fewer affected genes, lack of a second hit, or perhaps protective factors. It is also possible that SPD, like schizophrenia, is a common final pathway that can come about because of several etiologic factors that affect crucial neurodevelopmental periods. Future directions in SPD work might include the use of vulnerability markers to essentially subtype schizophrenia spectrum patients and create simpler endophenotypes to understand the phenomenologic and neurobiologic substrate. The use of vulnerability markers along with clinical symptoms may help to improve the predictive power for identifying individuals at risk for schizophrenia for early intervention. Finally, genetic studies have yet to be performed in SPD.

Understanding predisposition to schizophrenia: toward intervention and prevention

OBJECTIVE

Early intervention to prevent schizophrenia is one of the most important goals of schizophrenia research. However, the field is not yet ready to initiate trials to prevent prodromal or psychotic symptoms in people who are at risk for developing the disorder. In this paper, we consider some of the major obstacles that must be studied before prevention strategies become feasible.

METHOD AND RESULTS

One of the most important hurdles is the identification of a syndrome or set of traits that reflects a predisposition to schizophrenia and that might provide potential targets for intervention. In a recent reformulation of Paul Meehl's concept of schizotaxia, we integrate research findings obtained over the last 4 decades to propose a syndrome with meaningful clinical manifestations. We review the conceptualization of this syndrome and consider its multidimensional clinical expression. We then describe preliminary research diagnostic criteria for use in adult, nonpsychotic, first-degree relatives of patients diagnosed with schizophrenia, based on negative symptoms and neuropsychological deficits. We follow this with evidence supporting the validity of the proposed syndrome, which mainly includes social dysfunction and response to a low dosage of one of the newer antipsychotic medications.

CONCLUSIONS

Continued progress toward the eventual initiation of prevention strategies for schizophrenia will include sustained efforts to validate the traits reflecting a predisposition to develop the disorder (for example, schizotaxia), follow-up studies to confirm initial findings, and the identification of potentially useful preventive interventions.

Childhood-onset schizophrenia: premorbid and prodromal diagnostic and treatment histories

OBJECTIVE

There is increasing interest in the possible relationship between the early diagnosis and treatment of schizophrenia during adolescence and improved long-term outcome. This study reviews the premorbid and prodromal diagnostic and treatment histories for childhood-onset schizophrenia, to assess whether early identification and treatment is possible in this school-age group.

METHOD

Parents of 17 children with childhood-onset schizophrenia or schizoaffective disorder were questioned retrospectively regarding symptoms, exposure to mental health professionals, diagnoses, and treatments.

RESULTS

Initial presenting symptoms clustered around violent aggression and school problems. Age of first recognized psychotic symptoms ranged from 2 to 11 years, followed 2.0+/-2.0 years later by a diagnosis of schizophrenia. Prior to a schizophrenia diagnosis, these children were exposed to stimulants, antidepressants, lower-dose typical neuroleptics, mood stabilizers, alternative treatments, and individual and family therapy.

CONCLUSION

Early diagnosis of childhood-onset schizophrenia is met with caution in the psychological and medical community. These children received many diagnoses before schizophrenia or schizoaffective disorder was diagnosed. A diagnosis of schizophrenia or schizoaffective disorder and utilization of effective atypical neuroleptic treatment was delayed until evaluation by a child and adolescent psychiatrist. Obstacles to early identification and treatment are discussed.

An integration of schizophrenia with schizotypy: identification of schizotaxia and implications for research on treatment and prevention

The liability to schizophrenia (schizotaxia) is associated with deficits in a variety of domains, including negative symptoms and neuropsychological deficits, even in the absence of psychosis or pre-psychotic prodromal symptoms. Conceptually, this view of schizotaxia is similar to negative schizotypy (i.e., schizotypal personality disorder minus the positive symptoms). It is broader than DSM-IV schizotypal personality disorder (SPD), however, in that more relatives of patients with schizophrenia show core symptoms of schizotaxia than meet the diagnostic criteria for SPD. Three lines of evidence support the validity of schizotaxia. First, evidence of concurrent validation was obtained by showing that schizotaxic subjects were more impaired than non-schizotaxic subjects on a variety of independent clinical scales. Second, schizotaxic subjects showed higher levels of negative symptoms on the Structured Interview for Schizotypy than non-schizotaxic subjects, but did not differ on positive symptoms. Third, subjects who met predetermined criteria for schizotaxia (i.e., negative symptoms and neuropsychological deficits) showed positive effects following treatment with low doses of risperidone (0.25-2.0 mg). Thus, clinical deficits in schizotaxia may be identifiable, and to a significant extent, reversible. Implications for the conception of schizotypy and the prevention of schizophrenia will be discussed.

Broad therapeutic uses of atypical antipsychotic medications

The atypical antipsychotics have a low incidence of extrapyramidal side effects (EPS), have improved tardive dyskinesia profiles, and have a broad range of therapeutic efficacy. These agents offer important therapeutic advantages that extend beyond their initial regulatory approval in several conditions and patient groups. The use of atypical antipsychotics is most relevant in the treatment of mood disorders, where these medications are being used increasingly for acute mood stabilization and in patients who are resistant to other treatments. Similar circumstances and clinical advantages pertain to the use of atypical antipsychotics in the treatment of behavioral disturbances in patients with dementia and in the management of personality disorders-both circumstances where conventional antipsychotics were initially poorly tolerated because of EPS. The low incidence of EPS associated with atypical antipsychotics is highly beneficial in several neuropsychiatric conditions. The extent to which endocrine and metabolic dysregulations associated with atypical antipsychotics will influence antipsychotics' role remains to be determined. As therapeutic opportunities evolve and diversify, atypical antipsychotics, because of favorable adverse-effect profiles, will have enhanced patient tolerability and use in nonpsychiatric conditions.

Concurrent validation of schizotaxia: a pilot study

BACKGROUND

Many first-degree relatives of patients with schizophrenia show deficits in clinical, neuropsychological, neurobiological and social domains, in the absence of psychosis. We recently reformulated Meehl's concept of schizotaxia to conceptualize the liability to schizophrenia, and we proposed preliminary criteria based on the presence of negative symptoms and neuropsychological deficits. Here we investigate the concurrent validity of schizotaxia by comparing a group of subjects who met criteria for schizotaxia with a group who did not on independent measures of clinical function, and on lifetime rates of selected comorbid psychiatric disorders.

METHODS

Twenty-seven adults who were first-degree, biological relatives of patients with schizophrenia were evaluated for schizotaxia based on our predetermined criteria involving negative symptoms and neuropsychological deficits. Subjects also received portions of the Diagnostic Interview for Genetic Studies, the Structured Interview for Schizotypy, the Family Interview for Genetic Studies, the DSM-IV Global Assessment of Functioning, the Physical Anhedonia Scale, the Social Adjustment Scale and the Symptom Checklist-90-Revised. Subjects who met criteria for schizotaxia were compared with those who did not on each of the clinical measures, and on their rates of comorbid DSM-IV psychiatric diagnoses.

RESULTS

Eight subjects met criteria for schizotaxia, and 19 did not. Subjects with schizotaxia showed significantly lower levels of function on each of the clinical scales. Differences in comorbid psychiatric diagnoses were not significant, although the rate of lifetime substance abuse diagnoses in the schizotaxic group (50%) approached levels that are often seen in schizophrenia.

CONCLUSIONS

These findings provide the first evidence of concurrent validation for a proposed syndrome of schizotaxia. They are also consistent with the view that the vulnerability to schizophrenia may be defined, at least partially, although larger studies to assess both the concurrent and predictive validity of schizotaxia will be required to confirm these results.

Family and twin strategies as a head start in defining prodromes and endophenotypes for hypothetical early-interventions in schizophrenia

In an effort to share the experiences of 'genotype-hunters'-who have approached the difficult task of forecasting future schizophrenia in the young offspring or other relatives of index cases, in new samples guided by the prior probabilities of 15% in offspring or 50% in identical co-twins-with 'early-interventionists'-who focus on purported prodromal symptoms in children who would be treated pharmacologically to prevent the development of schizophrenia-we provide a focused review that emphasizes the hazards of false positives in both approaches. Despite the advantages prospective high-risk strategies have had from clinical and laboratory findings that implicate some prodromal signs and endophenotypes, e.g. attention, memory, and information processing evaluations, the yields are not sufficient for practical applications involving antipsychotic drugs for undiagnosed children. Even more caution than usual is required, given the suggestions that the developing neocortex is vulnerable to dopaminergic exposure.

Ethics and early intervention in psychosis: keeping up the pace and staying in step

The intense clinical and research interest in early psychosis in recent years has highlighted a range of ethical issues which need to be considered carefully. Our perspective is based on 16 years of clinical and research experience with young people at this phase of illness as well as the research contributions of many others. We discuss the ethical dilemmas in relation to the three key foci, which make up the early psychosis paradigm. These are the pre-psychotic or prodromal phase, the period of untreated psychosis and the first psychotic episode and the critical period of recovery, which follows this. Most attention is devoted to the pre-psychotic period, however ethical considerations related to research in the other two clinical foci are briefly covered as well. Our contention is that the ethical issues are essentially identical to those arising in early intervention research in mainstream medicine. This has been concealed by inconsistency and emotion, which has great potential to confuse, politicize and derail rational debate. The legacy of the isolation of psychiatry from medicine and consequent prejudice and stigma in the professional as well as the public mind seems to be fueling a tendency in some societies to view psychiatric research as qualitatively different from other medical research. Sound clinical research data should be allowed to illuminate the options for potential consumers across all phases of illness. The alternative is research paralysis, which would force clinical practice to expand blindly without an evidence base.

Childhood 'risk characteristics' and the schizophrenia spectrum prodrome

This review identifies similarities between behavioural indicators of children with future schizophrenia-spectrum disorders and prodromal symptoms in the first episode of schizophrenia. An alternative concept of prodrome is described with implications for early recognition, monitoring and intervention of individuals at risk of future schizophrenia spectrum disorders.

Two double-blind placebo-controlled pilot studies of eicosapentaenoic acid in the treatment of schizophrenia

Evidence that the metabolism of phospholipids and polyunsaturated fatty acids (PUFA) is abnormal in schizophrenia provided the rationale for intervention studies using PUFA supplementation. An initial open label study indicating efficacy for n-3 PUFA in schizophrenia led to two small double-blind pilot studies. The first study was designed to distinguish between the possible effects of two different n-3 PUFA: eicosapentaenoic acid (EPA) and docohexaenoic acid (DHA). Forty-five schizophrenic patients on stable antipsychotic medication who were still symptomatic were treated with either EPA, DHA or placebo for 3 months. Improvement on EPA measured by the Positive and Negative Syndrome Scale (PANSS) was statistically superior to both DHA and placebo using changes in percentage scores on the total PANSS. EPA was significantly superior to DHA for positive symptoms using ANOVA for repeated measures. In the second placebo-controlled study, EPA was used as a sole treatment, though the use of antipsychotic drugs was still permitted if this was clinically imperative. By the end of the study, all 12 patients on placebo, but only eight out of 14 patients on EPA, were taking antipsychotic drugs. Despite this, patients taking EPA had significantly lower scores on the PANSS rating scale by the end of the study. It is concluded that EPA may represent a new treatment approach to schizophrenia, and this requires investigation by large-scale placebo-controlled trials.

Genes, environment and schizophrenia

BACKGROUND

Data from family, twin and adoption studies show overwhelming evidence of a substantial genetic component in schizophrenia and although molecular genetic studies have been more difficult to replicate, recent improvements in technology have resulted in the implication of genes at several chromosomal loci. Nevertheless, it remains clear that environmental factors both add to and interact with genetic factors to produce the disorder.

AIMS

To incorporate genetic and environmental risk factors into a neurodevelopmental model in order to conceptualise the liability to schizophrenia.

METHOD

A representative selection of the literature related to this issue is reviewed, together with a reformulation of Meehl's term 'schizotaxia' to describe the liability to the disorder.

RESULTS

The literature supports a multi-factorial view of the liability to schizophrenia, which includes both genetic and environmental components.

CONCLUSIONS

Schizotaxia provides a useful way to conceptualise both the liability for schizophrenia, and also the development of treatment strategies aimed at the eventual prevention of the illness.

Schizophrenia: family studies and treatment of spectrum disorders

A substantial part of the contribution of genetic studies to the treatment of schizophrenia involves its emphasis on reliable and valid diagnoses. One consequence of this focus is the recognition that schizophrenic illness is broader than the diagnostic entity of schizophrenia itself, and instead consists of a “spectrum” of related disorders. Because some of the symptoms in these disorders differ from each other, they provide an opportunity to determine which ones reflect a common etiology. To the extent that such symptoms are identifiable, they may provide a foundation for treatment and even prevention strategies. In this paper, we focus on a clinical condition - “schizotaxia” - that may reflect the liability for schizophrenia. To characterize the nature and extent of this proposed syndrome, we will review results from family studies in our laboratory, and consider conceptual foundations and criteria for assessment. A more general consideration of treatment strategies for schizophrenia spectrum disorders follows, along with suggestions for future research. Our initial attempts to treat and validate schizotaxia are encouraging, and raise the possibility that early treatment might eventually prevent or attenuate the development of other, more severe disorders in the schizophrenia spectrum, including schizophrenia itself.

Schizophrenia: vulnerability versus disease

One of the most important trends in the treatment of schizophrenia involves its early diagnosis and intervention. The ultimate goal of research is the prevention of the disorder, A major impediment to the development of prevention strategies, however, is that we do not yet know what the liability for schizophrenia is before the onset of psychosis. Consequently, early treatment attempts are focused on the “prodrome,” which involves the early symptoms of psychosis. In a companion paper, we recently suggested that prevention work should focus not only on the prodrome, but also on “schizotaxia,” which is a clinically meaningful condition that may reflect the vulnerability to schizophrenia in the absence of psychosis. Because schizotaxia can be assessed prior to the prodrome, studies of schizotaxia might lead to more effective prevention programs. We continue the characterization of schizotaxia in this paper by focusing on the etiological roots of schizotaxia, plus its likely neurodevelopmental course, clinical expression, and treatment. Finally, the importance of including neurobiological variables in the conceptualization and eventual diagnosis of schizotaxia is reviewed.

Towards the prevention of schizophrenia

There is a growing emphasis on attempts to identify the early signs and symptoms of schizophrenia, largely because early detection and treatment of psychosis (i.e., secondary prevention) are associated with relatively favorable clinical outcomes. This raises the issue of whether prevention of psychosis itself is possible. The achievement of this goal will require the identification of a premorbid state that could serve as the foundation for treatment strategies aimed ultimately at the prevention of schizophrenia. Fortunately, evidence for such a state is emerging, in part because schizophrenia may result from a neurodevelopmental disorder that is associated with a variety of clinical, neurobiological, and neuropsychologic features occurring well before the onset of psychosis. These features may serve as both indicators of risk for subsequent deterioration and the foundation of treatment efforts. We reformulated Meehl's term schizotaxia to describe this liability and discuss here how its study could form the basis for future strategies of prevention. We also include a description of our initial attempts to devise treatment protocols for schizotaxia. It is concluded that schizotaxia is a feasible concept on which to base prevention efforts, and that treatment of adult schizotaxia may be among the next steps in the process.

Meeting report; "Molecular neurobiological mechanisms in schizophrenia: seeking a synthesis," April 11-14, 1999

A meeting on the molecular and neurobiological basis of schizophrenia was held April 11-14, 1999 at the Banbury Center of The Cold Spring Harbor Laboratory, Cold Spring Harbor, New York. This report is a summary of the predominant views of the participants, as perceived by the organizers. The purpose of this meeting was integrative-to bring together in a relaxed environment three dozen outstanding scientists in disparate underlying disciplines: psychiatry, psychology, genetics, neurobiology, biochemistry, molecular biology, and pharmacology. Brief talks emphasized concepts and questions rather than presentation of data. Exchanges of information and concepts provided an emerging synthesis of current and novel, even highly speculative, ideas. The reader is cautioned that the ideas, data supporting them, and data interpretations are not critiqued in this report. Nor is there much distinction made between speculations and findings that have more experimental support. The main questions and conclusions that emerged are presented in this report, which covers the following: 1) macrobiology (what schizophrenia is in terms of definition and improved diagnostics, genetics and environment, brain structure, development, and mind), 2) cell and molecular biology (defects of the expressed disease at both the membrane and nuclear levels, molecular defects of development, neuroreceptor genes and transcriptional control, and ligands), 3) therapies (current approaches, possible targets, and animal models), and 4) newer approaches (gene expression, early treatment and prevention strategies, and other problems). Two references per participant and abstracts (available from the organizers) served as a common basis.