Towards the prevention of schizophrenia

Bilateral anterior corona radiata microstructure organisation relates to impaired social cognition in schizophrenia

OBJECTIVE

The Corona Radiata (CR) is a large white matter tract in the brain comprising of the anterior CR (aCR), superior CR (sCR), and posterior CR (pCR), which have associations with cognition, self-regulation, and, in schizophrenia, positive symptom severity. This study tested the hypothesis that the microstructural organisation of the aCR, as measured by Fractional Anisotropy (FA) using Diffusion Tensor Imaging (DTI), would relate to poorer social cognitive outcomes and higher positive symptom severity for people with schizophrenia, when compared to healthy participants. We further hypothesised that increased positive symptoms would relate to poorer social cognitive outcomes.

METHODS

Data were derived from n = 178 healthy participants (41 % females; 36.11 ± 12.36 years) and 58 people with schizophrenia (30 % females; 42.4 ± 11.1 years). The Positive and Negative Symptom Severity Scale measured clinical symptom severity. Social Cognition was measured using the Reading the Mind in the Eyes Test (RMET) Total Score, as well as the Positive, Neutral, and Negative stimuli valence. The ENIGMA-DTI protocol tract-based spatial statistics (TBSS) was used.

RESULTS

There was a significant difference in FA for the CR, in individuals with schizophrenia compared to healthy participants. On stratification, both the aCR and pCR were significantly different between groups, with patients showing reduced white matter tract microstructural organisation. Significant negative correlations were observed between positive symptomatology and reduced microstructural organisation of the aCR. Performance for RMET negative valence items was significantly correlated bilaterally with the aCR, but not the sCR or pCR, and no relationship to positive symptoms was observed.

CONCLUSIONS

These data highlight specific and significant microstructural white-matter differences for people with schizophrenia, which relates to positive clinical symptomology and poorer performance on social cognition stimuli. While reduced FA is associated with higher positive symptomatology in schizophrenia, this study shows the specific associated with anterior frontal white matter tracts and reduced social cognitive performance. The aCR may have a specific role to play in frontal-disconnection syndromes, psychosis, and social cognitive profile within schizophrenia, though further research requires more sensitive, specific, and detailed consideration of social cognition outcomes.

Corpus Callosum Microstructural Tract Integrity Relates to Longer Emotion Recognition Reaction Time in People with Schizophrenia

Objective: Schizophrenia is a complex functionally debilitating neurodevelopmental disorder, with associated social cognitive impairment. Corpus Callosum (CC) white matter tracts deficits are reported for people with schizophrenia; however, few studies focus on interhemispheric processing relative to social cognition tasks. This study aimed to determine if a relationship between the CC and social cognition exists. Method: In this cross-section study, a sample of n = 178 typical controls and n = 58 people with schizophrenia completed measures of mentalising (Reading the Mind in the Eyes), emotion recognition outcome and reaction time (Emotion Recognition Test), and clinical symptoms (Positive and Negative Symptom Scale), alongside diffusion-based tract imaging. The CC and its subregions, i.e., the genu, body, and splenium were the regions of interest (ROI). Results: Reduced white matter tract integrity was observed in the CC for patients when compared to controls. Patients performed slower, and less accurately on emotion recognition tasks, which significantly and negatively correlated to the structural integrity of the CC genu. Tract integrity further significantly and negatively related to clinical symptomatology. Conclusions: People with schizophrenia have altered white matter integrity in the genu of the CC, compared to controls, which relates to cognitive deficits associated with recognising emotional stimuli accurately and quickly, and severity of clinical symptoms.

Achieving the Lowest Effective Antipsychotic Dose for Patients with Remitted Psychosis: A Proposed Guided Dose-Reduction Algorithm

Continuing antipsychotic treatment in patients with schizophrenia under clinical remission remains controversial. Even though the mainstream opinion declares an outweighed balance against medication discontinuation, recent reviews and critiques suggest that some patients may remain symptom free and well functioning after stopping antipsychotics, but few predictors can identify who can try medication discontinuation, whilst no guidelines exist for reducing medication to reach the lowest effective dose safely. Analyzing the findings from studies employing different methodologies, adopting evidence from pharmacodynamic research, and observing dose reduction in stable patients, as well as taking inspiration from the metaphor of the Cantor set in natural philosophy, we introduce an alternative solution and propose a guided dose-reduction algorithm that follows a set of clear precautions and instructions. The algorithm recommends only a fraction (no more than 25%) of the dosage to be reduced at a time, with at least a 6-month stabilization period required before reducing another 25% of the dose. Patients are empowered to actively participate in decision making when they are ready for further dose tapering, or should they retreat to a previous dosage if warning signs of a relapse re-emerge. An intermittent or irregular dosing schedule can be used to adapt this algorithm to real-world practice. Our preliminary findings suggest that patients with remitted psychosis can do well along this path. We anticipate that this approach can help optimize the risk-benefit ratio and instill a hope in patients with schizophrenia that they can maintain in stable remission under a lower antipsychotic dose without an increased risk of relapse.

Cross Cultural Validation and Extension of the Clinical Assessment Interview for Negative Symptoms (CAINS) in the Chinese Context: Evidence from a Spectrum Perspective

The Clinical Assessment Interview for Negative Symptoms (CAINS) was designed in accordance with the recent theory and research in social affective neuroscience and to address the psychometric and conceptual limitations of other instruments assessing negative symptoms. The present study aimed to provide a large-scale validation of the CAINS in China and examine its applicability and validity evidence across the schizophrenia spectrum. Using confirmatory factor analysis, our results replicated the original findings in the US development samples that the CAINS possesses a stable 2-factor structure, namely "motivation/pleasure" and "expression". We also found significant correlations between the CAINS and other negative symptom measures. The CAINS demonstrated good discriminant validity in differentiating negative symptoms in people with schizophrenia, nonpsychotic first-degree relatives and people with social anhedonia. People with schizophrenia exhibited significantly higher CAINS subscale scores than first-degree relatives and healthy controls. In addition, first-degree relatives had higher "motivation/pleasure" scores than healthy controls. The "motivation/pleasure" subscale scores of individuals with social anhedonia were also significantly higher than healthy controls.

Clashing Diagnostic Approaches: DSM-ICD Versus RDoC

Since at least the middle of the past century, one overarching model of psychiatric classification has reigned supreme, namely, that of the Diagnostic and Statistical Manual of Mental Disorders and the International Statistical Classification of Diseases and Related Health Problems (herein referred to as DSM-ICD). This DSM-ICD approach embraces an Aristotelian view of mental disorders as largely discrete entities that are characterized by distinctive signs, symptoms, and natural histories. Over the past several years, however, a competing vision, namely, the Research Domain Criteria (RDoC) initiative launched by the National Institute of Mental Health, has emerged in response to accumulating anomalies within the DSM-ICD system. In contrast to DSM-ICD, RDoC embraces a Galilean view of psychopathology as the product of dysfunctions in neural circuitry. RDoC appears to be a valuable endeavor that holds out the long-term promise of an alternative system of mental illness classification. We delineate three sets of pressing challenges--conceptual, methodological, and logistical/pragmatic--that must be addressed for RDoC to realize its scientific potential. We conclude with a call for further research, including investigation of a rapprochement between Aristotelian and Galilean approaches to psychiatric classification.

Dimensionality vs taxonicity of schizotypy: some new data and challenges ahead

Heterogeneity in the expression of schizotypy may arise from underlying dimensional processes or a taxonic population structure. In a 2-phase study, we tested the taxonicity of self-reported schizotypy within a general psychiatric sample (n = 109) and examined taxon validity by testing its association with clinical schizotaxia in follow-up subsamples. Taxometric analyses indicated a taxonic structure (schizotypy prevalence = 38.8%) provided the best description of the underlying population distribution. After a year, schizotypal (n = 14) and nonschizotypal (n = 14) subsamples returned for diagnosis of clinical schizotaxia by assessment of executive functioning, attention, memory, and negative symptoms. Seven patients met diagnostic criteria, all members of the schizotypy class. Schizotypy was associated with impaired attention and memory, more negative symptoms, poorer global functioning, and more extensive psychiatric histories. We reconcile inconsistencies in the literature by discussing threats to the validity of this and similar research on Meehl's taxonomic model of schizotypy, including conceptual limitations of the lexical hypothesis and conventions of factor analysis. Scrutiny of Meehl's model should involve disambiguation and better measurement of the schizotaxia-schizotypy phenotype.

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.

Antipsychotic interventions in prodromal psychosis: safety issues

In recent years, psychopharmacological intervention in prodromal psychosis, also known as the ultra-high risk (UHR) mental state for psychosis, has attracted much attention. Whilst it has been shown that antipsychotic use in UHR individuals may be effective in potentially delaying or even averting progression to frank psychosis, their use in subjects that do not necessarily convert to psychosis has raised considerable ethical concerns because of their adverse effects. Recent treatment guidelines for patients at UHR for psychosis recommend the use of antipsychotics only in exceptional conditions and with great precautions. To date only a few studies have investigated the use of antipsychotic medications in UHR patients and the potential benefits and risks related to their use in prodromal psychosis remain unclear. We review here all published studies that included UHR patients treated with antipsychotics, regardless of study design. These studies were all of second-generation antipsychotics, given that first-generation antipsychotics cannot be recommended because of their adverse drug reactions. We specifically examine the available descriptions of adverse reactions of the individual antipsychotic medication in each study and discuss the potential effects of various demographic and clinical factors that may impact on safety issues of pharmacological interventions in UHR patients. Clinical trials to date investigating potential benefits of antipsychotic treatments in preventing transition to psychosis were of relatively short duration and have involved a small number of patients. Whilst it appears that pharmacological intervention at this stage may be effective in both reducing the psychopathology and decreasing transition rates, and is potentially safe, in the absence of sufficient evidence-based knowledge to guide treatment, definitive clinical recommendations and guidelines cannot be derived. Certain adverse events take time to develop, such as metabolic syndrome and endocrine-related effects, thus longer term clinical trials with a larger number of patients are needed to determine the effectiveness of antipsychotic intervention and the relationship of its duration to emergence of adverse events. This can inform the development of timely strategies to prevent serious negative impacts and thus maximize the benefits of antipsychotic intervention in UHR patients that outweigh the risks associated with their use.

Engaging Youths with Serious Mental Illnesses in Treatment: STARS Study Consumer Recommendations

OBJECTIVE

The purpose of this study was to identify better methods of engaging youths in mental health services by asking experienced mental health consumers for suggestions for clinicians.

METHODS

177 members of an integrated health plan, ranging in age from 16-84 years and diagnosed with schizophrenia, schizoaffective disorder, bipolar disorder, or affective psychosis, completed four in-depth semistructured interviews over 24 months as part of a study of recovery from serious mental illness. We transcribed and coded interviews, extracted a set of common themes addressing consumer recommendations to clinicians, and compared these themes across age groups.

RESULTS

Five primary themes emerged in participants' recommendations: (1) use an age-appropriate approach that reflects youth culture and lifestyles; (2) foster development of autonomy; (3) take a personal, rather than diagnostic, approach; (4) be empathetic and authentic; and (5) create a safe and supportive environment. Consumers age 30 and older described three additional areas in which clinicians could contribute to youths' well being: (1) help find the right diagnosis and the right medication, (2) counsel youths to avoid using alcohol and drugs, and (3) take steps to help prevent social isolation.

CONCLUSIONS

Study findings suggest that many strategies recommended for working with adults may benefit young people, but that developmentally appropriate modifications to these approaches are needed to foster treatment engagement among youths.

Glutamate signaling in the pathophysiology and therapy of schizophrenia

Glutamatergic neurotransmission, particularly through the N-methyl-d-aspartate (NMDA) receptor, has drawn attention for its role in the pathophysiology of schizophrenia. This paper reviews the neurodevelopmental origin and genetic susceptibility of schizophrenia relevant to NMDA neurotransmission, and discusses the relationship between NMDA hypofunction and different domains of symptom in schizophrenia as well as putative treatment modality for the disorder. A series of clinical trials and a meta-analysis which compared currently available NMDA-enhancing agents suggests that glycine, d-serine, and sarcosine are more efficacious than d-cycloserine in improving the overall psychopathology of schizophrenia without side effect or safety concern. In addition, enhancing glutamatergic neurotransmission via activating the AMPA receptor, metabotropic glutamate receptor or inhibition of d-amino acid oxidase (DAO) is also reviewed. More studies are needed to determine the NMDA vulnerability in schizophrenia and to confirm the long-term efficacy, functional outcome, and safety of these NMDA-enhancing agents in schizophrenic patients, particularly those with refractory negative and cognitive symptoms, or serious adverse effects while taking the existing antipsychotic agents.

Differential propensity in recognition of prepsychotic phenomena among psychiatrists, clinical psychologists and school counsellors

AIM

The prodromal symptoms of schizophrenia are difficult to differentiate from other common psychiatric illnesses or stress reactions. Despite the development of new diagnostic instruments, non-specificity and poor awareness of this clinical entity are still major barriers to early identification of individuals at risk for schizophrenia. This study was conducted to assess differences among three types of mental health professionals in the recognition of prepsychotic phenomena.

METHODS

A questionnaire was developed that presented 11 case vignettes. The vignettes represented a hypothetical gradient of clinical severity, including stress reactions; very early stage, intermediate-risk stage and very high-risk stage of the schizophrenia prodrome; and full-blown psychosis. The questionnaire was completed by 57 psychiatrists, 44 clinical psychologists and 50 school counsellors. For each vignette, respondents indicated their top three choices among nine different diagnostic considerations.

RESULTS

As a group, psychiatrists were most likely to consider schizophrenia for all stages of clinical severity, whereas school counsellors were least likely to. Still, only about half of psychiatrists selected schizophrenia as their first choice for very high-risk cases, and even fewer psychologists and counsellors did so. A proportion of school counsellors failed to recognize full-blown psychosis. Despite the differential propensity in recognition of prepsychotic phenomena, a gradient in considering schizophrenia as a possible diagnosis across the stages of clinical severity was obvious.

CONCLUSIONS

Psychiatrists, clinical psychologists and school counsellors all need further education, targeting their group-specific proclivities, to improve their sensitivity and specificity in early identification of individuals at risk for schizophrenia.

Systematic reviews of categorical versus continuum models in psychosis: evidence for discontinuous subpopulations underlying a psychometric continuum. Implications for DSM-V, DSM-VI, and DSM-VII

Diagnostic systems, phenotype models, and theories of etiology incorporate propositions on the underlying nature of psychosis and schizophrenia phenotypes. These propositions, whether implicit or explicit, are that the distributions of the phenotypes, or the phenotype experiences themselves, are dimensional or categorical. On one hand, evidence on the epidemiology of schizophrenia phenotypes suggests symptom phenotypes may not be bound by conventional diagnostic thresholds but instead may blend imperceptibly with subclinical, statistically frequent experience, supporting continuum viewpoints. On the other hand, evidence on the population structure suggests a latent categorical structure; the population may be composed of two types of people. However, both sets of evidence are beset by methodological limitations that point unequivocally to the need to move beyond current diagnostic conceptualizations, observation, and anamnesis of psychosis, and toward responsive and scientifically refutable formulations of schizophrenia.

Neuroimaging predictors of transition to psychosis--a systematic review and meta-analysis

OBJECTIVES

In early stage psychosis research the identification of neurobiological correlates of vulnerability to schizophrenia is an important hurdle.

METHODS

We systematically reviewed the neuroimaging publications on high-risk subjects with subsequent transition to psychosis (HR-T) and conducted a meta-analysis calculating the effect size Cohen's d.

RESULTS

Out of 30 identified studies 25 met the inclusion criteria. Structural (s)MRI studies showed small to medium effect sizes of decreased prefrontal, cingulate, insular and cerebellar gray matter volume in HR-T compared to high-risk subjects without transition (HR-NT). Meta-analysis revealed relatively larger whole brain volumes in HR-T compared to HR-NT subjects (mean Cohen's d 0.36, 95% CI 0.27-0. 46). Compared to HR-NT, HR-T subjects showed in functional imaging studies reduced brain activation in prefrontal cortex, reduced neuronal density, and increased membrane turnover in frontal and cingulate cortex with medium to large effect sizes.

CONCLUSIONS

Despite methodological differences between studies, structural and neurochemical abnormalities in prefrontal, anterior cingulate, medial temporal and cerebellar cortex might be predictive for development of psychosis within HR subjects.

Prospective outcome of early intervention for individuals at ultra-high-risk for psychosis

AIM

Based on previous reports of second-generation antipsychotic agents having a beneficial effect on prodromal symptoms, we investigated the effectiveness and tolerability of atypical antipsychotic therapies in individuals at high risk for developing psychosis.

METHODS

We examined prodromal symptoms and functioning in individuals at ultra-high-risk for psychosis using an uncontrolled prospective design with pre- and post-treatment measures.

RESULTS

Of the 27 subjects taking antipsychotics during the study period, 15 took part in at least one follow-up assessment. Overall Comprehensive Assessment of At-Risk Mental States scores significantly improved at the last evaluation point, with a medium-size effect of Cohen's d = 0.54 (95% confidence interval, -0.02 to 1.08) (mean follow-up period = 8.8; SD = 8.3 months). Depression and anxiety symptoms were markedly reduced, and global and social functioning also significantly improved. Of the 27 subjects, two (7.4%) converted to psychosis and 16 (59.3%) experienced at least one treatment-emergent adverse event, but no subjects exhibited serious adverse events.

CONCLUSIONS

The results of this study support treating high-risk individuals with antipsychotics to reduce prodromal symptoms with adequate safety.

Gene-environment interaction during early development in the heterozygous reeler mouse: clues for modelling of major neurobehavioral syndromes

Autism and schizophrenia are multifactorial disorders with increasing prevalence in the young population. Among candidate molecules, reelin (RELN) is a protein of the extracellular matrix playing a key role in brain development and synaptic plasticity. The heterozygous (HZ) reeler mouse provides a model for studying the role of reelin deficiency for the onset of these syndromes. We investigated whether early indices of neurobehavioral disorders can be identified in the infant reeler, and whether the consequences of ontogenetic adverse experiences may question or support the suitability of this model. A first study focused on the link between early exposure to Chlorpyryfos and its enduring neurobehavioral consequences. Our data are interesting in view of recently discovered cholinergic abnormalities in autism and schizophrenia, and may suggest new avenues for early pharmacological intervention. In a second study, we analyzed the consequences of repeated maternal separation early in ontogeny. The results provide evidence of how unusual stress early in development are converted into altered behavior in some, but not all, individuals depending on gender and genetic background. A third study aimed to verify the reliability of the model at critical age windows. Data suggest reduced anxiety, increased impulsivity and disinhibition, and altered pain threshold in response to morphine for HZ, supporting a differential organization of brain dopaminergic, serotonergic and opioid systems in this genotype. In conclusion, HZ exhibited a complex behavioral and psycho-pharmacological phenotype, and differential responsivity to ontogenetic adverse conditions. HZ may be used to disentangle interactions between genetic vulnerability and environmental factors. Such an approach could help to model the pathogenesis of neurodevelopmental psychiatric diseases.

Are auditory-evoked frequency and duration mismatch negativity deficits endophenotypic for schizophrenia? High-density electrical mapping in clinically unaffected first-degree relatives and first-episode and chronic schizophrenia

BACKGROUND

Mismatch negativity (MMN) is a negative-going event-related potential (ERP) component that occurs in response to intermittent changes in constant auditory backgrounds. A consistent finding across a large number of studies has been impaired MMN generation in schizophrenia, which has been interpreted as evidence for fundamental deficits in automatic auditory sensory processing. The aim of this study was to investigate the extent to which dysfunction in MMN generation might represent an endophenotypic marker for schizophrenia.

METHODS

We measured MMN to deviants in duration (25 msec, 1000 Hz) and deviants in pitch (50 msec, 1200 Hz) relative to standard tones (50 msec, 1000 Hz) in 45 chronic schizophrenia patients, 25 of their first-degree unaffected biological relatives, 12 first-episode patients, and 27 healthy control subjects.

RESULTS

In line with previous work, MMN amplitudes to duration deviants (but not to pitch deviants) were significantly reduced in patients with chronic schizophrenia compared with control subjects. However, both duration and pitch MMNs were completely unaffected in the first-degree biological relatives and this was also the case for the first-episode patients. Furthermore, length of illness did not predict the extent of MMN deficit.

CONCLUSIONS

These findings suggest that the MMN deficit seen in schizophrenia patients is most likely a consequence of the disease and that MMN, at least to basic auditory feature deviants, is at best only weakly endophenotypic for schizophrenia.

Treating early psychosis: who, what, and when?

Early intervention and prevention in schizophrenia is just over 10 years old. The assumption guiding this field is that intervention is likely to be most effective if it begins before psychosis sets in, ie, during the prodromal phase. Although a substantial number of prodromal treatment programs have been initiated around the world, three early programs have generated most of the intervention findings to date: Personal Assessment and Crisis Evaluation (PACE) in Australia, and the Prevention through Risk Identification, Management, and Education (PRIME) and Recognition and Prevention (RAP) programs in the USA. The data suggest that early intervention leads to a reduction in prodromal symptoms and clinical distress. However, prevention of psychosis remains an unresolved question. Other issues include defining who should be treated, with what, and when. In addition, treatment targets associated with functional disability, such as early prodromal negative symptoms and risk factors, continue to emerge. Newly identified targets, in turn, suggest the need for a variety of novel interventions and treatment strategies.

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.

Targeting synapses and myelin in the prevention of schizophrenia

Many of the functions that are mediated by the prefrontal cortex (PFC) are severely impaired in schizophrenia. The maturation of these functions takes place during late adolescence and early adulthood, which coincides with the period of time when overt symptomatology of schizophrenia most commonly emerges. Two developmental processes occurring during the periadolescence period appear to mediate the functional maturation of the PFC: pruning of exuberant synapses and myelination of axons. It has long been speculated in the literature that disturbances of these processes may result in dysfunction of the PFC and thereby trigger the emergence of symptoms and deficits of schizophrenia. Alternatively, but not mutually exclusively, it has also been suggested that these late developmental processes may not be aberrant but they "unmask" preexisting deficits in the PFC, resulting in the onset of symptoms. The important implication of both of these scenarios is that in either case the emergence of PFC functional disturbances and the onset of symptoms and deficits of schizophrenia would in theory be preventable by pharmacologic manipulation of the synaptic pruning and/or axonal myelination processes. Thus, better understanding of the cellular and molecular mechanisms that mediate these processes will provide truly novel insight into the therapeutics and prevention of schizophrenia.

Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the treatment of schizophrenia and related disorders

BACKGROUND

The Royal Australian and New Zealand College of Psychiatrists is co-ordinating the development of clinical practice guidelines (CPGs) in psychiatry, funded under the National Mental Health Strategy (Australia) and the New Zealand Health Funding Authority. This paper presents CPGs for schizophrenia and related disorders. Over the past decade schizophrenia has become more treatable than ever before. A new generation of drug therapies, a renaissance of psychological and psychosocial interventions and a first generation of reform within the specialist mental health system have combined to create an evidence-based climate of realistic optimism. Progressive neuroscientific advances hold out the strong possibility of more definitive biological treatments in the near future. However, this improved potential for better outcomes and quality of life for people with schizophrenia has not been translated into reality in Australia. The efficacy-effectiveness gap is wider for schizophrenia than any other serious medical disorder. Therapeutic nihilism, under-resourcing of services and a stalling of the service reform process, poor morale within specialist mental health services, a lack of broad-based recovery and life support programs, and a climate of tenacious stigma and consequent lack of concern for people with schizophrenia are the contributory causes for this failure to effectively treat. These guidelines therefore tackle only one element in the endeavour to reduce the impact of schizophrenia. They distil the current evidence-base and make recommendations based on the best available knowledge.

METHOD

A comprehensive literature review (1990-2003) was conducted, including all Cochrane schizophrenia reviews and all relevant meta-analyses, and a number of recent international clinical practice guidelines were consulted. A series of drafts were refined by the expert committee and enhanced through a bi-national consultation process.

TREATMENT RECOMMENDATIONS

This guideline provides evidence-based recommendations for the management of schizophrenia by treatment type and by phase of illness. The essential features of the guidelines are: (i) Early detection and comprehensive treatment of first episode cases is a priority since the psychosocial and possibly the biological impact of illness can be minimized and outcome improved. An optimistic attitude on the part of health professionals is an essential ingredient from the outset and across all phases of illness. (ii) Comprehensive and sustained intervention should be assured during the initial 3-5 years following diagnosis since course of illness is strongly influenced by what occurs in this 'critical period'. Patients should not have to 'prove chronicity' before they gain consistent access and tenure to specialist mental health services. (iii) Antipsychotic medication is the cornerstone of treatment. These medicines have improved in quality and tolerability, yet should be used cautiously and in a more targeted manner than in the past. The treatment of choice for most patients is now the novel antipsychotic medications because of their superior tolerability and, in particular, the reduced risk of tardive dyskinesia. This is particularly so for the first episode patient where, due to superior tolerability, novel agents are the first, second and third line choice. These novel agents are nevertheless associated with potentially serious medium to long-term side-effects of their own for which patients must be carefully monitored. Conventional antipsychotic medications in low dosage may still have a role in a small proportion of patients, where there has been full remission and good tolerability; however, the indications are shrinking progressively. These principles are now accepted in most developed countries. (vi) Clozapine should be used early in the course, as soon as treatment resistance to at least two antipsychotics has been demonstrated. This usually means incomplete remission of positive symptomatology, but clozapine may also be considered where there are pervasive negative symptoms or significant or persistent suicidal risk is present. (v) Comprehensive psychosocial interventions should be routinely available to all patients and their families, and provided by appropriately trained mental health professionals with time to devote to the task. This includes family interventions, cognitive-behaviour therapy, vocational rehabilitation and other forms of therapy, especially for comorbid conditions, such as substance abuse, depression and anxiety. (vi) The social and cultural environment of people with schizophrenia is an essential arena for intervention. Adequate shelter, financial security, access to meaningful social roles and availability of social support are essential components of recovery and quality of life. (vii) Interventions should be carefully tailored to phase and stage of illness, and to gender and cultural background. (viii) Genuine involvement of consumers and relatives in service development and provision should be standard. (ix) Maintenance of good physical health and prevention and early treatment of serious medical illness has been seriously neglected in the management of schizophrenia, and results in premature death and widespread morbidity. Quality of medical care for people with schizophrenia should be equivalent to the general community standard. (x) General practitioners (GPs)s should always be closely involved in the care of people with schizophrenia. However, this should be truly shared care, and sole care by a GP with minimal or no specialist involvement, while very common, is not regarded as an acceptable standard of care. Optimal treatment of schizophrenia requires a multidisciplinary team approach with a consultant psychiatrist centrally involved.

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.

Is earlier better? At the beginning of schizophrenia: timing and opportunities for early intervention

The fundamental tenet is treating psychotic patients as quickly and as effectively as possible. Few would oppose this idea. Increasing community awareness of the services, enhancing accessibility, optimizing the treatment approaches, improving compliance, and addressing substance misuse should hopefully translate into improved outcomes for the patients and their families and are extremely encouraging and welcome developments. However, the field urgently needs properly designed randomized controlled trials to definitively determine their efficacy. If they are shown to be efficacious the emphasis should then shift to randomized controlled trials of prodromal intervention. If prodromal intervention is proven to be successful then earlier might indeed be better and primary prevention within reach.

The New York high risk project to the Hillside recognition and prevention (RAP) program

The sudden interest in initiating treatment before the onset of psychosis (i.e., during the prodromal stage of schizophrenia) has failed to integrate the earlier work on prediction generated by more traditional high-risk studies. Genetic high-risk research has most typically focused on the long-term, prospective study of children of parents with schizophrenia. In this paper, it will be argued that high-risk research can make at least two major contributions to prevention programs. First, previous findings can guide identification of risk factors and provide clues about causality, thus highlighting which pre-morbid deficits should be treatment targets. For example, as discussed here, data from the New York High Risk Project points to impaired attention as a highly promising candidate risk factor, with a possible causal association with later-emerging social deficits. Second, the high-risk approach can provide a framework for establishing the predictive validity of prodromal clinical indicators and for understanding the nature of the schizophrenia prodrome. Preliminary findings from the Hillside Recognition and Prevention (RAP) program, integrating high-risk methodology with an early intervention strategy, indicate that the prodrome is a developmentally complex phase of schizophrenia. In particular, a cluster of early features-including cognitive, academic, and social impairments, along with odd/disorganized behaviors-appear to anticipate positive symptoms and may constitute a core risk profile. Preliminary RAP treatment findings also suggest that medications other than anti-psychotics may be effective for treating early prodromal symptoms, challenging the widely held hypothesis that anti-psychotics should always be the first line preventive treatment.

Psychosis: conceptual and ethical aspects of early diagnosis and intervention

PURPOSE OF REVIEW

Interest in the early identification and treatment of incipient first-episode psychosis is rapidly expanding. In the present review we discuss the major conceptual and ethical problem areas related to research and clinical work in detection and treatment of prepsychosis.

RECENT FINDINGS

The recent literature shows that conceptualization of early psychosis is often inconsistent and even misleading. Ethical discussions mostly concern 'false positives' risk assignments, stigmatization, informed consent and acceptability of treatment procedures.

SUMMARY

At present there is a lack of consensus regarding which concepts to use in describing prepsychosis in prospective studies, and new concepts are needed for prospective description of emergent psychosis.

Preventing schizophrenia and psychotic behaviour: definitions and methodological issues

Although schizophrenia onset usually occurs in late adolescence or early adulthood, much research shows that its seeds are planted early in life and that eventual onset occurs at the end of a neurodevelopmental process leading to aberrant brain functioning. This idea, along with the fact that current therapies are far from fully effective, suggests that preventive treatments may be needed to achieve an ideal outcome for schizophrenia patients and those predisposed to the disorder. In this article, we review the methodological challenges that must be overcome before effective preventive interventions can be created. Prevention studies will need to define the target population. This requires the identification of risk factors that will be useful in selecting at-risk people for preventive treatment. We review currently identified risk factors for schizophrenia: genes, psychosocial factors, pregnancy and delivery complications, and viruses. We also review 3 different types of prevention programs: universal, indicated, and selective. For schizophrenia, we distinguish prevention programs that target prodromal cases and those that target the disorder's premorbid precursors. Although those targeting prodromal cases provide a useful framework for early treatment of the disorder, studies of premorbid individuals are needed to design a truly preventive treatment.

Genetics and genomics in neuropsychopharmacology: the impact on drug discovery and development

Genomics, the complete tabulation of all the genes in an organism, has made a major impact on the organisation of fully-integrated pharmaceutical companies. Drug discovery begins with bioinformatic elucidation of a human sequence encoding a potential drug target, followed by cloning and expression of the gene in a format for high throughput screening. Target validation is aided by reference to homologous genes in subhuman species as well as production of transgenic animals. In contrast, the impact of genetics on neuropsychopharmacology has been modest. It is interesting to compare the experience of genetics in the two major clinical disciplines dealing with disorders of the nervous system. Neurology has been at the forefront of human genetics with over 600 disorders mapped, of which causative mutations have been assigned to about 200 Mendelian disorders, each individually rare. Psychiatric genetics has been based on two log fewer diagnoses use of which has only yielded complex segregation patterns, a plethora of weak associations and no gene assignments. In neither case has genetics resulted in the development of a novel therapeutic agent. However, by refinements in diagnosis and genetic technology the promise for the future is great, not only for drug discovery, but also for subsequent preclinical and clinical development.

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.

Treatment of the schizophrenia prodrome: is it presently ethical?

Although the devastating consequences of schizophrenia have long been known, interest in preventive intervention has only recently emerged. The shift in focus toward early treatment has been encouraged by findings suggesting that the longer psychosis remains untreated, the poorer the prognosis, and by the recent introduction of novel antipsychotic medications with a more benign side effect profile than conventional neuroleptics. In this paper, we argue that interest in prevention has outpaced the necessary scientific and ethical underpinnings for clinical trials involving the schizophrenia prodrome. Specifically, we maintain that the prodromal phase of schizophrenia is, at present, essentially a retrospective construct and that, as a result, the defining signs and symptoms currently in use must be validated in naturalistic, longitudinal studies. In particular, it is essential to establish solid base rates for schizophrenia in prodromal individuals before early treatment can be effectively evaluated. Additional ethical/scientific issues discussed include: (1) the need for an exit strategy (i.e. the determination of when to discontinue treatment in an individual who does not develop schizophrenia), (2) the advisability of pharmacological interventions that specifically target neurocognitive deficits, and (3) the possibility that antidepressant medications may be as effective or more effective, with fewer side effects, than antipsychotic medication for prodromal individuals.