Clinical models of schizophrenia: a critical approach to competing conceptions

Cariprazine for negative symptoms in early psychosis: a pilot study with a 6-month follow-up

Background

Cariprazine, a novel antipsychotic drug that is a partial agonist with preferential binding to the D3 receptor, has demonstrated efficacy in clinical trials across all symptom domains, including negative symptoms, which can occur early in the course of psychotic illness. However, evidence, to date regarding its effects in early psychosis patients with primary negative symptoms has been limited.

Objectives

To evaluate the efficacy of cariprazine for negative symptoms in early psychosis patients.

Methods

Demographic and clinical information of the study population were collected from the electronic records and PANSS scale administered at baseline, 3 and 6 months. Tolerability and discontinuation reasons, where applicable, were also recorded.

Results

Ten patients with early psychosis (four men and six women, mean age - 25.5  years) with prominent or predominant negative symptoms were treated with cariprazine (range 1.5 - 3 mg). Three patients discontinued cariprazine within the first 3  months due to patient choice, lack of response and non-compliance, respectively. In the remaining patients, there was a significant reduction in the mean negative PANSS score from baseline to 6 months (from 26.3 to 10.6), mean total PANSS score (from 81.4 to 43.3) and in the mean positive PANSS score (from 14.4 to 9.9) which correspond to a 53.1, 41.5, and 28.5% mean score reduction.

Conclusion

This pilot study suggests that cariprazine is a safe and effective treatment in early psychosis, particularly for the alleviation of negative symptoms which remains an area of unmet treatment need.

Dimensional approaches to schizophrenia: A comparison of the Bern Psychopathology scale and the five-factor model of the Positive and Negative Syndrome Scale

The aim was to examine to what extent the dimensions of the BPS map the five factors derived from the PANSS in order to explore the level of agreement of these alternative dimensional approaches in patients with schizophrenia. 149 inpatients with schizophrenia spectrum disorders were recruited. Psychopathological symptoms were assessed with the Bern Psychopathology Scale (BPS) and the Positive and Negative Syndrome Scale (PANSS). Linear regression analyses were conducted to explore the association between the factors and the items of the BPS. The robustness of patterns was evaluated. An understandable overlap of both approaches was found for positive and negative symptoms and excitement. The PANSS positive factor was associated with symptoms of the affect domain in terms of both inhibition and disinhibition, the PANSS negative factor with symptoms of all three domains of the BPS as an inhibition and the PANSS excitement factor with an inhibition of the affect domain and a disinhibition of the language and motor domains. The results show that here is only a partial overlap between the system-specific approach of the BPS and the five-factor PANSS model. A longitudinal assessment of psychopathological symptoms would therefore be of interest.

Negative symptoms of schizophrenia as primary target of cognitive behavioral therapy: results of the randomized clinical TONES study

Clinical studies on cognitive behavioral therapy (CBT) that include schizophrenia patients primarily on the basis of negative symptoms are uncommon. However, those studies are necessary to assess the efficacy of CBT on negative symptoms. This article first gives an overview of CBT on negative symptoms and discusses the methodological problems of selecting an adequate control group. Furthermore, the article describes a clinical study (the TONES-Study, ISRCTN 25455020), which aims to investigate whether CBT is specifically efficacious for the reduction of negative symptoms. This multicenter randomized clinical trial comparing CBT with cognitive remediation (CR) for control of nonspecific effects is depicted in detail. In our trial, schizophrenia patients (n = 198) participated in manualized individual outpatient treatments. Primary outcome is the negative syndrome assessed with the positive and negative syndrome scale, analyzed with multilevel linear mixed models. Patients in both groups moderately improved regarding the primary endpoint. However, against expectation, there was no difference between the groups after treatment in the intention to treat as well as in the per-protocol analysis. In conclusion, psychotherapeutic intervention may be useful for the reduction of negative symptoms. However, there is no indication for specific effects of CBT compared with CR.

The contribution of epidemiology to defining the most appropriate approach to genetic research on schizophrenia

Psychosis is thought to have a strong genetic component, but many efforts to discover the underlying putative schizophrenia genes have yielded disappointing results. In fact, no strong associations emerged in the first genome-wide association studies in psychiatry and weakly observed associations were not related to the candidate genes identified in previous studies. These partially successful findings may be explained by the fact that genetic research in psychiatry suffers from confounding issues related to phenotype definition, the considerable degree of phenotypic variability and diagnostic uncertainty, absence of specific neuropathological features and environmental influences. To make progress it is first necessary to deconstruct psychosis based on symptomatology, and then to correlate particular phenotypes with genetic variants. Moreover, it is time to conduct studies that define persistent aspects of the schizophrenic profile that are more likely to represent an underlying biological pathogenesis, as opposed to fluctuating symptoms that are possibly environmentally mediated. In fact, progress in understanding the etiology of schizophrenia will depend upon the availability of good measures of genetic liability as well as relevant environmental exposures during critical periods of an individual's life. If environmental and/or genetic factors are not precisely measured, it is impossible to study their independent effects or interactions.

Evidenzbasierte Einzelpsychotherapie bei schizophrenen Psychosen 1Diese Arbeit wurde vom Bundesministerium für Bildung und Forschung gefördert (Förderkennzeichen 01GV0618)

Psychotherapie ist ein wirksamer Bestandteil der Gesamtbehandlung von Patienten mit schizophrenen Störungen. Dies wird durch evidenzbasierte Leitlinien und systematische Reviews klar belegt. In besonderer Weise haben Familieninterventionen für das Behandlungsziel der Rückfallverhütung und die Kognitive Verhaltenstherapie (KVT) als Einzelpsychotherapieverfahren für das Ziel der Symptomreduktion bei persistierenden psychotischen Symptomen ihre Wirksamkeit nachgewiesen. In diesem Beitrag werden die Wirksamkeitsnachweise von KVT für die Behandlung der Positiv-Symptomatik, der Negativ-Symptomatik sowie der Rückfallprophylaxe zusammengefasst. Die jeweiligen psychotherapeutischen Ansatzpunkte werden herausgearbeitet und die abgeleiteten Therapieziele vorgestellt. Die wesentlichen Therapiestrategien für die genannten drei Zielbereiche werden dargelegt und die Vorgehensweise bei der Durchführung erläutert.

Five-year stability of ICD-10 diagnoses among Chinese patients presented with first-episode psychosis in Hong Kong

BACKGROUND

Diagnostic stability is one measure of predictive validity for psychiatric syndromes. It is an under-studied area in functional psychosis despite its clinical and research implications. We aimed at evaluating the stability of ICD-10 diagnoses in a sample of young people with first-episode psychosis.

METHOD

One hundred and sixty-six Hong Kong Chinese enrolled in a regional first-episode psychosis treatment program were studied. Subjects' baseline and final 5-year consensus diagnoses were established via systematic medical records' review to determine diagnostic stability and to identify predictors of diagnostic shift towards schizophrenia spectrum.

RESULTS

The overall diagnostic consistency was 80.7%. Bipolar affective disorder and schizophrenia were the most stable diagnostic categories over 5 years with prospective consistency of 100% and 95.8% respectively. The least stable baseline diagnoses were unspecified non-organic psychosis, acute and transient psychotic disorders and delusional disorder. Around one-fifth (19.3%) of subjects had diagnostic revision in 5 years. The predominant pattern of diagnostic shift was towards schizophrenia spectrum disorder. Family history of psychosis and longer duration of untreated psychosis were associated with diagnostic transition towards schizophrenia spectrum.

CONCLUSIONS

Schizophrenia and bipolar affective disorder were diagnostically stable and could be reliably classified at intake in a Chinese first-episode psychosis sample using the ICD-10 criteria. Diagnostic instability in the least prevalent categories of functional psychosis highlights the limitations of current taxonomies and calls for ongoing revision of diagnostic criteria. In the absence of biological marker, longitudinal validation across consecutive episodes is necessary for accurate diagnostic ascertainment.

Schizophrenia, "Just the Facts": what we know in 2008 part 1: overview

For every disorder, there is a set of established findings and accepted constructs upon which further understanding is built. The concept of schizophrenia as a disease entity has been with us for a little more than a century, although descriptions resembling this condition predate this conceptualization. In 1988, for the inaugural issue of Schizophrenia Research, at the invitation of the founding editors, a senior researcher, since deceased (RJ Wyatt) published a summary of generally accepted ideas about the disorder, which he termed "the facts" of schizophrenia. Ten years later, in conjunction with two of the authors (MSK, RT), he compiled a more extensive set of "facts" for the purpose of evaluating conceptual models or theoretical constructs developed to understand the nature of schizophrenia. On the 20th anniversary of this journal, we update and substantially expand our effort to periodically summarize the current body of information about schizophrenia. We compile a body of seventy-seven representative major findings and group them in terms of their specific relevance to schizophrenia -- etiologies, pathophysiology, clinical manifestations, and treatments. We rate each such "fact" on a 0-3 scale for measures of reproducibility, whether primary to schizophrenia, and durability over time. We also pose one or more critical questions with reference to each "fact", answers to which might help better elucidate the meaning of that finding for our understanding of schizophrenia. We intend to follow this paper with the submission to the journal of a series of topic-specific articles, critically reviewing the evidence.

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

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

Empirical validation of competing definitions of schizophrenia: a poly-diagnostic study of cognitive impairment in non-affective psychosis

BACKGROUND

The empirical validation of diagnostic criteria for schizophrenia remains a controversial issue within psychiatry and allied sciences. Most diagnostic criteria are still influenced to a large extent by historical and consensus-based perspectives.

METHODS

A poly-diagnostic approach including a set of 23 operationalized diagnostic criteria were administered to probands with non-affective psychosis (n=169). In addition, participants completed a neuropsychological battery during a stable phase of the illness. Attentional, verbal and visual memory and executive functions were assessed. The control group was composed of 26 demographically matched healthy subjects. Analysis of variance was conducted taking neuropsychological performance as response variables and the 23 binary diagnostic systems as explanatory variables.

RESULTS

Four out of the 23 operationalized diagnostic systems for schizophrenia (Feighner, French, Kraepelin and Langfeldt criteria) demonstrated high empirical validity for memory and executive functions scores (medium to moderate effect sizes). These 4 systems resemble classic nosological approaches based upon the 'outcome principle' concept, which suggests that schizophrenia leads to deterioration. However, diagnostic effectiveness of neuropsychological tests for the 23 operationalized diagnostic systems of schizophrenia was low (likelihood ratio <2).

CONCLUSIONS

Neuropsychological functioning provides empirical validation to operationalized definitions of schizophrenia which are mainly based upon deterioration. It is suggested that some inconsistency of neurobiological studies in schizophrenia might result for using solely current consensus-based diagnostic systems. The implementation of poly-diagnostic strategies could contribute to improve the validity of the schizophrenia construct.

How do experts recognize schizophrenia: the role of the disorganization symptom

OBJETIVE: Research on clinical reasoning has been useful in developing expert systems. These tools are based on Artificial Intelligence techniques which assist the physician in the diagnosis of complex diseases. The development of these systems is based on a cognitive model extracted through the identification of the clinical reasoning patterns applied by experts within the clinical decision-making context. This study describes the method of knowledge acquisition for the identification of the triggering symptoms used in the reasoning of three experts for the diagnosis of schizophrenia. METHOD: Three experts on schizophrenia, from two University centers in Sao Paulo, were interviewed and asked to identify and to represent the triggering symptoms for the diagnosis of schizophrenia according to the graph methodology. RESULTS: Graph methodology showed a remarkable disagreement on how the three experts established their diagnosis of schizophrenia. They differed in their choice of triggering-symptoms for the diagnosis of schizophrenia: disorganization, blunted affect and thought disturbances. CONCLUSIONS: The results indicate substantial differences between the experts as to their diagnostic reasoning patterns, probably under the influence of different theoretical tendencies. The disorganization symptom was considered to be the more appropriate to represent the heterogeneity of schizophrenia and also, to further develop an expert system for the diagnosis of schizophrenia.

Decision support system for the diagnosis of schizophrenia disorders

Clinical decision support systems are useful tools for assisting physicians to diagnose complex illnesses. Schizophrenia is a complex, heterogeneous and incapacitating mental disorder that should be detected as early as possible to avoid a most serious outcome. These artificial intelligence systems might be useful in the early detection of schizophrenia disorder. The objective of the present study was to describe the development of such a clinical decision support system for the diagnosis of schizophrenia spectrum disorders (SADDESQ). The development of this system is described in four stages: knowledge acquisition, knowledge organization, the development of a computer-assisted model, and the evaluation of the system's performance. The knowledge was extracted from an expert through open interviews. These interviews aimed to explore the expert's diagnostic decision-making process for the diagnosis of schizophrenia. A graph methodology was employed to identify the elements involved in the reasoning process. Knowledge was first organized and modeled by means of algorithms and then transferred to a computational model created by the covering approach. The performance assessment involved the comparison of the diagnoses of 38 clinical vignettes between an expert and the SADDESQ. The results showed a relatively low rate of misclassification (18-34%) and a good performance by SADDESQ in the diagnosis of schizophrenia, with an accuracy of 66-82%. The accuracy was higher when schizophreniform disorder was considered as the presence of schizophrenia disorder. Although these results are preliminary, the SADDESQ has exhibited a satisfactory performance, which needs to be further evaluated within a clinical setting.

Functional brain mapping of psychopathology

In this paper, we consider the impact that the novel functional neuroimaging techniques may have upon psychiatric illness. Functional neuroimaging has rapidly developed as a powerful tool in cognitive neuroscience and, in recent years, has seen widespread application in psychiatry. Although such studies have produced evidence for abnormal patterns of brain response in association with some pathological conditions, the core pathophysiologies remain unresolved. Although imaging techniques provide an unprecedented opportunity for investigation of physiological function of the living human brain, there are fundamental questions and assumptions which remain to be addressed. In this review we examine these conceptual issues under three broad sections: (1) characterising the clinical population of interest, (2) defining appropriate levels of description of normal brain function, and (3) relating these models to pathophysiological conditions. Parallel advances in each of these questions will be required before imaging techniques can impact on clinical decisions in psychiatry.