Symptom dimensions in the course of childhood-onset schizophrenia

Deciphering the Heterogeneity of Schizophrenia: A Multimodal and Multivariate Neuroimaging Framework for Unveiling Brain-Symptom Relationships and Underlying Subtypes

BACKGROUND AND HYPOTHESIS

Schizophrenia manifests large heterogeneities in either symptoms or brain abnormalities. However, the neurobiological basis of symptomatic diversity remains poorly understood. We hypothesized that schizophrenia's diverse symptoms arise from the interplay of structural and functional alterations across multiple brain regions, rather than isolated abnormalities in a single area.

STUDY DESIGN

A total of 495 schizophrenia patients and 507 healthy controls from 8 sites were recruited. Five symptomatic dimensions of schizophrenia patients were derived from the Positive and Negative Syndrome Scale. Multivariate canonical correlation analysis was introduced to identify symptom-related multimodal magnetic resonance imaging composite indicators (MRICIs) derived from gray matter volume, functional connectivity strength, and white matter fractional anisotropy. The intergroup differences in MRICIs were compared, and the paired-wise correlations between symptom dimensions and MRICIs were resolved. Finally, K-means clustering was used to identify the underlying biological subtypes of schizophrenia based on MRICIs.

STUDY RESULTS

Canonical correlation analysis identified 15 MRICIs in schizophrenia that were specifically contributed by the neuroimaging measures of multiple regions, respectively. These MRICIs can effectively characterize the complexity of symptoms, showing correlations within and across symptom dimensions, and were consistent across both first-episode and chronic patients. Additionally, some of these indicators could moderately differentiate schizophrenia patients from healthy controls. K-means clustering identified 2 schizophrenia subtypes with distinct MRICI profiles and symptom severity.

CONCLUSIONS

Symptom-guided multimodal and multivariate MRICIs could decode the symptom heterogeneity of schizophrenia patients and might be considered as potential biomarkers for schizophrenia.

COSMIN systematic review and meta-analysis of the measurement properties of the Positive and Negative Syndrome Scale (PANSS)

Background

The Positive and Negative Syndrome Scale (PANSS) is the most widely used tool for assessing the symptoms of schizophrenia. Despite its widespread use, the psychometric properties of the PANSS have not been systematically reviewed. This study fills that gap in the scientific literature.

Methods

We utilized the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guideline for systematic reviews and meta-analytical procedures to assess the psychometric properties of the PANSS in its original three-subscale form as well as the quality level of the evidence available. On this basis we formulated recommendations for future research and use. A study protocol was registered under 10.17605/OSF.IO/5EGMD. The search period was until February 21, 2024.

Findings

We included 119 publications. According to COSMIN, the PANSS demonstrated sufficient reliability, construct validity, and responsiveness; but had significant shortcomings in content validity and structural validity. The original three-factor model showed poor structural validity, leading to its COSMIN classification as "not recommendable". The subscales showed overall acceptable measurement properties. However, the lack of structural validity of the three-subscale model renders its subscales less useful. Moreover, the PANSS negative subscale does not cover all domains of the National Institute of Mental Health consensus. Due to the length of the instrument (30-50 min), it is barely useable in clinical practice.

Interpretation

Although the PANSS is the standard scale for schizophrenia symptom severity, its shortcomings regarding fundamental psychometric domains and practical applicability warrant the development of new scales for which appropriate methods should be applied from the start.

Funding

There was no specific funding source for this research.

COSMIN review of the PANSS Marder factor solution and other factor models in people with schizophrenia

The Positive and Negative Syndrome Scale (PANSS) is widely used to assess schizophrenia symptoms. Initially designed with three subscales, Marder et al.´s 5-factor-Model (M5M) first proposed in 1997 has been frequently used in treatment trials, but it has never been systematically reviewed for its measurement properties. We utilized the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guideline for systematic reviews and meta-analytical procedures to assess the psychometric properties of the M5M-PANSS. COSMIN comprises several steps: literature search, risk-of-bias assessments, assessing the updated criteria for good measurement properties, feasibility aspects and grading the quality of the evidence. We further assessed the goodness of fit of other PANSS factor models. We included 95 publications. The M5M-PANSS showed good construct validity, but "insufficient" structural validity. Evidence of other COSMIN domains is largely lacking. Among the multiple (73) factor solutions examined with confirmatory methods, several other 5-factor solutions had better model fit. According to COSMIN rules the M5M should not be recommended for use. Other five-factor models such as the one proposed by Wallwork et al.1 warrant further evaluation. Nevertheless, the factor composition of the M5M and these other models was relatively similar, so previously published results should not be disregarded.

Negative symptoms in children and adolescents with early-onset psychosis and at clinical high-risk for psychosis: systematic review and meta-analysis

BACKGROUND

Early-onset psychosis (EOP) refers to the development of a first episode of psychosis before 18 years of age. Individuals at clinical high risk for psychosis (CHR-P) include adolescents and young adults, although most evidence has focused on adults. Negative symptoms are important prognostic indicators in psychosis. However, research focusing on children and adolescents is limited.

AIMS

To provide meta-analytical evidence and a comprehensive review of the status and advances in the diagnosis, prognosis and treatment of negative symptoms in children and adolescents with EOP and at CHR-P.

METHOD

PRISMA/MOOSE-compliant systematic review (PROSPERO: CRD42022360925) from inception to 18 August 2022, in any language, to identify individual studies conducted in EOP/CHR-P children and adolescents (mean age <18 years) providing findings on negative symptoms. Findings were systematically appraised. Random-effects meta-analyses were performed on the prevalence of negative symptoms, carrying out sensitivity analyses, heterogeneity analyses, publication bias assessment and quality assessment using the Newcastle-Ottawa Scale.

RESULTS

Of 3289 articles, 133 were included (n = 6776 EOP, mean age 15.3 years (s.d. = 1.6), males = 56.1%; n = 2138 CHR-P, mean age 16.1 years (s.d. = 1.0), males = 48.6%). There were negative symptoms in 60.8% (95% CI 46.4%-75.2%) of the children and adolescents with EOP and 79.6% (95% CI 66.3-92.9%) of those at CHR-P. Prevalence and severity of negative symptoms were associated with poor clinical, functional and intervention outcomes in both groups. Different interventions were piloted, with variable results requiring further replication.

CONCLUSIONS

Negative symptoms are common in children and adolescents at early stages of psychosis, particularly in those at CHR-P, and are associated with poor outcomes. Future intervention research is required so that evidence-based treatments will become available.

Large-scale evaluation of the Positive and Negative Syndrome Scale (PANSS) symptom architecture in schizophrenia

Although the Positive and Negative Syndrome Scale (PANSS) is widely utilized in schizophrenia research, variability in specific item loading exist, hindering reproducibility and generalizability of findings across schizophrenia samples. We aim to establish a common PANSS factor structure from a large multi-ethnic sample and validate it against a meta-analysis of existing PANSS models. Schizophrenia participants (N = 3511) included in the current study were part of the Singapore Translational and Clinical Research Program (STCRP) and the Clinical Antipsychotic Trials for Intervention Effectiveness (CATIE). Exploratory Factor Analysis (EFA) was conducted to identify the factor structure of PANSS and validated with a meta-analysis (N = 16,171) of existing PANSS models. Temporal stability of the PANSS model and generalizability to individuals at ultra-high risk (UHR) of psychosis were evaluated. A five-factor solution best fit the PANSS data. These were the i) Positive, ii) Negative, iii) Cognitive/disorganization, iv) Depression/anxiety and v) Hostility factors. Convergence of PANSS symptom architecture between EFA model and meta-analysis was observed. Modest longitudinal reliability was observed. The schizophrenia derived PANSS factor model fit the UHR population, but not vice versa. We found that two other domains, Social Amotivation (SA) and Diminished Expression (DE), were nested within the negative symptoms factor. Here, we report one of the largest transethnic factorial structures of PANSS symptom domains (N = 19,682). Evidence reported here serves as crucial consolidation of a common PANSS structure that could aid in furthering our understanding of schizophrenia.

Reduced sleep spindle density in adolescent patients with early-onset schizophrenia compared to major depressive disorder and healthy controls

OBJECTIVES

During adolescence schizophrenia and major depressive disorder (MDD) increasingly emerge. Overlapping symptomatology during first presentation challenges the diagnostic process. Reduced sleep spindle density (SSD) was suggested as a biomarker in adults, discerning patients with schizophrenia from patients with depression or healthy controls (HC). We aimed to compare SSD in early-onset schizophrenia (EOS), with MDD, and HC, and to analyse associations of SSD with symptomatology and neurocognitive measures.

METHODS

Automatic sleep spindle detection was performed on all-night high-density EEG (128 electrodes) data of 12 EOS, 19 MDD, and 57 HC (age range 9.8-19), allowing an age- and sex-matching of 1:2 (patients vs. HC). Severity of current symptoms and neurocognitive variables were assessed in all patients.

RESULTS

SSD was defined between 13.75 and 14.50 Hz as within this frequency range SSD differed between EOS vs. HC in bin by bin analyses (12-15 Hz). In EOS, SSD was lower over 27 centro-temporal electrodes compared to HC and over 9 central electrodes compared to MDD. Reduced SSD in EOS compared to MDD and HC was accompanied by a high variability of SSD in all adolescents. SSD did not differ between MDD and HC. In the pooled sample of patients, lower SSD was associated with more severe Positive and Negative Symptoms Scale total score, more impaired memory consolidation and processing speed.

CONCLUSION

A high variability of SSD in all adolescents may reflect the evolving character of SSD. The association of reduced SSD with the symptom dimension of impaired cognition cuts across diagnostical entities.

Developmental and symptom profiles in early-onset psychosis

Psychotic disorders in children are more heterogeneous than is captured by categorical diagnoses. In a new cohort of children and adolescents, we evaluated the relationships among age at onset (AAO), clinical symptoms and developmental impairments. Patients with schizophrenia and other "spectrum" psychotic diagnoses (N = 88; AAO 6-17, mean 12.6) were evaluated with diagnostic interviews, a new clinical scale (Lifetime Dimensions of Psychosis Scale-Child and Adolescent), and neuropsychological and medical evaluations. Key findings were replicated in an adult cohort of 2420 cases, including 127 with retrospective AAO<13. Factor and cluster analyses were carried out to identify clinical profiles. Five clinical factors were identified in each cohort: Positive, Bizarre Positive, Negative/Formal Thought Disorder, Depression and Mania. Earlier AAO predicted severity of bizarre positive symptoms in children and of bizarre and other symptoms in adults. Four clinical clusters in the child cohort were characterized by: more severe bizarre positive symptoms (N = 31); negative symptoms (N = 15); premorbid autism spectrum features and developmental delay (N = 12); and depressive symptoms with heterogeneous diagnoses and mild positive/negative symptoms (N = 25). Previous factor-analytic studies of childhood psychosis did not specifically consider bizarre positive symptoms. Here, bizarre positive symptoms emerged as clinical markers of severe, childhood-onset psychosis similar to adult schizophrenia. The four clusters are clinically meaningful and useful for treatment planning and potentially for biological research. Childhood-onset cases are rare and thus difficult to study, but additional, larger cohorts may be useful in dissecting the biological and developmental heterogeneity of psychotic disorders.

M. Staging of Schizophrenia With the Use of PANSS: An International Multi-Center Study

INTRODUCTION

A specific clinically relevant staging model for schizophrenia has not yet been developed. The aim of the current study was to evaluate the factor structure of the PANSS and develop such a staging method.

METHODS

Twenty-nine centers from 25 countries contributed 2358 patients aged 37.21 ± 11.87 years with schizophrenia. Analysis of covariance, Exploratory Factor Analysis, Discriminant Function Analysis, and inspection of resultant plots were performed.

RESULTS

Exploratory Factor Analysis returned 5 factors explaining 59% of the variance (positive, negative, excitement/hostility, depression/anxiety, and neurocognition). The staging model included 4 main stages with substages that were predominantly characterized by a single domain of symptoms (stage 1: positive; stages 2a and 2b: excitement/hostility; stage 3a and 3b: depression/anxiety; stage 4a and 4b: neurocognition). There were no differences between sexes. The Discriminant Function Analysis developed an algorithm that correctly classified >85% of patients.

DISCUSSION

This study elaborates a 5-factor solution and a clinical staging method for patients with schizophrenia. It is the largest study to address these issues among patients who are more likely to remain affiliated with mental health services for prolonged periods of time.

Meta-analysis of the positive and Negative Syndrome Scale (PANSS) factor structure

A meta-analysis of the results of 45 factor analyses (n = 22,812) of the Positive and Negative Syndrome Scale (PANSS) was conducted. Meta-analyses of the PANSS was conducted using both a co-occurrence similarity matrix and reproduced correlations. Both methods produced similar results. Five factors (Positive Symptoms, Negative Symptoms, Disorganization, Affect and Resistance) emerged clearly across both analyses. The factors and the items defining them were Positive Symptoms (P1 Delusions, G9 Unusual thought content, P3 Hallucinatory behavior, P6 Suspiciousness and persecution, P5 Grandiosity), Negative Symptoms (N2 Emotional withdrawal, N1 Blunted affect, N4 Passive apathetic social withdrawal, N6 Lack of spontaneity, N3 Poor rapport, G7 Motor retardation, G16 Active social avoidance), Disorganization often termed Cognitive (P2 Conceptual disorganization, G11 Poor attention, N5 Difficulty in abstract thinking, G13 Disturbance of volition, N7 Stereotyped thinking, G5 Mannerisms/posturing, G15 Preoccupation, G10 Disorientation), Affect often termed Depression-Anxiety (G2 Anxiety, G6 Depression, G3 Guilt feelings, G4 Tension, G1 Somatic concern) and a small fifth factor that might be characterized as Resistance or Excitement/Activity (P7 Hostility, G14 Poor impulse control, P4 Excitement, G8 Uncooperativeness). Items G1, G4, G10, P5, G5, G15 may not be core items for the PANSS factors and G12 lack of judgment is not a core item. Results of the PANSS meta-analyses were relatively similar to those for meta-analysis of both the BPRS and BPRS-E all of which contain the original 18 BPRS items. The PANSS is distinguished by a much larger number of items to clearly define and measure Negative Symptoms as well as a sufficient number of items to much more clearly identify a Disorganization factor than the BPRS or BPRS-E.

Symptom dimensions and subgroups in childhood-onset schizophrenia

OBJECTIVE

This study investigated symptom dimensions and subgroups in the National Institute of Mental Health (NIMH) childhood-onset schizophrenia (COS) cohort and their similarities to adult-onset schizophrenia (AOS) literature.

METHOD

Scores from the Scales for the Assessment of Positive and Negative Symptoms (SAPS & SANS) from 125 COS patients were assessed for fit with previously established symptom dimensions from AOS literature using confirmatory factor analysis (CFA). K-means cluster analysis of each individual's scores on the best fitting set of dimensions was used to form patient clusters, which were then compared using demographic and clinical data.

RESULTS

CFA showed the SAPS & SANS data was well suited to a 2-dimension solution, including positive and negative dimensions, out of five well established models. Cluster analysis identified three patient groups characterized by different dimension scores: (1) low scores on both dimensions, (2) high negative, low positive scores, and (3) high scores on both dimensions. These groups had different Full scale IQ, Children's Global Assessment Scale (CGAS) scores, ages of onset, and prevalence of some co-morbid behavior disorders (all p<3.57E-03).

CONCLUSION

Our analysis found distinct symptom-based subgroups within the NIMH COS cohort using an established AOS symptom structure. These findings confirm the heterogeneity of COS and were generally consistent with AOS literature.

Could PANSS be a useful tool in the determining of the stages of schizophrenia? A clinically operational approach

Staging in schizophrenia might be an important approach for the better treatment and rehabilitation of patients. The purpose of this study was to empirically devise a staging approach in a sample of stabilized patients with schizophrenia. One hundred and seventy patients aged ≥18 years (mean = 40.7, SD = 11.6) diagnosed by DSM-5 criteria were evaluated with the Positive and Negative Syndrome Scale (PANSS). Principal components analysis (PCA) with varimax rotation was used. The model was examined in the total sample and separately across a hypothesized stage of illness based on three age groups and between the two sexes. The PCA revealed a six factor structure for the total sample: 1) Negative, 2) Positive, 3) Depression and anxiety, 4) Excitement and Hostility, 5) Neurocognition and 6) Disorganization. The separate PCAs by stage of illness and sex revealed different patterns and quality of symptomatology. The Negative and Positive factors were stable across all examined groups. The models corresponding to different stages differed mainly in terms of neurocognition and disorganization and their interplay. Catatonic features appear more prominent in males while in females neurocognition takes two forms; one with disorganization and one with stereotype thinking with delusions. This study suggests that the three arbitrary defined stages of illness (on the basis of age) seem to reflect a progress from a preserved insight and more coherent mental functioning to disorganization and eventually neurocognitive impairment. Sexes differ in terms of the relationship of psychotic features with neurocognition. These results might have significant research and clinical implications.

The Clinical Presentation of Childhood-Onset Schizophrenia: A Literature Review

This literature review explores the research on the clinical presentation of childhood-onset schizophrenia (COS) that was conducted in the period 1994–2004. A literature search was done using Internet search engines and psychological databases to collect English-language journal articles from 1994 onwards. Research indicates that COS is a stable diagnosis. Generally, there is a clear history of premorbid abnormalities, an insidious onset and a deteriorating course. For the majority of cases there seems to be a poor outcome. Despite the limitations in the research conducted thus far, findings provide important insights into COS and several possibilities for future research.

Examination of the Positive and Negative Syndrome Scale factor structure and longitudinal relationships with functioning in early psychosis

AIM

We examined the factor structure of the Positive and Negative Syndrome Scale (PANSS) in early-episode psychosis and its relationships with functioning at baseline and follow-up.

METHODS

A total of 240 consecutive admissions to an early intervention in psychosis clinic were assessed at intake to the program with the PANSS, Global Assessment of Functioning (GAF) and Social and Occupational Functioning Assessment Scale (SOFAS). Seventy individuals were reassessed at follow-up. A maximum likelihood factor analysis was conducted on baseline PANSS scores and the ability of each factor to predict baseline and follow-up GAF and SOFAS was examined.

RESULTS

A five-factor model with varimax rotation was the best fit to our data and was largely congruent with factors found previously. The negative symptom factor was the best predictor of GAF and SOFAS at baseline and follow-up.

CONCLUSION

Negative symptoms are the best symptomatic predictor of functioning in individuals with early psychosis and are an important treatment target to improve recovery.

A dimensional comparison between delusional disorder, schizophrenia and schizoaffective disorder

INTRODUCTION

Since the early description of paranoia, the nosology of delusional disorder has always been controversial. The old idea of unitary psychosis has now gained some renewed value from the dimensional continuum model of psychotic symptoms.

AIMS

1. To study the psychopathological dimensions of the psychosis spectrum; 2. to explore the association between psychotic dimensions and categorical diagnoses; 3. to compare the different psychotic disorders from a psychopathological and functional point of view.

MATERIAL AND METHODS

This is an observational study utilizing a sample of some 550 patients with a psychotic disorder. 373 participants had a diagnosis of schizophrenia, 137 had delusional disorder and 40 with a diagnosis of schizoaffective disorder. The PANSS was used to elicit psychopathology and global functioning was ascertained using the GAF measure. Both exploratory and confirmatory factor analyses of the PANSS items were performed to extract psychopathological dimensions. Associations between diagnostic categories and dimensions were subsequently studied using ANOVA tests.

RESULTS

5 dimensions - manic, negative symptoms, depression, positive symptoms and cognitive - emerged. The model explained 57.27% of the total variance. The dimensional model was useful to explained differences and similarities between all three psychosis spectrum categories. The potential clinical usefulness of this dimensional model within and between clinical psychosis spectrum categories is discussed.

Functional and clinical insights from neuroimaging studies in childhood-onset schizophrenia

Childhood-onset schizophrenia is a rare pediatric onset psychiatric disorder continuous with and typically more severe than its adult counterpart. Neuroimaging research conducted on this population has revealed similarly severe neural abnormalities. When taken as a whole, neuroimaging research in this population shows generally decreased cortical gray matter coupled with white matter connectivity abnormalities, suggesting an anatomical basis for deficits in executive function. Subcortical abnormalities are pronounced in limbic structures, where volumetric deficits are likely related to social skill deficits, and cerebellar deficits that have been correlated to cognitive abnormalities. Structures relevant to motor processing also show a significant alteration, with volumetric increase in basal ganglia structures likely due to antipsychotic administration. Neuroimaging of this disorder shows an important clinical image of exaggerated cortical loss, altered white matter connectivity, and differences in structural development of subcortical areas during the course of development and provides important background to the disease state.

Validated five-factor model of positive and negative syndrome scale for schizophrenia in Chinese population

The Positive and Negative Syndrome Scale (PANSS) is the most widely used instrument to assess the severity of symptoms of schizophrenia. Most studies have showed that PANSS measures five dimensions of symptomatology of schizophrenia. However, few studies have ever investigated the structure of PANSS in Chinese schizophrenia population. We recruited two large independent study samples including 903 and 942 Chinese schizophrenia patients and examined the underlying structure of PANSS. By building a confirmatory factor analysis (CFA) model based on the factor loadings of the exploratory factor analysis (EFA) and by testing the CFA model in an independent validation sample, we found that PANSS scores consisted of five factors, which were positive factor, negative factor, excitement factor, depression factor, and cognitive factor. The items loaded on these factors were similar to the consensus items published in previous studies except for PANSS items P2 conceptual disorganization, P5 grandiosity, N5 abstract thinking, and G11 poor attention. This difference might be due to the influence of culture on clinical presentation of schizophrenia. By elucidating the structure, symptoms of Chinese schizophrenia patients could possibly be deconstructed and investigated in future studies.

Categorical vs dimensional classifications of psychotic disorders

OBJECTIVE

Both categorical and dimensional methods appear relevant to classifying psychotic disorders; however, there is no clear consensus on the most appropriate categories and dimensions or on the best approach for constructing nosologic criteria that integrate these 2 methods. This review examines the evidence on specific dimensions and categories that would best characterize psychoses.

METHOD

Entries in the MEDLINE database between 1980 and 2011 were searched for studies of the dimensional and/or categorical structure of psychosis. Studies were included if samples represented a spectrum of psychotic disorders and dimensions/categories were empirically derived using principal components analysis, factor analysis, or latent class analysis.

RESULTS

Most dimensional studies observed 4 or 5 dimensions within psychosis, with positive, negative, disorganization, and affective symptom domains most frequently reported. Substance abuse, anxiety, early onset/developmental, insight, cognition, hostility, and behavioral/social disturbance dimensions appeared in some studies. Categorical studies suggested 3 to 7 major classes within psychosis, including a class similar to Kraepelin's dementia praecox and one or more classes with significant mood components. Only 2 studies compared the relative fit of empirically derived dimensions and categories within the same data set, and each had significant limitations.

CONCLUSION

There is relatively consistent evidence on appropriate categories and dimensions for characterizing psychoses. However, the lack of studies directly comparing or combining these approaches provides insufficient evidence for definitive conclusions about their relative merits and integration. The authors provide specific recommendations for designing future studies to identify valid dimensions and/or categories of the psychoses and investigate hybrid approaches to model the structure of the underlying illnesses.

Searching for a consensus five-factor model of the Positive and Negative Syndrome Scale for schizophrenia

Although the developers of the Positive and Negative Syndrome Scale (PANSS) grouped items into three subscales, factor analyses indicate that a five-factor model better characterizes PANSS data. However, lack of consensus on which model to use limits the comparability of PANSS variables across studies. We counted "votes" from published factor analyses to derive consensus models. One of these combined superior fit in our Caucasian sample (n=458, CFI=.970), and in distinct Japanese sample (n=164, CFI=.964), relative to the original three-subscale model, with a sorting of items into factors that was highly consistent across the studies reviewed.

Trajectories of social withdrawal and cognitive decline in the schizophrenia prodrome

OBJECTIVE

Schizophrenia is a heterogeneous neurodevelopmental disorder. Patients with high levels of negative symptoms have been identified as a specific subtype, but little is known about how the neurodevelopmental course may differ in this group. This study aimed to characterize developmental trajectories of premorbid social withdrawal and cognitive decline between patients with high versus low levels of negative symptoms in youth with schizophrenia-spectrum disorders.

METHOD

A standardized timeline was used to delineate the emergence of psychosis, social withdrawal, and cognitive decline in 52 subjects aged 8 to 19 with schizophrenia (n=36), schizophreniform (n=6), or schizoaffective disorder (n=10). The sample was divided into subgroups of high- (n=26) versus low- (n=26) negative symptoms, and developmental trajectories of premorbid symptoms were compared between groups.

RESULTS

Mean ages for emergence of social withdrawal, cognitive decline, and psychosis were 11.1 years (SD=2.5), 11.9 (SD=4.4) and 13.2 years (SD=1.2), respectively. In the high-negative symptom group, the premorbid developmental trajectory for social withdrawal was more protracted. This group also had more severe cognitive decline at the onset of psychosis, but the premorbid trajectories for cognitive decline did not differ significantly between groups.

CONCLUSIONS

This work documents a more severe and protracted trajectory of premorbid social withdrawal in patients with high levels of negative symptoms in comparison to those with low-negative symptoms. The findings reported here are supportive of the hypothesis that patients with illness characterized by high levels of negative symptoms may represent a subgroup with distinct neurodevelopmental abnormalities.

A modeling study suggesting how a reduction in the context-dependent input on CA1 pyramidal neurons could generate schizophrenic behavior

The neural mechanisms underlying schizophrenic behavior are unknown and very difficult to investigate experimentally, although a few experimental and modeling studies suggested possible causes for some of the typical psychotic symptoms related to this disease. The brain region most involved in these processes seems to be the hippocampus, because of its critical role in establishing memories for objects or events in the context in which they occur. In particular, a hypofunction of the N-methyl-D-aspartate (NMDA) component of the synaptic input on the distal dendrites of CA1 pyramidal neurons has been suggested to play an important role for the emergence of schizophrenic behavior. Modeling studies have investigated this issue at the network and cellular level. Here, starting from the experimentally supported assumption that hippocampal neurons are very specific, sparse, and invariant in their firing, we explore an experimentally testable prediction at the single neuron level. The model shows how and to what extent a pathological hypofunction of a context-dependent distal input on a CA1 neuron can generate hallucinations by altering the normal recall of objects on which the neuron has been previously tuned. The results suggest that a change in the context during the recall phase may cause an occasional but very significant change in the set of active dendrites used for feature recognition, leading to a distorted perception of objects.

Characteristics of early psychosis

There is little research on characteristics related to course and prognosis of early-onset psychosis. The present article aims to advance our knowledge of this disorder for the purpose of proper diagnosis and treatment. It focuses on premorbid and prodromal characteristics, treatment history, symptoms and classifications, and differences between subgroups with affective and schizophrenic psychosis. A chart review was constructed to study a group of 129 subjects (12-18 years) with psychotic symptoms referred to the University Medical Center in Utrecht. The group was characterized by early-but nonspecific-treatment, developmental problems (mostly social), and clear prodromal symptoms. Drug abuse, depressive symptoms, and suicidal behavior were also frequent. Male sex, a relatively long prodromal phase, school problems, and drug abuse were more indicative of the schizophrenic subgroup. Introversion was characteristic for boys with schizophrenia. Classifications, however, were not stable. These findings suggest that early recognition of psychosis can be enhanced in health and youth care facilities. Careful examination of the prodromal phase seems helpful to differentiate between schizophrenic and affective psychosis.

Is adolescent-onset first-episode psychosis different from adult onset?

OBJECTIVE

To examine whether first-episode psychosis patients with onset during adolescence (ages 15-18) differ significantly from those with young-adult onset (ages 19-30).

METHOD

Consecutive patients presenting with first-episode psychosis (N = 242) were assessed for demographic and illness characteristics such as duration of untreated psychosis, diagnosis, length of prodromal period, premorbid adjustment, level of psychotic, negative, depressive, anxiety, and extrapyramidal symptoms, and alcohol and drug use.

RESULTS

Eighty-two patients (40.8%) had an onset of psychosis during adolescence (ages 15-18) and 119 (59.2%) during young adulthood (ages 19-30). The adolescent-onset group experienced longer delays in treatment of psychosis (duration of untreated psychosis) (p < .02), showed modestly worse premorbid functioning during late adolescence (p < .05), and were more likely to present with bizarre behavior (p < .01) and primary negative symptoms (p < .01).

CONCLUSIONS

Patients with adolescent onset of psychosis are more likely to present with clinical characteristics that portend a poorer outcome and may require a different approach to early identification and treatment.

Longitudinal course of schizophrenia spectrum symptoms in offspring of psychiatrically hospitalized mothers

OBJECTIVE

The aim of this study was to describe schizophrenia spectrum symptoms (SZSD) in children and adolescents with schizotypal personality disorder (SPD) as adults.

INTRODUCTION

There are no descriptive studies of children who develop into adults with SPD.

METHOD

Twelve offspring of psychiatrically hospitalized mothers (6 mothers with schizophrenia), were compared with 11 socioeconomic status (SES)-matched offspring of control, non-ill mothers. Offspring were evaluated clinically and psychometrically between infancy and 2, 10, 15 years of age, and adulthood. Adult Axis I and II diagnoses were made blind to infant and parent status.

RESULTS

Six hospitalized mothers were diagnosed with schizophrenia, 6 with other severe psychopathology. Offspring with SZSD more likely had schizophrenic mothers, and childhood deteriorating IQs, symptoms of social isolation, constricted affect, digressive speech, suspiciousness, and excessive social anxiety. Global assessment scores in SZSD offspring were lower in childhood and adulthood than comparison offspring.

DISCUSSION

Children with SZSD met currently accepted criteria for schizotypy; 3 by 10 years of age, and 2 by 19 years of age. Differential diagnosis is discussed. An appendix of case histories is presented.

Developmental precursors of child- and adolescent-onset schizophrenia and affective psychoses: diagnostic specificity and continuity with symptom dimensions

BACKGROUND

An increased rate of premorbid impairment has been reported in both child- and adolescent-onset schizophrenic and affective psychoses.

AIMS

To examine the evidence for a specific association between premorbid impairment and child- and adolescent-onset schizophrenia, and whether specific continuities exist between premorbid impairments and psychotic symptom dimensions.

METHOD

Retrospective case note study of 110 first-episode child- and adolescent-onset psychoses (age 10-17 years). DSM-III-R diagnoses derived from the OPCRIT algorithm showed 61 with schizophrenia (mean age 14.1 years) and 49 with other non-schizophrenic psychoses (mean age 14.7 years).

RESULTS

Premorbid social impairment was more common in early-onset schizophrenia than in other early-onset psychoses (OR 1.9, P=0.03). Overall, impaired premorbid development, enuresis and incontinence during psychosis were specifically associated with the negative psychotic symptom dimension.

CONCLUSIONS

Premorbid social impairments are more marked in child-and adolescent-onset schizophrenia than in other psychoses. There appears to be developmental continuity from premorbid impairment to negative symptoms.

[Early childhood psychosis versus early childhood autism? Differential diagnosis based on one week observation in an inpatient setting]

We report on the case of a 4-year old child suffering for the past six months from a lingering psychotic development. Several months of outpatient observation did not permit a clear differential diagnosis of either childhood autism or an early psychosis. During a one-week inpatient stay at our hospital recurring productive-psychotic episodes were observed that finally led to the exclusion of the diagnosis of "childhood autism" (ICD-10 F 84.0 (Dilling et al., 1993)) and to the diagnosis of "other disintegrative childhood disorder" (ICD-10: F 84.3 (Dilling et al., 1993)).