Diagnostic stability over one year in first-episode psychosis

Results of first-episode psychosis studies have shown that the diagnosis of schizophrenia is more stable across time than other diagnoses within the psychosis spectrum disorders. The objective of this study was to determine the diagnostic stability in a sample of first-episode patients and to determine the factors that predicted a diagnostic shift. Two hundred and twenty-eight individuals presenting for treatment with a first episode of non-affective psychosis were diagnosed at baseline and at one-year follow-up. Symptoms, functioning and cognition were also assessed. The overall consistency of diagnoses was 68% with an increase to 89% when schizophreniform was excluded. Schizophrenia was found to have the highest prospective consistency (95%), schizophreniform was less stable (36%) with shifts towards schizophrenia and other psychotic disorders were the least stable with a prospective consistency of 62%. Schizophrenia had the largest influx of cases at follow-up with a retrospective consistency of 63%. Schizophrenia can be reliably diagnosed at the initial assessment. There are clinical implications for dealing with the risk of shifting diagnosis for those who present with schizophrenia spectrum and other psychotic disorders.     

Diagnostic stability over 3 years in a total group of first-episode psychosis patients

First-episode psychosis (FEP) patients are often given diagnoses that later have to be changed. The aim of this study was to measure the diagnostic stability in a total group of FEP patients; 146 FEP patients were followed longitudinally and prospectively. Their revised baseline diagnoses were compared with their 3-year follow-up diagnoses. The schizophrenic spectrum disorders showed a high diagnostic stability as a group, but there was a great flow of patients between the different schizophrenic spectrum diagnoses. Also schizophrenia was a stable diagnosis. The affective psychosis group was homogenous without interaction of other psychosis groups. The other psychosis diagnoses, both regarded as a group and individually, turned out to be quite heterogeneous, with low stability values and a split course, often ending up in the schizophrenic spectrum. Fifty one per cent did not fulfil the criteria for DSM-IV axis 1 psychosis diagnosis at follow-up. In conclusion, our findings suggest that in the early phase of psychosis. Only three different diagnostic categories would be sufficient; "schizophrenic spectrum type", "affective psychosis," and for the rest "psychotic disorder NOS."     

Diagnostic stability in adolescent onset psychotic disorders

The purpose was to examine the long-term stability of a diagnosis of psychotic disorder in adolescence and to focus on diagnostic change over time. A total of 88 patients with a first episode of early onset psychosis (before 19 years) were followed up an average of 10.5 years (range 5.1-18.2) after admission. This report includes the 68 patients who could be traced and interviewed with the Positive and Negative Symptom Scale and lifetime Structured Clinical Interview for DSM-IV diagnosis. An initial diagnostic split between schizophrenia spectrum and affective disorder had a good (> 80 %) Positive Predictive Validity and Sensitivity. The main diagnostic shift was an influx to schizophrenia spectrum disorder (n = 6). These patients resembled the stable affective group (n = 27) in premorbid and prodromal aspects but changed over time to resemble the poor outcome of the stable schizophrenia spectrum group (n = 28) albeit with fewer negative symptoms and a better social function. Family history of nonaffective psychosis in first or second degree relatives was often found in the "change to schizophrenia group". A diagnosis in adolescence of schizophrenia spectrum or affective psychotic disorder is usually stable over time. A subgroup of non-schizophrenia patients go on to develop a schizophrenia spectrum disorder.     

Prevalence of item level negative symptoms in first episode psychosis diagnoses

The relevance of negative symptoms across the diagnostic spectrum of the psychoses remains uncertain. The purpose of this study was to report on prevalence of item and subscale level negative symptoms across the first episode psychosis (FEP) diagnostic spectrum in an epidemiological sample, and to ascertain whether items and subscales were more prevalent in a schizophrenia spectrum diagnoses group compared to an 'all other psychotic diagnoses' group. We measured negative symptoms in 330 patients presenting with FEP using the Scale for Assessment of Negative Symptoms (SANS), and ascertained diagnosis using the Structured Clinical Interview for DSM IV. Prevalence of SANS items and subscales were tabulated across all psychotic diagnoses, and logistic regression analysis determined which items and subscales were predictive of schizophrenia spectrum diagnoses. SANS items were most prevalent in schizophrenia spectrum conditions but frequently presented in other FEP diagnoses, particularly substance induced psychotic disorder and Major Depressive Disorder. Brief psychotic disorder and bipolar disorders had low levels of negative symptoms. SANS items and subscales which significantly predicted schizophrenia spectrum diagnoses, were also frequently present in some of the other psychotic diagnoses. Conclusions: SANS items have high prevalence in FEP, and while commonest in schizophrenia spectrum conditions are not restricted to this diagnostic subgroup.     

Familial association of schizotypal traits with psychotic and affective disorders

The criteria for schizotypal personality disorder were developed on the basis of traits observed in biologic relatives of schizophrenic and borderline schizophrenic probands from the Danish adoption studies. In this review, the relationship between schizotypal personality disorder and the schizophrenic spectrum, affective disorders, and psychotic disorders is explored. A dimension of psychosis may overlap with the schizophrenia spectrum to yield chronic schizophrenia, with the affective disorders spectrum to yield psychotic affective disorder, or by itself lead to other psychotic disorders. Schizotypal personality disorder in this model is posited to represent schizophrenia spectrum disorder that does not overlap with psychosis, whereas nonpsychotic affective disorders represent the affective disorders that do not overlap with psychosis. Delusional disorder represents another psychotic disorder that is not specifically related to either schizophrenia or the affective disorders. Evidence suggests that the schizotypal personality disorder criteria, particularly those emphasizing the negative symptoms or deficit-like symptoms of this disorder, specifically identify a unique relationship to the schizophrenia spectrum.     

Diagnostic stability 18 months after treatment initiation for first-episode psychosis

OBJECTIVES: (1) Assessment of diagnostic stability of psychotic disorders or psychotic mood disorders from 6 weeks to 18 months after initiation of treatment in a representative first-episode psychosis (FEP) sample. (2) Comparison between those patients who shifted from DSM-IV schizophreniform disorder to schizophrenia or schizo-affective disorder and those whose diagnosis of schizophreniform disorder remained stable. METHOD: The Early Psychosis Prevention and Intervention Centre (EPPIC) in Australia admitted 786 FEP patients from January 1998 to December 2000. Data were collected from patients' medical records (MRs) using a standardized questionnaire. Seven hundred four MRs were available, 36 of which were excluded owing to nonpsychotic diagnoses or a psychotic disorder due to a general medical condition. Of the remaining 668 patients, 176 (26.3%) were lost to follow-up. Four hundred ninety-two subjects were analyzed. Strategies to assure validity and reliability of diagnoses were applied. RESULTS: The same diagnosis was made at baseline (< or = 6 weeks after admission into EPPIC) and 18 months for 69.9% of the patients. Among the most consistent diagnoses were schizophrenia (97.3%), schizoaffective disorder (94.1%), and bipolar disorder (83.2%); the least stable, as expected, was schizophreniform disorder (40.0%). In subjects with schizophreniform disorder at baseline, the best predictors of a shift from schizophreniform disorder to schizophrenia or schizoaffective disorder were a higher baseline Clinical Global Impressions-Severity of Illness scale score and lower premorbid Global Assessment of Functioning score, although the variance accounted for was small (R2 = .07). CONCLUSIONS: A longitudinally based diagnostic process in FEP samples is needed, especially in schizophreniform disorder and bipolar disorder. However, a thorough initial assessment of patient and family by a specialized team of investigators regarding the kind and duration of patient symptoms may lead to high diagnostic stability, especially in schizophrenia and schizoaffective disorder, even in a FEP sample with a relatively short duration of untreated psychosis.     

Congruence of diagnoses 2 years after a first-admission diagnosis of psychosis

BACKGROUND: Diagnostic changes may reflect evolution of an illness, emergence of newly disclosed information, or unreliability of assessment. This study evaluates the stability of research diagnoses in a heterogeneous first-admission sample with psychosis. METHODS: A group of 547 subjects initially diagnosed with a psychosis were reassessed 6 and 24 months after enrollment. The DSM-IV consensus diagnoses were formulated by psychiatrists blind to previous research diagnoses. The analysis focuses on agreement over time and the effects of demographic, family history, and clinical variables on the shift from a nonschizophrenia diagnosis to schizophrenia. RESULTS: Seventy-two percent of 6- and 24-month diagnoses were congruent. The most temporally consistent 6-month categories were schizophrenia (92%), bipolar disorder (83%), and major depression (74%); the least stable were psychosis not otherwise specified (44%), schizoaffective disorder (36%), and brief psychosis (27%). The most frequent shift in diagnosis at 24 months was to schizophrenia spectrum (n=45). These 45 subjects had a similar illness course after 6 months as the 171 subjects in this category at both assessments, but their prior clinical functioning was better. Risk factors predicting change to a schizophrenia spectrum diagnosis include facility variables (schizophrenia diagnosis, longer stays, and given antipsychotic medication on hospital discharge); prehospital features (psychotic > or =3 months before admission, poorer adolescent adjustment, lifetime substance disorder); and negative symptoms. CONCLUSIONS: Changes in diagnosis, particularly to schizophrenia, are mostly attributable to the evolution of the illness. Rigid adherence to DSM-IV requirements may have led to underdiagnosis of schizophrenia. The findings support the need for a longitudinally based diagnostic process in incidence samples.     

Looking for childhood schizophrenia: case series of false positives

Extensive experience with the diagnosis of childhood-onset schizophrenia indicates a high rate of false positives. Most mislabeled patients have chronic disabling, affective, or behavioral disorders. The authors report the cases of three children who passed stringent initial childhood-onset schizophrenia "screens" but had no chronic psychotic disorder. For two, the European literature yielded more fitting diagnoses: psychosis not otherwise specified (e.g., reactive or psychogenic psychosis, paranoid schizophrenia), single episode in full remission (e.g., anxiety psychosis), and factitious disorder (DSM-IV 300.16). These cases illustrate that transient psychotic illnesses can be misdiagnosed as childhood-onset schizophrenia. Proper identification can prevent years of inappropriate therapies.     

Early onset psychotic disorders: Diagnostic stability and clinical characteristics

Objectives: To examine the clinical features and diagnostic stability of early-onset psychotic disorders. Methods: These data are from a two-year longitudinal prospective study of youth with psychotic disorders. Standardized diagnostic assessments are administered at baseline and at one and two-year's follow-up. Results: Fifty-one subjects have been recruited to date; 18 with schizophrenia, 14 with bipolar disorder, 7 with schizoaffective disorder, 1 with an organic psychosis, and 11 subjects whose symptoms where either questionable and/or did not meet diagnostic criteria for another disorder (classified as psychosis nos). Thirty-nine subjects were reassessed at year one, twenty-four at year two. Three subjects have been lost to follow-up. The study diagnosis was the same as the first onset diagnosis (prior to entering the study) in 50 % of subjects. Over the two-year period of the study, the diagnosis remained unchanged in over 90 % of subjects. Subjects with schizophrenia had higher ratings of premorbid impairment, including social withdrawal and dysfunctional peer relationships, than those with bipolar disorder. At the one-year follow-up, subjects with schizophrenia and schizoaffective disorder had significantly higher rates of delusions, bizarre behavior, and negative symptoms than those with bipolar disorder. Subjects with bipolar disorder tended to have cyclical courses, whereas those with schizophrenia and schizoaffective disorder were often chronically impaired. Subjects with psychosis nos had higher rates of dissociative symptoms and histories of child maltreatment. Conclusions: Early-onset psychotic disorders can be reliably diagnosed using standardized assessments and are stable over a two-year period. Compared to bipolar disorder, schizophrenia is associated with a poorer premorbid history, and persistent positive and negative symptoms.     

Early onset psychotic disorders: Diagnostic stability and clinical characteristics

To examine the clinical features and diagnostic stability of early-onset psychotic disorders. These data are from a two-year longitudinal prospective study of youth with psychotic disorders. Standardized diagnostic assessments are administered at baseline and at one and two-year’s follow-up. Fifty-one subjects have been recruited to date; 18 with schizophrenia, 14 with bipolar disorder, 7 with schizoaffective disorder, 1 with an organic psychosis, and 11 subjects whose symptoms where either questionable and/or did not meet diagnostic criteria for another disorder (classified as psychosis nos). Thirty-nine subjects were reassessed at year one, twenty-four at year two. Three subjects have been lost to follow-up. The study diagnosis was the same as the first onset diagnosis (prior to entering the study) in 50% of subjects. Over the two-year period of the study, the diagnosis remained unchanged in over 90% of subjects. Subjects with schizophrenia had higher ratings of premorbid impairment, including social withdrawal and dysfunctional peer relationships, than those with bipolar disorder. At the one-year follow-up, subjects with schizophrenia and schizoaffective disorder had significantly higher rates of delusions, bizarre behavior, and negative symptoms than those with bipolar disorder. Subjects with bipolar disorder tended to have cyclical courses, whereas those with schizophrenia and schizoaffective disorder were often chronically impaired. Subjects with psychosis nos had higher rates of dissociative symptoms and histories of child maltreatment Early-onset psychotic disorders can be reliably diagnosed using standardized assessments and are stable over a two-year period. Compared to bipolar disorder, schizophrenia is associated with a poorer premorbid history, and persistent positive and negative symptoms.     

Cognitive functioning in young people with first episode psychosis: relationship to diagnosis and clinical characteristics

OBJECTIVE: To examine the extent and nature of neuropsychological deficits in adolescents and young people with first episode psychosis (FEP), and to determine whether the pattern and extent of neuropsychological deficits varied according to diagnosis. METHOD: A total of 83 FEP subjects aged 13-25 years, and 31 healthy controls completed a comprehensive battery of neuropsychological tests, grouped into 10 cognitive domains. First episode psychosis subjects were stratified into three diagnostic groups (schizophrenia, affective disorders, substance-induced psychosis) and differences in cognitive profiles were examined. The contribution of demographic and clinical characteristics to cognitive performance was also explored. RESULTS: The schizophrenia group demonstrated significantly worse performance on tasks of verbal learning and memory than the affective disorders group. Compared to healthy controls, the schizophrenia group also demonstrated global impairment across the majority of cognitive domains. The substance-induced group's performance lay between that of the schizophrenia and affective disorders groups. Analyses of differential deficits revealed that verbal learning, verbal memory and current intellectual functioning were selectively impaired in the schizophrenia group, whereas the affective disorders group demonstrated a selective deficit in speeded processing. Premorbid intellectual functioning, negative symptomatology and medication levels were the strongest predictors of cognitive performance in FEP subjects. CONCLUSIONS: Verbal memory deficits differentiate individuals with schizophrenia from those with psychotic affective disorders. Although significant cognitive deficits are evident across all diagnostic FEP groups, individuals with schizophrenia appear to have more generalized impairment across a broad array of cognitive functions than other psychotic diagnoses. Lower premorbid intellectual functioning does not appear to contribute to greater cognitive deterioration following onset of psychosis, but severity of illness may be a more important factor than levels of mood disturbance.     

Reliability of clinical ICD-10 schizophrenia diagnoses

Concern has been expressed as to the reliability of clinical ICD-10 diagnosis of schizophrenia. This study was designed to assess the diagnostic reliability of the clinical ICD-10 diagnosis of schizophrenia in a random sample of Danish in- and outpatients with a history of psychosis. A sample of 100 subjects was assessed using the operational criteria OPCRIT checklist for psychotic and affective illness. The most recent principal and clinical ICD-10 diagnosis was compared with diagnoses generated by the OPCRIT instrument. Data documented very high sensitivity (93%) and positive predictive value (87%) of ICD-10 schizophrenia and an overall good agreement between clinical and OPCRIT-derived diagnoses (kappa=0.60). An even higher positive predictive value was obtained when diagnoses were amalgamated into a diagnostic entity of schizophrenia-spectrum disorders (98%). Near perfect agreement was seen between OPCRIT-derived ICD-10 and DSM-IV diagnoses (kappa=0.87). Thus, this study demonstrates high reliability of the clinical diagnosis of schizophrenia and even more so of the diagnosis of schizophrenia-spectrum disorder.     

Cognitive endophenotypes of psychosis within dimension and diagnosis

This study sought to characterize the psychosis phenotype, contrasting cognitive features within traditional diagnosis and psychosis dimension in a family sample containing both schizophrenia and psychotic bipolar I disorder. Seventy-six probands with psychosis [44 probands with schizophrenia, 32 probands with psychotic bipolar I disorder] and 55 first-degree relatives [30 relatives of schizophrenia probands, 25 relatives of bipolar probands] were recruited. Standardized clinical and neuropsychological measures were administered. No differences in cognitive performance emerged between probands with schizophrenia and probands with psychotic bipolar disorder, or between relatives of probands with schizophrenia and relatives of probands with bipolar disorder in the domains of working and declarative memory, executive function and attention. Relatives overall showed higher cognitive performance compared to probands, as expected. However, when we segmented the probands and relatives along a psychosis dimension, independent of diagnostic groups, results revealed lower cognitive performance in probands compared to relatives without psychosis spectrum disorders, whereas relatives with psychosis spectrum disorders showed an intermediate level of performance across all cognitive domains. In this study, cognitive performance did not distinguish either probands or their first-degree relatives within traditional diagnostic groups (schizophrenia and psychotic bipolar disorder), but distinguished probands and relatives with and without lifetime psychosis manifestations independent of diagnostic categories. These data support the notion that schizophrenia and psychotic bipolar disorder present a clinical continuum with overlapping cognitive features defining the psychosis phenotype.     

Cycloid psychotic disorder: validation of the concept by means of a follow-up and a family study

A 3-year prospective follow-up investigation and a family study were carried out in patients fulfilling the diagnostic criteria for cycloid psychotic disorder proposed by Perris and Brockington in 1981. The results show that cycloid psychosis differs in several respects from schizoaffective disorders as defined by current diagnostic criteria used in the United States. Furthermore, they seem to suggest that most cases of cycloid psychosis are not variants of either schizophrenia or major affective disorders.     

Diagnostic stability four years after a first episode of psychosis

OBJECTIVE: The objective of this study was to determine the stability of a diagnosis of psychosis four years after the first-episode diagnosis. METHODS: The study was a prospective four-year follow-up study (1995 to 1999) of 147 patients with schizophrenia, affective disorder, and other psychoses who presented with a first episode of psychosis in an epidemiologic catchment area in Ireland. All diagnoses were made on the basis of the Structured Clinical Interview for DSM-IV. RESULTS: One quarter of the patients evidenced a change in diagnosis at follow-up. The most common change was to a diagnosis of schizophrenia. The positive predictive values of schizophrenia and bipolar affective disorder were 97 percent and 80 percent, respectively. Fewer years spent in education, lower levels of initial psychopathology, and presence of comorbid alcohol or substance abuse were associated with change in diagnosis at follow-up. CONCLUSIONS: Among the diagnoses studied, schizophrenia was the most stable diagnosis after four years. The greatest instability occurred in the categories of drug-induced psychosis and psychosis not otherwise specified.     

Comparing algorithms for deriving psychosis diagnoses from longitudinal administrative clinical records

Purpose

Registers derived from administrative datasets are valuable tools in psychosis research, but diagnostic accuracy can be problematic. We sought to compare the relative performance of four methods for assigning a single diagnosis from longitudinal administrative clinical records when compared with reference diagnoses.

Methods

Diagnoses recorded in inpatient and community mental health records were compared to research diagnoses of psychotic disorders obtained from semi-structured clinical interviews for 289 persons. Diagnoses were derived from administrative datasets using four algorithms; ‘At least one’ diagnosis, ‘Last’ or most recent diagnosis, ‘Modal’ or most frequently occurring diagnosis, and ‘Hierarchy’ in which a diagnostic hierarchy was applied. Agreements between algorithm-based and reference diagnoses for overall presence/absence of psychosis and for specific diagnoses of schizophrenia, schizoaffective disorder, and affective psychosis were examined using estimated prevalence rates, overall agreement, ROC analysis, and kappa statistics.

Results

For the presence/absence of psychosis, the most sensitive and least specific algorithm (‘At least one’ diagnosis) performed best. For schizophrenia, ‘Modal’ and ‘Last’ diagnoses had greatest agreement with reference diagnosis. For affective psychosis, ‘Hierarchy’ diagnosis performed best. Agreement between clinical and reference diagnoses was no better than chance for diagnoses of schizoaffective disorder. Overall agreement between administrative and reference diagnoses was modest, but may have been limited by the use of participants who had been screened for likely psychosis prior to assessment.

Conclusion

The choice of algorithm for extracting a psychosis diagnosis from administrative datasets may have a substantial impact on the accuracy of the diagnoses derived. An ‘Any diagnosis’ algorithm provides a sensitive measure for the presence of any psychosis, while ‘Last diagnosis’ is more accurate for specific diagnosis of schizophrenia and a hierarchical diagnosis is more accurate for affective psychosis.     

Early-onset psychotic disorders: course and outcome over a 2-year period

OBJECTIVE: To examine the course and outcome of early-onset psychotic disorders. METHOD: These are data from a longitudinal, prospective study of youths with psychotic disorders. Standardized diagnostic and symptom rating measures were used. RESULTS: Fifty-five subjects with the following disorders have been recruited: schizophrenia (n = 18), bipolar disorder (n = 15), psychosis not otherwise specified (n = 15), schizoaffective disorder (n = 6), and organic psychosis (n = 1). Follow-up assessments were obtained on 42 subjects at year 1 and 31 subjects at year 2. Youths with schizophrenia had more chronic global dysfunction, whereas subjects with bipolar disorder overall had better functioning, with a cyclical course of illness. However, according to results of a regression model, premorbid functioning and ratings of negative symptoms, but not diagnosis, significantly predicted the highest level of functioning over years 1 and 2. CONCLUSIONS: Course and level of functioning differentiated bipolar disorder from schizophrenia. However, premorbid functioning and ratings of negative symptoms were the best predictors of functioning over the follow-up period. These findings are consistent with the adult literature, and they further support that psychotic illnesses in young people are continuous with the adult-onset forms.     

Changes in VA diagnosis of schizophrenic and affective disorders after DSM-III

DSM-III tightened the criteria for diagnosis of schizophrenia by excluding patients who exhibit a full affective syndrome before the onset of psychotic symptoms; such patients are to receive a diagnosis of affective disorder. The impact of this change on psychiatric diagnostic practices in Veterans Administration facilities before and after publication of DSM-III was assessed. Diagnoses of schizophrenia increased about half as much as would be expected based on the overall increase in psychiatric diagnoses, while diagnoses of affective disorders rose about two and a half times as much as would be expected. Patients whose diagnoses were changed from schizophrenic to affective disorders after publication of DSM-III had significantly fewer hospitalizations in both time periods than patients who retained diagnoses of schizophrenia. However, greater diagnostic inconsistency was found after implementation of DSM-III.