First-Episode Psychosis: Diagnostic Stability over One and Two Years

Abstract

Background: Diagnostic stability is important for daily clinical work and planning of treatment. The aims of this study were to measure diagnostic stability in a clinical epidemiologic sample and to identify markers of change in diagnosis. Sampling and Methods: Diagnostic stability and change were measured in a sample of 301 patients with first-episode psychosis from four national health care sectors in Norway and Denmark at baseline, 1 and 2 years. Results: Diagnostic stabilities were high for schizophrenia and schizoaffective disorder (85–99%), low for schizophreniform disorder (16–19%), and intermediate for other diagnoses. Diagnostic change from schizophreniform to schizophrenia was frequent in year 1 (72%). Characteristics discriminating schizophreniform patients keeping their diagnosis (i.e. having recovered within 6 months with no relapse) from those developing schizophrenia at 1 year were female gender, better childhood premorbid functioning, shorter duration of untreated psychosis and more severe general psychotic symptoms, especially excitation. Conclusions: Findings provide validation for the DSM-IV categories within the schizophrenic spectrum. The limitations of the study were: the raters were not blind to baseline assessments; patients with longer duration of untreated psychosis were more likely to refuse participation; not all patients were assessed at 1- and 2-year follow-up, but the attrition was rather low.

Diagnostic Stability of First-Episode Psychotic Disorders and Persistence of Comorbid Psychiatric Disorders over 1 Year

“…Further, we found that schizophrenia was the most stable diagnosis over time and that most diagnostic shifts were to schizophrenia and schizophrenia spectrum disorders. These findings replicate those of several other studies [2][3][4][5][7][8][9] conducted with samples of patients in different countries and indicate that schizophrenia is reliably diagnosed even in the early phases of the illness. Conversely, schizophreniform disorder and psychosis NOS were found to be among the least stable diagnoses, as has been observed in numerous other studies.…”

“…This figure is in keeping with several studies that have found overall stabilities ranging from 67% to 77%. [2][3][4][5]7 However, it is important to note that while most of these studies included diagnoses of organic psychotic disorder, substance-induced psychotic disorder, and brief psychotic disorder, these diagnoses are excluded from admission to the PEPP-Montreal program. Further, we found that schizophrenia was the most stable diagnosis over time and that most diagnostic shifts were to schizophrenia and schizophrenia spectrum disorders.…”

“…[1][2][3] Diagnostic stability is an important measure of the reliability and validity of psychiatric diagnoses and it has implications in clinical practice, as pharmacological and, to a lesser extent, psychosocial interventions may vary depending on a patient's diagnosis. 1,4,5 It is also important in ensuring the validity of research findings. 6 The validation of diagnosis over time is particularly important in the case of psychotic disorders because they typically follow a more chronic course than other psychiatric conditions and require long-term treatment.…”

Diagnóstico diferencial de primeiro episódio psicótico: importância da abordagem otimizada nas emergências psiquiátricas

“…39 Conversely, there is evidence suggesting good stability levels for the diagnosis of schizoaffective disorder in first-episode psychosis patients. 40,41 The latter results are probably related to the fact that these diagnoses were performed in research contexts, in large cohorts of cases with first-episode psychosis, and using scales and diagnostic interviews administered by experienced professionals.…”

Stimulant use disorders and psychosis: prevalence, correlates and impacts

“…"Diagnostic shifts" (Bromet et al, 2011) may reflect inter-rater variation, changes in available information, the evolution of illness or a combination of all of these (Bromet et al, 2011;Haahr et al, 2008 uncertainty; it is difficult to judge causation of psychosis when substance use persists (Mathias et al, 2008). Second, substance use may influence the course of psychosis.…”