S102. DIAGNOSTIC CHALLENGES AT TIME OF INPATIENT ADMISSION: DIAGNOSTIC SHIFTS IN PATIENTS WITH FIRST EPISODE PSYCHOSIS

BACKGROUND: First episode psychoses (FEP) may present with diffuse symptoms and a broad range of clinical phenotypes, leading to difficulties in the early detection of the different pluripotent trajectories and consequently to instability of the diagnoses. The aim of this study was to assess the stability of diagnoses at time of admission compared to discharge in patients with FEP at a newly established early psychosis inpatient unit within a general psychiatric service in a general hospital. METHODS: Charts of all patients admitted to the early psychosis inpatient unit of the Clinical Division of Social Psychiatry of the Medical University of Vienna between 01.01.2016 and 31.03.2017 were reviewed. FEP was defined as a first presentation of affective, schizophreniform, acute polymorphic, organic or substance-related psychosis according to ICD-10. RESULTS: 127 patients were admitted during the said period, among whom 92 (72,4%) were diagnosed with a psychotic disorder at time of admission. 39,1% (n=36) of those had a FEP, whereof 58,3% (n=21) were diagnosed with schizophrenia spectrum psychosis, 27,8% (n=10) with affective psychosis, 11,1% (n=4) with substance-related psychosis and 2,8% (n=1) with organic psychosis as main diagnosis at time of discharge. In 50% (n=18) of FEP patients, diagnosis at time of admission was not maintained. 54,2% (n=13) of FEP patients who were admitted with a schizophrenia spectrum diagnosis had a shift in diagnosis at time of discharge, whereof 46,2% (n=6) were adjusted to another diagnosis of the same spectrum and 53,8% (n=7) to a diagnosis of either affective spectrum, substance-related psychosis or organic psychosis. 100% (n=2) of those with a persistent delusional disorder had a different diagnosis at discharge, as well as 56,3% (n=9=) of those admitted with a diagnosis of acute and transient psychotic disorders. Changes in the admission diagnoses of affective psychosis were necessary in 44,4% (n=4), whereof one half was adjusted to another diagnosis of the same spectrum and the other half to a diagnosis of the schizophrenia spectrum. DISCUSSION: The diagnostic instability in this study underlines the concept of the highly dynamic and changeable nature of psychopathology in the early stages and the pluripotent trajectories of psychosis. Furthermore, inadequate information available for specific diagnosis at time of admission as well as diagnostic uncertainty at the onset of psychosis could be implicated in the described diagnostic instability. The broad range of clinical phenotypes of early psychosis and the limitations of current diagnostic risk and identification approaches for the assessment of first episode psychosis indicate psychopathology conformed to a more dimensional rather than categorical model, as well as the need of a more dynamic model of prediction, such as the clinical staging model.