A Six Year Follow-up of the Cavan/Monaghan First Episode Psychosis Study KingstonTara 2019 <p>Aspects of outcome in first episode psychosis require clarification. In doing so, boundaries between diagnoses within the psychosis spectrum of disorders may be better understood, thus contributing to improvement in operational diagnoses of psychotic disorders. In addition, the place within the spectrum of psychotic disorders of lesser studied diagnoses, such as major depressive disorder with psychotic features, is unclear. This study is a six year follow-up of the CavanMonaghan First Episode Psychosis Study, and investigates outcomes in a cohort characterised by substantive ethnic and socioeconomic homogeneity and stability. This study examines key aspects and predictors of outcome, including diagnostic stability, psychopathology, social and occupational functioning, quality of life and service-engagement. Three major diagnostic nodes, schizophrenia, bipolar disorder and major depressive disorder with psychotic features emerge from the data. Schizoaffective disorder appears to inhabit the territory between these three nodes. Schizophreniform disorder appears primarily a progenitor of schizophrenia, while delusional disorder appears primarily a variant progenitor of schizophrenia and schizoaffective disorder. Brief psychotic disorder appears to be related prospectively to bipolar disorder and major depressive disorder, while substance-induced psychosis and psychosis not otherwise specified appear to be related prospectively to schizophrenia and schizoaffective disorder. Follow-up data on psychopathology, functioning, QOL and service engagement result in an overall picture of SZ having the most adverse outcome of all the diagnoses within the psychotic spectrum. Systematic comparisons are made with SA, BD and MDDP. Additionally, the study illuminates rarely considered aspects of SF, DD, BrPsy, PNOS, SIP, SIM, PGMC and MGMC. Extent of psychopathology has a notably adverse effect on outcome for all diagnoses, whereas an ability to maintain social integration and a more 'normal' life course appears to have a positive effect on outcome. These fmdings have implications for the approach to treatment across psychotic disorders: broader symptom management, whether via pharmacological or psychotherapeutic approaches, may prevent particularly adverse outcomes, and interventions that promote occupational and social integration are key in raising outcomes beyond the level achievable by symptom management alone.</p>