Preliminary validation of a clinical staging model in schizophrenia and related disorders.

Clinical staging for schizophrenia and related disorders might provide an ideal means to overcome some limitations of the current diagnostic system and to facilitate early intervention. This study aims to retrospectively explore 1) the validity of a staging model 2) the stability of staging over time, and 3) the clinical factors associated with transition to more chronic stages. Data were derived from the Genetic Risk and Outcome of Psychosis study, a large cohort study of patients with a schizophrenia spectrum disorder. We assigned patients to a clinical stage, according to methods described by McGorry in 2010, using PANSS and GAF measures at baseline and three-year follow-up. Distinction between the stages was best explained by worse symptomatic, social and neurocognitive functioning in the first ('First Episode of Psychosis'), and last stage ('Severe/Persisting illness') as compared to the intermediate stages. Approximately half of the participants changed stages over time. Transition to more chronic stages was associated with worse premorbid functioning, higher levels of hostility and depressive symptoms and lower quality of life at baseline. We conclude that the clinical staging model was applicable in our sample. However, distinction between the intermediate stages and their prognostic validity could be improved.