Abstract
Patients with schizophrenia represent a group heterogeneous in clinical presentation and severity. Although severity has been operationalized in different ways, mostly on a gradient between symptom severity and functional impairment, such approaches are limited in capturing real-world functioning. We suggest adopting the severity model proposed by DSM-5 for autism spectrum disorders. The model defines three levels of severity based on the support required, directly addressing two barriers from previous models: real-world functioning and ease of implementation. Our adapted model includes three new features: first, this severity specifier is global, rather than for each symptom domain; second, the centrality of occupational functioning is emphasized to define the level of support; third, we propose a 1-month timeframe for severity appraisal, standardizing the assessment process. Considering practical utility, we indicate how severity assessment can guide clinical practice towards rehabilitation. Additionally, we outline operational definitions for severity and functioning in schizophrenia, aligned with the premises of our model. Finally, we acknowledge potential limitations, the most relevant being the need for empirical validation. The model is presented to foster discussion. Additional studies will follow to investigate inter-rater reliability and convergent validation with standard measures of symptom and functioning severity.