Subtyping Schizophrenia by Social Functioning - a Pragmatic Proposal for Clinics and Research.

Schizophrenia has been claimed to be a "heterogeneous" disorder despite the fact that a diagnosis is made without reliable biomarkers but sorely with a constellation of "common" observable symptoms that however may be overlooked. Alternatively functional impairments are the prerequisite to make a diagnosis and may be simpler and more pragmatic to express objectively. It would then be reasonable to categorize patients according to the magnitude of psychosocial impairments, as has been done in terms of the severity of "classical" symptoms. In this context the author proposes a new paradigm in which patients with schizophrenia are classified into three functional subtypes using the anchors for the Clinical Global Impression Functioning subscale (CGI-F, adopted from the CGI) and the Functional Assessment for Comprehensive Treatment of Schizophrenia (FACT-Sz): Class 1 patients are those with no to mild functional impairments (a score of 1-3 in the CGI-F and a score of 60-100 in the FACT-Sz), Class 2 patients are those with moderate to marked impairments (4 or 5 in the CGI-F and 40-59 in the FACT-Sz), and Class 3 patients are those with severe to most severe impairments (6 or 7 in the CGI-F 6,7 and 0-39 in the FACT-Sz). The author has no intention to ignore the importance of other domains of the illness but instead provides a simple framework as what the patient is actually doing is considered to represent the proximal "hard outcome" and certainly has the relevance in the management of schizophrenia. Implications of this pragmatic classification system for clinics and research are discussed.