title: Negative symptoms of schizophrenia: clinical features, relevance to real world functioning and specificity versus other CNS disorders.
abstract: Negative symptoms have long been recognized as a central feature of the phenomenology of schizophrenia, dating back to the early descriptions by Kraepelin and Bleuler. Over the ensuing century, there have been important clarifications and reconceptualizations regarding the phenomenology of negative symptoms in schizophrenia. This review explores these developments, including the delineation of two underlying subdomains of negative symptoms - amotivation (i.e., avolition/apathy and asociality) and diminished expression (i.e., poverty of speech and affective flattening). Further, advances in our understanding of specific motivational and hedonic deficits seen in schizophrenia are explored. The findings that negative symptoms stand apart from depressive and cognitive symptoms in schizophrenia are also discussed. In terms of the predictors of functional outcomes in schizophrenia, we explore both the direct role of negative symptoms in this regard, as well as their indirect role through cognition. We then broaden our examination of negative symptoms to related disorders across the schizophrenia spectrum, as well as to other neuropsychiatric illnesses, where negative symptoms have been increasingly recognized. We explore the differential characteristics of negative symptoms across these illnesses, and their relevance to functional outcomes. This transdiagnostic presence and relevance of negative symptoms highlights the need for continued exploration of their phenomenology and neurobiology as we move to develop effective interventions to address these debilitating symptoms and improve functional outcomes.
authors.affiliation: Centre for Addiction and Mental Health, University of Toronto, 250 College Street, Toronto, Ontario, Canada M5T 1R8; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, Canada M5T 1R8; Institute of Medical Science, Faculty of Medicine, University of Toronto, Medical Sciences Building, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8. Electronic address: george.foussias@camh.ca.
authors.forename: George
authors.initials: G
authors.lastname: Foussias
authors.affiliation: Centre for Addiction and Mental Health, University of Toronto, 250 College Street, Toronto, Ontario, Canada M5T 1R8; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, Canada M5T 1R8.
authors.forename: Ofer
authors.initials: O
authors.lastname: Agid
authors.affiliation: Centre for Addiction and Mental Health, University of Toronto, 250 College Street, Toronto, Ontario, Canada M5T 1R8; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, Canada M5T 1R8; Institute of Medical Science, Faculty of Medicine, University of Toronto, Medical Sciences Building, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8.
authors.forename: Gagan
authors.initials: G
authors.lastname: Fervaha
authors.affiliation: Centre for Addiction and Mental Health, University of Toronto, 250 College Street, Toronto, Ontario, Canada M5T 1R8; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, Canada M5T 1R8; Institute of Medical Science, Faculty of Medicine, University of Toronto, Medical Sciences Building, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8.
authors.forename: Gary
authors.initials: G
authors.lastname: Remington
mesh_terms: D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology / Q000503:physiopathology / Q000523:psychology; D008960:Models, Psychological; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D012565:Schizophrenic Psychology
keywords: Anhedonia; Cognition; Diminished expression; Motivation; Negative symptoms; Outcomes