title: Shared and divergent neurocognitive impairments in adult patients with schizophrenia and bipolar disorder: Whither the evidence?
abstract: Recent data from genetic and brain imaging studies have urged rethinking of bipolar disorder (BD) and schizophrenia (SCZ) as lying along a continuum of major endogenous psychoses rather than dichotomous disorders. We systematically reviewed extant studies (from January 2000 to July 2015) that directly compared neurocognitive impairments in adults with SCZ and BD. Within 36 included studies, comparable neurocognitive impairments were found in SCZ and BD involving executive functioning, working memory, verbal fluency and motor speed. The extent and severity of neurocognitive impairments in patients with schizoaffective disorder, and BD with psychotic features occupy positions intermediate between SCZ and BD without psychotic features, suggesting spectrum of neurocognitive impairments across psychotic spectrum conditions. Neurocognitive impairments correlated with socio-demographic (lower education), clinical (more hospitalizations, longer duration of illness, negative psychotic symptoms and non-remission status), treatment (antipsychotics, anti-cholinergics) variables and lower psychosocial functioning. The convergent neurocognitive findings in both conditions support a continuum concept of psychotic disorders and further research is needed to clarify common and dissimilar progression of specific neurocognitive impairments longitudinally.
authors.affiliation: Research Division, Institute of Mental Health, Singapore, 10 Buangkok View, Singapore 539747, Singapore.
authors.forename: Carissa
authors.initials: C
authors.lastname: Kuswanto
authors.affiliation: Research Division, Institute of Mental Health, Singapore, 10 Buangkok View, Singapore 539747, Singapore.
authors.forename: Rowena
authors.initials: R
authors.lastname: Chin
authors.affiliation: Research Division, Institute of Mental Health, Singapore, 10 Buangkok View, Singapore 539747, Singapore.
authors.forename: Min Yi
authors.initials: MY
authors.lastname: Sum
authors.affiliation: Department of General Psychiatry, Institute of Mental Health/Woodbridge Hospital, Singapore, 10 Buangkok View, Singapore 539747, Singapore.
authors.forename: Somnath
authors.initials: S
authors.lastname: Sengupta
authors.affiliation: Division of Psychiatry, Department of Molecular Medicine, University at Siena, Italy, Viale Bracci 1, 53100 Siena, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Fagiolini
authors.affiliation: Mood Disorders Psychopharmacology Unit, University of Toronto, University Health Network, 399 Bathurst Street, MP 9-325, Toronto, ON M5T 2S8, Canada.
authors.forename: Roger S
authors.initials: RS
authors.lastname: McIntyre
authors.affiliation: Bipolar Disorders Program, Institute of Neuroscience, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Barcelona, Catalonia, Spain.
authors.forename: Eduard
authors.initials: E
authors.lastname: Vieta
authors.affiliation: Research Division, Institute of Mental Health, Singapore, 10 Buangkok View, Singapore 539747, Singapore; Department of General Psychiatry, Institute of Mental Health/Woodbridge Hospital, Singapore, 10 Buangkok View, Singapore 539747, Singapore. Electronic address: kang_sim@imh.com.sg.
authors.forename: Kang
authors.initials: K
authors.lastname: Sim
mesh_terms: D001714:Bipolar Disorder / Q000175:diagnosis / Q000188:drug therapy / Q000523:psychology*; D018680:Cholinergic Antagonists / Q000627:therapeutic use; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology*; D056344:Executive Function / Q000502:physiology*; D006801:Humans; D011618:Psychotic Disorders / Q000235:genetics / Q000523:psychology*; D012559:Schizophrenia / Q000235:genetics / Q000503:physiopathology*
chemical_list: D018680:Cholinergic Antagonists
keywords: Bipolar disorder; Neurocognitive impairments; Schizophrenia