title: Problems in remembering to carry out future actions in first-episode schizophrenia: primary or secondary impairment?
abstract: Prospective memory (PM) is the ability to remember to carry out intended actions in the future. Empirical evidence suggests that PM deficits exist in individuals with chronic schizophrenia. However, it is unclear whether PM deficits in first-episode schizophrenia exist independently from other neuropsychological deficits. Moreover, prior research using patients with first-episode has been limited to small inpatient samples. We aimed to clarify the nature and extent of PM deficits in individuals with first-episode schizophrenia, using a large outpatient sample. Participants were 91 clinically stable outpatients with first-episode schizophrenia and 83 healthy controls. PM was assessed using both a subjective self-reported checklist and a laboratory-based task capturing time- and event-based PM. A battery assessing verbal and visuo-spatial working memory, as well as executive functions was also administered. ANOVA analyses showed that patients with first-episode schizophrenia performed significantly poorer than healthy controls in time- and event-based PM. Stepwise linear regression analyses suggested that cognitive flexibility predicted time- and event-based PM; and working memory predicted event-based PM. Subgroup analyses showed that "cognitive-preserved" patients with first-episode schizophrenia tended to perform poorer in time-based PM deficit than healthy controls who were matched in IQ and other neuropsychological functions. Overall, our results provide substantial evidence to support that time-based PM deficits in first-episode schizophrenia are apparent and not entirely attributable to other neuropsychological deficits. PM may constitute a neuropsychological marker for schizophrenia.
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China; Castle Peak Hospital, Hong Kong, China.
authors.forename: Simon S Y
authors.initials: SS
authors.lastname: Lui
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Tian-xiao
authors.initials: TX
authors.lastname: Yang
authors.affiliation: Castle Peak Hospital, Hong Kong, China.
authors.forename: Amy C Y
authors.initials: AC
authors.lastname: Liu
authors.affiliation: Castle Peak Hospital, Hong Kong, China.
authors.forename: William W H
authors.initials: WW
authors.lastname: Chui
authors.affiliation: Castle Peak Hospital, Hong Kong, China.
authors.forename: Hera K H
authors.initials: HK
authors.lastname: Yeung
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Li
authors.affiliation: Behavioural Basis of Health Research Program, Griffith Health Institute, Griffith University, Gold Coast, Australia.
authors.forename: David L
authors.initials: DL
authors.lastname: Neumann
authors.affiliation: Behavioural Basis of Health Research Program, Griffith Health Institute, Griffith University, Gold Coast, Australia.
authors.forename: David H K
authors.initials: DH
authors.lastname: Shum
authors.affiliation: Castle Peak Hospital, Hong Kong, China.
authors.forename: Eric F C
authors.initials: EF
authors.lastname: Cheung
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China. Electronic address: rckchan@psych.ac.cn.
authors.forename: Raymond C K
authors.initials: RC
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D003071:Cognition; D056344:Executive Function; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D061212:Memory, Episodic; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000175:diagnosis; D012565:Schizophrenic Psychology; D057566:Self Report; D013997:Time Factors; D014705:Verbal Behavior; D014796:Visual Perception; D055815:Young Adult
keywords: First-episode; Prospective memory; Schizophrenia