Problems in remembering to carry out future actions in first-episode schizophrenia: Primary or secondary impairment? Simon S.Y. Lui a, b, c , Ya Wang a , Tian-xiao Yang a , Amy C.Y. Liu c , William W.H. Chui c , Hera K.H. Yeung c , Zhi Li a, b , David L. Neumann d , David H.K. Shum d , Eric F.C. Cheung c , Raymond C.K. Chan a, * a Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China b University of Chinese Academy of Sciences, Beijing, China c Castle Peak Hospital, Hong Kong, China d Behavioural Basis of Health Research Program, Griffith Health Institute, Griffith University, Gold Coast, Australia article info Article history: Received 22 June 2014 Received in revised form 13 November 2014 Accepted 14 November 2014 Keywords: Prospective memory Schizophrenia First-episode 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 neuro- psychological 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 out- patients with first-episode schizophrenia and 83 healthy controls. PM was assessed using both a sub- jective 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 an- alyses 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. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction Prospective memory (PM) refers to the ability to remember to carry out intended actions in the future (Einstein and McDaniel, 1990; Kvavilashvili and Ellis, 1996), and is typically classified into time-based (e.g., remembering to attend a meeting at a certain time) and event-based (e.g., remembering to pass on a message when a classmate shows up). This type of memory has attracted a growing research interest in the healthy ageing populations (Einstein and McDaniel, 1990) and psychiatric patients, including people with schizophrenia (Wang et al., 2009). Impairments in prospective remembering could lead to difficulties in everyday life, and contribute to non-adherence to medications and treatment in people with schizophrenia (Lam et al., 2013; Raskin et al., 2014). In contrast to retrospective memory (RM), PM is a complex cognitive function that is thought to be dependent on other cognitive func- tions such as RM, attention, and cognitive flexibility (Lui et al., 2011; Shum et al., 2004). Ellis (1996) proposed that prospective remembering involves five stages, namely, (1) intention formation and encoding, (2) maintenance of the intention, (3) detection of cue and retrieval of * Corresponding author. Institute of Psychology, Chinese Academy of Sciences,16 Lincui Road, Beijing 100101, China. Tel./fax: þ86 10 64836274. E-mail address: rckchan@psych.ac.cn (R.C.K. Chan). Contents lists available at ScienceDirect Journal of Psychiatric Research journal homepage: www.elsevier.com/locate/psychires http://dx.doi.org/10.1016/j.jpsychires.2014.11.007 0022-3956/© 2014 Elsevier Ltd. All rights reserved. Journal of Psychiatric Research 61 (2015) 141e149