brain sciences Article The Effects of Major Depressive Disorder on the Sequential Organization of Information Processing Stages: An Event-Related Potential Study Daniel Kwasi Ahorsu 1 , Ken Chung 1, Ho Hon Wong 2, Michael Gar Chung Yiu 2, Yat Fung Mok 1, Ka Shun Lei 1 and Hector Wing Hong Tsang 1,* 1 Neuropsychiatric Rehabilitation Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China; [email protected] (D.K.A.); [email protected] (K.C.); [email protected] (Y.F.M.); [email protected] (K.S.L.) 2 Yung Fung Shee Psychiatric Center, Department of Psychiatry of United Christian Hospital, The Hong Kong Hospital Authority, Hong Kong SAR, China; [email protected] (H.H.W.); [email protected] (M.G.C.Y.) * Correspondence: [email protected]; Tel.: +852-2766-6750 Received: 23 October 2020; Accepted: 1 December 2020; Published: 4 December 2020 Abstract: The adverse effects of depression on patients’ life have been reported but information about its effects on the sequential organization of the information processing stages remains poorly understood as previous studies focused only on distinct stages. This study adds to existing knowledge by examining the effect of major depressive disorder (MDD) on the sequential organization of information processing, executive and community functioning. Fifty-seven participants with 19 participants each for first episode depression (FMDD), recurrent episodes depression (RMDD), and healthy controls (HCs) participated in this study. They completed assessments on executive and community functioning measures, and choice reaction time task (CRTT) for the event-related potential (ERP) data. Findings revealed no significant between-group difference in executive functioning but participants with depression (FMDD and RMDD) were found to be more depressed, with FMDD participants having worse community functioning skills compared with HCs. There was no significant between-group main effect on behavioral data. ERP data showed significantly less positive-going P3b among RMDD participants compared with HCs. FMDD participants used a different information processing strategy at P1, while HCs and RMDD participants used a different processing strategy at N2b compared with the other group(s), respectively. The results suggest the use of multifaceted assessment to get a holistic view of the health status of people with MDD in order to inform clinicians on the appropriate interventional strategies needed for the patient. Keywords: major depressive disorder; information processing; executive function; community function; event-related potential; choice reaction time task; cognitive-energetical linear stage model; parallel model; linear model 1. Introduction Depression, especially major depressive disorder (MDD), has been reported to affect all facets of a patient’s life, particularly cognitive processes and functions. More specifically, perception, attention, inhibition, executive function, and memory were reported to be compromised [1–4]. It is also well documented in behavioral studies that MDD patients suffer impaired decision making or response choices during tasks which may be attributed to their inability to perform or psychomotor retardation [5,6]. Psychomotor retardation, a major symptom of depression, is associated with general slowness and poor performance [7] which can be separated from the effect of arousal or sleepiness [8–11]. Despite these findings, the effect of depression along information processing stages [12,13] remains poorly understood, Brain Sci. 2020, 10, 935; doi:10.3390/brainsci10120935 www.mdpi.com/journal/brainsci Brain Sci. 2020, 10, x FOR PEER REVIEW 2 of 19 Braingeneral Sci. 2020 slowness, 10, 935 and poor performance [7] which can be separated from the effect of arousal2 of 18or sleepiness [8–11]. Despite these findings, the effect of depression along information processing stages [12,13] remains poorly understood, especially retardation. 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The models use defined task characteristics the parallel) is time (e.g., reaction time and latency). The models use defined task characteristics that that modify the time needed to execute the elementary operation of each stage. The stability and modify the time needed to execute the elementary operation of each stage. The stability and functionality of each information processing stage can, therefore, be tested by manipulating certain functionality of each information processing stage can, therefore, be tested by manipulating certain variables that are believed to affect a particular stage [13]. Furthermore,