Archives of Depression and Anxiety Citation: Patterson JL, Toukhsati SR (2016) Electrophysiological Proiling of Depression in the Elderly. Arch Depress Anxiety 2(1): 031-036. DOI: 10.17352/2455-5460.000012 031 to stimulus (i.e., probability, inter-stimulus interval) and sample (i.e., age, medication status) variables. More recent indings from studies that control for such factors have revealed prolonged P300 latency amongst depressed elderly relative to their age-matched, non-depressed counterparts [13-15]. Moreover, such abnormalities have been associated with poorer performance on tasks of executive functioning, psychomotor retardation and poorer treatment response [13,14]. Presently, the inluence of depression on ERP amplitude in the elderly is largely unknown. his is notable because it is the most consistent cognitive marker of depression in younger cohorts [6]. As a general principle, age-related structural changes in the brain and other physiological factors have been shown to produce diferences in ERPs between young and older adults. Indeed, research has revealed diferences in the spatial distribution of ERP components, temporal properties (i.e., lower amplitude and longer latency in the elderly), as well as a general increase in the degree of individual ERP variability in older cohorts [16]. For example, elderly samples typically demonstrate a more ‘U-shaped’ P300 spatial distribution, with higher amplitude at the frontal and posterior sites, as opposed to the singular maximal posterior P300 distribution seen in younger samples [17]. Such diferences in ERPs between young and old suggest that the characterization of ERPs in elderly with and without depression is an important area of inquiry. From a cognitive perspective, the high temporal resolution of ERPs means that this technique has the potential to provide important information about the stage of information processing that may be disrupted in elderly with depression. To date, the limited available data has revealed signiicant increases in P200 amplitude, consistent with over-processing of irrelevant stimuli, which may explain downstream P300 abnormalities [18,19]. Further research that examines early ERP components will provide a more comprehensive insight into the electrophysiological proile of geriatric depression. To this end, the aim of this study was to explore the electrophysiological proile of elderly individuals with varying severity of depression, with a speciic focus on latency and amplitude of the P200 and P300 auditory ERPs. Method Participants Following ethics approval by the Monash University Human Research Ethics Committee (Project number CF07/4928 – 2007002107), participants were recruited from 15 Residential Aged Care facilities (RACFs) in Melbourne, Australia. Exclusion criteria were (1) a formal diagnosis of dementia or delirium; (2) legal blindness; (3) deafness or severe hearing impairment; (4) lack of English luency. Participants were screened using the Standardized Introduction Frontostriatal system functioning has been proposed to underpin performance on executive functioning tasks; these structures are abnormally activated in adults with depression. In this study, the P200 and P300 event-related potentials (ERPs) were elicited during a classic two-tone auditory oddball task to compare the electrophysiological proiles of elderly people (N = 54; Mean age = 85.46 ± 6.21) diagnosed with clinical depression (n = 17), subthreshold depression (n = 25) or no depression (n = 12). he P200 results revealed higher amplitude and signiicantly longer latencies in depressed groups relative to non-depressed participants. In contrast, smaller P300 amplitude and shorter latency was observed in depressed relative to non-depressed participants. Findings are discussed in terms of cognitive information processing models of ERPs and the potential for non-cognitive factors to impact on the resulting electrophysiological proile. Executive functioning is impaired in the setting of depression [1]. Frontostriatal system functioning has been proposed to underpin performance on executive functioning tasks and research has shown that these structures are abnormally activated in adults with depression [2-4]. hese structures have also been implicated in generating the P200 and P300 event-related potentials (ERPs), which provide an electrophysiological index of cognitive functioning. Corresponding with the known disruption to executive functioning in depressed cohorts, research amongst young adults with depression has tended to reveal lower P300 amplitude relative to their non- depressed counterparts [5-8]. he research is less consistent with regard to latency; however, prolonged latency has been observed in speciic subtypes of depression in which psychomotor retardation is a prominent feature [6]. Collectively, ERP and neuropsychological data appear to provide converging evidence of prefrontal dysfunction in depression amongst young cohorts; however, little research has utilized electrophysiological methods to explore cognitive dysfunction arising in the context of depression amongst the elderly. Early reports found no signiicant diferences in P300 latency for depressed elderly [9-12], however, these studies tended to be poorly controlled with regard Research Article Electrophysiological Proiling of Depression in the Elderly Jenny Lee Patterson 1 and Samia Rachael Toukhsati 2 * 1 School of Psychology and Psychiatry, Monash University, Clayton, VIC 3800, Australia 2 University of Melbourne and Department of Cardiology, Austin Health, Heidelberg, 3084 Victoria, Australia Dates: Received: 26 April, 2016; Accepted: 21 July, 2016; Published: 23 July, 2016 *Corresponding author: Samia Rachael Toukhsati , University of Melbourne, Department of Cardiology, Austin Health, Heidelberg, 3084 Victoria, Australia, Tel: +61 3 9496 3209; Fax: +61 3 9496 5026; E-mail: www.peertechz.com ISSN: 2455-5460