title: Reduced prefrontal cortex activation during the working memory task associated with poor social functioning in late-onset depression: multi-channel near-infrared spectroscopy study.
abstract: A number of studies have demonstrated impairment of working memory (WM) in patients with major depressive disorder (MDD). However, the relationship between the underlying brain activity associated with impairment of WM function in MDD patients and their clinical characteristics is not yet clear. The objective of this study is to evaluate prefrontal hemodynamic response related to a WM task in patients with late-onset depression (LOD) and to assess the relationship between activation in the prefrontal cortex and clinical characteristics. Thirty-six patients with LOD and 35 age- and gender-matched healthy controls were recruited for the present study. We measured hemoglobin concentration changes in the prefrontal and temporal regions during a WM (2-back, letter version) task using 52-channel near-infrared spectroscopy (NIRS). LOD patients were associated with reduced increase in prefrontal and temporal activation compared with healthy controls. Moreover, reduced activation in the prefrontal and temporal regions was significantly related to lower scores on the Social Adaptation Self-Evaluation Scale (SASS) in the patient group. More specifically, the reduced hemodynamic response in the frontopolar region was associated with functional impairment related to interpersonal relationship factor scores on the SASS. These findings suggest that hemodynamic response in prefrontal and temporal regions during a WM task may act as a biological marker of social functioning in LOD patients.
authors.affiliation: Department of Brain and Neuroscience, Tottori University Faculty of Medicine, Tottori, Japan. pshh0517@yahoo.co.jp
authors.forename: Shenghong
authors.initials: S
authors.lastname: Pu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamada
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Yokoyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsumura
authors.forename: Hideaki
authors.initials: H
authors.lastname: Mitani
authors.forename: Akiko
authors.initials: A
authors.lastname: Adachi
authors.forename: Koichi
authors.initials: K
authors.lastname: Kaneko
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Nakagome
mesh_terms: D000367:Age Factors; D000368:Aged; D001931:Brain Mapping; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007398:Interpersonal Relations; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010108:Oxyhemoglobins / Q000378:metabolism; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012737:Sex Factors; D012919:Social Behavior; D019265:Spectroscopy, Near-Infrared; D013702:Temporal Lobe / Q000503:physiopathology
chemical_list: D010108:Oxyhemoglobins