Alterations in prefrontal cortical activity in the course of treatment for late-life depression as assessed on near-infrared spectroscopy.
OBJECTIVE
To evaluate the severity of depression by measuring alterations in prefrontal cortical activity associated with mood disorders, as assessed on near-infrared spectroscopy.


METHODS
Ten of 27 subjects hospitalized for late-life depression from May 2006 to June 2007, were examined. In these 10 subjects changes in hemoglobin concentration were measured on near-infrared spectroscopy during two types of the rock, paper, scissors game as the cognitive tasks affecting prefrontal cortical activity on 2 days, including 1 day on which depressive symptoms had slightly improved due to treatment, and then on another day >4 weeks later. Severity of depression and cognitive impairment were also simultaneously assessed.


RESULTS
The change in oxygenated hemoglobin concentration during a difficult task (intentional loss task) was significantly larger than that during an easy task (try to win task) on the left side (left, P = 0.010; right, P = 0.059). On the left side there was a significant negative correlation between the ratio of oxygenated hemoglobin measurements on the second day to those on the first day, and the severity of depression on the second day (left, P = 0.012; right, P = 0.090). Thus, the more left prefrontal cortical activity tended to increase, the fewer depressive symptoms tended to be present on the second day of testing.


CONCLUSIONS
Measuring of alterations in prefrontal cortical activity associated with mood disorders, as assessed on near-infrared spectroscopy, is feasible in subjects with depression.
Onishi
Yasunori
Y
Department of Psychiatry, Jichi Medical University, Shimotsuke, Japan. yas2@jichi.ac.jp
Kikuchi
Senichiro
S
Watanabe
Eiju
E
Kato
Satoshi
S
D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use*; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D004292:Dominance, Cerebral / Q000502:physiology; D004565:Electroconvulsive Therapy; D005260:Female; D005500:Follow-Up Studies; D006454:Hemoglobins / Q000378:metabolism*; D006760:Hospitalization; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010108:Oxyhemoglobins / Q000378:metabolism*; D010555:Personality Inventory; D010988:Play and Playthings; D017397:Prefrontal Cortex / Q000098:blood supply / Q000503:physiopathology*; D011340:Problem Solving / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D019265:Spectroscopy, Near-Infrared
D000928:Antidepressive Agents; D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin