Psychiatry Investig.  2020 Aug;17(8):804-813. 10.30773/pi.2020.0045.

Reduced Temporal Activation During a Verbal Fluency Task is Associated with Poor Motor Speed in Patients with Major Depressive Disorder

• Kiriyama T
• Tanemura R
• Nakamura Y
• Takemoto C
• Hashimoto M
• Utsumi H

• KMID: 2505278
• DOI: http://doi.org/10.30773/pi.2020.0045

Abstract

Objective
Substantial research has revealed cognitive function impairments in patients with major depressive disorder (MDD). However, the relationship between MDD cognitive function impairment and brain activity is yet to be elucidated. This study aimed to reveal this relationship using near-infrared spectroscopy (NIRS) to extensively measure frontotemporal cortex function.
Methods
We recruited 18 inpatients with MDD and 22 healthy controls. Regional oxygenated hemoglobin changes (oxy-Hb) were measured during a verbal fluency task and its relationship to cognitive function was assessed. Cognitive function was assessed using the Japanese version of the Brief Assessment of Cognition in Schizophrenia.
Results
Compared to healthy controls, patients with MDD displayed poorer motor speed, attention and speed of information processing, and executive function. In the bilateral prefrontal and temporal surface regions, regional oxy-Hb changes were significantly lower in patients with MDD than in healthy individuals. Moreover, we observed a correlation between reduced activation in the left temporal region and poor motor speed in patients with MDD.
Conclusion
We suggest that reduced activation in the left temporal region in patients with MDD could be a biomarker of poor motor speed. Additionally, NIRS may be useful as a noninvasive, clinical measurement tool for assessing motor speed in these patients.

Keyword

Major depressive disorder, Near-infrared spectroscopy, Temporal cortex, Motor speed, Cognitive function