Journal of International Psychiatry

Objective To explore the working memory performance and associated brain activation in patients with major depressive disorder using functional near-infrared spectroscopy (fNIRS) imaging technology. Methods 26 patients with MDD diagnosed according to the DSM-5 criteria were selected as the study group, and 22 healthy adults were chosen as healthy controls. The 17-item Hamilton Depression Scale (HAMD17) was used to assess depressive symptoms in patients, and the digit n-back test was used to evaluate working memory. Functional near-infrared spectroscopy was employed to measure activation in the frontal brain regions during the execution of the n-back working memory task. Results 1. Significant main effects of load level were observed in both accuracy and reaction time (P < 0.05), with a significant interaction between group and load level (P < 0.05). Simple effect analyses revealed that under the 0-back condition, there were no significant differences in accuracy and reaction time between MDD patients and healthy adults (P > 0.05), while under the 1-back and 2-back conditions, MDD patients exhibited significant differences in accuracy and reaction time (P < 0.05). 2. Compared to the healthy control group, MDD patients exhibited a significant reduction in activation of the dorsolateral prefrontal cortex (channels 3, 4, 5, 6, 8) and the frontopolar cortex (channel 47) [oxy-Hb] during the 2-back working memory task (P < 0.05). Conclusion Patients with major depressive disorder demonstrate impaired working memory function, with reduced activation in the dorsolateral prefrontal cortex and frontopolar cortex during the 2-back working memory task. This provides a theoretical basis for future clinical assessment and neural regulatory treatment approaches.

[Keywords] major depressive disorder;n-back;working memory;functional near-infrared spectroscopy