A study on the functional near-infrared spectroscopy on impaired prefrontal activation and impulsivity during cognitive task in patients with major depressive disorder

This study aimed to examine the association between prefrontal activation during a verbal fluency task (VFT) and impulsivity among patients with major depressive disorder (MDD), using functional near-infrared spectroscopy (fNIRS). We enrolled a total of 119 participants, 60 with MDD patients and 59 with healthy controls (HCs), aged 18 to 34 years. The Barratt Impulsiveness Scale–11 (BIS-11) was used to assess impulsivity after completing baseline demographic, clinical, and physical assessments. A VFT was used to examine prefrontal activation during cognitive executions while fNIRS was monitored. The changing values of oxygenated hemoglobin (oxy-Hb) and their associations with the BIS-11 score were analyzed. The data analysis comprised 109 participants in total (54 MDD; 55 HCs). Spearman's correlation analysis of the MDD group showed a negative correlation between changes in oxy-Hb and BIS-11 values in the right prefrontal cortex, notably the right frontopolar cortex (FPC) and ventromedial prefrontal cortex (VMPFC). After adjusting for sex, age, years of education, and Hamilton Depression Rating Scale (HAMD), significance was maintained in the right FPC [ρ = −0.317, p = 0.027], and the right VMPFC [ρ = −0.327, p = 0.022]. Furthermore, multivariate linear regression suggested a significant association in the right prefrontal cortex with BIS-11 score [β = −1.904, SE = 0.799, p = 0.0214]. Impaired prefrontal activation during a verbal fluency task, led to higher impulsivity in patients with MDD.