Relationship between cognitive function and brain activation in major depressive disorder patients with and without insomnia: A functional near-infrared spectroscopy (fNIRS) study.

Our study suggests that MDD patients with insomnia have more cognitive impairment, which is associated with impaired frontal brain activity. Our findings may provide new insights to understand the underlying neural mechanisms of both disorders MDD patients and provide potential clinical value for developing treatment strategies for insomnia in MDD patients.