Altered resting-state prefrontal activity and network topology in adolescents with depression: an fNIRS study

Compared with HC, the DD group exhibited elevated prefrontal fALFF in multiple channels (e.g., ch11, ch26, ch31), reduced average functional connectivity within and between bilateral frontal regions (including FPA and Broca's area), and lower clustering coefficient, local efficiency, and global efficiency relative to healthy controls, whereas path length and small-worldness were preserved. Region-specific associations with cognition were observed: fALFF in ch11 positively correlated with verbal fluency, whereas fALFF in ch31 negatively correlated with executive functioning, these associations remained significant after controlling for depressive and anxiety symptom severity. <i>Conclusions:</i> Adolescents with depression show elevated prefrontal fALFF and reduced network efficiency, with region-specific associations with cognitive performance. These findings suggest that resting-state fNIRS is a developmentally suitable method for probing prefrontal neurocognitive alterations in youth depression.