Neural Sleep Signatures in Major Depressive Disorder: Altered Oscillatory and Aperiodic Components

Patients with MDD exhibited significantly reduced SO-spindle coupling and a flattened spectral slope across NREM and REM sleep compared to controls. MDD patients showed a reduced spindle density. Standard polysomnographic parameters did not differ between the groups in the current sample DISCUSSION: : This study provides the first evidence that MDD is characterized by reduced slow oscillation-spindle coupling and a flattened spectral slope during sleep. These alterations suggest attenuated thalamocortical coordination and may represent a mechanistic link between sleep physiology and clinical symptoms.