<scp>NREM</scp> Sleep Oscillations Are Associated With Anxiety and Negative Affect in Young Adults

Non-rapid eye movement sleep (NREM) oscillations are critical for cognitive and affective processing. While several studies link anxiety and depression symptoms to sleep quality, a critical gap remains in elucidating the role of NREM physiology in sleep-dependent processing of affect and anxiety symptoms. The goals of the present study were to investigate sleep-dependent consolidation of emotional memory and the relations of NREM oscillations with state anxiety and affect upon awakening in a non-clinical sample enriched for trait anxiety. Forty-two participants were recruited from a larger cohort of college students based on self-reported high (> 2 SD cohort mean, n = 26) versus moderate-low levels of trait anxiety (< 2 SD cohort mean, n = 16) for a 2-h polysomnography monitored mid-day nap. Memory for negative and neutral picture stimuli was tested over this nap interval. Sleep spindles and slow oscillations (SOs) predicted post-nap state anxiety and negative affect. Importantly, these were independent relationships in opposing directions such that higher SO activity was associated with reduced negative affect and state anxiety, whereas spindle activity correlated with higher negative affect and anxiety. We observed significantly reduced SO activity in the high-anxiety group but no associations of anxiety with macro-features of sleep (sleep duration, latency, efficiency or stage distributions). There were no group differences in emotional memory, nor did sleep parameters correlate with memory performance. These findings reflect that NREM oscillations are uniquely sensitive to both trait and state level variability in anxiety and highlight their potential as a novel target to attenuate anxiety and negative affect.