NREM sleep microarchitecture is associated with internalizing symptoms and emotional functioning in early adolescence

Sleep disturbances are common in youth with anxiety disorders, yet most prior work relies on subjective measures and does not capture underlying neural processes. We examined whether alterations in non-rapid eye movement (NREM) sleep oscillations are present in children with anxiety disorders and whether these features relate to internalizing symptoms and emotional functioning.

Children aged 9-13 years with diagnosed anxiety disorders (ANX; n = 17) and typically developing non-psychiatric comparison participants (NC; n = 26) completed overnight polysomnography. Slow oscillations (SO) and slow and fast sleep spindles were characterized using validated automated detection algorithms. Participants also completed a pre-sleep emotional processing task, and parents provided standardized measures of youth mental health. Group differences and dimensional associations between NREM oscillations, internalizing symptoms, and behavioral indices of emotional processing were examined.

Sleep architecture did not differ between groups. Slow spindle duration was shorter in the ANX group. Across the full sample, shorter slow spindle duration was associated with greater internalizing symptoms, whereas higher SO density was positively associated with internalizing symptoms. Children in the ANX group exhibited greater facial emotional arousal and more frequent look-away behavior during the emotional processing task. Across participants, greater emotional arousal and look-away behavior were associated with shorter spindle duration during subsequent sleep.

Specific features of NREM microarchitecture were associated with individual differences in internalizing symptoms and emotional functioning during early adolescence. These findings highlight the potential relevance of NREM oscillations for understanding developmental links between sleep and youth psychopathology.

Sleep disturbances are common in youth with anxiety disorders, yet most research has relied on subjective reports and broad measures of sleep quality. This study demonstrates that specific features of non-rapid eye movement sleep microarchitecture, particularly sleep spindle duration, are associated with anxiety, depression, and emotional responding during early adolescence even in the absence of differences in overall sleep quality or sleep stage distribution. These findings highlight the importance of examining neural features of sleep when investigating emotional functioning and internalizing psychopathology during development. More broadly, the results suggest that adolescence may represent a sensitive developmental window during which alterations in sleep physiology are linked to emotional functioning. Longitudinal studies are needed to determine how these sleep features relate to developmental trajectories of youth psychopathology.