title: Widespread reduction in sleep spindle activity in socially anxious children and adolescents.
abstract: Social anxiety disorder (SAD) is one of the most prevalent psychiatric diseases typically emerging during childhood and adolescence. Biological vulnerabilities such as a protracted maturation of prefrontal cortex functioning together with heightened reactivity of the limbic system leading to increased emotional reactivity are discussed as factors contributing to the emergence and maintenance of SAD. Sleep slow wave activity (SWA, 0.75-4.5 Hz) and sleep spindle activity (9-16 Hz) reflect processes of brain maturation and emotion regulation. We used high-density electroencephalography to characterize sleep SWA and spindle activity and their relationship to emotional reactivity in children and adolescents suffering from SAD and healthy controls (HC). Subjectively rated arousal was assessed using an emotional picture-word association task. SWA did not differ between socially anxious and healthy participants. We found a widespread reduction in fast spindle activity (13-16 Hz) in SAD patients compared to HC. SAD patients rated negative stimuli to be more arousing and these arousal ratings were negatively correlated with fast spindle activity. These results suggest electrophysiological alterations that are evident at an early stage of psychopathology and that are closely linked to one core symptom of anxiety disorders such as increased emotional reactivity. The role of disturbed GABAergic neurotransmission is discussed as an underlying factor.
authors.affiliation: University Children's Hospital Zürich, Switzerland; Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Switzerland; Department of Experimental Psychopathology and Psychotherapy, University of Zürich, Switzerland.
authors.forename: Ines
authors.initials: I
authors.lastname: Wilhelm
authors.affiliation: University Children's Hospital Zürich, Switzerland.
authors.forename: Sabine
authors.initials: S
authors.lastname: Groch
authors.affiliation: Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric Hospital, University of Zürich, Switzerland.
authors.forename: Andrea
authors.initials: A
authors.lastname: Preiss
authors.affiliation: Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric Hospital, University of Zürich, Switzerland.
authors.forename: Susanne
authors.initials: S
authors.lastname: Walitza
authors.affiliation: University Children's Hospital Zürich, Switzerland; Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric Hospital, University of Zürich, Switzerland. Electronic address: reto.huber@kispi.uzh.ch.
authors.forename: Reto
authors.initials: R
authors.lastname: Huber
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001245:Association Learning / Q000502:physiology; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D002648:Child; D004569:Electroencephalography; D004644:Emotions / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D000072861:Phobia, Social / Q000503:physiopathology*; D011569:Psychiatric Status Rating Scales; D012890:Sleep / Q000502:physiology*; D013057:Spectrum Analysis; D014851:Wakefulness
keywords: Arousal; Emotional reactivity; High density EEG; Sleep spindles; Social anxiety