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.

Circadian preference towards morningness is associated with lower slow sleep spindle amplitude and intensity in adolescents

“…Changes in spindle characteristics, e.g. decreases in spindle number, density, duration or amplitude, are seen in neurodegenerative and psychiatric diseases 49 , such as social anxiety disorder 50 , Alzheimer’s disease and Mild Cognitive Impairment 42 , 51 , schizophrenia 52 – 54 and autism 55 . Among healthy adults, individual night to night variation in spindle characteristics is low 56 – 58 , influenced by a high, 96% heritability estimate 59 .…”

Emotional Memory Moderates the Relationship Between Sigma Activity and Sleep-Related Improvement in Affect

“…While previous studies have more often linked REM sleep (Cartwright et al, 1998; Palagini et al, 2013; Motomura et al, 2017) and SWS/slow wave activity (Landsness et al, 2011; Cheng et al, 2015; Finan et al, 2015) to mood, some recent studies have implicated sleep spindles in relation to mood. Reduced spindle activity has been seen in children and adolescents with social anxiety, with greater fast spindle activity (13–16 Hz) related to less severe symptoms (Wilhelm et al, 2017). A reduction in spindle activity was also observed in children and adolescents with or at risk for depression (Lopez et al, 2010).…”

“…To our knowledge, no links between sleep spindles and mood have been reported in non-clinical samples. However, lower sleep spindle activity has been observed in individuals with anxiety and depression (Lopez et al, 2010; Wilhelm et al, 2017), suggesting that spindle activity may also be important for regulating mood.…”

Early Life Trauma Has Lifelong Consequences for Sleep And Behavior

“…Furthermore, many aspects of sleep physiology and sleep architecture appear to be altered in different psychopathological states, and across the lifespan 6 . Decreases in NREM sleep spindles and alterations in NREM spectral power have been linked to various emotional and behavioral problems in children and adolescents 14,15 , as well as to dementia 16 in later life. Clinical depression, also a well-known consequence of developmental trauma 17–22 , has been shown to present with reductions in slow wave sleep, NREM sleep fragmentation, and increases in rapid eye movement (REM) sleep parameters 23 .…”