Increased frontal sleep slow wave activity in adolescents with major depression

Abstract

Sleep slow wave activity (SWA), the major electrophysiological characteristic of deep sleep, mirrors both cortical restructuring and functioning. The incidence of Major Depressive Disorder (MDD) substantially rises during the vulnerable developmental phase of adolescence, where essential cortical restructuring is taking place. The goal of this study was to assess characteristics of SWA topography in adolescents with MDD, in order to assess abnormalities in both cortical restructuring and functioning on a local level. All night high-density EEG was recorded in 15 patients meeting DSM-5 criteria for MDD and 15 sex- and age-matched healthy controls. The actual symptom severity was assessed using the Children's Depression Rating Scale—Revised (CDRS-R). Topographical power maps were calculated based on the average SWA of the first non-rapid eye movement (NREM) sleep episode. Depressed adolescents exhibited significantly more SWA in a cluster of frontal electrodes compared to controls. SWA over frontal brain regions correlated positively with the CDRS-R subscore “morbid thoughts”. Self-reported sleep latency was significantly higher in depressed adolescents compared to controls whereas sleep architecture did not differ between the groups. Higher frontal SWA in depressed adolescents may represent a promising biomarker tracing cortical regions of intense use and/or restructuring.

The influence of REM sleep and SWS on emotional memory consolidation in participants reporting depressive symptoms

“…However, the between-group differences in positive behavioural consolidation in the early sleep condition are modest [p = .156], and does not provide an adequate explanation for the observed differences in neutral memory consolidation. Interestingly, it has recently been shown that slow-wave activity over the prefrontal cortex during the first NREM sleep episode is greater in depressed adolescents than matched controls (Tesler et al, 2016). The authors of this study speculate that the increase of frontal slow-wave activity in MDD may reflect an altered pruning of synapses in this area, which results in a failure to reduce irrelevant connections.…”

Sleep and slow-wave activity in depressed adolescent boys: a preliminary study

“…In the only study using a homogeneous sample in terms of age, gender and medication use, a lower delta amplitude and power has been shown in depressed adolescent girls as compared to healthy girls [37]. Recently, it has also been shown that the topographical pattern of SWA distribution in depressed adolescents is characterized by increased SWA over the frontal cortex compared to healthy controls [38]. However, currently there are no studies that measure SWA abnormalities using a homogeneous sample of depressed boys.…”

Heritability of Sleep EEG Topography in Adolescence: Results from a Longitudinal Twin Study

“…Furthermore, differences in sleep EEG power between patient populations and healthy controls are almost always over a circumscribed brain region and may be a result of the neural circuitry implicated in a specific disorder. For example, in children with attention deficit hyperactivity disorder, an increase in SWA in central regions is observed 41 , while in adolescents with major depressive disorder an increase of SWA over frontal regions is observed 48 . These studies imply that the topography of the sleep EEG may be an additional marker of functional brain circuitry.…”