Ultradian rhythms and temporal coherence in sleep EEG in depressed children and adolescents.
ABSTRACT It has been suggested that a primary ultradian (80-120 minute) rhythm disturbance in EEG underlies sleep abnormalities in adults with depression. The present study evaluated ultradian rhythm disturbances in childhood and adolescent depression.
Sleep macroarchitecture and temporal coherence in quantitative EEG rhythms were investigated in 50 medication-free outpatients with major depression (25 children and 25 adolescents) and 15 healthy normal controls (5 children and 10 adolescents).
Few of the macroarchitectural measures showed significant group effects. In fact, age and sex effects were stronger than disease-dependent components. Temporal coherence of EEG rhythms during sleep did differentiate those with MDD from controls. Both depressed children and adolescents had lower intrahemispheric coherence, whereas interhemispheric was only lower in depressed adolescents in comparison with controls. Gender differences were evident in adolescents, but not children, with MDD with lowest interhemispheric coherence in adolescent girls.
These findings are in keeping with increased risk for depression in females beginning at adolescence and extending throughout adulthood. It was suggested that low temporal coherence in depression reflects a disruption in the fundamental basic rest-activity cycle of arousal and organization in the brain that is strongly influenced by gender.
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ABSTRACT: Sleep disturbances, present in more than 90% of major depressive disorder (MDD) patients, are moderated by sex in adult MDD. In particular, slow-wave electroencephalo-graphic activity (SWA; 0.5-4 Hz) accumulation is low and dissipation impaired. This SWA abnormality in depressed adult males does not change with age, suggesting that SWA abnor-mality appears at early ages. The present study evaluated sex differences in SWA in adoles-cents with MDD compared to healthy controls. We evaluated regularized sleep-wake sched-ules at home for 5-7 days, followed by two con-secutive nights of sleep EEG recording. The study included 104 participants, 52 sympto-matic and depressed subjects (MDD: 20 males and 32 females) and 52 healthy controls (HC: 20 males and 32 females), aged 13-18 years. SWA power and dissipation, and duration and latencies to each Non-Rapid Eye Movement (NREM) sleep period were calculated for each group. Results showed that SWA accumulation in the first NREM period was lower and its dis-sipation across the night more irregular in MDD males compared to HC males (P<0.009). By contrast, SWA was equivalent in MDD and HC females. In conclusion, as reported in adult MDD, the accumulation and dissipation of SWA was abnormal in depressed adolescents, but only in males. SWA abnormalities in ado-lescent MDD may relate to different depressive symptoms in females and males. These results underscore the need to develop sex-specific therapies to enhance and restore SWA in depressed adolescents.01/2012; 4(1). DOI:10.4081/mi.2012.e4
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ABSTRACT: Depression and disturbed sleep are intimately and bidirectionally related. During adolescence, the incidence of both insomnia and major depression increase simultaneously, in a gender-specific manner. The majority of depressed adolescents suffer from different types of subjective sleep complaints. Despite these complaints, the results from polysomnographic studies in depressed adolescents remain inconsistent. In general, similar features to those seen among adults with depressive disorder (e.g. abnormalities in rapid-eye-movement sleep, and difficulties in sleep onset) have been reported, but expressed to a lesser degree. The inconsistency in findings may be linked with maturational factors, factors related to the stage of illness, and greater heterogeneity in the clinical spectrum of depression among adolescents. The exact neurobiological mechanisms by which sleep alterations and depression are linked during adolescence are not fully understood. Aberrations in brain maturation, expressed at different levels of organization, e.g. gene expression, neurotransmitter and hormone metabolism, and activity of neuronal networks have been suggested. The circadian systems may change in adolescent depression beyond that observed during healthy adolescent development (i.e. beyond the typical circadian shift towards eveningness). A number of therapeutic approaches to alleviate sleep disruption associated with depression have been proposed, but research on the efficacy of these interventions in adolescents is lacking. Knowledge of the neurobiological links between sleep and depression during adolescence could lead to new insights into effective prevention and treatment of depression.This article is protected by copyright. All rights reserved.Acta Physiologica 04/2015; 213(4):758-77. DOI:10.1111/apha.12449 · 4.25 Impact Factor