ISSN: 2575-9981
Authors: Lopez J*, Pokala S, Hoffmann R and Armitage R
Background: Major Depressive Disorder (MDD) is associated to substantial sleep disturbances and reduced neuroplasticity. Sleep spindles, involved in neuroplasticity mechanisms during brain development, are more abundant in children and adolescents than in adults, and as such, might be a sensitive measure of sleep alterations in early-onset MDD. This study investigated the effects of sex and age on sleep spindles in children and adolescents with MDD. Methods: The study included 69 depressed [34 children 8-12 years of age (18 males and 16 females) and 35 adolescents 13-18 years of age (14 males and 21 females)], and 42 healthy [18 children 8-12 years of age (10 males and 8 females) and 24 adolescents 13-18 years of age (12 males and 12 females)] youth. All participants maintained a regular sleep-wake schedule for 5 days followed by two consecutive nights in the laboratory. Spindle density (SD) was analyzed in Stage 2 of non-rapid eye movement sleep. Results: Children and adolescents with MDD showed lower SD than healthy controls (p<.02). SD was lower in depressed female children (p=0.006) and depressed adolescent males (p=0.01) compared to their corresponding healthy controls. Conclusions: Low sleep spindles generation characterized children and adolescents with MDD, indicating that low sleep-dependent neuroplasticity are a feature of early-onset MDD. Young girls and adolescent boys with MDD showed the lowest spindle generation, suggesting that sleep-associated neuroplasticity alterations in MDD are moderated by sex and age. The earlier reduction in sleep-dependent neuroplasticity in depressed females, compared to depressed males, may increase susceptibility for depressive episodes in subsequent years.
Keywords:
Brain development; Children; Adolescents; Early-onset depression; Sex differences; Sleep spindles; Neuroplasticity
