• CAP
• children
• depression
• sleep
• spindles

Major depressive disorder is very common worldwide and its clinical importance reveals the need for a global attention focused at identifying early risk biomarkers of the disorder.
Among these, sleep alterations have recently emerged as potential markers of depression and other psychiatric conditions. A large body of literature has documented that familiarity is a major component of the susceptibility of MDD and depression is more likely to occur among the offspring of depressed mothers. Intriguingly, sleep in children at high risk for depression has only scarcely been evaluated and research on this topic is still at an early stage. For these reasons, the present study was aimed at comparing electrophysiological features and CAP micro-architecture of sleep between a group of twenty children born to mothers with MDD and a group of eleven sex- and age-matched controls. Our most relevant results were a reduction of low-frequency spindle activity and related spatio-temporal characteristics and an altered distribution of CAP phase A subtypes in high-risk children. Our hypothesis is that the existence of a predisposing genetic programming for depression may trigger the development of a neuronal circuitry with limited spindles generation and increased cerebral arousability; this would produce functional anomalies in brain maturation, thus resulting in an altered cortical plasticity that could in turn represent a pathogenic factor for major depression.