Brain activity during sleep may provide a unique window onto adolescent cortical maturation. Especially electrophysiological sleep characteristics such as slow waves and sleep spindles were shown to be involved in short-term and long-term modifications of the developing brain. There is increasing evidence for sleep playing an active role during processes of synaptic plasticity shaping neural networks and supporting waking functioning. Sleep also seems to be bidirectionally related to altered processes of emotions, perceptions, and cognitive functioning. Long before technical and imaging advances shed light on sleep characteristics, disturbed sleep was found to be a core feature of many mental disorders such as ADHD, anxiety disorders, depression, and schizophrenia. Sleep disruptions seem to precede onset of these disorders and may enhance symptomatology. These findings highlight the importance of understanding when and how deviations from typical sleep characteristics occur and how this impacts pathophysiology of emerging mental disorders to improve prevention and targeted treatment. Prof. Huber and Dr. Tarokh will chair the session putting all of the presentations into context and identifying their relevance for future research and potential clinical implications. First, Dr. Tarokh will review characteristics of the sleeping and waking EEG during adolescence and present data regarding the degree to which genes and environment contribute to sleep physiology. She will provide data with relevance for public health and for clinical work with adolescents reporting sleep disturbances. Dr. Prehn-Kristensen will present data that highlight the impact of sleep on the consolidation of emotional and rewarded memories in children with ADHD. Here, especially the role of slow oscillations in deviant sleep-associated memory in processes will be emphasized. Dr. Wilhelm will present recent findings indicating differential effects of sleep on emotional memory consolidation in socially anxious and healthy children and adolescents. Finally, Dr. Gerstenberg will focus on sleep spindle oscillations, waxing and waning deflections in the EEG during early deep sleep. The synchrony and density of sleep spindle oscillations may be crucial for the organization of thalamocortical pathways. Dr. Gerstenberg will shed light on associations of disturbed sleep spindle density with specific domains of psychopathology in adolescents with a major depression or early-onset schizophrenia.