Sleep, Depression, and Resilience: Connecting the Sleeping and Waking Brain.

Abstract

Depression is among the world’s most debilitating psychiatric illnesses, and often leads to suicide. Consequently, significant resources have been invested towards understanding depression and its underlying mechanisms. While notable research efforts have led to important discoveries, there continues to be questions that remain unanswered. Most importantly, depression research has been largely organized between those who examine depression during wake, and those who investigate depression during sleep. For example, while very robust and compelling research has established that there are changes in sleep architecture associated with depression, how such changes affect the phenomenology of depression is poorly understood. Similarly, psychopathologists typically examine depression without considering how sleep, a major mediator of mood and cognition, affects depressive symptoms. This partitioned approach to research has inadvertently created gaps in our knowledge and presents a unique opportunity for integration and extension of existing evidence that may provide insights into more effective treatments and prevention. In order to address the sleep/wake divide, this three study dissertation compares brain physiology across states of wakefulness and sleep. Additionally, this dissertation also examines how cortical activity during both sleep and wakefulness is related to mood and severity of depressive symptoms. This dissertation also aims to examine the role of sleep not only as a risk for depression, but also a factor in enhancing mental health. In particular, the relationship between psychological resilience and sleep is examined, along with its role in buffering against the negative affective consequences of sleep disruption.