Characterising Circadian Timing, Sleep Variability and Functional Outcomes of Delayed Sleep-Wake Phase Disorder for Improvement of Screening and Diagnostic Approaches

Sleep disorders cost Australia more than $5 billion dollars annually, a large proportion of which results from lost productivity, in addition to the direct and indirect health care costs. Delayed Sleep-Wake Phase Disorder significantly contributes to the societal burden of disease, as it is often misdiagnosed and therefore inadequately treated. This thesis aimed to characterise features of the disorder in order to develop a simplified method for predicting circadian phase that could be incorporated into diagnostic criteria. Improving diagnostic approaches enables better identification of the disorder and enhancement of treatment outcomes, reducing the personal and societal cost of the disorder.