A good laugh and a long sleep : insights from prospective and ambulatory assessments about the importance of positive affect and sleep in mental health

This dissertation focuses on the application of the Experience Sampling Method (ESM) in mental health and sleep studies. ESM is a journaling technique that measures daily mood, experience, and behaviour. ESM was used in this study to examine the link between sleep, mood, and depression. The results revealed a correlation between poor perceived sleep quality and a less positive mood the next day, as well as an increase in depressive symptoms in the long term. ESM was successfully used for the first time for therapeutic purposes. Information about the mood and behaviour of clinically depressed patients, electronically collected using ESM research, was linked to these results to provide further insight.