While previous studies have indicated significant benefits of mindfulness practice for psychological wellbeing, the present study was the first to systematically explore the potential effects of an intensive period of mindfulness meditation. This was achieved by examining a group of people who underwent a unique, intensive intervention. The effects of this intervention were assessed using validated psychological measures and a rigorous scientific design, incorporating an innovative internal attention-switching task. Furthermore, while previous research has tended to focus largely upon the effects of mindfulness meditation, the present study represents an attempt at understanding some of the mechanisms underlying these effects. This study synthesises research on attention, self-regulation, mindfulness meditation, depression, and other mood disorders. While the results here must be interpreted with caution, they point the way toward potential areas of interest for future researchers.