This chapter explores the complex interplay between obstructive sleep-disordered breathing (OSDB) and mental health in adults. It delves into the potential mechanisms by which chronic sleep disruption and oxygen deprivation associated with OSDB can associate with various mental health conditions. The shared symptoms between OSDB and conditions like depression, anxiety, and psychotic disorders will be covered. Furthermore, the chapter explores the potential benefits of treating OSDB to reach better mental health outcomes. Surgical interventions such as surgery and continuous positive airway pressure (CPAP) therapy in adults are discussed as potential avenues for improving both sleep quality and mental well-being. This chapter emphasizes the need for further investigation, not only to solidify the understanding of the established links between OSDB and mental health conditions but also to explore potential connections with a wider range of mental disorders.