Sleep deprivation and sleep disruption have long been associated with mood disorders, both as a cause as well as an effect. Sleep-disordered breathing results in significant and persistent sleep disruption, which in turn leads to significant neurocognitive deficits [1,2] and major depression [3-6]. Various pathophysiologic mechanisms may play a role in modulating mood changes in these patients. Treatment for sleep-disordered breathing often improves mood [4, 7], though the data may suggest a placebo response . Patients with sleep-disordered breathing should be carefully screened for mood disorders, and patients with major depression should be screened for possible underlying sleep-disordered breathing.