RecruitingPhase 3Drug trialContinuous Positive Airway Pressure, Arousability and Links to Mechanisms in Obstructive Sleep ApneaThe study design is a randomized, controlled clinical trial to test the hypothesis that arousal threshold (ArTH) will affect how individuals with obstructive sleep apnea (OSA, Apnea-Hypopnea Index (AHI) of 10/hour of higher) respond to CPAP therapy regarding adherence and cognitive function (executive function). Investigators hypothesize that raising ArTH with eszopiclone will improve adherence to CPAP and neurocognitive function with CPAP therapy. Investigators also hypothesize that a lower baseline ArTH is associated with worse CPAP adherence, while a higher baseline ArTH is associated with improved neurocognitive outcomes with CPAP therapy.