Obstructive sleep apnea (OSA) is common and has major health implications but treatment options are limited. Some OSA patients with low arousal threshold wake up prematurely during an obstructive event and do not have time for spontaneous upper airway (UA) dilator muscle recruitment. As a consequence they are exposed to apnea and hypopnea cycling. In this protocol the investigators will test the effect of trazodone administered before sleep on OSA traits and OSA severity during sleep.