This analysis examined whether patients with Alzheimer disease ( AD) tolerate continuous positive airway pressure ( CPAP). Method: Thirty patients with AD were randomized to CPAP or sham CPAP and completed sleep, depression, and quality-of-life questionnaires. Participants could choose to continue treatment after the trial. Results: Patients wore CPAP for 4.8 hours per night. More depressive symptoms were associated with worse adherence (r(S) = -0.37; N = 30, p < 0.04). Patients who continued using CPAP had fewer depressive symptoms (t [19] = 2.45, p = 0.02) and better adherence (t[19] = 2.32, p = 0.03) during the trial. Conclusion: Patients with AD with obstructive sleep apnea can tolerate CPAP. Adherence and long-term use may be more difficult among those patients with more depressive symptoms.