['Obstructive sleep apnea (OSA) is frequently comorbid with late-life depression. The purpose of this project was to determine, using a sample of older adults with major depressive disorder, whether patient-reported diagnosis of OSA was associated with rate of response to venlafaxine.', 'Participants from this multisite study were adults ≥60 years old (n = 468) with major depressive disorder and a Montgomery Asberg Depression Rating Scale (MADRS) score of ≥15. Depression response was the outcome variable, defined as a MADRS score of ≤10 for two consecutive assessments at the end of 12 weeks of open-label treatment with venlafaxine 300 mg/day. To assess OSA, participants were asked if they had been diagnosed with OSA using polysomnography.', 'Eighty participants (17.1%) reported a diagnosis of OSA prior to baseline. Participants with OSA were more likely to be male, report greater impairment on measures of health, experience a longer duration of the index episode, and receive an adequate antidepressant trial prior to entering the study. During the 12 weeks of treatment, 40.8% responded to treatment with venlafaxine (43.6%, n = 169/388 of the no OSA group, and 27.5%, n = 22/80 of the OSA group). Participants without OSA were 1.79 times more likely to respond to treatment (HR: 1.79 [95%CI: 1.13-2.86], P < .05) compared to those with OSA.'] Is self-reported obstructive sleep apnea associated with nonresponse to antidepressant pharmacotherapy in late-life depression?