If eligible, participants will be given a clinical Automatic Positive Airway Pressure (APAP) device for up to 3 months, while they are waiting for their clinical evaluation from a sleep physician. The APAP device will we will be using is the ResMed Airsense 11 Autoset. APAP is a smart positive airway pressure (PAP) device, where the pressure changes as needed to provide optimal pressure to splint the upper airway. Dr. Lee and Dr. Schmickl will oversee management of the device.

During the first month of APAP use, individuals will participate in weekly phone calls or in-person visits to ensure optimal adherence and troubleshoot any issues (improper mask fitting, discomfort, etc) that may arise.

Acceptance of PAP trial (based on post-adherence program survey taken after the completion of the 4 sessions.) Acceptability will be rated by % individuals who rate high level of satisfaction with the intervention.

OSA self-efficacy will be assessed using the Self-Efficacy Measure for Sleep Apnea (SEMSA). The SEMSA is a 26-item, self-administered questionnaire. The SEMSA has 3 categories: perceived risk, outcome expectancies, and treatment self-efficacy. In the perceived risk category, individuals answer questions about their perceived vulnerability to health risks. In the outcome expectancies, individuals answer questions regarding the potential behavior to reduce those risks, and in the treatment self-efficacy, the participant rates the level of validity of the statements on a 4-point scale regarding their perceived ability to perform behavior. Each of the 3 categories has a 4-point ordinal scale (1= irrelevant, 4 = extremely relevant) ranging from very low to very high. The mean of the 3 subscales are calculated. Higher scores indicate greater perceived self-efficacy, perceived response efficacy, and higher perceived susceptibility.

PAP usage will be assessed using mean hours/night - which will be obtained from the PAP machine data.

Cognitive functioning will be measured with the MATRICS Cognitive Consensus Battery (MCCB).159 The MCCB assesses six cognitive domains (attention/vigilance**, verbal learning/memory**, processing speed, working memory, auditory learning/memory, and reasoning), and has excellent test-retest reliability (ICC = 0.88) with minimal practice effects.159, 160 Executive functioning is the one cognitive domain that is less ideally covered within the MCCB. The closest MCCB domain, reasoning, is measured by a single timed-mazes task that can be readily affected by non-executive functions. We use subtests from the Delis-Kaplan Executive Functioning System (D-KEFS) battery161 [Color Word Interference, Letter Number Sequencing, and phonemic (FAS) and semantic (Animals) fluency] to assess Executive Functioning*. We have successfully employed these measures as a supplement to the MCCB in multiple prior studies in PwS.