B - 98 Interactive Effects of Sleep Apnea and Depression Symptoms on Cognition in Older Adults

This study examined interactions between symptoms of sleep apnea and depression in predicting cognition in healthy older adults.From the Memory and Aging Project (Rush Alzheimer's Disease Center, Rush University, 2019), the sample consisted of 3345 community dwelling older adults including 2552 women (76.3%) and 1093 men (23.7%) with an average age of 80 years. Measures included the Berlin Questionnaire (for sleep apnea symptoms, Center for Epidemiological Studies Depression Scale, and neuropsychological measures of semantic memory, visuospatial ability, and processing speed.ANOVAs indicated significant main effects of depression on visuospatial ability, processing speed, and semantic memory (p's < 0.001), and no main effect for sleep apnea. However, when sleep apnea was analyzed between those with any depressive symptoms versus those without, significant interactions were found for visuospatial ability, processing speed, and semantic memory (ps < 0.05). Sleep apnea symptoms had a detrimental effect on visuospatial skills (p = 0.027) only when any depression symptom was present. In contrast, sleep apnea symptoms predicted slower processing speed when depressive symptoms were not present (p = 0.001) Similarly, depression symptoms had a greater negative effect on semantic memory for those who reported no sleep apnea symptoms compared to those who did (p = 0.016).There seems to be differential main and interactive effects of sleep apnea symptoms and depression on semantic memory, visuospatial ability, and processing speed. Clinicians may need to consider even mild symptoms of sleep problems and depression if they suspect changes in these cognitive domains in older adults.