Ghodsi Boushehri, Maral2025-09-172025-09-172025-09-172025-08-29https://hdl.handle.net/10012/22461Introduction: Anxiety and depression are prevalent neuropsychiatric issues among older adults with cognitive impairment. They are associated with accelerated cognitive decline, increased caregiver burden, and reduced quality of life. Given the noticeable side effects of pharmacological treatments, there is growing interest in non-pharmacological approaches to tackle anxiety and depression. Physical activity and sleep quality have shown promise in reducing anxiety and depression in the general population, but their potential benefits remain largely underexplored in older adults with cognitive impairment. The objectives of this thesis were to: 1) examine the associations between physical activity and sleep quality with odds of having anxiety and depression among older adults with different cognitive statuses; 2) investigate whether physical activity moderates the association between sleep quality with anxiety and depression; and 3) explore whether the associations between sleep, physical activity, and anxiety and depression vary by dementia subtype. Methods: This was a secondary analysis of data from the Comprehensive Assessment of Neurodegeneration and Dementia study. Physical activity was assessed using the Physical Activity Scale for the Elderly (PASE) and sleep quality with the Pittsburgh Sleep Quality Index (PSQI). Anxiety and depression symptoms were assessed using the Generalized Anxiety Disorder 7–item (GAD-7) and the Geriatric Depression Scale (GDS). Cutoff scores of GAD-7 ≥ 5 and GDS ≥ 10 were used to identify participants who are likely to have at least mild anxiety or depression. Logistic regression models with a backward selection of covariates were used to evaluate associations. Results: The study sample included 956 older adults: 150 with no cognitive impairment, 116 with subjective cognitive impairment, 460 with mild cognitive impairment, and 230 with dementia. Poor sleep quality was strongly associated with increased odds of both anxiety (OR = 1.138, CI = 1.09–1.19, p < 0.001) and depression (OR = 1.355, CI = 1.137–1.646, p = 0.001). Increased physical activity was associated with lower odds of depression (OR = 0.996, CI = 0.994–0.999, p = 0.038), but higher odds of anxiety (OR = 1.003, CI = 1.000–1.006, p = 0.007). The relationship between physical activity and outcomes was consistent across cognitive groups, whereas the association between sleep quality and depression was weaker among people with dementia. Moreover, no significant interaction between sleep quality and physical activity was found, suggesting that there is no moderating effect in their relationship with anxiety and depression. Additionally, none of the associations varied by dementia type, indicating consistent relationships across different types of dementia. Conclusion: The consistent association between poor sleep quality and higher odds of anxiety and depression emphasizes the need to prioritize sleep interventions among older adults with various cognitive statuses. Physical activity may be beneficial in reducing depressive symptoms, but its unexpected positive association with anxiety highlights the need for further investigation.enanxietydepressionphysical activitysleep qualitycognitive impairmentMaster Thesis