Psychosocial risk factors and Alzheimer's disease: the associative effect of depression, sleep disturbance, and anxiety

OBJECTIVES: Alzheimer's disease (AD) dementia is a neurodegenerative condition, which leads to impairments in memory. This study predicted that sleep disturbance, depression, and anxiety increase the hazard of AD, independently and as comorbid conditions. METHODS: Data from the National Alzheimer's Coordinating Center was used to analyze evaluations of 12,083 cognitively asymptomatic participants. Survival analysis was used to explore the longitudinal effect of depression, sleep disturbance, and anxiety as predictors of AD. The comorbid risk posed by depression in the last two years coupled with sleep disturbance, lifetime depression and sleep disturbance, clinician-verified depression and sleep disturbance, sleep disturbance and anxiety, depression in the last two years and anxiety, lifetime depression and anxiety, and clinician-verified depression and anxiety were also analyzed as predictors of AD through main effects and additive models. RESULTS: Main effects models demonstrated a strong hazard of AD development for those reporting depression, sleep disturbance, and anxiety as independent symptoms. The additive effect remained significant among comorbid presentations. CONCLUSION: Findings suggest that sleep disturbance, depression, and anxiety are associated with AD development among cognitively asymptomatic participants. Decreasing the threat posed by psychological symptoms may be one avenue for possibly delaying onset of AD.