Anxiety of Alzheimer's Disease: Prevalence, and Comorbidity

Background: Anxiety may be associated with psychiatric morbidity, disability, increased health care utilization, and mortality in Alzheimer's disease (AD) patients as it is in the general adult population. However, the phenomenology of anxiety symptoms in AD and its relationship to dementia progression, comorbid depression, and the presence of other problematic behaviors have not yet been examined.

Method: Data on anxiety symptoms and their coexistence with other factors were obtained in 523 community-dwelling AD patients through interviews with their caregivers and direct physical examination. The prevalence of anxiety symptoms and their association to patient depression, other behavioral problems, gender, and age was investigated.

Results: Anxiety symptoms were common, occurring in 70% of subjects. Anxiety symptoms were significantly correlated with ADL impairment and other behavioral disturbances, including wandering, sexual misconduct, hallucinations, verbal threats, and physical abuse. Comorbidity of anxiety-depression was also prevalent: 54% of the sample had both anxiety and depression symptoms. ADL impairment and problem behaviors were significantly associated with comorbidity; however, the latter association was explained entirely by the presence of anxiety.

Conclusion: Anxiety symptoms were common and significantly related to ADL and additional neuropsychiatric problems in this sample. These results indicate the need for additional research into the phenomenology of anxiety and comorbid anxiety-depression in AD and for the development and investigation of effective assessment and treatment of anxiety in AD clinical practice.