Anxiety and depression in patients with AD have been extensively studied; however, the pathogenic explanations of their association with AD remain unclear.2 A history of depressive disorders have been established as risk factors for the development of dementia.3,4 It is also well known that neuropsychiatric symptoms and AD share common biological bases.2 When considering the causes of anxiety and depression, it has been proposed that as AD progresses, anxiety and depression increase due to psychosocial factors (e.g., loss of independence and increased awareness of AD) and pathological factors (e.g., neuronal atrophy and changes in metabolism).2 As a result of chronic distress, occurrence of neurodegeneration may lead to progression of AD.2 Once AD has progressed to late stages, the extensive brain damage may reduce depression and affective symptoms due to impairment of memory and executive functions.2 As stronger negative symptoms require adequate cerebral function,2 patients may not be able to produce this type of emotional response if cognitive impairment is severe.5 When considering the cause of AD, individuals experience dysthymia in the early stages of AD as an emotional reaction to the occurrence of cognitive decline, and anxiety, as an initial compensatory behaviour.2 As a result, anxiety and depression may arise from difficulties in adapting to the disease, and may represent a psychological response to the loss of independence.2
Depression, Anxiety, and Alzheimer’s disease
