Psychiatric complications of Alzheimer's disease overlapping with parkinsonism: Depression, apathy, catatonia, and psychosis

Abstract

Depression is a frequent comorbid condition in Alzheimer's disease (AD) and is associated with the presence of parkinsonism. Apathy in AD was reported to predict more severe parkinsonism, suggesting that apathy may be an early manifestation of a more aggressive AD phenotype characterized by loss of motivation, increasing parkinsonism, a faster cognitive and functional decline, and more severe depression. Catatonia may be found in a small proportion of patients with AD, but rates are higher in hospitalized patients. Catatonia is signifi cantly associated with more severe parkinsonism and depression and older age. Psychotic symptoms are relatively frequent in the late stages of AD. Current treatment with atypical antipsychotics has a concomitant risk of increased parkinsonism.