Dementia, depression and parkinsonism: A frequent association in the elderly

Depression and parkinsonism constitute two frequent findings in elderly demented patients. A large body of research, including epidemiological, retrospective, and prospective studies have contributed to the understanding of complex and common situations in the elderly, in which depression, parkinsonian signs, and cognitive impairment coexist. Many aspects regarding the "associated syndromes of dementia", however, are still object of debate as well as under current active investigation. The recent dramatic aging of the population is leading to an increasing prevalence of neuropsychiatric comorbidities. This is a problem of great clinical and socio-economical interest, because, when present in the same subject, depression, parkinsonism-related motor impairment and cognitive impairment may not only act additively or synergistically in deteriorating the functional outcome of the patient, but also lead to their institutionalization. We observed that one half of institutionalized subjects in two nursing homes of Central Italy suffer from an associated syndrome dementia / parkinsonism / depression, that these subjects are significantly more dependent than subjects hospitalized for the same reasons, and that their grade of depression or cognitive impairment is independent of which disease is diagnosed first. Depressed mood, memory impairment and motor difficulties, however, are often underestimated in the elderly, being considered as "normal" aspects of the aging process. The aim of this review is to highlight the clinical relevance of the associated syndromes of dementia, in a way that early diagnosis and treatment of these pathologies are attempted.