<p>This literature review addresses the problems of the relationship between dementia and depression, the role of depression as a risk factor for the development of dementia, and the place of depression in the structure of neurocognitive impairment in dementia. Epidemiological data are provided and the mechanisms of the relationship between these disorders are discussed. The search for sources included only qualitative studies, meta-analyses, and full-text articles and was run in the PubMed and Google systems using the keywords dementia and depression. The epidemiological and biological data presented here indicate that depression increases the risk of dementia, confi rming the hypothesis that it operates as a causal factor. The main areas of research on the relationship between depression and dementia in the context of the prevention of Alzheimer’s disease are discussed.</p>