Cognitive disorders are frequently found during late-life depression. Many cognitive functions may be concerned and can be explained by fronto-striatal brain circuits and hippocampus dysfunctions partly through abnormalities related to cerebrovascular diseases. It seems important to distinguish between early and late onset depression whose cognitive characterisation and etiopathogenia differ in some aspects. Cognitive impairment may represent markers of depression but it is still unclear whether one should consider potential biomarkers of disease state or trait or risk factor. These disorders may precede depression and persist despite symptomatic remission. Moreover, the interest of specifying these disorders is multiple because they can have pejorative consequences such as the modification of emotional content, promote suicidal act, limit the effectiveness of psychotherapy, be a risk factor for poor response to antidepressants. or be a potential risk factor for progression to a minor or major neurocognitive disorder, especially Alzheimer's disease.
Keywords: Cognitive decline; biomarker; dementia; late-life depression; risk factor.