This study aims at a comprehensive analysis of the relationships betwe
en two psychiatric syndromes, in the elderly : dementia and depression
. The various clinical pictures are described : depressive pseudodemen
tia, regressive depression, dementia in the course of a depression, ps
eudodepressive dementia, depression in the course of a dementia. Patho
genic hypotheses are proposed in, each case and therapeutic targets ar
e defined.