Is late onset depression a prodrome to dementia?
BACKGROUND
Recent research suggests there are clinical and biological differences between late onset depression (LOD) and early-onset depression (EOD).


OBJECTIVE
In this paper we review clinical, epidemiological, structural neuroimaging and genetic investigations of late life depression that have been performed over the past two decades and offer evidence that LOD is often a prodromal disorder for dementia.


RESULTS
LOD patients are more likely to have cognitive impairment and to have more deep white matter lesions (DWMLs). Evidence concerning cortical and temporal lobe atrophy is conflicting, while the ApoE 4 allele is not associated with LOD.


CONCLUSIONS
It is likely that LOD is not a prodrome for a particular type of dementia, but the majority of patients who do develop dementia will acquire Alzheimer's disease (AD) or a vascular dementia, as these are by far the most common causes of dementia. This issue requires further clarification with follow-up of patients over the long term.
Schweitzer
Isaac
I
Department of Psychiatry, University of Melbourne, Australia. i.schweitzer@medicine.unimelb.edu.au
Tuckwell
Virginia
V
O'Brien
John
J
Ames
David
D
D017668:Age of Onset; D000368:Aged; D001057:Apolipoproteins E / Q000235:genetics; D001284:Atrophy / Q000209:etiology; D002540:Cerebral Cortex / Q000473:pathology; D003072:Cognition Disorders / Q000150:complications; D003430:Cross-Sectional Studies; D003704:Dementia / Q000235:genetics / Q000523:psychology*; D003866:Depressive Disorder / Q000150:complications* / Q000235:genetics; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D013702:Temporal Lobe / Q000473:pathology
D001057:Apolipoproteins E