Case for and against specificity of depression in Alzheimer's disease.
OBJECTIVE
The aims of this study were to assess the epidemiological, phenomenological, and pathophysiological evidence that suggests the specificity of depression associated with Alzheimer's disease (AD).


METHODS
We reviewed the English-language literature.


RESULTS
Depression occurs significantly more often in patients with AD than in the general elderly population. While development of depression in response to the disability and emotional stress of AD may be a contributory factor in some patients, several studies showed that depression was not, or was only seldom, related to self-awareness of AD and these studies could not explain the high prevalence figures. To overcome the overlapping phenomenology of the two diseases, specific diagnostic criteria have been developed for depression in this context. Mixed findings have come from neuropathological and neuroimaging studies, with some evidence linking the underlying neural substrate of AD and depression, suggesting an overlapping cause of primary depression and depression comorbid with AD. Few randomized controlled trials for depression associated with AD have been conducted, with rather poor results for the use of antidepressants.


CONCLUSIONS
Currently, depression associated with AD is not considered a separate disorder by regulatory authorities and is unlikely to be considered as such in the near future. Several obstacles remain to support such a specific position, including the heterogenous nature of depression in general and within AD itself, the lack of a distinct set of symptoms, and limited treatment.
Even
Christian
C
Clinique des Maladies Mentales et de l'Encéphale, Centre Hospitalier Sainte-Anne - Université Paris-V René Descartes, INSERM U675, Centre de Psychiatrie et Neurosciences, Paris, France. c.even@ch-sainte-anne.fr
Weintraub
Daniel
D
D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000523:psychology*; D000928:Antidepressive Agents / Q000627:therapeutic use; D003866:Depressive Disorder / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy / Q000523:psychology; D018450:Disease Progression; D006801:Humans; D001523:Mental Disorders / Q000150:complications; D011569:Psychiatric Status Rating Scales
D000928:Antidepressive Agents