Published online by Cambridge University Press: 24 June 2014
The aim of this study was to evaluate whether risk factors for depression in the general population are also markers for depression in Alzheimer's disease (AD) and to identify additional disease-specific markers for depression in AD.
A logistic model of five risk factors for depression in the general population was constructed using the data of 217 patients with AD, of whom 63 (29%) suffered from major depressive disorder. In a next step, five potential disease-specific markers were individually added to this model to see whether the strength and predictive power of the model would improve.
The multivariate model of five risk factors for depression in the general population was not a good model to predict depression in AD. In this multivariate approach, only ‘a history of depression’ was an independent marker for depression. The only disease-specific variable that improved the logistic model was ‘disability due to AD’. An interaction between these two markers became apparent.
Of the established risk factors for depression in the general population, only ‘a history of depression’ was found to be an independent marker for depression in AD. ‘Disability due to AD’ was the only disease-related marker for depression in AD, although this marker cannot be considered specific for AD. The importance of controlling for general risk factors for depression in the search for disease-specific markers for depression in AD is stressed.