[Depression: A predictor of dementia].

Many studies suggest that in 10-25% of cases of Alzheimer's, the most common dementia in our society, can be prevented with the elimination of some risk factors. Barnes and Yaffe found that one-third of Alzheimer's cases are attributable to depression, but in the scientific literature it is not clear if it has a real causal effect on the development of dementia. The purpose of this study is to analyse the scientific evidence on the hypothesis that depression increases the risk of developing dementia. A systematic review and a meta-analysis were performed on the scientific literature published up until the present day, searching articles that were published between 1990 and 2014. Ten of the studies found met the selection criteria -similar to a) size and characteristics of the sample (origin, age…), b) process of gathering data c) method of studying the relationship (within and/or between group comparison), and d) statistical analysis of the results- and the previously established quality. The value of odds ratio varied from 1.72 to 3.59, and the hazard ratio from 1,72 to 5.44. This indicates that the subjects with a history of depression have a higher risk of developing dementia than others who did not suffer depression.