The risk of a person developing dementia has been shown to significantly increase if two known causative factors are combined.
Researchers at the University of Washington and Kaiser Permanente examined more than 20,000 patient histories. They observed that those who had both type 2 diabetes and depression were shown to have their chance of developing dementia within five years of initial screening double, when compared to those diabetes patients who were not depressed.
Depression was seen in 20 per cent of diabetes sufferers and senior author of the study Rachel Whitmer said this study builds on previous scientific work which has analysed the causes of dementia.
Doctors hope the work can lead to new methods of diagnosing dementia earlier being developed, which could help improve the quality of life of many sufferers.
According to Age UK, there are an estimated 820,000 people in the UK who suffer from dementia, and while the disease mainly affects those over the age of 65 it can affect younger people as well.