Depression linked to increased Alzheimer’s risk

People who have had depression are more likely to develop Alzheimer’s disease, according to a new study.

Researchers at the Erasmus University Medical Centre in Rotterdam found that people who have experienced depression were 2.5 times more likely to develop the form of dementia than those who had never experienced it.

People who had depression before the age of 60 were nearly four times more likely to develop Alzheimer’s than those with no depression.

The findings are based on a study of 486 people aged 60 to 90 who had no dementia.

Of this group, 134 had experienced at least one episode of depression that prompted them to seek medical advice.

The researchers followed the participants for an average of six years, during which time 33 people developed Alzheimer’s disease.

“We don’t know yet whether depression contributes to the development of Alzheimer’s disease or whether another unknown factor causes both depression and dementia,” said study author Dr Monique Breteler.

A second study published today in the Archives of General Psychiatry reinforced the Dutch researchers’ findings.

Scientists at the Rush University Medical Centre, Chicago, found that although individuals with depression may be more likely to develop Alzheimer’s disease, symptoms of depression do not appear to increase in the years before a diagnosis is made.

The researchers suggest that depression is not a consequence of developing Alzheimer’s disease but may instead be a risk factor for dementia.