***Depression linked to Alzheimer's disease

People who have had depression are more likely to develop Alzheimer's disease than people who have never had depression, according to a study published in the April 8, 2008, issue of Neurology.

The study involved 486 people age 60 to 90 who had no dementia. Of those, 134 people had experienced at least one episode of depression that prompted them to seek medical advice.

The participants were followed for an average of six years. During that time 33 people developed Alzheimer's disease. People who had experienced depression were 2.5 times more likely to develop Alzheimer's disease than people who had never had depression. The risk was even higher for those whose depression occurred before the age of 60; they were nearly four times more likely to develop Alzheimer's than those with no depression.

"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 Monique M.B. Breteler, MD, PhD, with the Erasmus University Medical Centre in Rotterdam, the Netherlands. "We'll need to do more studies to understand the relationship between depression and dementia."

One theory was that depression leads to loss of cells in two areas of the brain, the hippocampus and the amygdala, which then contributes to Alzheimer's disease. But this study found no difference in the size of these two brain areas between people with depression and people who had never had depression.

The study also assessed whether the participants had symptoms of depression at the start of the study. But those with depressive symptoms at the start of the study were not more likely to develop Alzheimer's than those with no depression at the start of the study.

Studies have shown that depression is very common in Alzheimer's with some saying that up to 70% of sufferers may be depressed during their illness. If you would like to try to improve depression with the use of supplements it is worth noting that vitamins B1, B3, B6, B12 and biotin are naturally involved in the production of serotonin - the good mood hormone, or you could try 15 minutes of exercise three times a week as this can also do the trick!