If you suffer from depression you've probably noticed that your memory isn't as sharp as it used to be. Now, new research conducted at the University of California at Los Angeles (UCLA) indicates that having these two conditions can increase a person's risk of developing Alzheimer's disease.

According to Aaron Nelson and Susan Gilbert, authors of The Harvard Medical School Guide to Achieving Optimal Memory, mood disorders such as depression can affect cognitive functions such as concentration, focus, and absorbing new information - which all impact memory. Furthermore, chronic or long-term depression may damage neurons in the brain that play a role in memory.

Memory, Mild Cognitive Impairment and Alzheimer's Disease

It's normal for memory to decline as we get older. However, according to the UCLA researchers, people who suffer from depression and have mild cognitive impairment or memory problems have a greater chance of developing Alzheimer's than people who aren't depressed.

As the researchers explain, mild cognitive impairment is the transitional stage between cognitive decline of normal aging and Alzheimer's disease. People who are in this transitional period tend to have more memory problems than those usually associated with normal aging, but they don't necessarily have other symptoms of Alzheimer's.

The Depression Connection

The UCLA team assessed 756 people between ages 55 and 91 who had mild cognitive impairment. Of those, 208 had depression, as indicated by a test that measured the severity and intensity of depressive symptoms. For every one-point increase on the test, a participant's risk of getting Alzheimer's increased by three percent.

"Our longer-term findings add to the body of evidence that suggests depression is a major risk factor for Alzheimer's disease," said Po H. Lu, an assistant professor of neurology and a member of the UCLA Mary S. Easton Center for Alzheimer's Disease Research.

However, the study also revealed that the drug donepezil, which is used to treat dementia, could delay the onset of Alzheimer's in people suffering from depression who had memory problems or mild cognitive impairment.

How to Protect Your Memory and Avoid Developing Alzheimer's

Several factors make you more likely to develop mild cognitive impairment, which can lead to Alzheimer's disease. They include:

  • Hypertension or high blood pressure
  • Diabetes
  • Stroke
  • Depression and anxiety
  • Cigarette smoking
  • Excessive alcohol consumption
  • Head injuries
  • Drug abuse (taking too many narcotic type drugs)

Fortunately, you can alter many of these risk factors, which isn't the case with genetic factors, such as carrying the APOE4 gene that plays a key role in early onset Alzheimer's disease:

  • Consult your doctor as soon as possible for help treating underlying disease such as depression, diabetes or hypertension, or for advice on smoking cessation plans.
  • Consider joining a 12-step program to cope with alcohol or drug abuse.
  • Wear protective head gear where necessary.
  • Some research suggests that increasing the intake of folic acid or vitamin B12 supplements can help to prevent Alzheimer's disease and preserve your memory. These two nutrients have also been recommended for treating depression.
  • Finally, studies show that regularly playing games--memory and card games, puzzles, and crosswords--can help to protect your memory. Try to squeeze in one or two games daily.

Source: UCLA press release "Depression may increase Alzheimer's risk in people with memory problems."

Mayo Clinic, The Harvard Medical School Guide to Achieving Optimal Memory by Aaron Nelson and Susan Gilbert (online), Journal of Psychopharmacology