LateLife Depression Antidepressant Use and Decreased Brain Size Linked

The Journal of Alzheimer's Disease recently published a study that measured brain volume of older adults without dementia who had symptoms of depression and/or were taking an antidepressant medication. What they were trying to determine was if depression and/or the use of antidepressant medications affected brain size.

This is important because previous research has shown that brain volume in people with Alzheimer's disease is smaller than in those without dementia. Additionally, depression has been identified as a risk factor for Alzheimer's.

In this latest study, researchers analyzed 630 older adults whose average age was 80 and whose cognitive functioning was intact. They used MRI scanning to measure amounts of total brain volume; left, right and total hippocampal volume (size of the hippocampus); and amount of white matter volume/lesions. (Lesions in the brain are areas of damaged or dead cells.)

Here are the study's results:

• Increased symptoms of depression (as measured by the Center for Epidemiologic Studies-Depression scale) were not correlated with smaller brain size.

• However, antidepressant use was correlated with a decrease in total brain volume and hippocampus size, and with an increase in the amount of white matter (lesions) in the brain.

The study's authors offered a few ideas about why this may be the case, including the possibility that antidepressants are prescribed for symptoms other than depression, and that those receiving antidepressants were likely to have more severe depression.

The researchers concluded that depression, and perhaps specifically antidepressant use, in older adults is correlated with brain shrinkage and white matter lesions.

My 2 cents: It's been generally accepted that antidepressants are fairly safe for older adults (although all medications have the potential for some level of risk), have less side effects than other psychoactive medications, and can provide significant benefits for people who are challenged by depression. This study's results demonstrate the need for further research on antidepressant use in older adults.

So, should you run out to your doctor to discontinue your antidepressant medication? Not necessarily. Keep in mind that some antidepressants have to be decreased gradually or you can have serious withdrawal symptoms. Also, the benefit you receive from your medication may be very important for your well-being. If you're concerned, you should consider talking with your doctor about the ongoing risk and benefit of your antidepressant medication.