Depression and Silent Stroke

Dateline: 10/07/99

Researchers have discovered a link between silent strokes and depression. Persons over the age of 50 who develop depression are more likely to have had a silent stroke. Silent stroke occurs when blood vessels in the brain burst or become blocked.

Silent strokes are so named because they do not have the traditional warning signs associated with strokes: loss of balance, dizziness, and headaches. Due to the lack of warning signs, people who have silent strokes are often not aware that they have had one. The problem usually compounds over time until severe consequences such as memory loss occur.

In the study, researchers found that depression could indicate the presence of blockages in the brain. The silent strokes were diagnosed by examining lesions in the basal ganglia (subcortical gray matter) in the brain. The number of small lesions in the brain was positively associated with depression. The lesions may represent a breakdown of sorts. The basal ganglia may have trouble communicating with the cortex.

There were approximately 3,600 participants in the study. The researchers divided the participants into four distinct groups based on a continuum of how they scored on a depression questionnaire. They found that those with the lesions had approximately a forty percent increased risk of being depressed when compared to those without the lesions.

Age was also a factor in that depression is often not diagnosed accurately in older individuals. The symptoms of depression in older individuals vary from those observed in younger individuals. Apathy and a lack of participation in social activities may mark depression in older individuals. On the other hand, sadness and dismay most often mark depression in younger individuals.

Future research will focus on whether or not those who develop silent strokes are more prone to larger strokes and vascular episodes.

The researchers are optimistic that with the proper testing in place, many of those who have silent strokes could be treated more effectively.

What do you think? Should all persons over the age of fifty with depression be tested for brain abnormalities? Come on over to the Biology Forum to share your thoughts, feelings, and opinions.

For additional information see:

• Silent Stroke Linked to Depression
  The original news release about the study.