For many medical professionals, it is not uncommon to find late-life depression more difficult to treat. Now, scientists have found an important clue in the effort to understand why and how to keep patients well over time.
A recent Science Daily release examines a study led by Toronto’s Baycrest in which it w was found that older adults with depression don’t respond normally to emotional stimuli, including when they see happy, sad or neutral faces.
"In our study we found significant differences between older depressed subjects and older healthy subjects in how they emotionally respond to and perceive facial expressions," said principal investigator Dr. Linda Mah, a clinician-scientist in the Mood Clinic at Baycrest, in the Science Daily.
The majority of studies examining late-life depression have focused on the link with cognitive decline, suggesting that the more impaired the cognitive functions the greater the changes of a poor diagnosis in depression.
"Our data suggest that we need to also focus on emotion to better understand the neurobiology of late-life depression, so we can treat it more effectively and help people feel better longer," said Dr. Mah.
The study focused on 11 un-medicated outpatients with major depressive disorders and 11 healthy comparison subjects. All subjects were between the age of 60 to 87. Both groups participated in two tasks that involved looking at photographs of faces with happy, sad, fearful or neutral expressions.
Study results reveal that healthy controls were 16 percent slower in making judgments about physical features of the faces with positive or negative emotional expressions relative to neutral faces.
Depressed participants showed no differences in response time to rating physical aspects of faces with emotional expressions or neutral faces. This suggests they were less sensitive to the effects of positive or negative emotional expressions.