News

Emotional Flatness Can Be Mistaken for Depression in Patients With Alzheimer’s

Patients with Alzheimer’s can appear withdrawn and apathetic, symptoms often attributed to memory problems or difficulty finding the words to communicate. A new University of Florida study found that they may also have a decreased ability to experience emotions; that is, they do not feel emotions as deeply as their healthy peers. This finding in a small group of patients may be useful for doctors assessing whether Alzheimer’s patients are clinically depressed.
 
The study, published online in the Journal of Neuropsychiatry & Clinical Neurosciences, suggests that when Alzheimer’s patients are asked to place an emotional value on pictures, they measure the pleasant images as less pleasant and the negative scenes as less negative compared with a control group of normal elders. This emotional flatness could be incorrectly interpreted as a symptom of depression.
 
“We found that the Alzheimer’s patients as a rule tend to go more toward the middle,” says Kenneth Heilman, MD, senior author of the paper and a neurology professor at the College of Medicine and University of Florida’s McKnight Brain Institute.
 
Further research is needed, but the findings could be valuable for clinicians trying to learn whether a patient is depressed as well as for families concerned about a loved one’s apparent indifference.
 
The study presented seven patients with Alzheimer’s disease pictures of positive and negative scenes, such as babies and spiders, and asked them to rate each picture. Patients recorded their emotional reaction to the picture by marking on a piece of paper with a happy face on one and a sad face on the other. The closer their mark was to either emoticon, the stronger they felt.
 
Most of the time they placed their mark in the appropriate direction, says Heilman. “For a puppy, they wouldn’t rate it as high (as the control group members did), but they would put it more toward the happy face, showing that they appear to understand the picture,” he says. “But they also made more inconsistent markings than the normal control group, such as when being shown a spider putting their mark toward the happy face.”
 
The study’s authors proposed several reasons for why patients with Alzheimer’s show a flattened affect.
 
Previous studies reveal that such symptoms of Alzheimer’s are caused by deterioration of neural systems, Heilman says. “Even in its early stages, Alzheimer’s destroys the areas of the brain that produce chemical neurotransmitters such as norepinephrine, which is essential for experiencing fear and anger,” he adds. “If we prescribed medication to patients that replace or increase these neurotransmitters, maybe they would better experience emotions.”
 
Misinterpreting the images or not understanding the meaning of some pictures—a comprehension disorder—could have skewed the results, but the volunteers were given a naming test to minimize this possibility. Though Alzheimer’s patients often suffer from depression, researchers ruled it out as a cause for lower emotional response based on yearly face-to-face evaluations conducted throughout the study.
 
— Source: University of Florida Health Science Center