A small study suggests that the apathy shown by many Alzheimer's patients may not simply be due to memory or language problems, but to a decreased ability to experience emotions. The seven patients were asked to rate pictures of positive and negative scenes (such as babies and spiders) by putting a mark closer or further to either a happy face or a sad face emoticon. Closeness to the face indicated the strength of the emotion felt. Although most of the time the Alzheimer’s patients placed their mark in the appropriate direction, they did make more inappropriate choices than the control group, and typically also gave less intense judgments.

Both comprehension problems and depression were ruled out. A lower emotional response may result from damage to brain areas that produce neurotransmitters, which typically occurs early in Alzheimer’s. It may be that medication to replace or increase these neurotransmitters would improve emotional experience.

This finding is a warning that apathy should not be automatically taken to mean that the patient is depressed. The researchers, enabled by the small size of the study, tested more thoroughly for depression than is usually the case in large studies. It may be that in these studies, this apathy has often been confounded with depression — which may explain the inconsistencies in the research into depression and Alzheimer’s (see the news item just previous to this).

The finding may also help caregivers understand that any emotional indifference is not ‘personal’.