Apathy and Depression Predict Progression from Mild Cognitive Impairment to Dementia

One line of research being carried out examines the progression from normalcy to mild cognitive impairment, and from mild cognitive impairment to dementia. (People who have mild cognitive impairment can function reasonably well in everyday activities, but have trouble remembering details or solving difficult problems.) Prior research has suggested that depression, apathy, and agitation might predict progression from mild cognitive impairment to dementia. Now, a team from the Mayo Clinic has studied a large population to test how well depression and apathy predict progression to dementia.

The team studied a group of 358 people with mild cognitive impairment and used a questionnaire to judge the presence of depression and apathy. Apathy was defined as a loss of motivation without associated feelings of being depressed or blue, whereas depression caused changes in mood, thinking, physical well-being, and behavior. They then followed the people (for a median of 2.8 years) to see who developed dementia, including Lewy body disease and Alzheimer's disease.

• Of 87 people with depression, 30 developed dementia (34.5%). Of the 271 people without depression, 59 developed dementia (21.8%).

  After adjusting for age, gender and education, those with mild cognitive impairment and depression had a 66% increased risk of developing dementia than those with mild cognitive impairment without depression.

• Of 60 people with apathy, 22 developed dementia (36.7%). Of the 298 people without apathy, 67 developed dementia (22.5%).

  After adjustments, those with mild cognitive impairment and apathy had a 99% increased risk of developing dementia than those with mild cognitive impairment without apathy.

The researchers now plan to study whether treating depression or apathy can delay the onset of dementia.

This research was reported at the International Conference on Alzheimer's Disease in Honolulu on July 11, 2010. The Mayo Clinic press release is available.