Overview of the problem
It may seem obvious that depression and dementia are different disorders, but in the elderly distinguishing between these two conditions can be quite difficult and physicians often get it wrong. The mistake is more likely to be made in the direction of diagnosing the depressed older person as having dementia rather than the other way around. In a recent research study physicians were asked to make a diagnosis based on case descriptions; the cases were all exactly alike except for age. The physicians were more likely to diagnose the older people with dementia and the younger people with depression.
Why do errors occur?
One reason for this common error is a lack of training. In my previous article for CareConnection.com, “Never Trust Anyone Over Thirty—Ageism in the Health Care System,” I reported that “only 10 percent of medical schools in the United States require courses in geriatrics…” Physicians have a general lack of knowledge about the normal aging process and this lack of knowledge can cause doctors to erroneously believe that growing old means becoming automatically demented.
Another reason for this frequent misdiagnosis is that it simply is not easy to distinguish between depression and dementia. They both have much in common. It takes careful observation and the kind of time that probably only a caregiver spends with an elderly person in order to properly distinguish between the two.
What are the differences?
For a person to be diagnosed with dementia there must be multiple cognitive deficits and one of these deficits must be an impairment in memory. The depressed person, however, may also exhibit cognitive deficits including memory problem, but the normal cognitive changes that occur with aging are not the same as those that come with dementia or depression. It is not unusual for an older person to temporarily forget the name of acquaintances or places. These incidents are what we often refer to as “Senior Moments.” However, it is not usual for older adults to forget the names of members of their own family or where they live.
