HOLLYWOOD, FLA. – Common psychiatric disorders such as depression and dementia can be hard to distinguish in elderly patients, but there are some simple techniques that physicians can use to draw out the differences, Dr. Kevin Gray said at the annual symposium of the American Medical Director's Association.
“Dementia and depression can occur together or separately,” said Dr. Gray of the department of neurology at the University of Texas Southwestern Medical Center at Dallas.
One of the reasons that there is so much confusion about what is dementia and what is depression is that the symptoms can overlap to some degree, he said.
In a typical case, a family member will describe a patient's passivity, weight changes, sleep disturbances, sweet tooth, restlessness, declines in cognition, or lack of interest in favorite activities. All of these symptoms could be depression, he said.
The key elements in distinguishing between depression and dementia in that type of patient include the presence of true suicidality or feelings of worthlessness and guilt. These symptoms are characteristic of depressive syndrome but are rare in dementias such as Alzheimer's disease, he said.
When eliciting depression symptoms, Dr. Gray suggested using the mnemonic device SIG-E-CAPS, which represents the diagnostic elements of major depressive disorder: sleep, interest, guilt, energy, concentration, appetite, psychomotor activity, and suicidal ideation. Also look for changes in self-attitude, including helplessness, hopelessness, and worthlessness, he said.
It can be misleading to focus too much on some of the somatic issues related to depression, such as sleep problems and appetite, because these can be affected by so many of the conditions common in older adults, such as chronic pain, he said.
“The key is to tap into changes in self-attitude,” Dr. Gray said.
There are a variety of scales available and he uses the five-item version of the Short Geriatric Depression Scale since it can be performed quickly.
When depression is nonresponsive to treatment, confirm or refine your diagnosis, Dr. Gray advised. You could be dealing with patients with an underlying delirium or dementia, early parkinsonism, involuntary emotional expression disorder, or apathy syndromes. Performing a mental status exam in these patients is critical, he said.
Physicians also may run into difficulties distinguishing the symptoms of Alzheimer's disease from other types of dementia. Alzheimer's disease is characterized by an inability to learn new information that is in many ways unique, Dr. Gray said.
Physicians can demonstrate that a patient is “losing information” without having to have a PET scanner in the office, Dr. Gray said.
Instead, try a three-word cued recall test with patients. Ask the patient to try to remember three words, such as Oldsmobile, carrot, and piano. Wait a few minutes and ask the patient to try to recall the words. If they can't recall the words spontaneously, give them clues or choices to prompt them.
Impaired recall by itself enough isn't enough to indicate Alzheimer's disease, Dr. Gray said.
Many individuals without dementia of any kind can be forgetful.
However, the cued recall test, which includes providing hints to the patient, can help demonstrate whether the new information is available to be recalled.
Beware of making a diagnosis of Alzheimer's disease if memory loss is not a major feature, the recognition memory is intact, and there are early personality changes, Dr. Gray said.
Other dementias are generally characterized by executive impairment, mood and motor symptoms, and other impairments such as slow processing.