Depression isn't always in your head

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My mother had been depressed for years despite taking antidepressants. She was unpleasant to be around, and I was making excuses not to see her. Then I took her to a new doctor. Because at times Mom felt tingling in her toes and fingertips, she was started on B12 injections. Her mood and energy level have improved tremendously. How could this have been overlooked?

Your story demonstrates an important principle that geriatricians use in the care of older adults: Before attributing symptoms to old age, senility, or depression, we doctors have to look for potentially treatable problems that may go undetected.

A deficiency of B12 is probably a major unrecognized problem in the elderly. It is notorious for causing a variety of changes in the way the nervous system functions-things that can make a person of any age feel just plain rotten. We aren't sure whether depression is a logical consequence of feeling so awful or if it's a result of actual nervous system changes. But either way, I've cared for patients with B12 deficiency where depression was the overwhelming symptom, and the depression clearly lifted once the vitamin deficiency was treated.

There are several causes of vitamin B12 insufficiency, but the most common cause is that as we age, our stomachs produce less of the acid that is needed to extract B12 from our food. In addition, a substance produced by the stomach that is needed to absorb B12 into the bloodstream may also be decreased in older adults.

Major Warning Signs
Here are the major warning signs of B12 deficiency:

Anemia low red blood cell count), which can contribute to low energy and tiredness because red blood cells carry oxygen to the organs.
Gastrointestinal problems, such as diarrhea or changes on the surface of the tongue or mouth (a classic indicator is a "beefy" red tongue).
Neurological problems, which can range from tingling or numbness in the extremities to weakness to severe memory loss and dementia-which can look like Alzheimer's disease if misdiagnosed.
These symptoms can occur together or alone. Textbook cases of most diseases, including B12 deficiency, are the exception and not the rule in the elderly; if doctors look only for "by the book" symptoms, they're likely to miss a lot of important diagnoses. For example, as in your mom's case, neurological symptoms without the anemia certainly do occur. That's why many physicians will include B12 testing to evaluate a variety of neurological and psychiatric problems (including depression), even if the symptoms don't fit neatly into a condition they learned about in medical school. When the level of B12 in the blood is "borderline" but the problem is still suspected, there are other blood tests that can help make a clear diagnosis.

While the B12 deficiency can be corrected in some patients through a B12-rich diet or nutritional supplements, often this won't do the trick. That's because the deficiency is frequently caused by the person's inability to absorb the nutrient in the intestines. So the vitamin needs a more direct route into the body-generally through monthly injections. Once treatment is started, the anemia and gastrointestinal symptoms of the disease usually improve quickly. Unfortunately, if untreated for too long, dementia and other nerve damage from B12 insufficiency may have a less impressive improvement with therapy. This is why it's critical to catch the problem as early as possible.

Your mom's improved mood may have been a result of the B12 therapy itself or her reaction to feeling better generally. Besides B12 deficiency, there are other medical conditions that can cause or contribute to depression (see "Nondrug Rx for the Blues," below).

Quick Tip
Once B12 treatment is started, symptoms can improve quickly. Early diagnosis is vital to reverse mental problems.

Nondrug Rx for the Blues
Without question, most cases of depression in older adults are best treated with antidepressants. But taking time to look for underlying problems can be worth the time and effort.

Depression is still a highly underrecognized and undertreated problem in the elderly and can be a response to an underlying medical condition, a medication, or some other psychosocial problem. Before an older person is prescribed antidepressants, I recommend that his or her physician rule out these problems with a thorough history and physical exam and, if indicated, lab tests (such as for B12 deficiency). When I evaluate such patients, I ask several things:

First, have all medical problems been diagnosed? For example, an underactive thyroid gland (the organ that controls body metabolism) can cause changes in mood; in such cases, the treatment is to give thyroid hormone, not antidepressants. Thyroid disease is just one example of many medical conditions that can influence mood.

Second, are they being properly treated? A patient with arthritis accompanied by severe pain is a prime candidate for depression; the pain should be aggressively controlled as part of a treatment plan for depression.

Third, are all meds working properly? When taken in certain combinations, some medicines can cause depression in older adults. I'm especially suspicious of medicines when the symptoms of depression coincide with the start of a new medication.

Finally, are there treatable nonmedical causes? Social isolation is a common problem for many older adults. I always ask whether an older person has lost a friend (from bereavement or a move) when depression sets in. I also check for changing sleep patterns or signs of alcohol problems, which can either be a symptom of depression or contribute to it.

The American Federation for Aging Research is a leading national nonprofit organization dedicated to supporting new investigators conducting cutting-edge biomedical and clinical research to promote healthier aging.

PHOTO (COLOR): B12 injections can help lift depression.

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By Mark S. Lachs, MD, MPH in association with the American Federation for Aging Research

with Pamela Boyer

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