July 20, 2004 — Why is it that so many people with depression are never identified as having the condition, while about half of those who are diagnosed fail to improve with medications proven to be effective? New research shows the explanations may be in their initial symptoms.

Depression is a mood disorder diagnosed by tell-tale symptoms such as fatigue, lethargy, or poor sleep. But depression may manifest itself in physical aches and pains that offer no obvious cause, such as unexplained chest pain, muscle ache, trembling, or hot flashes.

“If you have stomach pain and there’s an ulcer, that’s an explanation for it. But often, physical ills occur for no apparent reason — and depression could be a likely cause,” says study researcher Robert D. Keeley, MD, of the University of Colorado Health Sciences Center. “Yet unless they are specifically screened for depression, it’s hard for some doctors to pick up that it may be depression, especially in the primary care setting.”

After studying 200 patients eventually diagnosed with depression, he reports in the Journal of General Internal Medicine that doctors often failed to make the initial diagnosis, instead misattributing their ill-defined physical symptoms to explanations other than depression. Therefore, no treatment was recommended for those who need it.

Drugs Not for Everyone

But even when a depression diagnosis was made, Keeley finds that patients with these physical symptoms were more likely to resist the use of the most-often prescribed therapy — antidepressant medication — because they didn’t think they were depressed.

In fact, he reports that those diagnosed with depression based on psychological symptoms were four times more likely to continue taking prescribed antidepressants for six months than those given the drugs based on physical maladies.

This may explain what experts have long known — that many depressed patients stop taking their medication, often within weeks of starting it. It also confirms a study last year, published in the American Journal of Managed Care, that the vast majority of depressed patients are unhappy with their treatment.

In that study, researchers found that nearly eight in 10 depressed patients are given antidepressant prescriptions and almost all had them filled. But within three months, many stopped taking the drugs. Many experts say that at least six to nine months of treatment — sometimes longer — is needed to best prevent a depression recurrence.

“Since the 1990s, evidence suggests that patients with depression do better when the treatment is matched to their preference,” Keeley tells WebMD. “For instance, patients who have physical symptoms with no explanation appear to prefer a counseling approach as opposed to getting antidepressants.”

Physical Ills Common

Meanwhile, in the June issue of the British Journal of Psychiatry, Dutch researchers report that at least one in six depressed patients seen by general practitioners inthe Netherlands have no diagnosable general medical condition that account for their physical symptoms.

The take-home message of Keeley’s study: “Even if your doctor doesn’t mention it to you, you should consider the possibility that unexplained physical problems may indicate depression,” he tells WebMD.

“And as the number of these symptoms with a lack of explanation increase, so does the odds that you have depression. If you’re having four or five symptoms that can’t attribute to a likely cause, such as back pain and you didn’t strain your back, the odds are pretty good that you have depression. You really should mention this possibility to your doctor, even if your doctor doesn’t mention it to you.”

And while antidepressants are the usual recommended course of treatment, there are other options — namely counseling.

Patients with psychological symptoms often do very well with medication. “But those with unexplained physical symptoms whose treatment is based around antidepressants don’t seem to benefit as well from the drugs.”