Researchers from the Department of Veterans Affairs (VA) have determined that clinical depression can be effectively diagnosed through doctor-patient interviews. Published in the March 6 issue of the Journal of the American Medical Association, the study reveals that only the observational skills of a physician asking the right questions can assure a reliable diagnosis of depression.

Reviewing previous studies of clinical depression VA investigators examined depression questionnaires, interview techniques and the pitfalls of diagnosing depression, such as physical conditions that mimic depression and evasive patients.

Depressive disorders cause great personal suffering and can shorten lives. The World Health Organization estimates that major depression alone was the fourth leading cause of disability worldwide in 1990, and will soon be second only to heart disease as a cause of disability.

According to author John Williams, M.D., of the San Antonio and Durham VA Medical Centers, over the past decade awareness of these staggering figures has prompted increased emphasis on depression among primary care physicians.

"They are more attuned to depression and they have more tools to treat it when they find it," said Williams. "But finding it is a key first step."

No blood test or X-ray can determine whether someone is suffering from clinical depression. A trained interviewer must provide a diagnosis based on a patient's response to a series of questions. There are two recommended approaches to recognizing and diagnosing depression. Both methods rely upon clinical interviews to make a diagnosis. One approach, called case-finding, administers a depression questionnaire to every patient during a routine office visit. The other evaluates patients only when depression is suspected.

"A high percentage of patients with depression who visit the doctor don't mention a depressed state or attribute their ailments to feelings of depression. Somewhere between a third to half of all patients with major depression go undetected," said Williams.

According to researchers, the right questions produce a highly reliable diagnosis. The initial questions range from broad inquiries such as "How are things at home?" to more mood-specific questions such as "Have you been feeling sad or blue?" If the patient indicates a depressed mood, focused questioning follows to determine the risk of clinical depression. Suicide risk is also an important factor to be probed at this point, although questioning is complex, requiring a more direct approach since patients rarely volunteer such thoughts or intentions.

Sometimes physical disorders can masquerade as depression or complicate effective treatment. Conditions such as hypothyroidism require treatment of the underlying cause rather than the condition itself. Medications such as steroids or a patient's substance abuse withdrawal can also produce symptoms of depression that are not indicative of true clinical depression. Once again, the right questions, here in concert with a physical examination, are likely to produce a reliable diagnosis.

According to Dr. Williams, some patients also have a tendency to play down their symptoms. This appears to be more prevalent among men, particularly when men are talking to a male doctor. Again, effective communication, asking the right questions and effectively interpreting potentially vague answers can be vital for an accurate diagnosis.

"Among the general public there is still a stigma attached to being treated for depression. But there has been some progress. As public acknowledgement of treatment grows, so too does the public's willingness to accept the possibility that they might be suffering from clinical depression," Williams said.

This project was funded by the Department of Veterans Affairs with additional funding from the Agency for Healthcare Research and Quality. Research is an intrinsic part of the VA mission that benefits veterans and non-veterans.