Study indicates majority of physicians are not following DSM-IV guidelines for major depressive disorder

• Patients might not be accurately diagnosed
• Patients who do not have major depressive disorder may be prescribed medications that will not work
• Calls for a briefer definition of the DSM-IV criteria for MDD

A new study led by Mark Zimmerman, MD, of Rhode Island Hospital indicates that a majority of non-psychiatrist physicians and a substantial minority of psychiatrists reported that they often do not use the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) when diagnosing major depressive disorder (MDD) in patients. The study appears online ahead of print in the Journal of Clinical Psychiatry.

The criteria for MDD in DSM-IV have remained relatively unchanged for nearly 30 years. In a previous study, Zimmerman and colleagues questioned the clinical utility of the criteria. This study looks at the habits of physicians in using the criteria. The researchers asked physicians attending a continuing medical education conference to complete a brief questionnaire. A total of 291 physicians responded to the six questions, with one question asking about the use of the diagnostic criteria for depression.

The question read: "When diagnosing depression, how often do you determine whether the patients meet the DSM-IV diagnostic criteria for major depressive disorder?" A multiple choice response offered the following answers: a) less than 25% of the time; b) 26-50% of the time; c) 51-75% of the time and d) more than 75% of the time.

Nearly 25 percent of the psychiatrists indicated that they used the DSM-IV MDD criteria to diagnose depression less than half of the time. In contrast, more than two-thirds of the non-psychiatrist physicians indicated that they used the DSM-IV MDD criteria less than half of the time when diagnosing MDD. The difference between the psychiatrists' and the non-psychiatrists use of the criteria was significant.

Zimmerman, director of outpatient psychiatry at Rhode Island Hospital, says, "Our results suggest that a minority of psychiatrists and majority of non-psychiatrist physicians do not use the DSM-IV MDD criteria the majority of the time. These findings are disconcerting. While the symptom criteria for diagnosing MDD have not been changed much over the last 30 years, psychiatrists, especially older psychiatrists, apparently have not uniformly embraced their use and non-psychiatrist physicians seem to have rejected the formal application of the criteria."

Zimmerman, who is also an associate professor of psychiatry and human behavior at The Warren Alpert Medical School of Brown University, theorizes that doctors are not using the DSM-IV MDD criteria because of the length of the criteria, and some may not be able to recall all of the criteria. He says that if incomplete recall of the criteria is the reason it is not being used to diagnose MDD, then a shortened definition of MDD may help to facilitate appropriate application of the criteria across all practitioners.

The researchers suggest that if physicians are not determining whether the criteria for MDD are met, then it is possible that many patients who are diagnosed as depressed do not have major depression. This is of critical importance because there is little evidence that antidepressants are effective for patients who do not have major depression; thus, some patients may be prescribed medications unnecessarily.

Zimmerman found that the older psychiatrists reported that they were less likely to use the DSM-IV diagnostic criteria than younger psychiatrists. He offers the following as a possible explanation. "Perhaps older psychiatrists who were training in the pre-DSM-III era never bought into the importance of using operational criteria to make a diagnosis."

The researchers note that the study has limitations in that the reasons for not following DSM-IV guidelines were not asked, and interpretation of the question about the use of diagnostic criteria for MDD may not be consistent for all respondents. The results of the present study should be interpreted with caution because they did not conduct a random survey of psychiatrists and non-psychiatrist physicians practicing in the country and the physicians who did respond may not be representative of all physicians.