To the Editor: Self-reports of behaviors are strongly influenced by the specific wording, format, and context of a researcher's questions (1). For this reason, the accuracy of the findings in the study reported by Green-Hennessy and Hennessy (2) in the February 1999 issue may be compromised by a discrepancy between the reference period associated with a question about major depression and the reference period for a question about medication use.
Using data from the National Health Interview Survey, the authors identified 1,189 persons who responded positively when asked if they had experienced an episode of major depression within the past 12 months. A related question asked if the subjects had taken prescription medication "for any ongoing mental or emotional condition" (emphasis added).
Given that the average duration of a depressive episode is less than 12 months, it is likely that many of the individuals who responded positively to the question about experiencing an episode of major depression were not suffering from an ongoing condition. They may have taken medication for the duration of their depressive episode and yet could have truthfully answered no to a question about use of medication for an ongoing condition. Based on the wording of the questions, it is possible that the reported data are most accurate for a subset of individuals who suffered from chronic rather than episodic depression.
Dr. Schacht is professor in the department of psychiatry and behavioral sciences in the James H. Quillen College of Medicine at East Tennessee State University in Johnson City.