To the Editor.—
The June 16 issue of JAMA presented a report from the Multicenter AIDS Cohort Study entitled "No Evidence for a Role of Alcohol or Other Psychoactive Drugs in Accelerating Immunodeficiency in HIV-1—Positive Individuals."1 In this study, results obtained from a questionnaire about, for the most part, illicit drug use were compared with laboratory test results of human immunodeficiency virus type 1 antibody testing and peripheral blood lymphocyte phenotyping. Apparently, there was no attempt to measure urine or plasma drug levels.Drug verification is common practice in most medical fields, eg, psychiatry, internal medicine, pediatrics, and emergency medicine, and in many employment environments and sporting endeavors. Although history taking is a valuable tool, no conclusion of this nature can be drawn without acceptable verification.