Evaluating the Centers for Disease Control’s Empirical Chronic Fatigue Syndrome Case Definition

Abstract

The Centers for Disease Control and Prevention (CDC) recently developed an empirical case definition that specifies criteria and instruments to diagnose chronic fatigue syndrome (CFS) in order to bring more methodological rigor to the current CFS case definition. The present study investigated this new definition with 27 participants with a diagnosis of CFS and 37 participants with a diagnosis of a Major Depressive Disorder. Participants completed questionnaires measuring disability, fatigue, and symptoms. Findings indicated that 38% of those with a diagnosis of a Major Depressive Disorder were misclassified as having CFS using the new CDC definition. Given the CDC’s stature and respect in the scientific world, this new definition might be widely used by investigators and clinicians. This might result in the erroneous inclusion of people with primary psychiatric conditions in CFS samples, with detrimental consequences for the interpretation of epidemiologic, etiologic, and treatment efficacy findings for people with CFS.