Fatigue, brain, behavior, and immunity: summary of the 2012 Named Series on fatigue.

The focus on fatigue for the 2012 Named Series in brain, behavior, and immunity reflects the growing wave of research examining immune underpinnings of fatigue in healthy and clinical populations. Fatigue is prevalent in the general population and in patients with a variety of medical conditions. However, the etiology of fatigue remains elusive. Psychoneuroimmunological approaches to fatigue have yielded important advances in our understanding of this complex symptom and are represented in the twelve articles included in the Named Series. These articles include animal and human models of fatigue and cross a variety of different medical conditions, including cancer, chronic fatigue syndrome, and diabetes. This review briefly summarizes the articles included in the series and highlights the themes that have emerged from this body of work.