It is called psychoneuroimmunological because it refers to the science of psychoneuroimmunology, which studies the interaction between mind, central nervous system, and the immune system. So for example, when you talk about the effect that a cytokine from the immune system has on the brain, and the mental symptoms (like say depression) that the cytokine may cause, then that is psychoneuroimmunology. VanElzakker is in fact talking about sickness behavior. Sickness behavior involves a lot of symptoms, including fatigue and sleepiness, depression, anxiety, concentration problems, and pain sensitivity. This comment is a little inappropriate, because VanElzakker is doing a sterling job. He is a psychologist who is searching for physical causes of the mental and cognitive symptoms of ME/CFS. It is great to see psychologists like VanElzakker who are also very knowledgeable about immune system and the nervous system, and who thus are able to examine how physical abnormalities in the body might lead to the mental and cognitive symptoms of ME/CFS. The ME/CFS community certainly had a legitimate complaint against Wessely School psychologists and psychiatrists, who trivialized ME/CFS by saying it was a psychogenic disease (ie, a disease having a psychological origin rather than a physical origin). But when it comes to psychologists like VanElzakker who believe that ME/CFS has a physical cause, and who is working to find this cause, then we should sing their praises. We need psychologists who also have expertise in the immune and nervous systems to study ME/CFS. VanElzakker's hypothesis that vagus nerve infection may cause ME/CFS is very interesting.