April 2011

Document Type


Degree Name



Oregon Health & Science University


Illness is associated with a constellation of symptoms including weakness, malaise, anorexia, weight loss, and inability to concentrate. Motivation and arousal are suppressed, and patients report hypersensitivity to pain and a lack of interest in normally enjoyable activities. Remarkably, these features are present in a wide spectrum of diseases, regardless of etiology. Perhaps because these symptoms are so common, they have in the past been underestimated as being an uncomfortable side effect of the illness process. However, this response represents an evolved adaptive strategy with important survival implications. Known collectively as "sickness behavior", this coordinated set of physiologic changes represents a critical element of the host response to disease. By suppressing an animal's motivational drive, metabolically expensive activities are restricted, allowing energy to be diverted into fueling heat generation (fever) and immune system mobilization. When viewed in the context o




Neuroscience Graduate Program


School of Medicine



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.