Shifter's Disease was coined by the members of Shifters.org circa 2001. Individuals who are researching Therianthropy may begin to trick themselves into thinking that normal feelings and sensations that can be explained rationally, are actually therianthropic shifts or evidence of Therianthropy. This in turn, leads them to falsely identify as a Therian for a short period of time. 
"...occurs when a person starts reading some therianthropic meaning into mundane, everyday occurances." 
This is similar to Medical Student's Disease (MSD) in which medical students perceive themselves to be experiencing the symptoms of a disease that they are studying.
- Pinky "Shifter's Disease" https://web.archive.org/web/20010203200900/http://www.shifters.org/newbies/disease.shtml
- Polar "What is Shifter's Disease" https://web.archive.org/web/20010702102741/http://www.shifters.org/newbies/polar1.shtml