A pronounced state of indifference or lack of interest. Can have many possible causes, including brain trauma or disorders, certain medications, heavy drug use, or witnessing a horrific event.
Example: A prisoner condemned to death sits passively in his cell, ignoring his meal and several unopened letters.
Grinnell, R. (2008). Apathy. Psych Central. Retrieved on February 6, 2016, from http://psychcentral.com/encyclopedia/apathy/