"anhedonia"
[an-hee-doh-nee-uh]
the inability to feel pleasure.
interesting, huh?
i found this word in a scientific journal article.
...it was used to describe rats going through withdrawal from amphetamine.
{if you're interested, here's the reference to the article:}
Barr, A. M., & Phillips, A. G. (1999). Withdrawal following repeated exposure to d-amphetamine decreases responding for a sucrose solution as measured by a progressive ratio schedule of reinforcement. Psychopharmacology (Berlin), 141, 99–106. doi:10.1007/s002130050812
peace out.