Published research from Dr. Mark West’s lab has shown that chronic fentanyl self-administration generates a shift toward negative affect in rats during drug use, emphasizing that escape/avoidance of negative affect is a salient motivational factor reinforcing opioid addiction and supporting negative reinforcement as a driving factor for drug addiction. Read the article and learn more about how chronic fentanyl use generates negative affect in rats here: https://www.mdpi.com/2076-3425/11/8/1064
