"To test the drug’s rewarding effects, an important component of their addictive potential, the team studied its effects in rats who had been trained to press a lever for a dose of the pain-relieving drug. They found that animals readily self-administered DFNZ, indicating that it does produce some rewarding effect. However, when the drug was replaced with saline, animals stopped the drug-seeking behavior. The immediate behavior change is in contrast with what researchers see with other opioids such as heroin, morphine, and fentanyl. In those cases, animals typically persist in seeking the drug even after it is removed."
They seem to be suggesting it merely triggers pseudo-addiction
www.nih.gov
