I've got a question regarding the behaviour of nicotine dependence in the brain.
Suppose a heavy user of nicotine stops consuming it entirely. The first 72 hours are typically the hardest, with consistent cravings, and various withdrawal symptoms. As time continues to pass, these symptoms will typically go away, and cravings will become less common.
After let's say one week, the user consumes a small amount of nicotine (perhaps one cigarette, chews some nicotine gum, or borrows a friend's vape). Will all of their progress of eliminating the brain's dependence on nicotine be lost? Or will this be just a small setback on the overall trend downwards?
For the context of this question, I am only interested in the physical neurochemical effect of resuming nicotine use, rather than any effects on a phycological level. Previous research on this topic has generally resulted in answers focusing on the psychology, and how resuming nicotine use can jeopardize quitting due to the continuation of it as a habit. Thanks!