Why You Shouldn't Quit Anything Cold Turkey
Anything addictive, that is.
Things we know. We know quitting some things is healthy. We know that your last impression of something has a stronger impact on how you feel about it than the rest of your impressions.
One can imagine desire, or addiction, as a process with a balloon. The balloon inflates at a certain pace, a pace based on how strong the desire returns. Unfulfilled, a balloon will slowly shrivel.
The reason you don't want to quit cold turkey is you don't want a large shrivelled balloon, you want a small one.
Slowly, and programmatically, scaling back your intake of the addictive substance, reduces the size the balloon will get. You will also create more negative impressions of the "last" (or most recent) variety, as one would constantly being extending the time between fixes.
A possible plus is one can find that usage at the newer, lower levels reduces the health risk, and, in all likelihood, any other associated risks.
Given the example of cigarettes, one can easily imagine a stopwatch which provides cues to when a quitting/scaling-back smoker can have their next cigarrette. The stopwatch-computer could be "trained" to learn the smoker's habits over a month (the user will get used to hitting a button each time a cigarrette is smoked in this period), and also show "time since last cigarrette."