This exploit allows the player to cheese boredom, stress, and sadness, removing the depth these functions add to the game.
If you run while smoking a cigarette as a smoker, you can interrupt the process while still getting stress and sadness reduction.
This can be abused over 5 times per cigarette. Imagine living off worms and never getting sad.
Below photos show, before and after, half of a cigarette eliminating severe depression.
The caveat is the lighter/matches will be the limiting factor since they are used after each interruption. Stress however becomes insanely easy to manage since it disappears after each occurance.
The "smoker" becomes a positive trait with free points and eliminates the value given by antidepressants.
I imagine a decent solution is to delay the positive mood buff until after the cigarette is finished. This should balance this exploit.