Basically, it goes like this.
Nicotine increases dopamine.
And MAOI's prevent dopamine from being re-absorbed at its normal rate.
So, put the two together and you get a CRAPLOAD of dopamine floating around your brain. Remove one or the other, and you still have more dopamine than your average Joe, but not as much as you did when you put the two together.
A lot of people have a hard time dealing with the drop in dopamine that happens when you remove MAOI's from the equation, and normal re-absorption resumes. The nicotine is still giving you extra dopamine - but it's definitely an over-all decrease.
And still other people have a strong habitual addiction. The habitual aspect of cigarettes, for people whose personalities are built this way, can be as compulsive as hair-pulling, nail biting, or skin picking.
As far as how this may affect you, no way to tell.
Personally, like most people here, I had tried everything short of Chantix (which scares the hell out of me) to quit, and every attempt was a miserable failure.
But I didn't experience any serious withdrawal when switching to e-cigs. I did have cravings, but they were incredibly mild compared to what I had with every other quitting method.
For me, the combination of getting nicotine and sating my habitual addiction was more than adequate for me to let the MAOI's in cigarettes go. I
vape 18mg to 12mg,
Other people struggle more with it. Some take several weeks, or even months, to taper completely off cigarettes. Some find they need to use a very high nic strength to make up for lost MAOI's. Some use Swedish snus with e-cigs to get the MAOI's without cigarettes.
So, everyone's different. Some people are more addicted to nicotine than MAOI's, some are more addicted to MAOI's than nicotine, and some are very addicted to both. And some are addicted to the habitual/compulsive habit of smoking.
For me, I am more addicted to nicotine than MAOI's, and I am also very addicted to the compulsive habit of smoking.
YMMV.