It could be the interaction between the MAOIs and the nicotine. Or more accurately, the MAOIs altering how your body handles nicotine.

There are sibling comments discussing MAOIs, and I've heard about them before in relation to smoking. It makes me wonder if MAOIs alone would be better for smoking cessation. I don't think I'm all that addicted to the nicotine itself. There are plenty of other supposedly-addictive stimulants that I can take or leave at will and with no feelings of withdrawal, and nicotine does nothing to alleviate cigarette withdrawal for me, so I'm not sure it's even a necessary component. There are some NIH studies about MAOIs and smoking, but I'm not going to link them because I find them incomprehensibly dense.

I don’t remember what family of antidepressant Bupropion (Wellbutrin/Zyban) is, but it helped me immensely the first time I quit. I literally just woke up one day (a few days before my target quit date) and had no craving at all.

It also made me a little bit manic, and weaning off it sucked, but it worked well in general.