Yeah, Kratom definitely has a lot of potential to do a lot of good for opiate addicts. I disagree with the analogy to e-cigs though. With e-cigs you can put a much stronger concentration of nicotine in each hit depending on the liquid used. It's still exactly the same chemical, ie. nicotine, binding to the exact same receptors in the same way. With Kratom, you are binding to the same receptors as opiates, but it's a different chemical which binds/antagonizes the receptors differently than other opiates. It's this difference which makes tapering Kratom easier than other opiates. This difference does not apply to cigs and e-cigs.

Sorry, I was being unclear. I was speaking only in terms of addictive potential and difficulty of quitting. MAOIs in cigarettes make them more addictive than e-cigs (nicotine alone) as the different action of other opiates makes them more addictive than mitragynine.

I see. I wasn't aware of the MAOIs in tobacco. Though I wasn't able to find a good source on how much they might contribute to the addiction (lots of questions about it around the web though).

Do you happen to know of credible sources or studies which have looked at this?

Dunno about credible, but here’s one rat study with a lot of citations, and I think it’s where I first read about it: http://jneurosci.org/content/25/38/8593.full