I will speak as an alcoholic in recovery, in addition to being a person actively (regularly) involved in drinking the Hoasca (so-called "vegetal tea").
It is my experience that only a Higher Power can cure an addiction--of any type. Until a person finds a H.P. (Higher Power) which works in his/her life, s/he WILL use again; or substitute one substance for another.
I think this is the "spirit" of the question you may be asking: if, upon taking hoasca once, if it will lead to a relapse of drinking? Or, if Hoasca Herself is addictive, to an addictive personality?
As an alcoholic in recovery, I go to A.A. meetings almost daily (5, or 6 times a week), and work the AA principles in my life. I have done the steps with a sponsor, and am willing to take others through this program of recovery.
I personally feel it extremely important for one in recovery to find him/herself a homegroup, and attend regular meetings; to get a sponsor, and live within the precepts of the AA program. For this alcoholic in recovery, there is no substitute to proper daily living; to find a life within the auspices of the program of recovery, period.
For those suffering other substances addictions, the same applies to the NA or similar, program. There is no substitute for the addict in recovery, than in a 12-step program. The PRIMARY means of recovery is through the loving assistance of one's H.P.
Again, it is through God's Spirit: Her grace, mercy and wisdom, which keeps me sober and living in the solution, not rolling around in the problem, as the problem.
Hopefully, at this point, you can see where I'm going with the "drinking of the vegetal tea" (as we call a session of Hoasca ceremony.)
"Drinking the tea" (ingesting hoasca) is not a recreational, nor casual exercise. Drinking the hoasca tea is a life-changing experience, best done only when someone is serious about changing his/her life.
Until one is ready to analyze or evaluate their reasons for drinking, or other addictive behavious, one is also not ready for the Tea. If one is not ready to stop drinking, that one is not ready for the tea either.
Whether or not one wants it, within the Hoasca ceremony, he or she will get in touch with a Higher Power, which will cause that one to see many of their glaring defects, immediately. If one is not ready to address his, or her defects of character, leading to the addiction--or addict behaviour, he or she is likely to have an unwelcome experience with the vegetal tea.
Drinking the Tea, is an intense, life-changing experience. Often, even a hard-core addict/alcoholic will be changed after only a few sessions, as that one is faced with the "why" of the addiction.
Drinking the Tea is not in itself addictive, except for the understanding that becoming a better person, truer to one's true self, is "addicting"--if that is entirely possible.
I am a member of the Unao do Vegetal Church(UDV), and treat the sessions of drinking the Tea as a church, or religious/spiritual experience. This does not replace, nor substitute for my attendance at regular AA/12-step meetings. These two groups do different, yet related, things.
All the above stated, I generally don't share this side of my life with many people I attend meetings with.
Most won't/don't understand the place that the tea holds in my life. This is fine. I'm not trying to change anyone else, nor get folks involved in a different program, or change their minds.
The orthodox belief of the program is that there should be no "drug usage", except what is prescribed by a licensed doctor. Yet, having been to enough doctors, I have not found one which has diagnosed my "problem" correctly.
Relative to an addict, or alcoholic in recovery: if s/he finds that the Program itself isn't addressing additional mental inbalances, or issues, or one is "dually diagnosed"; then perhaps the answer might be found within a session of drinking the Tea.
So while the Tea provides a number of physical benefits (a type of internal, and mental cleaning, in addition to psychic clearing, improved memory, and emotional stability) which no "anti depressant" can provide, it is important to remember that drinking the tea is a spiritual pursuit.
If one is not ready to embark on a spiritual journey and solution to his or her problem, then the Tea may prove more detrimental, or harmful than it would prove to be beneficial.