Hi Fabio,
Interesting subject, but one I have no presonal experience in. I have read some on it though.
Hypnosis (from the Greek hypnos, "sleep") is a trance-like state that resembles sleep, and is induced by a person. From the mental standpoint, my understanding is a person is relaxed yet alert and always aware at some level.
You know your conscious mind works to evaluate all your thoughts, makes decisions and puts certain ideas into action. But when you're asleep your subconscious takes over and it also takes care of all the stuff you do automatically.
Hypnosis is like you absolutely convince somebody of something in their subconscious, they register this information as a fact. Like any fact, this information will take root in the subconscious mind. So, even if the hypnotic state is nothing more than a figment of the subject's imagination, this suggestions can still reform their deeply held beliefs.
The practiced of regression seems to me to be questionable, to say the least. It is would be impossible to distinguish a true memory from something believed by suggestion or a false memory. I put no credence in it at all.
The hypnotic behavioral modification is habit-control hypnotic treatment, and is what would be used to aid cigarette smokers in quitting. By connecting a negative response with the bad habit or to build up willpower, suggesting to your subconscious that you don't need cigarettes, and you don't want them. Even if the treatment does yield positive results in the short term, there's a good chance that the subject will relapse eventually.
Think about how this could be likened to the placebo effect, people who are given ordinary sugar pills behaved and felt differently only because they thought they should. It's clear that the mind can influence all aspects of the physical body.
People also enter a trance like state doing many ordinary things, when you tune out most of the stimuli around you. I would think meditation is a form of this.
Also think about losing yourself in a book or movie. I have a daughter that does this while watching TV, she becomes so engrossed it's hard to get her attention even when you call here name over and over. As you get engrossed in the plot, the worries of the world fade away and you can even experience real fear, sadness or happiness, and you may even jolt in your seat if you are surprised by something (a monster leaping from the shadows).
So there is my very brief understanding of hypnosis. I believe that it is applied in many ways that we are not aware of and we should be very carefully how we malnipulate and what we put in our minds. The mind is a complicated and wonderfully made, it is a mystery as to all it's functions. My opinion is seeking God guidance is advisable over hypnosis
mercy, peace and love
Kat