Pharmaceutical researchers use two groups of subjects to prove if a specific drug is effective.
In clinical trials, one group is given the actual drug. This group is called the "experiment group".
The other group, called the "control group" is given a sugar pill.
Both groups are told they are given a drug and that they should start feeling the effects of it.
They are then monitored at intervals to document the effects of the drug.
When participants in the control group react as if the drug is real,this is called the "placebo effect".
The mere fact that they been given a suggestion they believe in, gives their subconscious permission
to allow for the effects of the drug.
This is a pretty strong statement in regards to how powerful suggestion are.
Most studies conducted have indicated that, the belief in treatment, combined with the expectation of the outcome, strongly effects the results.
For more information, see this FDA article on the placebo effect.
This is interesting because we now have concrete evidence of how certain parts of the brain respond
to thoughts and beliefs.
In hypnosis, YOU are able to tap into this power and use it to your advantage.
The only thing different is that we are intentionally making something happen.
With the placebo effect, scientists are just observing what does happen. And thanks to their efforts,
we have proof of the power of suggestion.
Here is a link to wiki for more information on the placebo effect