I have found by doing and researching through follow up calls with people that experience a past life regression the majority of the people claim they miss their old life.
Having a past life experience is like having a dream. Through using Regression therapy I have seen people so happy it is beyond belief, however the ones that miss family, friends and their old life can be as much as a few weeks of morning the loss of the old days.
I have preformed hundreds and other than the slight morning period I have never seen any other risks