Past life regression is a technique that uses hypnosis to recover what practitioners believe are memories of past lives. Past life regression is typically undertaken under hypnosis sleep.
The technique used during past life regression involves the subject answering a series of questions while hypnotized to reveal identity and events of alleged past lives, a method similar to that used in regression."Memories reported during past life regression have been investigated, and revealed historical inaccuracies that are easily explained through a basic knowledge of history, elements of popular culture or books that discuss historical events. Experiments with subjects undergoing past life regression indicate that a belief in reincarnation and suggestions by the hypnotist are the two most important factors regarding the contents of memories reported"(From Wikipedia, the free encyclopedia).
The memories thus recollected may be the result of Cryptomnesia which occurs when a forgotten memory returns without it being recognized as such by the subject, who believes it is something new and original.
In my experience,it is true.It can be treated equivalent to faith healing.But the end justifies the means.If it had some therapeutic value or placebo effect on the individual it is fine.