There recently was an article in the Inquirer about the validity of hypnotic regression.
While this article speaks positively about it, I do think thaat one should be very cautious when it comes to memories that are being accessed in the hypnotic state.
The very nature of the hypnotic state makes it a lot easier to create fake memories that seem realistic. And when I say fake memories, I do not mean that the person who creates them knows that he or she is creating a fake memory. Sometimes, it is just something that happens accidentally, but then it can seem all the more real.