From a Shaman standpoint, past lives are very influential in the managing of our everyday lives. Through a simple guided journey one can gain access to memories from past lives in order to perhaps remedy a recurring theme in one's present life.
A past life regression can potentially help a depressed client bring awareness to the source of depression. Oftentimes what troubles us in our current life is rooted in a lifetime from the past.
A past life regression is simply a way to connect to a past life. We all have challenges that are affecting us currently and sometimes those challenges are not from this life but have been sourced from another life.