Modern medicine has made tremendous advances since its healing methods were all based on 'what works', without knowledge of causes. The physical bases - yes, they need to be known. They exist, to be observed. The psychological bases are trickier, because the psycho-dynamics are kaleidoscopic. I think Christian models of healing and psychotherapy may sometimes take on too much from the secular.
Forgiveness is in large part about helping people to forget, rather than exhuming rotting memories.
The man told by Jesus that his sins were forgiven had no need to relate them. The one told to forgive his brother seventy times seven times had no need to set out what he had to forgive. The rite of confession was intended to be a one-off each time, sending a sinner away clean of the past, until more sins were accumulated. General confession in the Book of Common Prayer did not require the minister to list the assumed sins of the congregation. Wesley's converts had a dramatic psychological dunking that washed away unnamed vestiges of sinning and being sinned against.