przemyt
Interestingly, in talk therapy it seems to be the patient's own talking that helps, rather than how the therapy is done or who's the therapist. Mark Manson sums the research up nicely in this piece:
https://markmanson.net/how-to-get-better
Turns out that any way to examine and express one's thoughts and emotions that otherwise run unattended is helpful. Therapy, journaling, meditation.
Still, to me this is by it's very nature limited - to what you can consciously dig out and express. If the issues that cause trouble are not conscious, tough luck. Like trying to fix email infrastructure issues by rigorously applying inbox zero.
Perhaps lasting improvements in such cases require forms of therapy that involve consciousness altering techniques? Psychedelics are recently making a comeback in therapy. "How to Change Your Mind" by Michael Pollan is on my reading list: