I think this is a real problem with the way that most psychotherapy is set up and while there isn't an easy answer to it, it would be a huge start if the problem were at least acknowledged as such within the field. I cannot imagine that if the best minds in the industry got to work on this, they would not be able to figure out a somewhat more satisfactory way to address the phenomenon of heightened distress between sessions associated with the activation of attachment anxiety or other retraumatization.

It seems like their main strategy for coping with this is simply to further pathologize the person experiencing it. The irony of course being that the modality of therapy that does tend to offer the most between-session support (DBT) is specifically designed for the most pathologized group of patients (BPD) but is also among the coldest and least humanistic. It seems to work for a lot of people though.

One of the aspects of this that strikes me as especially egregious and distinct from other types of healthcare is the lack of informed consent. Specifically, I have never had a therapist sit with me at the outset of therapy and say "so there's a thing you should know about called transference, it can be exceedingly painful especially if you have a history of insecure attachments. Even if this becomes a huge problem, I will not really be there for you more than an hour a week. You might want to give some thought as to how and whether you want to proceed."

One strategy might be to offer access to support groups, group therapy or on-call therapist networks. Also there needs to be lots of access to teaching and coaching on wellness, mindfulness and centering techniques all the way through. Like someone you can call to talk you through it when you're losing it. I think any solution has to support the client in their distress while not overly nurturing the fantasy of the therapist as perfect parent. The therapist needs to be protected from burnout but the client needs to be protected from freakout. As it stands, only the therapist's needs are really considered in this equation.