Rule 1020 There is no privilege under this article as to a communication relevant to an issue of breach, by the psychotherapist or by the patient, of a duty ari…

If a therapist or patient is accused of breaking a duty that comes from their therapy relationship, the normal right to keep therapy conversations private does not apply.

For example, if a patient sues their therapist for malpractice, or if a therapist takes legal action against a patient for something related to their treatment, either side can use what was said during therapy sessions as evidence. The usual protection that keeps therapy conversations secret gets set aside when the lawsuit itself is about something that happened within that therapy relationship.