Key points from summary and commentary:

For the American Psychological Association, this review amalgamated findings relating psychotherapy outcomes to the therapist’s character integration, personal awareness and authenticity (‘congruence’) or the closely related quality of conveying ‘genuineness’.

The overall link between congruence/genuineness and outcomes was moderate but statistically significant, and in individual studies almost uniformly in the direction of greater congruence/genuineness being associated with better outcomes.

Though causality cannot be established by the types of studies included in the analysis, it is probable, and the safest stance for trainers, supervisors, therapists, and counsellors is to presume that conveying genuineness and authenticity is an important way therapists underpin an effective therapeutic relationship.