Working with emotion predicts sudden gains during experiential therapy for depression.

Objective: This study involves the first attempt to identify sudden gains in a sample of clients undergoing experiential therapy for depression while also investigating client and therapist change processes related to sudden gains.Method: Pre- and post-session Beck Depression Inventory, short form (BDI-SF) questionnaires were used to identify sudden gains and differentiate between in-session and between-session symptom changes in thirty-six client-therapist dyads. Archival videotape data of a sub-sample were coded using the Experiencing Scale, Classification of Affective Meaning States, and the Coding System for Therapist Focus.Results: The study revealed that 63.9% of clients experienced a sudden gain and the bulk of the total mean symptom decrease (74.9%) was found to occur within the session preceding the sudden gain. During this critical session, clients were more likely to display deepened experiencing (p < .01, η2 = .34), clients were more likely to express "primary adaptive emotions" (p < .05, r = .38), and therapists were found to be more likely to focus on unmet client needs (p < .01, d = .75).Conclusion: The majority of the sudden gain change occurs within session in experiential therapy, and primary adaptive emotions as well as addressing unmet needs are possible processes of sudden gains.