Date of Award


Publication Type

Doctoral Thesis

Degree Name





Alliance, Helpful Aspects of Therapy, Integrative Therapy, Process Research, Sudden Gains


Antonio Pascual-Leone




Sudden gains, or sharp decreases in client’s symptoms and distress, are highly predictive of positive therapy outcome. However, why sudden gains occur remains unanswered. This study sought to analyze the processes that arise during sudden improvements in symptoms by examining clients’ own insight into what they found to be helpful in therapy while focusing on phases of therapy and treatment approach as moderators of these change processes. To do so, an archive of weekly therapy session data was obtained of clients at an outpatient psychotherapy clinic. Therapy was provided by advanced graduate psychology students at a partnering university and consisted of either a CBT, EFT, psychodynamic, or an integrative approach. Clients completed the OQ-45 progress monitoring measure at baseline and prior to every session as well as the Helpful Aspects of Therapy (HAT) questionnaire and the Working Alliance Inventory (WAI) at the end of each therapy session. Sudden gains were identified using criteria adapted from Tang and DeRubeis’s (1999) and Kelly et al. (2005) requirements. Clients’ written responses on the HAT questionnaire were categorized using a modified version of the Helpful Aspects of Experiential Therapy Content Analysis System (HAETCAS; Elliot, 1988). Analyses found that the proportion of sudden gains (30.9%, n = 70) and the average magnitude of sudden gains (24.16 OQ-45 points) differed from the only other study to examine sudden gains using the OQ-45. The only sudden gain characteristics (i.e., rate of reversal, magnitude, proportion, change from pre- to post-treatment) that differed by phases of therapy (early vs. working vs. late phase) was that sudden gains were greater than expected during the early phase of therapy and lower than expected during the working phase of therapy. The sudden gain characteristics that differed between treatment approach (i.e., CBT vs. humanistic/psychodynamic therapy) was that clients receiving CBT experienced a greater number of reversals than clients who received humanistic/psychodynamic therapy. Regarding the therapeutic alliance, clients reported a strengthening of the alliance during and after the sudden gain while simultaneously during the same period provided less frequent unsolicited reports about the therapeutic alliance being the most helpful aspect of therapy. Further analysis of what clients reported as most helpful events found that “self-exploration” was rated less often and “finding a solution” was rated more often during a pregain session than during a comparison session among clients receiving CBT. For clients receiving humanistic/psychodynamic therapy, “insight” was rated more often during a pregain session than during a comparison session from prior to the sudden gain.