Date of Award


Document Type

Campus Access Thesis

Degree Name

Master of Arts (MA)


Clinical Psychology

First Advisor

Sarah Hayes-Skelton

Second Advisor

Lizabeth Roemer

Third Advisor

Abbey Eisenhower


Despite the established effectiveness of gold standard CBT treatments for SAD, such as Cognitive Behavioral Group Therapy (CBGT; Heimberg & Becker, 2002), partial and/or nonresponse to treatment are common concerns. Examining nuanced, data-driven response trajectories across treatment can help identify differences in treatment effects between responders and nonresponders. In addition, investigating the role of longitudinal treatment variables in predicting treatment outcomes can help enhance efficacy of existing treatments, particularly for nonresponders. This might be particularly important given the added barriers that individuals with SAD face in accessing and engaging in effective treatments. Therefore, this study examined weekly symptom change trajectories among 63 clients (mean age = 27.9, 57.6% female, 50.8% White) undergoing 12 sessions of CBGT for SAD.

Based on study findings, three distinct stages of treatment emerged; with a sharp decrease in symptom severity from sessions 1-5 (early stage), followed by relative plateauing of symptom severity between sessions 5-8 (mid stage), followed by a gradual decrease in symptom severity from sessions 8-12 (late stage). The greatest gains in treatment were found in early stage treatment, predominantly between sessions 3 to 5. Session-to-session symptom change trajectories across treatment were found to be largely similar for responders and nonresponders, with neither baseline symptoms, nor rate of symptom change predicting responder status. However, differences in treatment response trajectories between these subgroups were found in the late stage of treatment, but not in the early or middle stages. As would be expected, symptom severity at the start of each treatment stage predicted post treatment symptom reductions and quality of life improvements. However, contrary to expectations, symptom change during early and late treatment, but not mid treatment, predicted symptom reduction, whereas only symptom change during early treatment predicted quality of life improvements, post treatment.

Overall, study findings highlight the importance of early stage treatment as a period when participants tend to make sudden gains and a period when symptom change predicts treatment outcomes. Furthermore, findings highlight mid stage treatment as a period of potential instability and late treatment stage as when nonresponders begin to emerge. Taken together, findings offer suggestions for potential indicators to identify whether clients are “on track” (e.g., making sudden gains early in treatment), as well as possible targets for preventing risk of nonresponse (e.g., providing longer treatment or integrating treatment augmentations in the mid and late stages of treatment).


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