D-Cycloserine Augmentation of Cognitive Behavioral Group Therapy of Social Anxiety Disorder: Prognostic and Prescriptive Variables

Objective: The aim of the current study was to identify individual characteristics that (a) predict symptom improvement with group cognitive behavioral therapy (CBT) for social anxiety disorder (SAD; i.e., prognostic variables) or (b) moderate the effects of d-cycloserine (DCS) versus placebo augmentation of CBT for SAD (i.e., prescriptive variables). Method: Adults with SAD (N = 169) provided Liebowitz Social Anxiety Scale scores in a trial evaluating DCS augmentation of group CBT. Rate of symptom improvement during therapy and posttreatment symptom severity were evaluated using multilevel modeling. As predictors of these 2 parameters, we selected the range of variables assessed at baseline (demographic characteristics, clinical characteristics, personality traits). Using step-wise analyses, we first identified prognostic and prescriptive variables within each of these domains and then entered these significant predictors simultaneously in 1 final model. Results: African American ethnicity and cohabitation status were associated with greater overall rates of improvement during therapy and lower posttreatment severity. Higher initial severity was associated with a greater improvement during therapy but also higher posttreatment severity (the greater improvement was not enough to overcome the initial higher severity). DCS augmentation was evident only among individuals low in conscientiousness and high in agreeableness. Conclusions: African American ethnicity, cohabitation status, and initial severity are prognostic of favorable CBT outcomes in SAD. DCS augmentation appears particularly useful for patients low in conscientiousness and high in agreeableness. These findings can guide clinicians in making decisions about treatment strategies and can help direct research on the mechanisms of these treatments.