Dose Timing of D-Cycloserine to Augment CBT for Social Anxiety Disorder

The purpose of this study is to examine the efficacy of 50 mg of d-cycloserine in comparison to placebo (a pill containing no medication) for improving the effectiveness of cognitive-behavioral therapy (CBT) in reducing symptoms associated with social anxiety disorder. In addition, the study will examine whether the effectiveness of d-cycloserine depends on the timing of the pill administration (i.e., 1- hour before the session or immediately after the session) as well as the success of the CBT therapy sessions. The investigators hypothesize that the tailored post-session DCS administration condition will outperform the other conditions (pre-session DCS, placebo, and non-tailored post-session DCS). This will be evidenced by short- and long-term improvements in social anxiety severity.