The effect of D-cycloserine on social anxiety treatment using a behavioral outcome measure and a post-session administration strategy.

Abstract

BACKGROUND The drug D-Cycloserine (DCS) has been used as an adjunct to increase the pace of symptom reductions during exposure therapy for anxiety disorders. This procedure has met with mixed results andmany questions remain. Aims: The findings from two investigations are reported here, highlighting important domains for furthering our understanding of DCS effects. METHOD Study 1 (n = 16) treated social anxiety among a sample of emerging adults, and in addition to self-report utilized a behavioral measure of symptom improvement to evaluate outcomes. Study 2 (n = 16), utilizing a similar design, introduced an algorithm based post-session administration strategy following sessions where anxiety reductions were evident. Both investigations were double-blind, placebo controlled, randomized trials with participants diagnosed with social anxiety. Treatment was an exposure-based CBT-protocol adopted in other investigations that tested DCS. RESULTS Findings of Study 1 yielded an interaction effect in favor of DCS for self-reported distress ratings (p=.02) and on a behavioral measure of anxiety (p=.01). Findings from Study 2 revealed a significant effect for self-reported subjective distress ratings (p=.002). CONCLUSIONS Although limitations of small sample size constrain generalization and limit power, results illustrate some beneficial effects of DCS within the context of exposure-based intervention for social anxiety, yet are discussed in the context of statistical vs. clinical significance and the DCS literature as a whole. Present findings highlight the potential usefulness of a post-session administration strategy and the behavioral measure for future efforts with an eye towards preventing bias through more nuanced and powered studies.