Participants in this double-blind study will first partake in an initial 10-week phase in which they will be treated with sertraline. Participants who do not respond to sertraline treatment will proceed to phase two of the study, in which they will be randomly assigned to one of three treatment groups. One group will receive both sertraline and clonazepam, another group will receive both sertraline and placebo, and the third group will receive only venlafaxine. All treatments will continue for 12 weeks. Sertraline and venlafaxine are both FDA-approved for the treatment of GSAD. Clonazepam is widely used for the treatment of anxiety, but is not FDA-approved for the treatment of GSAD. All participants will attend weekly study visits at Weeks 1, 2, 4, 6, 8, and 10. Participants who continue into phase two will attend weekly study visits at Weeks 11-14, 16, 18, 20, and 22. Symptom remission rates and post-treatment social phobia severity will be assessed at Week 22.