Participants in this single blind study will be randomly assigned to one of three conditions: intensive CBT treatment including family members, intensive CBT treatment without family members, or a waitlist control group. All participants in the intensive CBT treatment groups will undergo 8 days of intensive CBT, for a total of 6 sessions. On Days 1 through 3 of treatment, participants will attend daily, 2-hour CBT sessions. The CBT sessions will include psychoeducation about anxiety, tactics to restructure anxiety-provoking thoughts, and exposure to bodily sensations that trigger panic. On Days 4 and 5, participants will meet with a therapist to learn ways to approach previously feared situations. On Days 6 and 7, participants will continue working independently or with family members to solidify skills. On Day 8, participants will attend a final 2-hour session to consolidate skills, review the independent weekend activities, and discuss ways to apply skills to the home environment. Parents of participants in the parental involvement group will attend the last 30 minutes of sessions, complete homework assignments, learn ways to coach their children through episodes, and participate in selected exposures. After 6 weeks of waitlist, participants in the waitlist control group will receive active treatment following the same procedures as the initial active treatment. All participants will be assessed at Months 3, 6, and 12 post-treatment.