A Study to Assess the Long-term Use of Alprazolam Extended Release (XL) in the Treatment of Adolescents With Panic Disorder

Inclusion Criteria: * A primary Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision diagnosis of panic disorder with or without agoraphobia based on the Mini-International Neuropsychiatric Interview for Children and Adolescents * Subjects with an average of 1) at least one 4-symptom panic attack per week over the last 4 weeks before screening; 2) at least one 4-symptom panic attack per week over the last 4 weeks before baseline; and 3) at least one 4-symptom panic attack in the 7 days prior to baseline * To enter Study A6131007, subjects must have completed Study A6131002, had an acceptable tolerability to study drug, and in the clinical judgment of the investigator, could have benefited from continued study treatment. Exclusion Criteria: * Subjects must continue to meet all of the exclusion criteria enumerated in the Acute Efficacy Study (Protocol A6131002) with the following exception: Subjects will be allowed to undergo cognitive-behavioral or other panic-specific therapy and any other psychotherapy (e.g., supportive and/or family therapy) during the expected study period in this study.