Please see Detailed Description for termination reason.

The purpose of this study is to evaluate the efficacy, safety, tolerability, and pharmacokinetics of alprazolam extended release (XR) for the treatment of adolescents with panic disorder

Due to recruitment difficulties in this adolescent population, the clinical program for alprazolam XR was cancelled and this study was terminated on 1 September 2004. There were no safety concerns that led to this decision.

Inclusion Criteria:

• A primary DSM-IV-TR diagnosis of panic disorder with or without agoraphobia based on the Mini International Neuropsychiatric Interview for Children and Adolescents
• At least an average of one 4-symptom panic attack per week over the last 4 weeks prior to screening
• At least an average of one 4-symptom panic attack per week over the last 4 weeks prior to baseline
• At least one 4-symptom panic attack in the 7 days prior to baseline

Exclusion Criteria:

• Current (in the past 6 months) DSM-IV-TR diagnosis of obsessive compulsive disorder, major depressive disorder, dysthymic disorder, or alcohol and/or substance dependence
• Primary DSM-IV-TR diagnosis of social anxiety disorder, post-traumatic stress disorder, simple phobia, separation anxiety disorder, generalized anxiety disorder, conduct disorder, oppositional defiant disorder, or attention deficit hyperactivity disorder
• Any current or past history of schizophrenia or psychosis; bipolar disorder or cyclothymia; dementia, delirium or other organic brain disease; an Axis I eating disorder; mental retardation, Asperger's disorder, or any other serious developmental disorder
• A CDRS-R score >35