• Clinical Global Impression (CGI) Scale [ Time Frame: Change from Baseline in CGI score at 12 or 16 weeks after treatment SSRI or CBT, respectively). Measured before treatment, at each treatment study visits, and after treatment ] [ Designated as safety issue: No ]
  

• Liebowitz Social Anxiety Scale (LSAS) [ Time Frame: Change from Baseline in LSAS score at 12 or 16 weeks after treatment SSRI or CBT, respectively). Measured before treatment, at each treatment study visits, and after treatment ] [ Designated as safety issue: No ]
  

Anxiety disorders are common and highly disabling conditions of children and adolescence that often do not remit, and increase the risk of depression, anxiety, substance abuse, and suicide in adulthood. Available treatments are only modestly successful. When they are effective, however, early treatment of anxiety disorders can reduce subsequent morbidity.

This study will examine variations in genetics and brain reactivity among children and adolescents who do and do not respond to SSRIs and Cognitive Behavioral Therapy. Through this, the study will identify neurological and genetic biomarkers that can predict responsiveness to SSRI/CBT treatment in those with anxiety disorders.

For SSRI/medication treatment arm:

Although selective serotonin reuptake inhibitors (SSRI) are medications widely prescribed for children and adolescents with anxiety disorders, little is known about the neurobiological factors that predict which patients respond to treatment. Current theory suggests that neurological functioning and genetics may influence a patient's response to treatment.

Participation in this study will last approximately 14 weeks. Both healthy participants and participants with anxiety disorders will be recruited to participate. All participants will complete similar study visits at entry, within 2 weeks of entry, and 12 weeks after that. The first visit, which will occur at study entry, will include screening questionnaires, an interview with research staff, a medical screening, and collection of saliva samples for genotyping. The second visit and the last visit, which will be separated by 12 weeks, will involve MRI scans and behavioral tasks to be conducted inside and outside the MRI scanner. Over the 12 weeks between MRI scanning sessions, participants with anxiety disorders will take sertraline, a common SSRI, on a daily basis. They will also attend nine additional visits during this time to complete assessments of their symptoms. These visits will occur 0, 1, 2, 3, 4, 6, 8, 10 and 12 weeks after the first scan. Participants with anxiety disorders will therefore be completing a symptom assessment, MRI scans, and behavioral tasks all on the final visit, 12 weeks after the second visit. In addition, participants will complete tasks while connected to an Electroencephalography(EEG) machine before and after the 12 weeks of treatment, and will have the option of additional EEG's at weeks 2, 4, and 8.

For CBT arm:

Participation in this study will last 16 weeks. All participants will complete similar study visits at entry, within 2 weeks of entry, and approximately 16 weeks after that. The first visit, which will occur at study entry, will include screening questionnaires, an interview with research staff, a medical screening, and collection of saliva samples for genotyping. The second visit and the last visit, which will be separated by approximately 16 weeks, will involve MRI scans and behavioral tasks to be conducted inside and outside the MRI scanner. Over the 16 weeks between MRI scanning sessions, participants with anxiety disorders will participate in type of talk therapy--Cognitive Behavioral Therapy--on a weekly basis. In addition, participants will complete tasks while connected to an Electroencephalography(EEG)machine before and after the 16 weeks of treatment, and will have the option of additional EEG's at weeks 2, 4, and 8.