Generalized Anxiety Disorder

Anxiety-, obsessive-compulsive and trauma- and stressor-related disorders reflect a significant public health problem. This study is designed to evaluate the predictive power of a novel biomarker based on a CO2 challenge, thus addressing the central question "can this easy-to-administer assay aid clinicians in deciding whether or not to initiate exposure-based therapy?"

Anxiety disorders are the most common form of psychopathology, and frequently begin in childhood, resulting in lifelong impairment. Increased brain activity after making mistakes, as reflected by the error-related negativity (ERN), is observed in people with anxiety disorders, even before disorder onset. The ERN is therefore of great interest as a potentially modifiable risk factor for anxiety. However, methodological issues can make the ERN difficult to measure.

Increased brain activity in response to a balance disturbance, as reflected by the balance N1, resembles the ERN, but does not share its methodological issues. The investigators' preliminary data demonstrate that the balance N1 and the ERN are associated in amplitude in adults, suggesting they may depend on the same brain processes. The balance N1 has never been investigated in individuals with anxiety disorders, but it increases in amplitude within individuals under anxiety-inducing environmental contexts. Further, balance and anxiety are related in terms of brain anatomy, daily behavior, disorder presentation, and response to treatment.

The present investigation will measure the ERN and the balance N1 in children (ages 9-12) with anxiety disorders, and further, how these brain activity measures change in response to a brief, 45-minute, computerized psychosocial intervention that was developed to reduce reactivity to errors, and has been shown to reduce the ERN. The investigators will recruit approximately 80 children with anxiety disorders, half of whom will be randomly assigned to the active intervention condition. The other half will be assigned to an active control condition, consisting of a different 45-minute computerized presentation. Participants assigned to the control condition can access the computerized intervention after participation in the study.

The purpose of this investigation is to test the hypothesis that the balance N1 and the ERN will be reduced to a similar extent after the intervention, to demonstrate that these brain responses arise from shared brain processes. Transfer of the effect of the psycho-social intervention to the balance N1 would provide insight into prior work demonstrating that balance training can alleviate anxiety in young children, and well-documented benefits of psychotherapy to balance disorders. Collectively, these data may guide the development of multidisciplinary interventions for the prevention and treatment of anxiety disorders in children.

The investigators are conducting this study to learn more about the cognitive and attentional processes among individuals with three types of repetitive negative thinking (RNT): mental rituals (as seen in obsessive compulsive disorder, OCD), worries (as seen in generalized anxiety disorder, GAD), and ruminations (as seen in major depressive disorder, MDD). Specifically, the investigators are studying whether psychological treatment can help people with RNT who have trouble stopping unwanted thoughts and shifting their attention.

The aim is to evaluate short term and longer term treatment effects of internet-delivered cognitive behavioral therapy compared to treatment as usual for college students with anxiety and/or depression in low-middle income countries of Latin America.