Biomarkers Research in Anxiety for Validation and Efficacy

Inclusion Criteria: * Age between 3;0 and 6;11 years old * A diagnosis of autism spectrum disorder using DSM-5 diagnostic criteria * A diagnosis of anxiety disorder using DSM-5 diagnostic criteria * Use of fluent 2-3 word phrases or fluent speech (i.e., Module 2 or 3 for ADOS-2) * Cognitive ability (either verbal or non-verbal IQ) \> 80 using the DAS-2 * A parent/guardian who is willing/able to participate and respond to interviews/surveys in English and willing/able to participate in Being Brave parent training in English and support homework activities. Exclusion Criteria: * Presence of seizures * Premature birth (\<36 weeks) or low birth weight (\<2500 gms) * Known genetic or medical disorders (e.g., Fragile X), or injuries (e.g., stroke) with implications for the nervous system or that require regular psychoactive medication that alter EEG/RSA/EDR signal (e.g., anti-convulsants) * Significant sensory or motor impairment (e.g., blindness) * Major physical abnormalities * Exposure to environmental factors that could contribute to neurocognitive delays (significant alcohol exposure in utero, extreme environmental deprivation) * Previous CBT for anxiety * Presence of conduct or oppositional defiant disorder or ADHD so severe as to interfere with the child's ability to take part in treatment * Presence of a primary presenting problem for which the intervention would be inappropriate (e.g., obsessive-compulsive disorder, severe mood disorder, suicidality) * Psychotic symptoms in the child or parents * Parent/caregiver who is not fluent in English or English is spoken in the home less than half of the time.