Combined Effects of Early Behavioral Intervention and Propranolol on ASD

The investigators' specific aim is to examine the effects of serial doses of propranolol in
combination with early intensive behavioral intervention on social interaction, and
secondarily on language tasks, anxiety, adaptive behaviors, and global function in children
with autism in a double-blinded, placebo-controlled trial. The investigators will also
examine whether response to treatment can be predicted based upon markers of autonomic
functioning, such as pupillary light reflex and heart rate variability, and whether anxiety
predicts treatment response. The investigators' hypothesis is that propranolol will augment
the effects of behavioral therapy on social functioning and language abilities. The
investigators have demonstrated benefits of propranolol on social functioning and language in
previous single-dose studies in adults and adolescents with autism. The investigators also
predict that those with the greatest degree of autonomic dysregulation will demonstrate the
greatest benefit from the drug.

Inclusion Criteria:

- Diagnosis of autism spectrum disorder (ASD), defined in this study by the DSM-V
criteria plus Autism Diagnostic Observation Schedule (ADOS) criteria for Autism.

- Aged 3-8

- Participants must also be enrolled in an early behavioral intervention program at the
Thompson Center or another institution in Missouri for the duration of the study.

Exclusion Criteria:

- Non-autism learning disability (e.g. dyslexia)

- Major psychiatric diagnosis (e.g. major depression, schizophrenia, bipolar disorder)

- Other neurological diagnosis

- Major head trauma

- Any of the following exclusionary criteria related to propranolol (diabetes, reactive
airway/pulmonary disease, thyroid disease, bradyarrhythmias, unexplained syncope,
narrow angle glaucoma, known hypersensitivity/adverse reaction to beta-blockers,
potentially interacting drugs, underweight < 15 kg)

- Any of the following exclusionary criteria related to the use of electrocardiogram
(history of rash from adhesives)

- Any of the following exclusionary criteria related to the pupillary reflex measurement
(uncorrectable visual acuity impairment).

- Participants with a heart rate of less than 60 or a systolic blood pressure of less
than 75 at the outset of the study will be excluded.