Investigator decided to terminate the study - no participant enrolled.

The goal of this flexible single-subject design vagus nerve stimulation (VNS) study is to examine the behavioral, cognitive, and biorhythmic effects of VNS in children and adults with autism and developmental disabilities. The main aims are:

• Pilot the creation of a profile for those who will respond to VNS with the long-term goal of designing clinical trials.
• Examine the effects of VNS on a broad range of symptoms.

Participants will select between 1, 2, or 3 months of daily VNS treatment and complete study visits each month.

Intellectual and developmental disabilities (IDD) cover a wide variety of disorders. Although we know the causes of some of the disorders and some of them could even be prevented (e.g., lead exposure), most causes remain unknown. Without having a clear understanding of the causes, prevention is very difficult to achieve. Previous studies have shown abnormal autonomic nervous system (ANS) regulations in young children with autism spectrum disorder (ASD) and these abnormalities are also observed during sleep. ANS is the part of the nervous system that controls the unconscious bodily functions, such as breathing, heart beating, and digestion.

The vagus nerve strongly influences these autonomic functions including digestion, breathing, heart rate variability, and metabolic function and central nervous system (CNS) activity that affect mood, pain, stress management, sleep, and even memory and cognitive functions. The vagal influence over neurotransmitter release has been implicated in the regulation of inflammation and immune cell activity.

Here, we are using a non-invasive vagus nerve stimulator to monitor changes in cognitive function and other symptoms in people with IDD, both with and without ASD. The device is FDA-approved for migraine and cluster headaches in people 12 years and older. VNS activates the vagus nerve with mild electrical stimulation through the skin.

Rather than embarking on a rigorously designed study, we will conduct a series of single-subject studies that reflects each participant's symptoms. We will select the most appropriate dependent variables based on each person's symptom presentation.

Inclusion Criteria:

1. Children and adults aged 12-40 with intellectual and developmental disability (IDD) and/or autism spectrum disorder (ASD). Participants who are decisionally-impaired will be eligible with assent.
2. Able to tolerate wearing an Apple Watch, EEG, and sit for a neurocognitive test
3. Be on a stable dose of psychotropic medication for at least one month prior to enrollment
4. Agree not to initiate new or change existing medications or behavior intervention

Exclusion Criteria:

1. Have an active implantable medical device (e.g., pacemaker, implanted hearing aid, etc.) or a metallic device, such as a stent, bone plate, or bone screw
2. Have a comorbid physical or psychiatric disorder which would disrupt ability to tolerate vagal stimulation or comply with study demands (e.g., insulin dependent diabetes, bipolar, etc.)
3. Vagus nerve lesion, damage, or structural abnormality (e.g., lymphadenopathy, neoplasm, previous surgery), or pain (e.g., dysesthesia, neuralgia and/or cervicalgia)
4. Current or past history of neurological disorders or trauma, including uncontrolled epilepsy and head injury.
5. Current or recent (within 12 months) participation in a clinical trial of a drug or a medical device.
6. Use of drugs (within 4 weeks) that affect the autonomic nervous system (beta blockers, beta stimulant, etc.).
7. Use of marijuana (including medical marijuana) for any indication
8. Any condition per the investigators' clinical judgment that precludes participation in the study (e.g., pregnancy).
9. Lack of capacity to consent and without a legally authorized representative (LAR) who is a parent, spouse, or an adult child.
10. Living in a residential program (e.g., group home)
11. Wards of state

Study withdrawn.