Inclusion:
- Man or woman, at least 30 to 80 years old
- Have early-stage Parkinson's disease
- Not be on any current treatments for PD
- If of reproductive potential, willing and able to use a highly effective form of birth control during the study and for 30 days following last dose of study material

* Other criteria for eligibility apply

Exclusion:
- Diagnosis of secondary or atypical parkinsonism
- Onset of any parkinsonian motor sign or symptom >5 years before Screening Visit
- Previous surgical procedure for PD
- Clinically significant medical, surgical, psychiatric, or laboratory abnormality
- Has an ECG or clinical evidence of potentially unstable heart disease
- Medical or recreational use of marijuana or THC-containing compounds within 3 months of the Screening Visit

* Other criteria for exclusion apply

You may be eligible if you:
• Are Between the ages of 40 to 80 years
• Are willing to practice effective birth control, or remain abstinent during the trial and for 4 weeks after the last dose of trial if you are a sexually active man or woman of childbearing potential
• Were diagnosed more than 3 years ago
• Willing and able to not use any PD medications that are not permitted by the protocol (including dopaminergic agents) throughout participation in the trial.

You will be excluded if you:
• Have a history or clinical features consistent with essential tremor, atypical or secondary parkinsonian syndrome (including, but not limited to, progressive supranuclear palsy, multiple system atrophy, cortico-basal degeneration, or drug-induced or post-stroke parkinsonism).
• Have had previous surgical intervention (eg, deep brain stimulation) for PD or for whom such a procedure is planned or anticipated during the trial period.
• Have hypertension.
• Have previously participated in any tavapadon trial, including this trial, and received IMP.
• Have received treatment with any other investigational drug within 60 days before signing the ICF.

1. Male or female, age 30 or older
2. Has not received deep brain stimulation, Carbidopa (CD)/Levodopa (LD) enteral suspension, or any other Parkinson's Disease (PD) medication as continuous daily infusion
3. Subject does not have a history of significant skin conditions or disorders
4. Subject does not have a recent (within 6 months before screening) history of drug or alcohol abuse
5) Subject does not have a history or presence of psychotic episodes
6) Subject does not have other clinically significant unstable medical conditions
7) Subject must have a diagnosis of levodopa-responsive idiopathic PD

* other eligibility criteria to be discussed/reviewed with the study team

Inclusion Criteria:
-adults aged 65 and older
- Must be independently-living and community-dwelling
- Participants must be willing to undergo a health interview to rule out outstanding medical and psychiatric conditions
- Adequate sensory abilities

Exclusion Criteria:

- A history of psychiatric illness necessitating inpatient treatment
- Participants with self-reported depression and/or anxiety exceeding mild levels of clinical severity

- You must be between the ages of 40 and 85
- Willing to have MRI imaging of the brain

You may be eligible if you:
* Over the age of 18
* Able and willing to provide informed consent
* Clinical diagnosis of idiopathic Parkinson's Disease
* Implanted Boston Scientific DBS system

Exclusion Criteria

* You are currently participating in any study with an investigational medicinal product (IMP) or investigational device.

- You are at least 45 years old
- Clinical diagnosis of ischemic stroke* of unknown cause (ESUS or cryptogenic) in the last 120 days
- Underwent an echocardiogram as part of your stroke work up
- No history of atrial fibrillation (irregular heartbeat)
- No known allergy or intolerance to aspirin or apixaban

*An “ischemic” stroke is an injury to the brain caused by a blocked blood vessel supplying the brain.

Inclusion Criteria:
1. Age 18–and older at the time of enrollment
2. Individuals who are experiencing lower extremity pain e.g. neuropathy, Complex Regional Pain Syndromes (CRPS) type-1, neuropathic leg pain following Failed Back Surgery (FBS) etc.
3. Those who have an implanted epidural Spinal Cord Stimulator (SCS)
4. The SCS implantation for at least three months prior to enrollment

You may be eligible if you:
- Have a diagnosis of dementia (mild to moderate)
- Are age 60 and older
- Able to follow simple instructions

EXCLUSION CRITERIA:
-Unable to walk 10 feet unassisted
-Presence of bone disorder that impacts walking
-Presence of other neurologic diagnosis that impacts cognitive or motor function such as stroke, Parkinson disease or traumatic brain injury

--Age: 50-85
--Diagnosis: dementia with Lewy bodies (DLB) or Parkinson's disease dementia (PDD), presence of visual hallucinations that occur more days than not.
--MMSE Score: greater than or equal to 18 (Mini-Mental State Exam--Coordinator will explain)
--Must have a study partner willing to attend visits and ensure compliance with the study