This study will evaluate a new form of non-invasive deep brain therapy for individuals with generalized chronic pain. Low-intensity transcranial focused ultrasound stimulation will first be delivered using a range of stimulation parameters during psychophysical and physiological monitoring. A well-tolerated stimulation protocol will be selected for subsequent testing in a blinded randomized sham-controlled cross-over trial. The trial will evaluate brain target engagement using magnetic resonance imaging and CVAS and PROMIS numerical rating scales of pain.

Inclusion Criteria:

1. Age 18-65, any gender
2. Primary diagnosis of generalized chronic pain or widespread chronic pain.
3. Moderate-to-severe chronic pain lasting at least 2 months
4. Stated willingness to comply with all study procedures and avoid changes to current treatments (medications, physical therapy, cognitive behavioral therapy) for the duration of the study
5. For females of reproductive potential: negative pregnancy test or use of highly effective contraception for at least 1 month prior to baseline; agreement to use such a method throughout the study
6. Capacity to provide informed consent; provision of a signed and dated consent form

Exclusion Criteria:

1. History of serious brain injury or other neurologic disorder
2. Poorly managed general medical condition
3. Pregnant or breast feeding
4. Implanted device in the head or neck
5. MRI intolerance or contraindication
6. Brain stimulation (e.g., VNS, TMS) in the past month
7. Lifetime history of a serious suicide attempt (Hooley et al., 2014)
8. Clinically inappropriate for participation in the study as determined by the study team