Investigating the effects of a placebo cream on thermal pain responses in the brain

Placebo Effects on Anxiety and Pain

This study is testing if a placebo cream can change how the brain responds to pain from heat in different parts of the body.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 150 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Trustees of Dartmouth College (Academic / other)
• Locations: 1 site (Hanover, New Hampshire)
• Trial ID: NCT04653064 on ClinicalTrials.gov

What this trial studies

This study uses functional magnetic resonance imaging (fMRI) to explore how the brain processes thermal pain across different body sites. Participants will receive both a placebo cream and a control cream while undergoing painful thermal stimulation. The research aims to understand the brain's somatotopic representation of pain and how these representations are affected by the presence of a placebo. By comparing brain activity before and during pain stimulation, the study seeks to reveal insights into pain perception and modulation.

Who should consider this trial

Good fit: Ideal candidates are healthy adults aged 18 and older who can provide informed consent and have no recent history of pathological pain.

Not a fit: Patients with current or recent pathological pain or those unable to tolerate the study's procedures may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance our understanding of pain management and the role of placebo effects in pain treatment.

How similar studies have performed: While the approach of using fMRI to study pain and placebo effects is established, the specific focus on somatotopic representations in this context may provide novel insights.

Eligibility criteria

Inclusion Criteria:

* Subject must be a volunteer with a minimum age of 18 years and must be able and willing to provide written informed consent.
* If female, the subject must be non-lactating, not pregnant, and using a reliable contraception method.
* Subject must be able to read and speak English.
* Subject must be able to understand and follow the instructions of the investigator and understand all screening questionnaires.
* Subject must have no current or recent history of pathological pain.
* Subject must have abstained from alcohol and substance use for 48 hours.
* Subject must pass all fMRI screening tests.

Exclusion Criteria:

* If female, pregnancy.
* Inability to tolerate the scanning procedures (e.g., claustrophobia).
* Metal in body or prior history working with metal fragments (e.g., as a machinist).
* Inability to tolerate heat pain applied to the forearm.
* Reporting temporary abnormal levels of pain.
* Allergic response to the exfoliating cream.
* Current presence of pain.
* Current or past history of psychoactive substance abuse or dependence.
* Dementias.
* Movement disorders except familial tremor.
* CNS infection.
* CNS vasculitis.
* Inflammatory disease or autoimmune disease.
* CNS demyelinating disease (e.g. multiple sclerosis).
* Space occupying lesions (mass lesions, tumors).
* Congenital CNS abnormality (e.g. cerebral palsy).
* Seizure disorder.
* History of closed head trauma with loss of consciousness.
* History of cerebrovascular disease (stroke, TIAs).
* Abnormal MRI (except changes accounted for by technical factors or UBOs.
* Neuroendocrine disorders (e.g., Cushings disease).
* Uncorrected hypothyroidism or hyperthyroidism.
* Current or past history of cancer.
* Recent history (within two years) of myocardial infarction, severe cardiovascular disease, or currently active cardiovascular disease (e.g. angina, cardiomyopathy).
* Uncontrolled hypertension or hypotension.
* Chronic pain syndromes.
* Chronic fatigue syndromes.
* A history of neurologic disease or neuropathic pain.
* Prior treatment within the last month with any of the following: antidepressants, mood stabilizers, glucocorticoids, opiates.
* Prior treatment with any of the following: antipsychotics, isoniazid, centrally active antihypertensive drugs (e.g. clonidine, reserpine).
* Any other contraindications for MRI examination (e.g., metallic implants such as pacemakers, surgical aneurysm clips, or known metal fragments embedded in the body).
* Current treatment for psychiatric disorders including mood, anxiety, substance abuse, attention-deficit/hyperactivity disorder (ADHD), psychosis.
* Neurological disorders (e.g., taking dopamine agonists for Parkinson's) Cardiovascular disease or medication (e.g., taking ACE (angiotensin-converting-enzyme) inhibitors for cardiac remodeling).
* Frequent smoking (\> 5 cigarettes / day).
* Frequent alcohol use (\> 14 drinks / week).
* Frequent migraines (\> 5 / month on average).

Where this trial is running

Hanover, New Hampshire

• Dartmouth College — Hanover, New Hampshire, United States (Recruiting)

Study contacts

• Principal investigator: Tor D Wager, PhD — Dartmouth College
• Study coordinator: Tor D Wager, PhD

Conditions Pain