Brain Mechanisms Supporting Cannabis-induced Pain Relief

This study is looking into how inhaled cannabis affects brain activity and reduces chronic low back pain. Many people with chronic low back pain don't get enough relief from current treatments. Researchers want to understand how 400 mg of vaporized active cannabis (5.1% THC) works in the brain compared to a placebo cannabis (less than 0.1% THC). You may be able to join if you are 21-65 years old, have had lower back pain for at least three months, and have not used cannabis for 30 days. The main goal is to measure changes in blood flow in your brain. The study status is currently unclear, and they plan to enroll 100 participants.

Study design: This is an interventional study planning to enroll 100 participants. It compares active cannabis to a placebo.
What's involved: You will have one study visit at the Keck Center for Functional MRI at UC San Diego. This visit includes screening, questionnaires, pain testing, and brain imaging before and after inhaling cannabis.
Compensation: Not stated in the trial record.
Follow-up: All data will be collected at the single study session (Day 1).

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

Brain Mechanisms Supporting Cannabis-induced Pain Relief

Recruiting

EARLY_PHASE1Ages 21–65InterventionalBasic science

University of California, San Diego

~100 participants

Updated 2026-06-03 on ClinicalTrials.gov

What's tested:Active CannabisPlacebo Cannabis

At a glance

Recruiting sites

1 of 1 listed site is recruiting right now

RecruitingSuspended, closed, or not yet open

What they're measuring

Cerebral Blood Flow (CBF)

Measured over All data will be collected at the single study session (Day 1).

Conditions

Sciatica

Lumbar Radiculopathy

Lower Back Pain

Degenerative Disc Disease

Chronic Low-back Pain (cLBP)

Chronic Low Back and Leg Pain

Back Pain

Where it's being run

1 sites across 1 states

California1

Who to contact

Madelynn Meredith, BS

[email protected]

619-431-1850

Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Between 21-65 years old

Currently 30 days cannabis free

Lower back pain for three months or more

Are not taking opioids

If female and of a child bearing potential age, are not pregnant or nursing mothers

Do not have mental or neurological conditions inhibiting sensory/motor functions

Do not have a lifetime history of dependence on cannabis

Do not have a lifetime history of DSM-IV schizophrenia, bipolar disorder, panic disorder, or psychosis

Prior THC-containing cannabis experience within the past two years

Agrees not to use cannabis outside of the study during participation in the study

Agrees not to use opioids or barbiturates during participation in the study

Agrees not to drive a motor vehicle within 4 hours following last use of inhaled cannabis during participation in the study

Exclusion

Active pulmonary disease

Allergy or past adverse effects or negative past experiences from cannabis

Positive urine drug test for THC, barbiturates, opioids, oxycodone, or methadone

Any significant illness, including cardiovascular disease, diabetes, renal and liver disease.

Any current or history of an immunocompromising disease or condition (such as lupus, psoriasis, multiple sclerosis, etc.)

Any current or history of neurologic conditions, including Parkinson disease, dementia, cognitive impairment, history of seizure disorder, and history of traumatic brain injury/head injury

Any current major psychiatric illness, such as bipolar disorder, major depression, psychosis, substance use disorder, or schizophrenia

Any current or history of suicidal ideation or attempt

Overt sensitivity to thermal stimulation

Resting blood pressure \> 140/90

Resting heart rate \> 100 beats/minute

Prisoner

Institutionalized

Claustrophobia

MRI contraindications

Participation in any new (within 2 weeks prior or any time after enrollment) pain management procedures during the study period

Known history of vasovagal fainting, syncope, or severe adverse reactions associated with blood draws or needle procedures

What this trial measures

Cerebral Blood Flow (CBF)All data will be collected at the single study session (Day 1).
Changes in brain blood flow and oxygen levels will be measured using non-invasive MRI-based brain imaging methods. These scans will assess how much blood is reaching brain tissue and how oxygen levels in the brain change over time.

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