Propofol-Enhanced Assessment of Ketamine for Chronic Pain and Depression

Randomized, Double-blind, Placebo-controlled, Single-center, Noninferiority Trial of Ketamine Given During Sedation to Patients With Chronic Pain and Depression

The goal of this clinical trial is to compare ketamine to a placebo when given as a single infusion during IV sedation in adults with chronic pain and depression. We do not know whether ketamine will be more effective than placebo under these circumstances.

This study aims to:

• Evaluate whether placebo is non-inferior to ketamine in treating chronic pain and depression, when delivered under propofol sedation
• Confirm that propofol sedation is a safe way to keep participants blinded to treatment
• Assess patients' comfort with the sedation process to improve future studies
• Explore whether patient expectations affects their pain and depression

Participants will:

• Need to qualify for the study based on stringent medical criteria
• Undergo sedation with propofol
• Randomly receive either a ketamine or a placebo (saline) infusion during sedation
• Complete several study assessments over 5-7 weeks

Ketamine is a dissociative anesthetic that has been in clinical use for more than 50 years. In addition to its well-known anesthetic and pain-relieving properties, ketamine has been found to have fast-acting antidepressant effects in patients with depression. However, the mechanisms underlying ketamine's ability to treat chronic pain and depression are poorly understood. A most basic question regarding ketamine's therapeutic mechanism is still unresolved: do patients need to consciously experience and recall ketamine's acute dissociative effects to receive lasting analgesic and antidepressant benefits? In this clinical trial, participants will receive either ketamine or a placebo when they are under sedation with propofol. A n=6 pilot feasibility phase will precede the fully-powered n=34 randomized controlled trial.

Enrollment for the n=6 pilot phase is complete as of 6/19/2025.

Inclusion Criteria:

• Age 18 to 70 years old
• Comfortable speaking and writing in English
• Chronic pain present daily for at least 3 months
• Currently experiencing depression
• Able to comply with the study protocol and communicate with study personnel about adverse events and other clinically important information

Exclusion Criteria:

• Pregnant or breastfeeding
• One or more health conditions that makes study unsafe or unfeasible, determined by study physicians
• Regular use of medications that may have problematic interactions with the study drugs
• Participating in another clinical trial which may conflict with this one