Study Overview: This study is about testing different treatments for chronic pain, which is long-lasting pain. It focuses on conditions like knee osteoarthritis, chronic low back pain, and diabetic nerve pain. The study will use special tests to understand how much pain people feel and how treatments work. Each treatment will be tested independently as they become available.

Eligibility: To join, you should have had daily pain for at least 12 weeks and be willing to keep your current non-drug pain treatments stable. You should not have certain heart problems, planned surgery, or a history of serious medical issues. Some conditions, like cancer within the last 2 years or fibromyalgia, might exclude you.

• Study involves stopping most pain medications, except rescue meds.
• No new non-drug pain treatments should be started during the study.
• Ensure a stable medical condition without serious health risks.