Outcomes Registry After Ketamine Infusions for Chronic Pain: A Longitudinal Evaluation

Some key questions this study would like to answer: 1. How do patients respond to ketamine over time? This study will use surveys to track pain, sleep, mood, function, and other experiences for up to 16 weeks after a ketamine infusion. 2. Does the dose matter? This study aims to find out whether patients who get higher doses of ketamine have longer-lasting pain relief, and whether there is a point of diminishing returns. 3. What makes some patients respond better than others? For example, there are some early data suggesting that patients who worry more about their pain might have more trouble reducing their opioids after ketamine treatment even if they had pain relief. 4. Are ketamine infusions addictive when used for pain treatment? This study will track cravings and drug liking for up to 16 weeks after a ketamine infusion. Addiction risk is expected to be low, but this study will document this risk systematically. 5. What happens to patients who were recommended ketamine but denied insurance coverage? This study will compare their outcomes to patients who received ketamine, to better understand the impact of insurance denials and the real-world effects of ketamine treatment. STUDY PROCEDURES SUMMARY Upon consenting to the study, eligible participants will be asked to share their contact information, some background health information, details about their scheduled infusion, prior ketamine experience, and baseline symptoms. All personal information will be kept private and secure. Participants will be assigned a unique study number, and their name and contact details will not be shared with anyone outside the core study team. Afterwards, participants will: * Complete an online survey a few days before their infusion; then one survey each week for up to 16 weeks after their infusion. These surveys will track pain, mood, sleep, medication use, and other symptoms over time. * Optionally allow the study team to review medical records related to their ketamine treatment (such as the ketamine dose, side effects, and diagnoses linked with treatment). * Patients who were recommended ketamine but denied insurance coverage will have to opportunity to complete the same surveys