Experimental: Arm 1

Blinded study medication. This is a within-subject study so all session procedures will be identical. The specific medications administered that study day will be the only change each session. Study days will last approximately 8 hours and will be conducted on an outpatient basis. Participants will be asked to complete standardized pain testing procedures, do brief physical functioning testing, undergo blood draws and complete questionnaires and cognitive testing at multiple points over the course of each study visit.

Drug: Blinded study medication

Blinded study medication: This is a double-blind within-subject Phase II trial. Study medications will remain blinded. Participants may receive a dose of medication from one or more of the following categories: prescription stimulants, prescription benzodiazepines, prescription opioids, prescription cannabinoids, over-the-counter medications or placebo (sugar pill). All subjects will serve as their own control. Study medication administration will be randomized within each participant.

Other Name: stimulants, benzodiazepines, opioids, cannabinoids, OTC medications, placebo