The overall aim of this study is to examine the effects of Delta-9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) on chronic pain symptoms, specifically we will examine the effects of different doses of THC/CBD on symptoms of chronic pain and life functioning. Participants will include individuals with chronic pain, who will be randomized into one of three intervention conditions: high THC/low CBD, low THC/high CBD, or placebo. In addition to receiving THC/CBD/placebo, participants also will complete symptom assessments of chronic pain data (intensity, quality, interference/disability) throughout the study. These measures will be gathered prior to and following the fifth doses (dosing will occur once per day for five days) of CBD/THC or placebo. A secondary objective will be to examine the association between clinical and neurocognitive variables and use of CBD/THC, including the potential side effects of THC/CBD. Other secondary objectives include the use of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS), acquired before and after final administration with CBD/THC or placebo to examine differences in brain metabolism, brain connectivity, and brain structure. Imaging analyses will focus on regional brain changes before and after administration of THC/CBD/placebo.