Chronic low back pain (CLBP) afflicts up to 50 million U.S. adults and is a primary cause of disability and reduced quality of life. The prescription of opioids for chronic low back pain (CLBP) has increased substantially within the past decade in the U.S. As noted by the CDC in their recent Guideline (released in March 2016): "Opioids are commonly prescribed for pain. An estimated 20% of patients presenting to physician offices with noncancer pain symptoms or pain-related diagnoses (including acute and chronic pain) receive an opioid prescription. Interestingly, patients scoring very high on measures of psychological distress tend to be systematically excluded from RCTs, even though this subgroup of patients is highly prevalent within the chronic pain population.