Chronic pain is associated with higher levels of pain-related distress, depression, emotional dysfunction, helplessness, hopelessness, and suicidality. Psilocybin is a psychoactive drug that may be well-suited to easing the psychological and emotional symptoms of distress associated with chronic pain. Previous studies testing psilocybin therapy have shown improvements on multiple behavioral and psychiatric outcomes, but it is unknown whether psilocybin therapy similarly enables patients to cope with chronic pain more effectively. The investigators will determine whether psilocybin therapy improves patients' ability to cope with chronic low back pain. If psilocybin therapy is an effective treatment in this population, its use could be incorporated into interventions for chronic low back pain and other psychological conditions.