Psilocybin as a Treatment for Chronic Pain in Smokers

Inclusion Criteria: * Veterans aged 21 to 65 years, who have been smoking tobacco cigarettes daily cigarettes for at least a year (confirmed with urine cotinine strips indicating smoking status (28) * not seeking treatment at the time of the study for tobacco use. * endorsement of bothersome or high-impact chronic non-cancer pain per the Graded Pain Scale - Revised (29); * in good health as verified by medical history, screening examination, and screening laboratory tests; and * body mass index (BMI) between 18 to 35 because there is limited information on the safety of psilocybin in individuals outside this range. * for women, not pregnant as determined by pregnancy screening, nor breastfeeding, and using acceptable birth control methods (e.g., oral contraceptives). Exclusion Criteria: * History of major medical disorders (e.g., diabetes, epilepsy, kidney or liver diseases, heart rhythm problems, heart failure, hypertension with BP greater than 140/90mmHg, history of cerebrovascular problems, severe asthma, etc.). * lifetime history of schizophrenia, bipolar disorder, dissociative disorders, or borderline personality disorder, current major depressive episode, or PTSD. * first- or second-degree relatives with a history of bipolar disorder or schizophrenia. * suicide attempt or ideation in the past year. * regular use of certain psychotropic medications (antidepressants, antipsychotics, mood stabilizers or anxiolytics) that are deemed to have the potential for adverse effe…