RecruitingEarly Phase 1Drug trialPsilocybin-facilitated Treatment for Chronic PainThe primary purpose of this study is to preliminarily estimate the efficacy of psilocybin-facilitated treatment for fibromyalgia. Investigators will assess the impact of psilocybin-facilitated treatment on pain, fatigue, and other fibromyalgia symptoms, in addition to the level of functioning and quality of life. Investigators will also evaluate potential mediators of treatment (e.g., treatment expectations, pain characteristics, personality, beliefs/cognitions, emotions). Investigators hypothesize psilocybin treatment will significantly reduce symptom severity in fibromyalgia patients.