Like most people of color in the United States, psychotherapist and researcher Monnica Williams has experienced myriad forms of racism. Early in her career, understanding its effects on her mind and body motivated her to help clients address their own racial trauma in therapy. But she found this was often long-term, painful work for them, punctuated by daily microaggressions and frequent reminders in the news of violence and oppression against people of color.

Williams often found herself wondering if there was a faster, deeper way to address the psychological effects of racial injustice—a way to heal the cultural and generational wounds of the past so that clients could feel stronger and readier to face new challenges. The field of trauma treatment was continually evolving. Was something out there that could help treat historical and racial trauma?

After years of research and meeting with scientists and other therapists looking for an answer to this same question, Williams decided to try for herself a promising but unconventional treatment she’d heard about. So, one afternoon last February, sitting in a room in Oakland with several spiritual guides at her side, she took a deep breath and swallowed a small handful of crushed psilocybin mushrooms. What happened next changed her forever.

“I saw my ancestors,”…