Researchers created a new questionnaire called the Afterglow Inventory to measure the positive effects people experience in the days and weeks after using psychedelics like psilocybin and LSD. These ‘afterglow’ effects include improved mood, feelings of spiritual connection, increased creativity, and better relationships. The study with over 1,300 participants showed the questionnaire works well at measuring these effects, which could help researchers better understand how psychedelics might help treat depression and other conditions.