A placebo can produce psychedelic-like experiences in some people when the setting and expectations are carefully arranged. In a 4-hour group study with music, colored lights, and visual projections, 33 students took a placebo described as a psilocybin-like drug. Many reported no changes, but others showed effects as strong as those from moderate or high psilocybin doses. Most (61%) verbally reported some effect, such as seeing paintings move or reshape, feeling heavy, or experiencing a "come down" and then another "wave." Context and expectations can mimic psychedelic effects even without the drug.
Delusional ideation, or false beliefs, is linked to social factors such as feeling the presence of unseen others, loneliness, social anxiety, and empathy. A survey of 2,200 healthy adults during the COVID-19 pandemic found that all measured aspects of social imagery were positively associated with delusional ideation. The strongest predictor was felt presence, followed by loneliness, social fear, and empathic concern. The findings suggest that delusions may arise from common mechanisms with social imagination, and that alterations in social cognition contribute to delusional thinking.