A self-blinding citizen science trial with 191 participants tested whether microdosing psychedelics produces psychological benefits beyond a placebo. All psychological outcomes improved from baseline to after the four-week dose period in the microdose group, but the placebo group also improved, and no significant between-group differences were observed. Small, significant differences in acute measures (emotional state, drug intensity, mood, energy, creativity) and post-acute anxiety appeared, but these could be explained by participants breaking blind. The findings suggest that anecdotal benefits of microdosing can be explained by the placebo effect.
The psychedelic drug DMT rapidly induces a highly immersive state of consciousness with vivid visual imagery. In a study of participants who received DMT or placebo (saline) while keeping their eyes closed, brain electrical activity showed a pattern of cortical travelling waves similar to that normally seen during visual stimulation. The typical alpha-brainwave rhythms of eyes-closed rest were significantly reduced, while forward-directed waves from lower to higher brain regions increased. These findings support the idea that psychedelics reduce the brain's reliance on prior expectations, shifting the balance from top-down to bottom-up information processing, which may be a key mechanism underlying altered states of consciousness.