Repeated low doses of LSD (20 μg twice weekly for six weeks) did not reduce ADHD symptoms more than placebo in adults with moderate-to-severe ADHD. In a double-blind randomized trial with 53 participants, the LSD group showed an average 7.1-point improvement on the ADHD symptom scale, while the placebo group improved by 8.9 points—a difference that was not statistically significant. The treatment was physically safe and psychologically well tolerated. The findings suggest that microdosing LSD, despite popular interest, offers no advantage over placebo for ADHD symptom relief.
Continuous intravenous infusions of DMT produce dose-dependent subjective effects that plateau after 30 minutes, with a ceiling effect for good drug effect at 1.8 mg/min. The highest dose tested (2.4 mg/min) caused greater anxious ego dissolution and significant anxiety compared to placebo. DMT showed dose-proportional pharmacokinetics and moderate acute tolerance. When participants could self-titrate their dose, they chose moderate to strong psychedelic effects comparable to the 1.8 mg/min rate. These findings can guide dose selection in future DMT research and show that subjective effects can be rapidly adjusted through dose titration.