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June 2026

LSD

What June 2026's 8 new studies found, synthesized from the papers below. All LSD research →

The synthesis

Synthesized from 4 studies in the library · AI-generated, grounded in the abstracts below

Found by searching the library for LSD, lysergic acid diethylamide, lysergide, then ranked by relevance.

Research on LSD in June 2026 shows mixed evidence: a small RCT found that repeated low-dose LSD (20 µg) improved temporal processing but not other cognitive domains in adults with ADHD, while a crossover trial in healthy subjects found that a higher dose (100 µg) improved motor learning and reduced stress one week later. However, a systematic review concluded there is insufficient evidence to recommend psychedelics for ADHD, and a narrative review highlighted risks of exacerbating psychosis in vulnerable individuals. The main caveats are the small sample sizes, secondary analyses, and lack of long-term safety data.

Confidence in the evidence

Low-Moderate
  • Only two human trials (one with 53 participants, one with 45) directly tested LSD effects, both with modest sample sizes.
  • The ADHD trial was a secondary analysis of a single RCT, limiting the strength of its conclusions.
  • A systematic review found insufficient evidence for psychedelics in ADHD, conflicting with the positive findings from the LSD trial.
  • The narrative review on schizophrenia highlights risks that are not addressed in the other studies, indicating incomplete evidence on safety.
How we rate confidence

Confidence reflects the strength of the underlying evidence, not whether the result is favorable. It weighs the number and size of studies, their design (randomized trials count for more than observational or single-case work), how consistently they point the same way, and their risk of bias.

Tiers run from Insufficient to High. High is rare in this field: small, early, or open-label studies land lower even when their direction is encouraging.

Evidence by study

Direction is each study's finding relative to your question: Supports, Opposes, No effect, Mixed, or Unclear.

Effects of repeated low-dose LSD on neuropsychological functioning in adults with ADHD: a randomized placebo-controlled study 2026
Mixed

Repeated low-dose LSD (20 µg) improved temporal processing but not attention, inhibition, or motivation in adults with ADHD.

RCT · Sample size: 53

Acute and post-acute neurobehavioral responses to lysergic acid diethylamide in healthy subjects: a randomized controlled study 2026
Supports

A single 100 µg dose of LSD improved offline motor learning the next day and reduced perceived stress and increased cognitive flexibility one week later.

RCT · Sample size: 45

The effects of psychedelics on attention deficit and hyperactivity disorder - a systematic review. 2026
No effect

There is not sufficient evidence to recommend psychedelics for ADHD; only one RCT found no statistically important difference compared to placebo.

systematic review

The intersection between psychedelics and schizophrenia spectrum disorders: Reevaluating risk and therapeutic potential. 2026
Opposes

Psychedelics can exacerbate pre-existing psychotic illness and may trigger psychosis in vulnerable individuals, though the magnitude of risk is not well quantified.

narrative review

Points of agreement

  • Both human trials found that LSD can produce measurable behavioral effects (improved temporal processing, motor learning, reduced stress) in controlled settings.
  • The systematic review and narrative review both indicate that evidence for therapeutic use is limited and that risks (e.g., psychosis) need further study.

Conflicts

  • The ADHD trial found improvements in temporal processing with LSD, while the systematic review concluded there is insufficient evidence for psychedelics in ADHD, highlighting a gap between a single positive trial and the overall evidence base.
  • The narrative review emphasizes risks of psychosis, whereas the human trials in healthy subjects and ADHD patients did not report such adverse effects, possibly due to exclusion criteria.

Gaps

  • No studies examined long-term safety or durability of effects beyond one week.
  • No research on LSD in clinical populations other than ADHD and healthy subjects was reported.
  • The ADHD trial was a secondary analysis, and the systematic review found only one RCT, indicating a need for more primary trials.
  • The relationship between dose, setting, and therapeutic outcomes remains unexplored in these studies.
Browse these studies in the library