Journal of psychopharmacology (Oxford, England)
June 25, 2026
Pavan S Brar, Rebecca B Price, Stephen Ross et al.
Psychedelic compounds like psilocybin and LSD are being studied again as potential treatments, but research usually excludes people at risk for psychosis. This narrative review examines the historical and theoretical links between psychedelics and schizophrenia spectrum disorders (SSDs), including the psychotomimetic hypothesis. The authors compare the phenomenological experiences induced by psychedelics with those of SSDs, finding both overlap and important qualitative differences that challenge a simple equivalence. They review neural mechanisms involving serotonin, dopamine, and glutamate. Clinical evidence shows psychedelics can worsen existing psychotic illness and may trigger psychosis in vulnerable individuals, though the risk magnitude is not well quantified. The authors suggest potential therapeutic applications for carefully selected symptoms in stable patients using low-dose, controlled approaches and provide recommendations for managing psychosis-related risk.
Psychopharmacology
June 20, 2026
E. C. H. M. Haijen-Bongers, P.p.m. Hurks, J. Schepers et al.
In adults with attention-deficit hyperactivity disorder, six weeks of biweekly low-dose lysergic acid diethylamide (20 µg) produced a limited effect on temporal processing, specifically on a time reproduction task, but did not improve performance on other neuropsychological measures of attention, inhibition, or motivational processing. The finding was observed in a secondary analysis of a double-blind, placebo-controlled trial with 46 completers. Baseline performance predicted some treatment outcomes differently between the LSD and placebo groups. The authors caution that the single positive result should be interpreted cautiously, especially because the parent trial showed no corresponding improvements in clinical symptoms.
Neuropsychopharmacology
June 18, 2026
Abigail E. Calder, Vincent J Diehl, Morten P. Lietz et al.
A single 100 µg dose of lysergic acid diethylamide (LSD) improved offline motor learning the next day and, one week later, reduced perceived stress and increased aspects of cognitive flexibility in 45 healthy adults. Electroencephalography showed that LSD acutely decreased N1 and P2 auditory event-related potential amplitudes, with P2 still modulated after one week. Transcranial magnetic stimulation revealed increased motor-evoked potential amplitude and faster latency under LSD. Brain-derived neurotrophic factor levels were unchanged. The findings suggest lasting effects of LSD on learning and neural signals, while highlighting challenges in measuring long-term potentiation in humans.
Acta neuropsychiatrica
June 10, 2026
Helerin Raikkerus, Andrea Bujour, Mark Kennedy et al.
A systematic review of research on psychedelics for ADHD identified only six studies meeting inclusion criteria. One randomized controlled trial found no statistically important difference compared to placebo. Three cross-sectional studies reported positive effects of psychedelics, and one found statistically important improvement measured by the Child Bipolar Questionnaire. A case study showed improvement in depressive symptoms and functioning with ketamine. The evidence is insufficient to recommend psychedelics for ADHD, and it remains unknown whether patients whose depression responds to ketamine also have ADHD. No research examined how psychedelics affect patient subgroups with different causes of symptoms.