{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,25]],"date-time":"2026-10-25T04:07:03Z","timestamp":1792901223550,"version":"4.5.0"},"reference-count":33,"publisher":"SAGE Publications","issue":"7","license":[{"start":{"date-parts":[[2026,6,28]],"date-time":"2026-06-28T00:00:00Z","timestamp":1782604800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["J Psychopharmacol"],"published-print":{"date-parts":[[2026,7]]},"abstract":"<jats:sec>\n                    <jats:title>Background:<\/jats:title>\n                    <jats:p>Psychedelic microdosing\u2014repeated sub-perceptual doses of lysergic acid diethylamide (LSD) or psilocybin\u2014has attracted scientific interest as a potential mood and cognitive intervention. The evidence base remains methodologically heterogeneous and vulnerable to expectancy bias.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>We conducted an umbrella review with narrative synthesis following Joanna Briggs Institute guidance and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 standards (International Prospective Register of Systematic Reviews [PROSPERO]: 2020 standards (PROSPERO: CRD420251077340). Six databases were searched through February 2026. Eligible studies were systematic reviews and\/or meta-analyses examining microdosing effects (\u2a7d20\u2009\u03bcg LSD or \u2a7d3\u2009mg psilocybin per session) on mood or cognitive outcomes in adults. Quality was appraised with A Measurement Tool to Assess Systematic Reviews-2; primary-study overlap was quantified via corrected covered area (CCA).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>\n                      Three meta-analyses met quantitative criteria, drawing on 14 studies (13 unique samples,\n                      <jats:italic toggle=\"yes\">N<\/jats:italic>\n                      \u2009=\u20091614); three reviews contributed to narrative synthesis. Primary-study overlap was very high (CCA\u2009=\u20090.29). The sole significant pooled effect was a small decrease in cognitive control (\n                      <jats:italic toggle=\"yes\">d<\/jats:italic>\n                      \u2009=\u2009\u22120.34, 95% CI: \u22120.62 to \u22120.06); all other domains were non-significant. No eligible meta-analysis provided pooled mood-outcome effect sizes within the microdose threshold; narrative evidence indicates that self-reported mood benefits are largely attenuated under placebo-controlled conditions. Short-term tolerability was acceptable, though cardiovascular signals and long-term risks via 5-HT\n                      <jats:sub>2<\/jats:sub>\n                      B activation remain uncharacterized.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions:<\/jats:title>\n                    <jats:p>Current evidence does not support cognitive enhancement through microdosing; the only consistent controlled finding runs counter to popular claims: microdosing was associated with a small but reliable impairment of cognitive control. Observed mood benefits are not replicated under blinded conditions, consistent with expectancy-driven responding. Adequately powered, preregistered, expectancy-controlled trials are required before clinical recommendations can be made.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/02698811261456196","type":"journal-article","created":{"date-parts":[[2026,6,28]],"date-time":"2026-06-28T12:20:21Z","timestamp":1782649221000},"page":"1091-1102","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":1,"title":["Classical psychedelic microdosing, mood, and cognitive function: An umbrella review with narrative synthesis"],"prefix":"10.1177","volume":"40","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-9441-036X","authenticated-orcid":false,"given":"Yi\u011fit","family":"\u00d6zayd\u0131n","sequence":"first","affiliation":[{"name":"Department of Child and Adolescent Psychiatry, D\u00f6rtyol State Hospital, Hatay, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-3729-5043","authenticated-orcid":false,"given":"Buket","family":"Canlan \u00d6zayd\u0131n","sequence":"additional","affiliation":[{"name":"Department of Child and Adolescent Psychiatry, D\u00f6rtyol State Hospital, Hatay, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2026,6,28]]},"reference":[{"key":"e_1_3_3_2_1","doi-asserted-by":"crossref","unstructured":"Anderson T Petranker R Rosenbaum D et al. 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