Journal of Psychopharmacology最新文献

{"title":"Beneficial adjunctive effects of the 5HT3 receptor antagonist ondansetron on symptoms, function and cognition in early phase schizophrenia in a double-blind, 2 × 2 factorial design, randomised controlled comparison with simvastatin.","authors":"Imran B Chaudhry, Muhammad Omair Husain, Ameer B Khoso, Tayyeba Kiran, Muhammad Ishrat Husain, Inti Qurashi, Raza Ur Rahman, Nasir Mehmood, Richard Drake, Nusrat Husain, Bill Deakin","doi":"10.1177/02698811241267836","DOIUrl":"10.1177/02698811241267836","url":null,"abstract":"<p><strong>Background: </strong>Variable benefits have been reported from the adjunctive use of simvastatin and the 5HT3 receptor antagonist, ondansetron, in patients with schizophrenia. We investigated their independent efficacy and possible synergy to improve negative symptoms of schizophrenia within a single trial.</p><p><strong>Methods: </strong>A 6-month, randomised, double-blind, placebo-controlled trial with a 4-arm, 2 × 2 factorial design, in three centres in Pakistan. In total, 303 people with stable treated schizophrenia aged 18-65 were randomly allocated to add-on ondansetron, simvastatin, both or neither. The primary outcome was a Positive and Negative Syndrome Scale (PANSS) negative score at 3 and 6 months.</p><p><strong>Results: </strong>Mixed model analysis and analysis of covariance revealed no main effects of simvastatin or ondansetron but a significant negative interaction between them (<i>p</i> = 0.03); when given alone, both drugs significantly reduced negative symptoms compared to placebo but they were ineffective in combination. Individual treatment effects versus placebo were -1.9 points (95%CIs -3.23, -0.49; <i>p</i> = 0.01) for simvastatin and -1.6 points for ondansetron (95%CIs -3.00, -0.14; <i>p</i> = 0.03). Combined treatment significantly increased depression and side effects. In those with less than the median 5 years of treatment, ondansetron improved all PANSS subscales, global functioning measures and verbal learning and fluency, whereas simvastatin did not.</p><p><strong>Conclusion: </strong>Small improvement in negative symptoms on simvastatin and ondansetron individually are not synergistic in combination in treating negative symptoms of schizophrenia. Ondansetron showed broad efficacy in patients on stable antipsychotic treatment within 5 years of illness. The findings suggest that ondansetron should be evaluated in patients at risk of psychosis or early in treatment.</p>","PeriodicalId":16892,"journal":{"name":"Journal of Psychopharmacology","volume":" ","pages":"818-826"},"PeriodicalIF":4.5,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11445972/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is lack of goal-conflict-specific rhythmicity a biomarker for treatment resistance in generalised anxiety but not social anxiety or major depression?","authors":"Shabah M Shadli, Carina J Donegan, Muhammad Ss Bin Mohd Fahmi, Bruce R Russell, Paul Glue, Neil McNaughton","doi":"10.1177/02698811241275627","DOIUrl":"10.1177/02698811241275627","url":null,"abstract":"<p><strong>Background: </strong>Anxiety and depression cause major detriment to the patient, family, and society - particularly in treatment-resistant (TR) cases, which are highly prevalent. TR prevalence may be due to current diagnoses being based not on biological measures but on symptom lists that suffer from clinical subjectivity, variation in symptom presentation, and comorbidity.</p><p><strong>Aims: </strong>Goal-conflict-specific rhythmicity (GCSR) measured using the Stop-Signal Task (SST) may provide the first neural biomarker for an anxiety process and disorder. This GCSR has been validated with selective drugs for anxiety. So, we proposed that GCSR could differ between TR and non-TR individuals and do so differently between those diagnoses normally sensitive to selective anxiolytics and those not.</p><p><strong>Methods: </strong>We recorded electroencephalograms (EEG) from 20 TR participants (4 GAD, 5 SAD and 11 MDD) and 24 non-TR participants (4 GAD, 5 SAD and 15 Comorbid GAD/MDD (GMD)) while they performed the SST.</p><p><strong>Results: </strong>There was significant positive GCSR in all groups except the GAD-TR group. GAD-TR lacked GCSR in the low-frequency range. However, TR had little effect in SAD or MDD/GMD populations with apparent increases not decreases.</p><p><strong>Conclusions: </strong>Overall, these results suggest that GAD may occur in two forms: one resulting from excessive GCSR and so being drug sensitive, and the other resulting from some other mechanism and so being TR. In SAD and MDD groups, heightened GCSR could be a consequence rather than the cause, driven by mechanisms that are normally more sensitive to non-selective panicolytic antidepressants.</p>","PeriodicalId":16892,"journal":{"name":"Journal of Psychopharmacology","volume":" ","pages":"789-797"},"PeriodicalIF":4.5,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11453030/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142108598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combining bioinformatics, network pharmacology and artificial intelligence to predict the target genes of S-ketamine for treating major depressive disorder.","authors":"Zhou Xianjin, Shen Fuyi, Yang Ti, Li Shan, Zhao Kang, Wang Ying, Deng Shengqiong","doi":"10.1177/02698811241268884","DOIUrl":"https://doi.org/10.1177/02698811241268884","url":null,"abstract":"<p><strong>Background: </strong>Ketamine has received attention owing to its rapid and long-lasting antidepressant effects; however, its clinical application is restricted by its addictiveness and adverse effects. S-ketamine, which is the S-enantiomer of ketamine, is considered safer and better tolerated by patients than ketamine.</p><p><strong>Aims: </strong>This study aimed to identify the key gene targets and potential signalling pathways associated with the mechanism of S-ketamine in major depressive disorder (MDD) treatment.</p><p><strong>Methods: </strong>The GSE98793 dataset was extracted from the Gene Expression Omnibus database, and differentially expressed genes were identified in blood samples from patients with MDD and healthy individuals. The hub genes among the differentially expressed genes were identified and enrichment analysis was performed. The therapeutic targets and related signalling pathways of S-ketamine in MDD treatment were analysed. The 3D structures of the target proteins were predicted using AlphaFold2, and molecular docking was performed to verify whether S-ketamine could be successfully docked to the predicted targets. A quantitative polymerase chain reaction was performed to determine the effect of ketamine on the screened targets. Among 228 target genes annotated using pharmacophore target gene analysis, 3 genes were identified and 2 therapeutic signalling pathways were discovered.</p><p><strong>Results: </strong>S-ketamine exerts downregulatory effects on TGM2 and HSP90AB1 expression but exerts an up-regulatory effect on ADORA3 expression. The protein structures of the therapeutic targets were successfully predicted using AlphaFold2.</p><p><strong>Conclusions: </strong>S-ketamine may alleviate depression by targeting specific genes, including <i>TGM2</i>, <i>HSP90AB1</i> and <i>ADORA3</i>, as well as signalling pathways, including the gonadotropin-releasing hormone and relaxin signalling pathways.</p>","PeriodicalId":16892,"journal":{"name":"Journal of Psychopharmacology","volume":" ","pages":"2698811241268884"},"PeriodicalIF":4.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141906884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compassionate use of esketamine intranasal in patients with severe major depressive disorder resistant to the treatment.","authors":"Luis Gutiérrez-Rojas, Julia Vendrell-Serres, J Antoni Ramos-Quiroga, Jon Iñaki Etxeandia-Pradera, Eduardo Aguilar, Ana Isabel De Santiago-Díaz, Daniel Hernández-Huerta, Vicente Tordera, Carlos Vázquez-Ventoso, Moisés Bolívar, Asunción Abril, Rubén Catalán-Barragán, Jesús García-Jiménez","doi":"10.1177/02698811241267837","DOIUrl":"https://doi.org/10.1177/02698811241267837","url":null,"abstract":"<p><strong>Background: </strong>Treatment-resistant depression (TRD) is defined as the failure of at least two antidepressants in adequate doses and timing during a major depressive episode. Esketamine intranasal (ESK-IN) has been approved by the Food and Drug Administration and the European Medicines Agency for the treatment of TRD in combination with other antidepressants.</p><p><strong>Aims: </strong>To assess the effectiveness and tolerability of a sample of TRD patients who received treatment with ESK-IN as part of the compassionate use program.</p><p><strong>Methods: </strong>A retrospective, observational study was carried out on patients with a diagnosis of TRD enrolled in the early access program of ESK-IN in nine centers. Effectiveness was assessed with the Montgomery-Asberg depression rating scale (MADRS) at four time points: baseline, 28, 90, and 180 days of treatment.</p><p><strong>Results: </strong>The sample included 71 patients (70% women) with a mean baseline MADRS score of 38.27 ± 5.9 and total or partial work disability rates of 85%. ESK-IN treatment was associated with a statistically and clinically significant reduction in the severity of depressive symptoms at all time points assessed. The presence of side effects was common but the majority were mild in severity and resolved after the observation period. Those patients who received psychotherapy in combination with ESK-IN showed a significantly lower MADRS score at 90 and 180 days than those patients who did not undergo psychotherapy.</p><p><strong>Conclusion: </strong>ESK-IN has proven to be effective and safe in a clinical sample of patients with severe TRD. To optimize clinical outcomes, the pharmacological treatment for TRD should always be integrated into a comprehensive therapeutic plan that encompasses strategies such as psychotherapy, social support, and family interventions.</p>","PeriodicalId":16892,"journal":{"name":"Journal of Psychopharmacology","volume":" ","pages":"2698811241267837"},"PeriodicalIF":4.5,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141902042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methylenedioxymethamphetamine is a connectogen with empathogenic, entactogenic, and still further connective properties: It is time to reconcile \"the great entactogen-empathogen debate\".","authors":"Kurt Stocker, Matthias E Liechti","doi":"10.1177/02698811241265352","DOIUrl":"10.1177/02698811241265352","url":null,"abstract":"<p><p>Science on methylenedioxymethamphetamine (MDMA) and MDMA-like substances is faced with the unique situation that this class of psychoactive agents is referred to with two basic names for its effects on the mind: empathogens and entactogens. Empathogen usually refers to the prosocial, empathetic, and openness properties of MDMA, while entactogen usually refers to the introspective and self-awareness properties of this substance. We review the origin and usage of the two terms, and also review recent findings that support that MDMA is an empathogen and an entactogen. Mostly no specified reasons can be detected whether research groups employ the term \"entactogenic,\" \"empathogenic,\" both, or neither, in their publications. A case is made that the use of two basic names for the effects on the mind for the same class of psychoactive substances is not warranted because a holistic principle underlies empathogenic and entactogenic properties of MDMA: an intense feeling of connection. Entactogenic characterizes being deeply connected to oneself, and empathogenic being deeply connected to others. We therefore suggest the name <i>connectogen</i> as the new basic name for the mind effects of MDMA and MDMA-like substances, a term having the connotation of <i>producing a joining together/producing a connection</i>. Thus, MDMA is basically a connectogen with at least the two major connective properties: entactogenic (intrapersonal) and empathogenic (interpersonal). Furthermore, first evidence shows that MDMA might also have further connectogenic properties such as a strong sense of connection with the here-and-now, the body, the world, and with spiritual principles. Finally, we compare connectogenic properties of MDMA with connectogenic properties of classic psychedelics, and lay out some future research in this regard.</p>","PeriodicalId":16892,"journal":{"name":"Journal of Psychopharmacology","volume":" ","pages":"685-689"},"PeriodicalIF":4.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11311894/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From chaos to kaleidoscope: Exploring factors in psychedelic self-treatment for mental health conditions.","authors":"Claire Walker, Timothy Piatkowski, Jason Ferris, Emma Davies, Monica Barratt, Adam Winstock, Cheneal Puljević","doi":"10.1177/02698811241265762","DOIUrl":"10.1177/02698811241265762","url":null,"abstract":"<p><strong>Introduction: </strong>This study explores how individuals self-treat psychiatric conditions with psychedelics outside medical guidance bridging the gap in understanding unregulated therapeutic use.</p><p><strong>Aims: </strong>The primary objective was to extract specific factors underlying the effects of psychedelics, exploring their relationship with the need for medication, particularly for mental health conditions like depression and anxiety. Additionally, we aimed to understand how the likelihood of being prescribed pharmacological medication varies based on mental health diagnoses and demographic factors.</p><p><strong>Methods: </strong>This research utilised the Global Drug Survey 2020, an annual online survey focused on substance use patterns and demographics, incorporating modules addressing mental health and psychedelic use. The study employed Exploratory Factor Analysis to discern latent factors underlying the self-reported effects of psychedelics. Bivariable and multivariable logistic regressions were conducted to investigate the association between identified factors and the likelihood of current prescribed medication usage.</p><p><strong>Results: </strong>In all, 2552 respondents reported using psychedelics for self-treatment of mental health conditions. Three significant factors were identified: Improved Mental Health, Improved Self-Awareness and Neuro-Sensory Changes. The majority of the sample reported a history of depression (80%) or anxiety (65.6%), with a significant association observed between reported factors of psychedelics' effects and current medication usage for mental health, especially notable in cases of depression or comorbid depression and anxiety.</p><p><strong>Conclusions: </strong>Perceived symptom improvement following psychedelic self-treatment may reduce the need for medically supervised pharmacological interventions. These findings highlight the potential of psychedelics to positively influence mental health and self-awareness, paving the way for further research into their therapeutic application.</p>","PeriodicalId":16892,"journal":{"name":"Journal of Psychopharmacology","volume":" ","pages":"749-760"},"PeriodicalIF":4.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11311900/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141792752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developing the Open Psychedelic Evaluation Nexus consensus measures for assessment of supervised psilocybin services: An e-Delphi study.","authors":"Philip Todd Korthuis, Kim Hoffman, Adrianne R Wilson-Poe, Jason B Luoma, Alissa Bazinet, Kellie Pertl, David L Morgan, Ryan R Cook, Sarann Bielavitz, Renae Myers, Robert Cameron Wolf, Dennis McCarty, Christopher S Stauffer","doi":"10.1177/02698811241257839","DOIUrl":"10.1177/02698811241257839","url":null,"abstract":"<p><strong>Background: </strong>Voter initiatives in Oregon and Colorado authorize legal frameworks for supervised psilocybin services, but no measures monitor safety or outcomes.</p><p><strong>Aims: </strong>To develop core measures of best practices.</p><p><strong>Methods: </strong>A three-phase e-Delphi process recruited 36 experts with 5 or more years' experience facilitating psilocybin experiences in various contexts (e.g., ceremonial settings, indigenous practices, clinical trials), or other pertinent psilocybin expertise. Phase I, an on-line survey with qualitative, open-ended text responses, generated potential measures to assess processes, outcomes, and structure reflecting high quality psilocybin services. In Phase II, experts used seven-point Likert scales to rate the importance and feasibility of the Phase I measures. Measures were priority ranked. Qualitative interviews and analysis in Phase III refined top-rated measures.</p><p><strong>Results: </strong>Experts (<i>n</i> = 36; 53% female; 71% white; 56% heterosexual) reported currently providing psilocybin services (64%) for a mean of 15.2 [SD 13.1] years, experience with indigenous psychedelic practices (67%), and/or conducting clinical trials (36%). Thematic analysis of Phase I responses yielded 55 candidate process measures (e.g., preparatory hours with client, total dose of psilocybin administered, documentation of touch/sexual boundaries), outcome measures (e.g., adverse events, well-being, anxiety/depression symptoms), and structure measures (e.g., facilitator training in trauma informed care, referral capacity for medical/psychiatric issues). In Phase II and III, experts prioritized a core set of 11 process, 11 outcome, and 17 structure measures that balanced importance and feasibility.</p><p><strong>Conclusion: </strong>Service providers and policy makers should consider standardizing core measures developed in this study to monitor the safety, quality, and outcomes of community-based psilocybin services.</p>","PeriodicalId":16892,"journal":{"name":"Journal of Psychopharmacology","volume":" ","pages":"761-768"},"PeriodicalIF":4.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141419549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chronic Cannabis users exhibit altered oscillatory dynamics and functional connectivity serving visuospatial processing.","authors":"Camilo A Castelblanco, Seth D Springer, Mikki Schantell, Jason A John, Anna T Coutant, Lucy K Horne, Ryan Glesinger, Jacob A Eastman, Tony W Wilson","doi":"10.1177/02698811241265764","DOIUrl":"10.1177/02698811241265764","url":null,"abstract":"<p><strong>Background: </strong>Cannabis is the most widely used psychoactive drug in the United States. While multiple studies have associated acute cannabis consumption with alterations in cognitive function (e.g., visual and spatial attention), far less is known regarding the effects of chronic consumption on the neural dynamics supporting these cognitive functions.</p><p><strong>Methods: </strong>We used magnetoencephalography (MEG) and an established visuospatial processing task to elicit multi-spectral neuronal responses in 44 regular cannabis users and 53 demographically matched non-user controls. To examine the effects of chronic cannabis use on the oscillatory dynamics underlying visuospatial processing, neural responses were imaged using a time-frequency resolved beamformer and compared across groups.</p><p><strong>Results: </strong>Neuronal oscillations serving visuospatial processing were identified in the theta (4-8 Hz), alpha (8-14 Hz), and gamma range (56-76 Hz), and these were imaged and examined for group differences. Our key results indicated that users exhibited weaker theta oscillations in occipital and cerebellar regions and weaker gamma responses in the left temporal cortices compared to non-users. Lastly, alpha oscillations did not differ, but alpha connectivity among higher-order attention areas was weaker in cannabis users relative to non-users and correlated with performance.</p><p><strong>Conclusions: </strong>Overall, these results suggest that chronic cannabis users have alterations in the oscillatory dynamics and neural connectivity serving visuospatial attention. Such alterations were observed across multiple cortical areas critical for higher-order processing and may reflect compensatory activity and/or the initial emergence of aberrant dynamics. Future work is needed to fully understand the implications of altered multispectral oscillations and neural connectivity in cannabis users.</p>","PeriodicalId":16892,"journal":{"name":"Journal of Psychopharmacology","volume":" ","pages":"724-734"},"PeriodicalIF":4.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11471968/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141860086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tripping into the unknown: Exploring the experiences of first-time LSD users through global drug survey insights.","authors":"Luke Baxter, Cheneal Puljević, Tim Piatkowski, Jason Ferris, Emma L Davies, Monica J Barratt, Adam Winstock","doi":"10.1177/02698811241254837","DOIUrl":"10.1177/02698811241254837","url":null,"abstract":"<p><strong>Background: </strong>The recreational use of LSD, a synthetic psychedelic drug, has surged in recent years, coinciding with a renewed research focus on its potential psychotherapeutic properties.</p><p><strong>Aim: </strong>This study aims to describe the experiences and perceptions of individuals engaging in LSD use for the first time, derived from a large international sample.</p><p><strong>Methods: </strong>This study utilised 2018 Global Drug Survey data collected from 6 November 2017 to 10 January 2018. Participants who initiated LSD use in the preceding 12 months answered questions on their experiences, social settings, harm-reduction behaviours, and demographics. Descriptive statistics were employed, and characteristics of those seeking emergency medical treatment (EMT) and those not planning further LSD use were compared with other respondents.</p><p><strong>Results: </strong>Among 3340 respondents who used LSD in the past year, their first-time experiences generally exceeded expectations, with 97.7% expressing excitement. Adverse and unwanted side effects were rarely reported, and only 17 individuals needed EMT. Feelings of fear were reported by most (64.1%), but only very mildly and not enough to put them off from wanting to use LSD again.</p><p><strong>Discussion: </strong>Although the occurrence of unwanted side effects seems low and the LSD experience is generally pleasurable, vigilance amid the rising illicit use of LSD through harm-reduction education is still important in preventing possible risks.</p>","PeriodicalId":16892,"journal":{"name":"Journal of Psychopharmacology","volume":" ","pages":"735-748"},"PeriodicalIF":4.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11311902/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141158265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research.","authors":"Vince Polito, Paul Liknaitzky","doi":"10.1177/02698811241254831","DOIUrl":"10.1177/02698811241254831","url":null,"abstract":"<p><p>Some recent research and commentary have suggested that most or all the effects reported by people who microdose psychedelics may be explained by expectations or placebo effects. In this rapid review, we aimed to evaluate the strength of evidence for a placebo explanation of the reported effects of microdosing. We conducted a PubMed search for all studies investigating psychedelic microdosing with controlled doses and a placebo comparator. We identified 19 placebo-controlled microdosing studies and summarised all positive and null findings across this literature. Risk of bias was assessed using the Cochrane risk-of-bias tool for randomised trials. The reviewed papers indicated that microdosing with LSD and psilocybin leads to changes in neurobiology, physiology, subjective experience, affect, and cognition relative to placebo. We evaluate methodological gaps and challenges in microdosing research and suggest eight reasons why current claims that microdosing is predominately a placebo are premature and possibly wrong: (1) there have been only a small number of controlled studies; (2) studies have had small sample sizes; (3) there is evidence of dose-dependent effects; (4) studies have only investigated the effects of a small number of doses; (5) the doses investigated may have been too small; (6) studies have looked only at non-clinical populations; (7) studies so far have been susceptible to selection bias; and (8) the measured impact of expectancy is small. Considering the available evidence, we conclude that it is not yet possible to determine whether microdosing is a placebo.</p>","PeriodicalId":16892,"journal":{"name":"Journal of Psychopharmacology","volume":" ","pages":"701-711"},"PeriodicalIF":4.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11311906/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141320985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}