Multimodal creativity assessments following acute and sustained microdosing of lysergic acid diethylamide

Creativity is commonly reported as a subjective benefit of psychedelic microdosing, yet controlled laboratory studies have rarely detected objective improvements on standard creativity measures. The literature reviewed by Murphy and colleagues highlights conceptual and methodological challenges: creativity is often defined as producing outputs that are both novel and useful, and this bipartite conception has motivated tests of divergent thinking (idea generation) and convergent thinking (idea evaluation). Previous high-dose psychedelic studies have suggested acute increases in associative or generative processes alongside reductions in evaluative control, and post-acute effects have been inconsistent across substances, contexts and measurement approaches. Microdosing is proposed as a way to obtain associative benefits while preserving cognitive control, but existing microdosing studies are mostly uncontrolled, rely on self-report, or have used creativity tasks whose construct validity has been questioned. This study set out to address the gap between subjective reports and laboratory measures by administering a multimodal battery of creativity assessments within a placebo-controlled microdosing trial (the MDLSD trial). The battery combined standard divergent and convergent tasks (Alternate Uses Test, AUT; Remote Associates Task, RAT), an applied visual-art Consensual Assessment Technique (CAT), and a bespoke Everyday Problem-Solving Questionnaire (EPSQ) to capture everyday idea generation and evaluation. Given the limited and mixed prior evidence, the investigators did not state directional hypotheses but aimed to test whether acute (on-dose) or durable (two days after a six-week regimen) changes in creativity could be detected across these modalities.

The MDLSD trial randomised 80 healthy male participants to receive either 10 µg LSD (n = 40) or placebo (n = 40). Creativity assessments were secondary measures within the trial. Testing occurred at three visits: a drug-free Baseline, a Treatment visit approximately one week later at which the first 10 µg dose was administered and creativity tasks were repeated at 240 minutes post-dose, and a Final visit two days after the final in-home dose (participants self-administered 13 further doses on an every-third-day schedule). Task order within the battery was AUT, CAT, RAT and was not counterbalanced. Some AUT and RAT administrations were moved to remote (home) completion in one study wave because of COVID-19 restrictions; Treatment visits remained on-site. The creativity battery comprised: (1) Remote Associates Task (RAT) — three counterbalanced testing versions of 20 trials each, with number correct and number attempted as outcomes; (2) Alternate Uses Test (AUT) — three counterbalanced versions, scored for frequency (fluency), flexibility, elaboration and originality; (3) Consensual Assessment Technique (CAT) — a 15-minute visual-art task (create a design conveying ‘silliness’) with photographs rated by 16 secondary school art teachers for creativity and technical goodness on 0–10 visual analogue scales; and (4) Everyday Problem-Solving Questionnaire (EPSQ) — a bespoke instrument in which participants nominated a real-life problem context and rated difficulty of idea generation (mean of difficulty thinking of and visualising solutions) and idea effectiveness (mean of practicality and satisfaction). Language ability was measured at Baseline using the NIH Toolbox Picture Vocabulary Test to control for lexical skill in linguistic tasks. Analyses used linear mixed effects models (lmerTest in R) with Group (LSD vs placebo) and Visit (Baseline, Treatment, Final) as fixed effects and Participant as a random effect, conducted on an intention-to-treat basis. Vocabulary was included as a covariate in AUT and RAT models. Study wave (to index home versus lab administration) was examined in follow-up analyses. Effect sizes were reported as partial eta squared and inter-rater reliability for subjective ratings was assessed via Cronbach's alpha; an alpha > 0.7 was the threshold for acceptable agreement. The extracted text does not clearly report the exact Cronbach alpha values or all details of withdrawals, but notes that 75 participants completed the full course of doses (placebo = 39, LSD = 36) and that a small number of task administrations were missing or corrupted.

Across the multimodal battery there was no evidence of a drug-by-visit interaction indicating acute or durable effects of microdosing on measured creativity. The AUT showed no Group x Visit interaction and no main effects of Group or Visit on fluency, flexibility, elaboration or originality. Vocabulary had a significant effect on all AUT scales (for example, flexibility F = 20.42, p < 0.001, ηp2 = 0.207), with higher baseline vocabulary associated with higher AUT scores. The RAT likewise showed no Group x Visit interaction and no main effects of Group or Visit for number of items correct or attempted; however vocabulary strongly predicted RAT accuracy (F = 45.04, p < 0.001, ηp2 = 0.355), and participants with higher vocabulary got more RAT items correct. The CAT (external assessment of visual-art outputs) produced no interaction or main effects of Group or Visit on either creativity or technical goodness ratings as provided by the teacher raters. The EPSQ showed no Group x Visit interaction on idea generation difficulty or idea effectiveness, but there was a significant main effect of Visit on idea generation difficulty (F = 47.35, p < 0.001, ηp2 = 0.378): participants, regardless of group, rated idea generation as more difficult at Baseline than at the Final visit, with an estimated marginal mean difference of 17 points (SE = 2.47, p < 0.001). Follow-up analyses found no effect of study wave (home versus lab administration) on AUT or RAT outcomes. The extracted text documents some missing or corrupted task data (three AUT missing at one Treatment session in the placebo group; one missing/corrupted RAT instance in the LSD group at Baseline and Final; one CAT missing in the placebo Final) but does not provide participant-level attrition beyond the summary completion counts.

Murphy and colleagues report null findings across multiple objective measures of creativity: neither acute on-dose effects at 240 minutes nor durable effects two days after a six-week microdosing regimen were detected on divergent thinking (AUT), convergent thinking (RAT), externally rated practical creativity (CAT), or the bespoke everyday problem-solving questionnaire (EPSQ). The authors note a clear influence of baseline vocabulary on performance in the linguistic tasks, emphasising the importance of controlling for domain-specific skill when interpreting RAT and AUT results. By contrast, a reduction in self-rated difficulty of idea generation across visits was observed regardless of group, suggesting trial participation or placebo/expectancy effects influenced this self-report measure. Several explanations for the discrepancy between subjective reports of enhanced creativity and the objective null results are considered. First, limited statistical power could conceal small effects given the parallel-group design with 40 participants per arm. Second, the controlled laboratory testing environment may not capture the contexts in which microdosers report benefits — set and setting could moderate creative effects and the standardised clinic setting may suppress them. Third, standard creativity tests have contested construct validity: domain-specific tasks, task impurity (overlapping cognitive processes), closed-problem formats, and lack of measures of effectiveness can all limit sensitivity to the kinds of creative change microdosers describe. For instance, the RAT may be affected in opposing directions by increased semantic associativity and impaired convergent control under psychedelics, producing net null effects. Finally, expectancy effects may play a role: creativity was the domain with highest baseline expectancy among participants and prior analyses of the trial showed dose-day increases in self-rated creativity and wellbeing; however objective task performance did not mirror those subjective shifts. The authors suggest that subjective feelings of creativity may reflect mood-related uplift rather than measurable improvements in creative output, yet they also note potential therapeutic value if such feelings enhance wellbeing or could be harnessed in conjunction with art therapies. Limitations acknowledged include potential underpowering for subtle effects, lack of counterbalancing within the battery (raising fatigue concerns), presentation of the creativity battery as a secondary measure which prevented scheduling at peak subjective effects, restriction to a single low dose (10 µg), absence of a baseline control measure of visual-art skill, unknown test–retest reliability for the specific item sets and timepoints used, and COVID-19-related protocol adaptations that necessitated some remote testing. The authors conclude that further research should explore set and setting manipulations, include domain-specific skill controls or expert samples, and consider alternative or more ecologically valid outcome measures to determine whether the subjective creative benefits of microdosing can be operationalised or are primarily expectancy- or mood-driven.

In this placebo-controlled trial, a six-week microdosing regimen of 10 µg LSD produced no measurable changes in creativity on a multimodal battery administered acutely and two days after the regimen concluded. Participants from the same sample reported feeling more creative on dose days, suggesting a dissociation between subjective creative feeling and objective creative performance. The authors posit that any microdosing-related creative effects may be too small for standard laboratory tests to detect, may be confined to a subjective mood-related experience, or may depend on contextual factors such as set and setting; they recommend future work to manipulate these factors and to assess whether subjective creative feelings can be translated into functional or therapeutic benefit.