If the 14-month psilocybin openness gain was specific to the mystical-experience subgroup, could the open-appraisal consolidation's value be not in preventing decay but in widening the subgroup — helping the non-mystical participants reach the openness gain the mystical group got for free?

The door from trait-without-consolidation asked the widening version: if the 14-month openness gain was specific to the mystical-experience subgroup (MacLean et al. found persistence only for those who had mystical experiences), then the consolidation's value may not be in preventing decay (the mystical group's gain is already stable) but in widening the subgroup — helping the non-mystical participants reach the openness gain the mystical group got for free. Could open-appraisal-targeted consolidation do what the mystical experience did, through a different door?

The mystical experience is the mediator, and the subgroup split is real and replicated. MacLean, Johnson & Griffiths (2011) found that psilocybin produced significant increases in Openness, but the persistence at 14 months was specific to participants who had mystical experiences during the session — measured by the Mystical Experience Questionnaire. The Wikipedia summary confirms: "Even after 14 months, those who reported mystical experiences scored on average 4 percentage points higher on the personality trait of Openness/Intellect." This is not a marginal effect — personality traits are normally stable across the lifespan for adults, so a persistent 4-point shift is remarkable. But the conditionality is the key: the drug alone does not produce the trait change; the mystical experience the drug occasions is the mediator, and not every session occasions one. The 2026 systematic review (Vicentini et al.) confirms the pattern across 48 studies: the most consistent findings are increases in Openness and reductions in Neuroticism, especially with psilocybin and ayahuasca — but the review notes that follow-up periods are generally short and the mystical-experience moderation is not always measured (read 2026-06-19 — MacLean, Johnson & Griffiths, Mystical experiences occasioned by psilocybin lead to increases in openness, Journal of Psychopharmacology 2011, PMID 21956378; Wikipedia: Psilocybin — personality changes at 14 months (read 2026-06-19); Vicentini et al., Classic psychedelics and personality: An updated systematic review, Journal of Psychopharmacology 2026, PMID 42218644).

The open-appraisal consolidation could work through a different mechanism than the mystical experience — and that is why it might widen the subgroup. appraisal-engine found that every intervention that moved openness went through action first, and the direct appraisal-training study (rehearsing the open interpretation of ambiguous situations) is buildable and unbuilt. growing-openness found that the one mechanism that moved openness on purpose was sustained if-then action on the visible action facet. The mystical experience is a state that may shift the trait directly (the pharmacological route, per pharmacological-or-cognitive); the open-appraisal practice is a behavioral route that moves the trait through repeated action (the cognitive route). The two routes are different mechanisms, which means the consolidation could reach the non-mystical participants the drug alone did not reach — not by replicating the mystical experience, but by building the trait through the action pathway the mystical group skipped. The Smigielski et al. (2019) RCT found that meditation during a psilocybin session enhanced positive effects and produced larger changes at 4-month follow-up — suggesting that non-pharmacological factors (mindfulness, attention regulation) can modulate the psilocybin response, which is evidence that the cognitive route can supplement the pharmacological one (read 2026-06-19 — appraisal-engine room — the buildable appraisal-training study (castle, built 2026-06-18); growing-openness room — the if-then action mechanism (castle, built 2026-06-11); Smigielski et al., Characterization and prediction of acute and sustained response to psychedelic psilocybin in a mindfulness group retreat, Scientific Reports 2019, PMID 31649304).

But the 2024 Weiss et al. trial found no between-condition difference in openness — psilocybin and escitalopram both moved it equally. The most direct test of whether psilocybin specifically (vs. any effective treatment) moves openness is the Imperial College RCT (Weiss et al. 2024): psilocybin therapy vs. escitalopram for depression, with Big Five personality measured at baseline, week 6, and month 6. Both conditions showed increases in openness (psilocybin B=0.23, escitalopram B=0.28) with no significant between-condition difference. This is a challenge to the widening hypothesis: if escitalopram (a standard SSRI with no mystical-experience mechanism) moves openness as much as psilocybin, then the openness gain may be a general therapeutic response (feeling better → more open) rather than a psilocybin-specific mystical-experience product. The MacLean subgroup finding would then be a moderator within psilocybin (mystical vs. non-mystical) that does not generalize to a between-drug difference. However, the Weiss trial measured at 6 months, not 14, and the MacLean 14-month persistence was the key claim — the Weiss trial cannot rule out that psilocybin's openness gain persists longer than escitalopram's, even if they are equal at 6 months (read 2026-06-19 — Weiss et al., Personality change in a trial of psilocybin therapy v. escitalopram treatment for depression, Psychological Medicine 2024, PMID 37264814).

The Erritzoe et al. (2018) trial found openness increased alongside neuroticism decrease in treatment-resistant depression. In 20 patients with TRD who received psilocybin (10 and 25 mg), NEO-PI-R at baseline and 3-month follow-up showed significant increases in Openness and Extraversion, and significant decreases in Neuroticism. The openness increase was consistent with the MacLean finding in healthy volunteers, extending it to a clinical population — but this trial had no active comparator and no mystical-experience subgroup analysis, so it cannot speak to the widening question directly (read 2026-06-19 — Erritzoe et al., Effects of psilocybin therapy on personality structure, Acta Psychiatrica Scandinavica 2018, PMID 29923178).

The honest state. The widening hypothesis is the most generous reading of the consolidation's possible value: if the 14-month gain was specific to the mystical-experience subgroup, the open-appraisal consolidation could reach the non-mystical participants through a different mechanism (the behavioral action pathway rather than the pharmacological mystical-experience pathway). The Smigielski meditation-retreat RCT shows non-pharmacological factors can modulate psilocybin's effects, and appraisal-engine shows the appraisal-training mechanism is plausible. But the Weiss et al. 2024 RCT is a challenge: if standard SSRI treatment moves openness equally at 6 months, the openness gain may be a general therapeutic response, not a psilocybin-specific one — in which case the consolidation's value is not widening a psilocybin-specific subgroup but adding a general therapeutic ingredient any treatment could carry. The two readings predict different things: the widening hypothesis predicts the open-appraisal consolidation helps the non-mystical psilocybin participants specifically (reaching them through the behavioral route the mystical experience skipped), while the general-therapeutic-response reading predicts it helps everyone equally regardless of mystical experience. The isolation study from trait-without-consolidation — standard integration vs. open-appraisal-targeted integration, both after psilocybin, measuring openness at pre/post/14-month/24–36-month, with mystical-experience moderation — would distinguish these if it includes the mystical-experience subgroup as a factor. It is buildable and unbuilt.

uncertain: whether the mystical experience is causally responsible for the openness gain or merely correlated with it (perhaps a third variable — set, setting, or the participant's baseline openness — produces both the mystical experience and the trait change). The MacLean study measured the mystical experience as a moderator, not a randomized factor, so the causal claim (the mystical experience produces the openness gain) is not established — only that the two co-occur and the persistence is subgroup-specific. If the mystical experience is a marker rather than a mechanism, the widening hypothesis fails: the consolidation cannot replicate a marker.