Changes in neuroticism and values after naturalistic use of psychedelics and MDMA: A prospective survey study

This prospective observational study examined whether planned naturalistic use of serotonergic psychedelics or MDMA was associated with changes in neuroticism (a personality trait linked to emotional instability and vulnerability to anxiety and depression) and personal values over four weeks.

Participants planned to take psychedelics or MDMA in a naturalistic context.

1. Neuroticism decreased after four weeks - Participants showed a significant reduction in neuroticism four weeks after their psychedelic or MDMA experience.

2. Shame and tension improved the most - The largest changes occurred in specific components of neuroticism rather than across every aspect of the trait.

3. Personal values shifted towards relationships and spirituality

One week after the experience, participants reported placing greater importance on:

• family,

• intimate relationships,

• citizenship/community,

• spirituality.

Most of these increases diminished over time. However, the increased importance placed on family remained statistically significant at four weeks.

4. Psychedelics and MDMA differed in their effects on spirituality

Although both psychedelics and MDMA were associated with reduced neuroticism, serotonergic psychedelics produced a significantly larger increase in spirituality than MDMA.

This suggests that while both classes may influence emotional functioning, classic psychedelics may have a stronger effect on spiritual or existential perspectives.

Abstract

Background

Serotonergic psychedelics and MDMA may improve mental health through reductions in neuroticism and changes in personal values. While decreases in neuroticism following serotonergic psychedelics are sometimes observed, it is unclear which facets of neuroticism respond the most, and MDMA remains understudied. People also report value shifts after psychedelic experiences, but prospective data are limited. This study examined changes in neuroticism and twelve personal values after planned, naturalistic use of psychedelics and MDMA.

Methods

Participants planning to use psychedelics or MDMA (N = 74) completed surveys at baseline, one day post-experience, one week, and four weeks follow-up. Neuroticism was assessed with the NEO-FFI and personal values with a modified Valued Living Questionnaire. Linear mixed effects models examined changes over time.

Results

Neuroticism significantly decreased at four weeks (β=-2.64, p<.001), though not at one week (β=0.01, p = 0.99), for users of both serotonergic psychedelics and MDMA. Reductions were most pronounced for items assessing shame and feelings of tension. Participants rated the values of citizenship (β = 0.68, t = 2.63, p = 0.01), family (β = 0.80, t = 3.64, p < .001), intimate relationships (β = 0.57, t = 2.88, p = 0.01), and spirituality (β = 1.04, t = 4.08, p < .001) as more important one week after their psychedelic experience; only family remained elevated at four weeks (β = 0.57, t = 2.41, p = 0.02). Serotonergic psychedelics were associated with greater spirituality increases than MDMA (β = 2.19, t = 4.19, p = .005).

Discussion

Planned consumption of psychedelics and MDMA in naturalistic settings was associated with decreased neuroticism and transiently increased importance of relational and spiritual values. The increased importance of family persisted longest, lasting up to four weeks. These findings expand the literature on self-reported changes in neuroticism and identify potential mechanisms underlying changes in well-being after psychedelic experiences.

Calder AE, Diehl VJ, Hinney B, Hasler G. Changes in neuroticism and values after naturalistic use of psychedelics and MDMA: a prospective survey study. J Affect Disord Rep. 2026;25:101127. doi:10.1016/j.jadr.2026.101127. Read Paper

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