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

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.