The Effect of Psychedelics on Individuals with a Personality Disorder: Results from Two Prospective Cohort Studies

Abstract

Background:

Personality disorders (PDs) are characterized by impairments in psychological functioning for which pharmacologic treatments have demonstrated limited efficacy. Psychedelics may offer a possible PD treatment, given preliminary evidence for their potential long-term positive effects on psychological functioning. However, little is known about the safety or potential therapeutic effects of psychedelics among individuals with a PD. Therefore, we examined the effects of psychedelic use on mental health among individuals who self-reported a PD diagnosis.

Methods:

Study 1 included data from three prospective observational studies where 21 individuals who reported a PD diagnosis completed mental health measures (depression symptoms, anxiety, and suicidal ideation [SI]) before, 2 weeks, and 4 weeks after psychedelic use. Study 2 involved a prospective observational study where 55 individuals who reported a PD diagnosis completed mental health measures (depressive symptoms, anxiety, cognitive flexibility, expressive suppression, and cognitive reappraisal) before, 2–4 weeks, and 2–3 months after psychedelic use.

Results:

In Study 1, all participants with high baseline risk of suicidal behavior (6.67%) became low-risk post-psychedelic use. Post-psychedelic increases in SI were rare (6.67%) with no increases to high risk of suicidal behavior. SI reduced at 4 weeks (Hedges’ g = 0.52). There were several cases of clinically significant worsening of anxiety (Study 1: 0%; Study 2: 7.7 − 8.2%) and depression symptoms (Study 1: 0 − 7.1%; Study 2: 0%). However, across both studies, psychedelic use was associated with reductions in anxiety (Study 1: g = −0.46 to −0.57; Study 2: g = −0.52 to −0.89) and depression (Study 1: g = −0.54 to −0.59; Study 2: r_s = 0.52–0.57). In Study 2, there were transient increases in cognitive flexibility at 2–4 weeks (g = 0.26) and sustained increases in cognitive reappraisal up to 2–3 months (g = 0.36). Increases in cognitive reappraisal were associated with reductions in anxiety (r = −0.33) and depression (r_s = −0.37).

Conclusion:

Psychedelic use was on average associated with improvements in mental health outcomes for individuals who self-reported a PD diagnosis. There were no clinically significant post-psychedelic increases in SI, but there were a few cases of clinically significant increases in anxiety and depression severity. These preliminary findings are limited by the small sample size, self-reported data, and lack of differentiation between PDs. Further research is needed to explore the safety and potential therapeutic effects of psychedelics among individuals with a PD.