Leo Sher, M.D.

A research report, “Effects of psilocybin therapy on personality structure” has been published in Acta Psychiatrica Scandinavica online ahead of print (1). The authors state that the goal of their study was to investigate whether psilocybin with psychological support modulates personality parameters in patients with treatment-resistant depression,  to examine whether these alterations correlate with the quality of the psychedelic experience and to examine whether such modulations could help us understand the long-term effects of psilocybin therapy.

Twenty individuals with unipolar major depression of at least moderate severity (≥17 on the 21-item Hamilton Depression Rating Scale) and no improvement despite two courses of pharmacologically dissimilar antidepressant drugs for an adequate time were enrolled in this open-labeled study.  Patients attended a preparation visit, followed by two dosing sessions, separated by one week. During the first and second sessions patients received 10 mg and 25 mg of psilocybin, respectively.

Personality was evaluated using the Revised NEO Personality Inventory (NEO-PI-R), which covers 5 domains, Neuroticism (anxious, insecure, emotional), Extraversion (sociable, optimistic, talkative), Openness to Experience (or short: Openness) (curious, imaginative, creative), Conscientiousness (hard-working, ambitious, persistent), and Agreeableness (good-natured, cooperative, helpful). Baseline vs. 3-month follow-up NEO-PI-R scores were compared. The subjective experience under psilocybin was evaluated using the Altered State of Consciousness Questionnaire (ASC). The Quick Inventory of Depressive Symptoms, (QIDS-SR16) was used to assess depressive symptoms at baseline and at selected time points.

The authors found that personality trait Neuroticism reduced, while traits Extraversion, Conscientiousness (trend-level), and Openness all increased from baseline to the 3-month follow-up after psilocybin therapy for treatment-resistant depression. The degree of insightfulness during the psychedelic experience predicted changes in Neuroticism and Extraversion. The authors suggest that the increases in Extraversion and Openness might constitute an effect more specific to therapy with a psychedelic.

Reference

1. Erritzoe D, Roseman L, Nour MM, MacLean K, Kaelen M, Nutt DJ, Carhart-Harris RL. Effects of psilocybin therapy on personality structure. Acta Psychiatr Scand. 2018 Jun 19. doi: 10.1111/acps.12904. [Epub ahead of print]