Personality change in a trial of psilocybin therapy v. escitalopram treatment for depression
Baker-Jones, M., Carhart-Harris, R. L., Erritzoe, D., Ginige, I., Giribaldi, B., Martell, J., Murphy, R., Murphy-Beiner, A., Nutt, D. J., Shannon, L., Weiss, B.
This analysis of an RCT (n=59) investigates the impact of psilocybin-assisted therapy (PAT) and escitalopram on personality traits in patients with moderate-to-severe major depressive disorder over a 6-week trial period. Significant decreases in neuroticism, introversion, disagreeableness, and impulsivity, and increases in absorption, conscientiousness, and openness were observed in the PAT group, while similar changes were seen in the escitalopram group.
Abstract
Background Psilocybin Therapy (PT) is being increasingly studied as a psychiatric intervention. Personality relates to mental health and can be used to probe the nature of PT's therapeutic action.Methods In a phase 2, double-blind, randomized, active comparator controlled trial involving patients with moderate-to-severe major depressive disorder, we compared psilocybin with escitalopram, over a core 6-week trial period. Five-Factor model personality domains, Big Five Aspect Scale Openness aspects, Absorption, and Impulsivity were measured at Baseline, Week 6, and Month 6 follow-up.Results PT was associated with decreases in neuroticism (B = −0.63), introversion (B = −0.38), disagreeableness (B = −0.47), impulsivity (B = −0.40), and increases in absorption (B = 0.32), conscientiousness (B = 0.30), and openness (B = 0.23) at week 6, with neuroticism (B = −0.47) and agreeableness (B = 0.41) remaining decreased at month 6. Escitalopram was associated with decreases in neuroticism (B = −0.38), disagreeableness (B = −0.26), impulsivity (B = −0.35), and increases in openness (B = 0.28) and conscientiousness (B = 0.22) at week 6, with neuroticism (B = −0.46) remaining decreased at month 6. No significant between-condition differences were observed.Conclusions Personality changes across both conditions were in a direction consistent with improved mental health. With the possible exception of trait absorption, there were no compelling between-condition differences warranting conclusions regarding a selective action of PT (v. escitalopram) on personality; however, post-escitalopram changes in personality were significantly moderated by pre-trial positive expectancy for escitalopram, whereas expectancy did not moderate response to PT.