This placebo-controlled study (n=56) investigated the acute effect of psilocybin (15mg/70kg) on empathy and moral decision-making in healthy human subjects. The results found the first such evidence that psilocybin has distinct effects on social cognition by enhancing emotional empathy but not moral behavior. It also supports previous findings, indicating that psilocybin may promote emotional empathy presumably through activation of serotonin 2A/1A receptors, showing that focusing on serotonin 2A/1A receptors has the potential to treat dysfunctional social cognition.
“Background: Impaired empathic abilities lead to severe negative social consequences and influence the development and treatment of several psychiatric disorders. Furthermore, empathy has been shown to play a crucial role in moral and prosocial behavior. Although the serotonin system has been implicated in modulating empathy and moral behavior, the relative contribution of the various serotonin receptor subtypes is still unknown.
Methods: We investigated the acute effect of psilocybin (0.215 mg/kg p.o.) in healthy human subjects on different facets of empathy and hypothetical moral decision-making using the multifaceted empathy test (n=32) and the moral dilemma task (n=24).
Results: Psilocybin significantly increased emotional, but not cognitive empathy compared with placebo, and the increase in implicit emotional empathy was significantly associated with psilocybin-induced changed meaning of percepts. In contrast, moral decision-making remained unaffected by psilocybin.
Conclusions: These findings provide first evidence that psilocybin has distinct effects on social cognition by enhancing emotional empathy but not moral behavior. Furthermore, together with previous findings, psilocybin appears to promote emotional empathy presumably via activation of serotonin 2A/1A receptors, suggesting that targeting serotonin 2A/1A receptors has implications for potential treatment of dysfunctional social cognition.“