Psilocybin With Pimavanserin Compared to Psilocybin Alone for the Treatment of Major Depressive Disorder

In this study, the researchers want to probe the role of the 5-HT2A receptor in mediating the subjective effects of psilocybin. While previous studies have shown that blockage of the 5-HT2A receptor reduces the psychedelic experience in humans, an animal study revealed that blockage of the 5- HT2A receptor abolished the psychedelic effects without affecting the antidepressant response. This suggests that the pathway responsible for the antidepressant response is dissociated from the psychedelic experience pathway, which is mediated by 5-HT2A signaling.