Regular ritual use of hoasca (ayahuasca) within a Brazilian religious group in the United States is associated with lower depression and confusion, higher agreeableness and openness, better memory performance, and less recent alcohol use compared to matched controls. The study of 30 members of the União do Vegetal and 27 non-user controls found no adverse effects on neuropsychological function. Lifetime hoasca use correlated with fewer physical health role limitations and less heavy alcohol use, suggesting the religious use of this psychedelic brew may have positive effects on mood and substance use.
A 10 mg dose of psilocybin produced a rapid, moderate-to-large reduction in compulsive symptoms in people with obsessive-compulsive disorder (OCD), lasting up to one week after dosing. In a blinded pharmacological challenge study, 18 adults with at least moderate OCD received a 1 mg and then a 10 mg dose of oral psilocybin, separated by four weeks. One week after the 10 mg dose, scores on the compulsion subscale of the Yale-Brown Obsessive Compulsive Scale showed a significant improvement compared to the 1 mg dose (Cohen's d = 0.74). No effect on depression was detected. The drug was well tolerated with no serious adverse events.