Abstract Background Ayahuasca, a psychoactive Amazonian preparation, is increasingly studied for substance-use disorders. Objectives Investigate whether oral lyophilised-ayahuasca attenuates ethanol-induced conditioned place preference (CPP) in mice and alters ΔFosB expression in nucleus accumbens (NAc). Methods Male Swiss mice received water or ayahuasca (130-1950 mg/kg, p.o.) 30 min before...