There are alternative ways to simulate the effects of psychedelics, one of which is holotropic breathwork. Developed by psychiatrist Stan Groff, it involves a pattern of fast and intense breathing accompanied by loud drumming, inducing a trance-like state similar to psychedelics. This method can produce vivid imagery and intense experiences without the use of drugs. It may affect the brain's default mode network by reducing oxygen supply. Humans may be more accepting of negative experiences in non-drug-induced states compared to drug-induced ones.