Without patient's knowledge fear over ramp and drug use and the spread of the counterculture movement. not to mention harvard professor timothy liri, urging people to turn on, tune in and drop out lead to a clamp down. >> this nation faces a major crisis in terms of the increasing use of drugs, particularly among our young people. >> in 1970, president richard nixon sayyed the controlled substances act nearly all scientific research in the us into the effects of psychedelics on people stopped. it wasn't until 2000. it's scientists, roland griffiths, one fda approval to study psilocybin this whole area of research has been in the deep freeze for 25 or 30 years. and so as a scientist, sometimes i feel like rip van winkle. >> once you saw results, yeah, that red lights start flashing. >> this is extraordinarily interesting. it's unprecedented and the capacity of the human organism to change. it just was astounding.