Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtainthe best experience, we recommend you use a more up to date browser (or turn off compatibility mode inInternet Explorer). In the meantime, to ensure continued support, we are displaying the site without stylesand JavaScript.AdvertisementYou have full access to this article via your institution.Scientists in search of psychedelic drug treatments have developed a way to determine whether a molecule is likely to cause hallucinations, without testing it on people or animals.Growing evidence...…Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtainthe best experience, we recommend you use a more up to date browser (or turn off compatibility mode inInternet Explorer). In the meantime, to ensure continued support, we are displaying the site without stylesand JavaScript.AdvertisementYou have full access to this article via your institution.Scientists in search of psychedelic drug treatments have developed a way to determine whether a molecule is likely to cause hallucinations, without testing it on people or animals.Growing evidence...WW…