Comparing the Detection of Endogenous Psychedelics in Individuals With and Without Alleged Mediumistic Experiences

•Dimethyltryptamine not detected in urine specimens from mediums and non-medium controls.•No difference in bufotenine detection in urine specimens between mediums and non-medium controls.•Mediums reported more anomalous experiences, but similar mental health scores. Mediumship is the alleged ability to communicate with deceased personalities. Previous studies have suggested that the endogenous psychotomimetic molecules bufotenine (BT) and dimethyltryptamine (DMT) may play a role in the pathogenesis of psychotic disorders. Distortion of perceptions observed during spiritual experiences could supposedly relate to these substances. To compare the presence of BT and DMT in human urine samples between individuals with and without mediumistic experiences. All participants (5 from medium's group - MG and 5 from non-medium's group - CG) undertook a single night continuous 6-h urine pool collection (6:00–11:59 PM). Mediums collected urine samples in nights when they reported having experienced mediumistic communication. A sensitive high-performance liquid chromatography-mass spectrometry (HPLC-MS) assay was used. Questionnaires were used to detect common mental disorders symptoms, and to screen and quantify anomalous experiences. DMT was not detected in any urine specimen tested. The presence of BT detection in urine samples was greater in CG (2/5) than in MG (1/5), with no significant differences (p > 0.99). MG reported more anomalous experiences than CG (6.6±0.8 vs. 2.2±1.5, p = 0.03), but there was no difference concerning their mental health. There were no differences between individuals with and without alleged mediumistic experiences concerning endogenous psychedelics. Both BT and DMT are highly sensitive to metabolism by monoamine oxidase and to N-oxidation, and do not survive in the periphery for long. Alternative strategies should be considered to further investigate the putative role of the endogenous psychedelics pathway for the spiritual experiences.