A multidisciplinary working group reviewed evidence on the similarities and differences between hallucinations induced by psychedelics and those occurring in schizophrenia-spectrum disorders, examining data from pharmacology, brain imaging, phenomenology, and anthropology. The authors highlight both shared features and distinct characteristics across these scales, and attempt to integrate findings using computational approaches. They conclude with recommendations for future research, emphasizing the need for further study to clarify the relationship between these types of hallucinations.
Trauma can contribute to voice-hearing but is not necessary for it. This article uses ethnographic and other data to show multiple pathways to voice-hearing in both clinical and nonclinical populations, excluding known causes like drugs or epilepsy. Trauma sometimes plays a major role, sometimes a minor role, and sometimes no role at all. Distinct phenomenological patterns in voice-hearing may reflect different salience of trauma for those who hear voices.