Abstract

This paper presents a taxonomy of altered states of consciousness (ASCs), primarily based on their central phenomenological features. Following taxonomic principles and a modified Delphi methodology, a multidisciplinary, international group identified eight distinct phenomenological/behavioral states (some with subcategories): proto and transitional, delirium, minimal to no awareness, experiential detachment, enhanced physicality, altered identity, imaginary/fantasy/visionary, and unity/mystical. We hope this taxonomy will be discussed and developed further, fostering conceptual clarity and stimulating research and integration across different specializations. A nuanced discussion of different states should reveal what is common and different across different triggers and antecedents of ASCs, and encourage their phenomenological, psychological, cultural, and neuroscientific understanding. This will pave the way to an integrated understanding of different modalities of experiencing.