APZ questionnaire

The APZ (Abnormal Mental States) questionnaire is one of the most widely used psychometric scales for assessing subjective experiences of altered states of consciousness.^[1] First published in 1998 by Adolf Dittrich, the APZ questionnaire comprises three dimensions: "Oceanic Boundlessness (OSE)", "Dread of Ego Dissolution (AIA)" and "Visionary Restructuralization (VUS)".^[2] According to Google Scholar, it has been cited at least 269 times.