Mystical delirium is a form of alteration of reality at the level of beliefs, perception and thought. It manifests clinically by the presence of various symptoms including cognitive symptoms such as memory impairment and disorganized thinking. These symptoms are observable through the subject’s language and verbalizations. The purpose of this article is to examine the extent to which speeches produced by radicalized people contain signs of mystical delirium. The study relates to 20 subjects who have posted online written and/or video productions considered to be “delusional” and having led to their hospitalization. The detailed analysis of the content of these verbalizations made it possible to highlight psycholinguistic markers of the grip, insertion and blocking of thought, by using the techniques of predictive linguistics and the tools of natural language processing (NLP). Key Words Psychopathology, Mystical Delirium, Religious Radicalization, Mental Health, Predictive Linguistics, NLP.