Because it is complex, the risk run by users of hallucinogenic drugs to have flashbacks and perceptive persistent disorders is hard to assess and understand. Synthesis of the rare scientific publications regarding this topic allows to define more accurately the nature and frequency of these disorders, which may be characterised as flashbacks of the psychedelic experience, i.e. specific alterations of consciousness resulting from intoxication. Currently the visual perceptive persistent disorders are defined as specific and exclusive disorder based on neurophysiologic observations of a neurobiological alteration resulting from intoxication. Taking into consideration the numerous undemonstrated hypotheses advanced regarding the psychological and/or neurobiological aetiology of the said disorder, new experimental studies based on rigorous methodology seem to be needed to assess the resulting neurobiological, neuropsychological and cognitive alterations.