[Problems of toxic psychosis as illustrated on the example of the so-called LSD psychosis].

The effects of LSD are characterized by a number of disturbances of perception and experience, which can be observed in the fields of visual, spatial and temporal perception and of affectivity. We also see disturbances of experience, which can otherwise be observed only in psychoses, for example reduction or change of cognitive functions, but also depersonalization and euphoria. In atypical courses of intoxication ("horror-trips") anxiety and excitement are predominant. Atypical courses of intoxication may be interrupted by "talk down" and additional application of tranquilizers. In a certain number of LSD-users in our clinic we saw psychoses. We classify them into flash-backs, exogenic (toxic) psychoses and so-called "endoform psychoses". The latter implies three possible constellations: accidental coincidence of LSD-use and psychosis; pre-existing psychosis with symptomatic use of LSD as an attempt of self-treatment; finally the onset of a psychosis may be triggered by the use of the halluzinogen. From the symptomatological cross-section they cannot reliably be distinguished from real schizophrenia. An independent nosological unit "LSD-psychosis" does not seem to exist.