[Relations of model and drug-induced psychoses to schizophrenic diseases].

From the clinical point of view, substance-induced psychosis can be rather similar to schizophrenia. However, the question whether phenomenological resemblances represent similar underlying causal mechanisms is unsolved. Whereas the interest in experimentally induced psychosis was purely academic until the mid-1960s, the widespread use of "recreational" drugs provided this research with an important practical impact. With respect to a given case the differential diagnosis between schizophrenia and drug-induced psychosis it is often problematic. The differences in psychopathology refer to the disturbances of experience in general (Ichstörungen), the character of the hallucinations and the quality and quantity of the alterations of consciousness. Contrary to the sharp distinctions which used to be drawn between schizophrenia and drug-induced psychotic states, we hold that these states are rather similar, and may even represent a common underlying pathology. Hence, the renewed interest in the study on experimentally induced psychotic states using advanced methodology seems justified.