The promises of the Prozac century have fallen short; the number of novel, therapeutically significant medications successfully completing development shrinks every year; and the demand for better treatments constantly grows. Answering these hardships is a renewed optimism concerning the efficacy of controlled psychedelic therapy, a renaissance that has seen the resurgence of a familiar concept: intoxication as model psychosis. And yet, little has been made of where this peculiar idea originates. Why did we come to liken psychosis to intoxication, and (...) why is this an idea we find so hard to shake? Questioning the conventional narrative that identifies the concept as emerging in the mid 19th century, this article seeks to uncover the conceptual foundations underlying what is now intended by ‘model psychosis’. This investigation begins with an assessment of both Moreau de Tours’s concept of hashish madness in 1845 and Emil Kraepelin’s study of artificial insanity in the 1880s–90s. In seeking to contextualize these ideas, this article further considers the deeper historical association between intoxication and psychosis, instead proposing that intoxication represents an originary conception of madness. Bringing this examination into the 19th century, it becomes apparent that perceptions of intoxicants, and intoxication, were immanently participatory in the emerging understanding of psychosis. The contemporary understanding of model psychosis comes into focus when these elements coalesce with the advent of psychological modelling. Ultimately, the goal is not merely to understand how and why model psychosis became thinkable, but to examine how overlooked concepts have engendered new ways of being neuro-psychiatric subjects. (shrink)