From madness to mental illness

Reports of psychotic episodes characterized by irrational, unintelligible behaviours and hallucinations are frequent throughout historical narratives. Appropriately contextualized, some of these descriptions appear to resemble the paranoid, and catatonic characteristics of schizophrenia, respectively, yet holistic accounts of schizophrenia-like syndromes rarely exist prior to the 19th century.1 Despite evolving diagnostic criteria and treatment approaches, and more than 100 years since the demarcation of schizophrenia by Eugen Bleuler in 1908, the etiology, neuropathology and pathophysiology of schizophrenia remain elusive.2-4 No biological markers possess the sensitivity and specificity expected of a diagnostic test, and schizophrenia persists conceptually as a broad clinical syndrome characterized by a range of subjective symptoms with varying patterns of course.5-8 This heterogeneity coupled with a lack of coherence between clinical and preclinical evidence have fueled speculation about the validity of current conceptualizations of the illness.9-12 Nevertheless, patients exhibit typical symptom progression over time, appear to respond favourably to particular treatment approaches, and despite inconsistencies in diagnostic classification, alternative proposals do not offer improvements in any of these categories.13,14 Undoubtedly, further parsing of schizophrenia and related disorders will be necessary to advance future treatment and diagnostic approaches. In this review, we briefly outline the origins of schizophrenia as it is conceptualized contemporarily by linking ancient medical descriptions with modern clinical perspectives, and discuss why historical accounts of schizophrenia may not accurately reflect its prevalence in the past.