The Invisible Plague: The Rise of Mental Illness from 1750 to the Present (review)

Torrey and Miller argue that schizophrenia and manic-depressive illness have grown into an epidemic over the past 250 years. They base their claim on an examination of a wide range of sources, including memoirs, medical reports, asylum records, and literary sources from Ireland, Britain, Canada, and the United States. Asserting that "throughout history" the "baseline rate of insanity ...was approximately one case per 1,000" in the adult population, they find that beginning in the eighteenth century the rate began its steady rise to today's rate, which exceeds five cases per 1,000 (pp. ix–x). The authors reject the conclusions of a wide spectrum of historians of psychiatry who have shown that variations in the prevalence of psychiatric illness reflect changing social categories of behavior and diagnosis. This epidemic, according to Torrey and Miller, has been obscured by the influence of Michel Foucault and his followers, R. D. Laing and the antipsychiatry movement, and even by mainline medical historians, including Gerald Grob and the late Roy Porter. Along the way, the authors dismiss all but organic explanations for mental illness.

Even those sympathetic with the authors' assertion of an increase in mental illness may not find that Torrey and Miller have made a wholly persuasive case even on their own terms. They have done impressive research locating an enormous number of examples of mental distress in the geographic and temporal areas of their focus. The question of meaning, however, remains because one cannot simply assert that past behaviors are interpretable according to the categories of the most recent edition of psychiatry's Diagnostic and Statistical Manual (DSM). Indeed, revisions of the DSM over the past twenty years often have substantially altered definitions and even eliminated whole categories of mental illness (homosexuality) while constructing entirely new ones. Historians of medicine generally are reluctant to apply current understandings of acknowledged organic diseases to earlier afflictions, even when they appear similar. Infectious diseases, such as rheumatic fever and tuberculosis, have mutated over time, changing from acute to chronic conditions, as Peter English argued in Rheumatic Fever in America and Britain (New Brunswick, N.J.: Rutgers University Press, 1999). Retrospective identification based on similar sign presentations often is misleading. Even the identity of the much-studied Black Death, which the authors adopt as an emblem of epidemics, remains contested: Samuel K. Cohen, "The Black Death: End of a Paradigm" (Am. Hist. Rev., 2002, 107, 704–38).

The authors' examples come from four English-speaking nations and are limited to English-language sources. Even if they had made an unassailable case, they nevertheless have excluded possible variations in the rest of the developed world. Because there are no comparative data that contextualize the Euro-American/English-speaking populations, a more modest, tentative claim would be appropriate.

Throughout the study, Torrey and Miller point to a persistent belief among observers that modern urban environments contributed to a rise in mental illness. Although this association has been contested, a case could nevertheless be made for a number of conditions based on the emerging evidence that some psychiatric disorders may result from cross-reactions to infections. Thus, urbanization and migration might provide the conditions for such an increased risk of exposure. Certainly, there is increasing associative evidence, as in Torrey's Surviving Schizoprenia (New York, N.Y.: Quill, 1994), that schizophrenia may be connected to downstream effects of exposure to infective agents. Despite Torrey's long career of constructing a case for the organic etiology of psychiatric disorders, no sustained discussion appears in these pages. Such an analysis might provide the most compelling explanation for the putative epidemic, but readers are offered only a brief, three-page list of possible biological scenarios in a final chapter. Thus, it is difficult to accept Torrey and Miller's claims because their revelations of increased concern with mental...