Disorder of the Natural Kind?

Neuropsychology of PTSD: Biological, Cognitive, and Clinical Perspectives. Jennifer J. Vasterling and Chris R. Brewin (Eds.). 2005. New York: The Guilford Press, 337 pp., $48.00 (HB). Philosophically, neuropsychologists believe the disorders they evaluate are of a natural kind: biologically real and existing independently of our means of classifying them, much like viruses or atomic structures exist separately from cultural outlook (McNally, 2004). We do not like to believe historical influences affect our evaluations, and nobody likes the idea that cognitive disorders can be created by merely marketing their existence. Social and cultural factors cannot be avoided when neuropsychologists move away from well-defined cerebral disorders to the study of subjectively defined disorders. Shorter (1994) elaborated the fluid presentation of hysteria over time, and ill-defined “railway spine” syndromes emerged when railroad accidents became compensable in 1800's Great Britain but not for orchard workers with similarly abrupt orthopedic strains. For a current controversy, consider how rising autism rates are believed to be biologically determined (e.g., mercury in vaccines) even though research underscores a proportional decline in mental retardation rates and autism rates still climbed long after mercury preservatives were eliminated in Denmark (Madsen et al., 2003). I refer to diagnostic “bracket creep” (e.g., “defining deviancy down” or “up” in the case of retardation), and “medicalization of misery,” variants of the idea that cultural pressures influence the vocabulary and scope of our inquiries. This can lead to increasing heterogeneity of our diagnostic categories, becoming a potentially insurmountable obstacle for those determined to discover a specific neurobiology for psychological suffering. Posttraumatic stress disorder (PTSD) is a myriad symptom constellation with widening boundaries under increasing neurocognitive scrutiny.