Diagnosing Liability: The Legal History of Posttraumatic Stress Disorder

Abstract

This Article examines the origins of the unique relationship between the psychiatric diagnosis Post-traumatic Stress Disorder (PTSD) and the law and considers the implications of that relationship for contemporary uses of the diagnosis in legal settings. PTSD stands apart from all other diagnoses in psychiatry’s standard classification system, the Diagnostic and Statistical Manual of Mental Disorders (DSM) - and is the focus of significant controversy within psychiatry - because its diagnostic criteria require a determination of causation. By diagnosing a person with PTSD, a clinician necessarily assigns responsibility to a specific event or agent for causing the person’s symptoms, a practice more commonly associated with the law. In short, the diagnosis uniquely medicalizes liability. The law has turned to PTSD, on the erroneous assumption that its location in the DSM signifies that it is well-settled science, to serve as a mechanism to resolve difficult problems in assessing legal responsibility. These uses include determining whether a criminal complainant is credible and when emotional distress from another’s negligence is sufficient in itself to serve as a basis for liability. However, by adopting PTSD’s conceptualization of causation of psychological injury, courts unknowingly delegate normative determinations of liability to psychiatry broadly and to the individual psychiatrists who present PTSD evidence at trial. I argue that the legal system should consider PTSD’s origins and its persistent controversies as part of a broader reexamination of the role of the diagnosis in the law.

Keywords: PTSD, posttraumatic, evidence, psychiatry, diagnoses, DSM, causation