The pitfalls of making a categorical diagnosis of post traumatic stress disorder in personal injury litigation.

Since it first became possible to diagnose Post Traumatic Stress Disorder (PTSD) categorically with the advent of DSM-III (American Psychiatric Association, 1980), its use in the American Courts to substantiate civil claims has burgeoned. This situation may be set to repeat itself in the UK. Mental health professionals need to be aware that there is a substantial body of evidence supporting the validity of the concept of a DSM diagnosis of PTSD. However, the reliability of such a diagnosis can be called into question. There are legal and ethical issues involved in assessing and interpreting the DSM criteria, some of which may lead the expert witness to make authoritative pronouncements that are outside his legitimate field of expertise. There is a danger that the legal profession will adopt the DSM as a 'gold standard' against which to judge expert testimony. The multiaxial classification of the DSM can be a useful framework for presenting a diagnosis of PTSD, but over-rigid adherence to the criteria at the expense of clinical judgement and experience should be avoided.