Abstract
Given the august undertaking and compendium of psychiatric/psychological knowledge encompassed in each successive iteration of the American Psychiatric Association’s (APA) nosology for mental disorders known as the Diagnostic and Statistical Manual of Mental Disorders (DSM), it is not feasible, within the parameters of this journal, to fairly provide a review of this expansive text. Consequently, in view of this journal’s attention toward the specialist fields of forensic psychiatry/psychology, the present review is orientated toward providing a brief overview of some notable developments to these fields in the recently released DSM-5 (5th ed.; APA, 2013).
In the opening section of the DSM-5 is the APA’s usual judicious warning concerning the use of the nosology in forensic matters. While the theme and substance of this warning is largely consistent with previous editions, what is notable in DSM-5 is the arguably far-more-prominent presentation of this warning in comparison with previous editions. This change is perhaps reflective of the increasing recognition surrounding its use in forensic contexts and, as such, a more explicit attempt to forewarn of its limitations and thus avoid potential misapplication of the nosologies by legal and mental health professionals.
Progressing into the diagnostic criteria found in Section II of DSM-5 is the newly conceived category of Neurodevelopmental Disorders. The formulation of this nomenclature is described as reflecting the conceptual shift away from terminology such as Mental Retardation and instead toward that predominantly favoured by contemporary mental health professionals of Intellectual Disability, wherein the diagnostic conceptualisation and accompanying criteria are orientated on the assessment of cognitive capacity (e.g., IQ) in conjunction with adaptive functioning. In this context, the severity of an individual’s disability is to be gauged by his or her degree of adaptive functioning instead of an IQ score. This is a welcome logical development but more importantly has considerable relevance to the forensic issue of evaluating competencies (also known as fitness to plead) to ensure that appropriate focus is placed on an individual’s functional ability to satisfy various legal parameters rather than any erroneous ipso facto conflation between the perfunctory identification of an intellectual disability equating with incompetence in an individual.
The following category in DSM-5 is the newly conceived Schizophrenia Spectrum and Other Psychotic Disorders. In this category, another significant shift in the DSM’s nosological paradigms is encountered with diagnostic conceptualisation now orientated toward a more dimensional approach. This change is brought about by an attempt to account for the heterogeneity in symptoms frequently observed in individuals who may present with some form of psychotic disorder. This change in diagnostic perspective will no doubt reverberate for forensic issues such as criminal responsibility and the interpretation of legal defences such as insanity.
Within the context of civil forensic practice, the DSM-5 also introduces substantial changes to the breakdown and categorisation of what were formerly known as the Anxiety Disorders. In DSM-5, three discrete categories are introduced, consisting of the traditional category of Anxiety Disorders as well as that of Obsessive-Compulsive and Related Disorders and Trauma- and Stress-Related Disorders. It is in this last, newly created category that Posttraumatic Stress Disorder (PTSD) has now been assigned and significant changes made to its diagnostic criteria. Given the prevalence of PTSD in civil suits involving compensatory claims for psychiatric/nervous injury, these diagnostic changes are likely to be of considerable significance.
Finally, what may be viewed as the most significant diagnostic shift in the DSM-5 relevant to the field of forensic psychiatry and psychology is the introduction of the alternative trait-based model of Personality Disorder diagnosis. It should, however, be noted that the previous diagnostic criteria based on categorical conceptions of Personality Disorder found in DSM-IV (4th ed.; APA, 1994) and DSM-IV-TR (4th ed., text rev.; APA, 2000) remain unchanged as the traditionally recognised criteria for the assessment of Personality Disorders in Section II of the DSM-5. However, in the subsequent Section III, the DSM-5 also presents an alternative platform for the evaluation and diagnosis of Personality Disorders. The DSM-5 indicates that the purpose of this duality in presented diagnostic models for the Personality Disorders is undertaken because
the inclusion of both models in DSM-5 reflects the decision of the APA Board of Trustees to preserve continuity with current clinical practice, while also introducing a new approach that aims to address numerous shortcomings of the current approach to personality disorders. (APA, 2013, p. 761)
It is within this framework that some of the most relevant Personality Disorders to the fields of forensic psychiatry and psychology feature prominently in the alternative DSM-5 model for Personality Disorders such as Borderline Personality Disorder, Narcissistic Personality Disorder, and, perhaps most significantly, Anti-Social Personality Disorder.
The DSM-5 represents one of the authoritative compendiums in the world for the nosology of mental disorders. As such, the sheer volume of information encompassed by it cannot, as already noted, be adequately appraised by this review. Consequently, numerous other notable conceptual advances and diagnostic alterations relevant to the fields of forensic psychiatry and psychology that are contained within its pages such as the Substance-Related and Addictive Disorders as well as the Paraphilic Disorders have not been discussed here. Suffice to say however, the DSM-5 continues to be one of the quintessential texts for all professionals in the field of forensic mental health and the benefits from its development will, with time, be felt in future forensic clinical practice and research.