Progress But No Cigar: Comment on Bach and Tracy (2022)

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition alternative model of personality disorder (AMPD) introduced innovations that are likely to be enduring features of a scientific classification of personality disorder: (a) an explicit definition of personality disorder, (b) a description of levels of severity, (c) a dimensional model of individual differences, and (d) the important principle that classifications should use and be consistent with the findings of normal personality science. Bach and Tracy's review of evidence of the clinical utility of the alternative model compared with traditional typal diagnoses clearly demonstrates that dimensional classification does not adversely affect clinical utility. Based on this evidence, they propose that the AMPD minus the hybrid component be adopted as the Diagnostic and Statistical Manual of Mental Disorders classification of personality disorder. It is argued that the recommendation is premature because evidence of clinical utility is insufficient in the absence of evidence of construct validity. The rest of the commentary explores the conceptual and methodological problems arising from the way the AMPD's innovative features are translated into a diagnostic classification.