Taxon Specific Applications for the DSM

There is one thing even more vital to science than intelligent methods and that is, the sincere desire to find out the truth, whatever it may be. 

Other taxometrics research has evaluated the validity of theoretical psychopathological subtypes. For example, Haslam and Beck (1994) used CCK procedures to test whether five proposed subtypes of major depression (e.g., endogenous, sociotropic, autonomous) reflect underlying categories. Again, because these theoretical subtypes of depression are not necessarily represented in the DSM, they do not speak directly to psychiatric nosology. 

In this section, we selected several representative diagnoses from the DSM and outlined approaches to analyzing them with CCK procedures. 

Nearly all the personality disorders are defined in a manner that should facilitate taxometric evaluation. This is noteworthy because there is a general lack of empirical support for the validity of personality disorder diagnoses, along with considerable controversy about the dimensional nature of personality and personality disorders (Clark, Livesley, Morey, 1997 Clark Watson, 1999 Widiger Frances, 2002). As a result, we expect taxometric investigations to be particularly fruitful in this area. 

Narcissistic personality disorder, which is organized similar to other personality disorder diagnoses, is described as a pervasive and enduring pattern of behavior indicated by at least five of nine criteria, including 

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