Comment on the DSM readings

Because I found the Widiger & Clark (2000) article to be the most interesting and controversial of the three readings, I will mostly comment on a few points raised by the authors. The article detailed several areas that need improvement or change in DSM-V, and while it may not have been authors' intent to comment on exactly how these changes should be accomplished, it left many questions unanswered for me. For instance, in the discussion about determining what is meant by a clinically significant impairment, the diagnosis of mental retardation is used to illistrate the possibility of using points of demarcation along continuous distributions of functioning. However, as the article points out, a question then arises about how to come to a consensus about exactly where the point of demarcation should be for specific disorders. In regards to an IQ of below 70 being necessary to diagnose MR, the whole idea of IQ itself is relatively controversial- what does IQ really measure, predict, and mean? (Neisser, 1996).
In somewhat relation to this, I found the discussion about including laboratory findings in diagnostic criterion sets interesting, but also puzzling. It certainly does not make much sense to include autonomic functioning in the diagnostic criteria for some disorders, yet require no physiological tests be done to prove that they exist. For instance, the article mentions panic attacks as an example-if a client tells a clinician that he/she feels nauseous, sweats, gets dizzy, etc. when nervous, is the clinician supposed to take their word for it? In addition, the article points out there is no reference in DSM-IV about standardized assessment instruments, such as brain imaging techniques, to use in making diagnoses, which seem necessary to me if the DSM is going to reference neurophysiological factors involved in certian mental disorders, such as references to neurotransmitters in depression. However, the article also brings up valid points about the availablity and costs of using laboratory data. Theoretically as a scientist, it makes sense to me to incorporate lab tests and findings into the dignostic criteria, but I'm not sure how practical or realistic it is to require for all diagnoses. This is a problem that I think needs to be addressed- just because it may not be practical and may be hard to implement doesn't mean its not necessary.