Taken together, do these findings suggest that the proposed DSM-V criteria represent an improvement over the DSM-IV criteria in terms of diagnostic validity? Results of the different assessments reported here do not clearly or consistently suggest that the new criteria are superior to the old with regards to identifying affected individuals. One advantage of the new criteria is their collapse into a single factor and the related inclusion of individuals who were formerly diagnostic orphans. However, these changes result in the exchange of one group of mildly affected individuals for another, with no indication that the newly included group is more severely affected or accurately diagnosed than the excluded group. The exclusion of the LP criterion could streamline clinical interviews, but there is no evidence that this criterion was resulting in inappropriate diagnoses. Finally, the genetic analyses suggest slight, but significant, differences in genetic influences underlying the two sets of criteria, though the total heritability is almost unchanged. There is no indication that this represents an improvement in the validity of the diagnosis. A study examining prognosis of the individuals
