In the proposals for revisions, strengths and weaknesses in the current criteria and no- sology were first identified. Novel scientific findings over the previous two decades were considered, leading to the creation of a research plan to assess potential changes through literature reviews and secondary data analyses. Four principles guided the draft revisions: 1) DSM-S is primarily intended to be a manual to be used by clinicians, and revisions must by research evidence; 3) where possible, continuity should be maintained with previous editions of DSM; and 4) no a priori constraints should be placed on the degree of change between DSM-IV and DSM-5.
Building on the initial literature reviews, work groups identified key issues within their diagnostic areas. Work groups also examined broader methodological concerns, such as the presence of contradictory findings within the literature; development of a re- fined definition of mental disorder; cross-cutting issues relevant to all disorders; and the revision of disorders categorized in DSM-IV as ”not otherwise specified.” Inclusion of a proposal for revision in Section II was informed by consideration of its advantages and disadvantages for public health and clinical utility, the strength of the evidence, and the magnitude of the Change. New diagnoses and disorder subtypes and specifiers were sub- ject to additional stipulations, such as demonstration of reliability (i.e., the degree to which two clinicians could independently arrive at the same diagnosis for a given patient). Dis- orders with low clinical utility and weak validity were considered for deletion. Placement amount of empirical evidence generated on the diagnosis, diagnostic reliability or valid- ity, presence of clear clinical need, and potential benefit in advancing research.
The use of field trials to empirically demonstrate reliability was a noteworthy improvement in- troduced in DSM-III. The design and implementation strategy of the DSM-5 Field Trials rep- resent several changes over approaches used for DSM-III and DSM-IV, particularly in obtaining data on the precision of kappa reliability estimates (a statistical measure that assesses level of agreement between raters that corrects for chance agreement due to prevalence rates) in the context of clinical settings with high levels of diagnostic comorbidity. For DSM-S, field trials were extended by using two distinctive designs: one in large, diverse medical-academic settings, and the other in routine clinical practices. The former capitalized on the need for large sample sizes to test hypotheses on reliability and clinical utility of a range of diagnoses in a variety of patient populations; the latter supplied valuable information about how proposed revisions performed in everyday clinical settings among a diverse sample of DSM users. It is anticipated that future clinical and basic research studies will focus on the validity of the re- vised categorical diagnostic criteria and the underlying dimensional features of these disor- ders (including those now being explored by the NIMI-I Research Domain Criteria initiative).
The medical-academic field trials were conducted at 11 North American medical-academic sites and assessed the reliability, feasibility, and clinical utility of select revisions, with priority given to those that represented the greatest degree of change from DSM-IV or those potentially having the greatest public health impact. The full clinical patient populations coming to each site were screened for DSM—IV diagnoses or qualifying symptoms likely to predict several spe- cific DSM-S disorders of interest. Stratified samples of four to seven specific disorders, plus a stratum containing a representative sample of all other diagnoses, were identified for each site.