Introduction 11
relationships within the classification are ba sed on current research and may need to be
modified as new evidence is gathered by fu ture research both within and across the do-
mains of proposed disorders. “Conditions for Further Study,” described in Section III, are
those for which we determined that the scient ific evidence is not yet available to support
widespread clinical use. These diagnostic crit eria are included to highlight the evolution
and direction of scientific advances in these areas to stimulate further research. 
With any ongoing review proces s, especially one of this co mplexity, different viewpoints
emerge, and an effort was made to consider various viewpoints and, when warranted, ac-
commodate them. For example, personality diso rders are included in both Sections II and
III. Section II represents an update of the te xt associated with the same criteria found in
DSM-IV-TR, whereas Section III includes the proposed research model for personality dis-
order diagnosis and conceptualization developed by the DSM-5 Personality and Personality
Disorders Work Group. As this field evolves, it is hoped that both versions will serve clin-
ical practice and research initiatives.
Harmonization With ICD-11
The groups tasked with revising the DSM and ICD systems shared the overarching goal of
harmonizing the two classifications as much as possible, for the following reasons: 
• The existence of two major classifications of mental disorders hinders the collection and
use of national health statistics, the design of clinical trials aimed at developing new
treatments, and the consideration of global ap plicability of the results by international
regulatory agencies.
• More broadly, the existence of two classificat ions complicates attempts to replicate sci-
entific results across national boundaries. 
• Even when the intention was to identify identical patient populations, DSM-IV and