Should our major classifications of mental disorders be revised?

Our major classification systems (DSM and ICD) face three main problems: the high rates of 'comorbidity' that are produced by our present diagnostic rules, the increasing use of 'not elsewhere classified' (NEC) by practising clinicians, and the fact that each new edition is longer and more complex than the one preceding it. A major simplification of the chapter structure used by each classification might pave the way to address these problems.