In DSM-IV mental disorders are essentially categorized as present
or absent on the basis of a set of symptoms that characterize them. However,
psychiatric patients often present with signs and symptoms of multiple mental
illnesses even if they meet criteria for only one disorder. At times, these
symptoms can be severe. This clinical reality is not well reflected in
DSM-IV. Thus some psychiatric scientists developing DSM-V
argued at a recent symposium that DSM-V should include dimensional
assessments of psychopathology along with categorical diagnoses (see
Researchers Lay Out Challenges
Facing Developers of DSM-V).
A study underscoring the feasibility and desirability of such a strategy
was also reported at the symposium at a poster session.
The study was conducted by the APA Practice Research Network (PRN) and the
American Psychiatric Institute for Research and Education (APIRE) and was
funded by the American Psychiatric Foundation. The lead investigator was Joyce
West, Ph.D., senior research scientist in the PRN. The senior investigator was
Darrel Regier, M.D., director of APA's Office of Research and executive
director of APIRE.
The study included some 3,000 patients with various mental disorders,
notably schizophrenia, major depression, or bipolar disorder, as well as the
psychiatrists caring for them. The psychiatrists not only listed all of the
DSM-IV-TR Axis I and Axis II disorders for which they had diagnosed
these patients, but also rated the severity of the patients' symptoms on a
simple dimensional scale.
When the researchers analyzed the results, they found that when the
severity of patients' symptoms was taken into consideration, a more complex,
yet also a more comprehensive, snapshot was created of the patients'
psychopathology than when the patients were simply diagnosed on the presence
or absence of symptoms.
For example, 62 percent of patients with major depression were found to
have moderate to severe anxiety symptoms, although only 29 percent of them had
been diagnosed with an anxiety disorder. Fifty-two percent of patients with a
substance use disorder were found to have moderate to severe depressive
symptoms, although only 27 percent had been diagnosed with a depressive
disorder. Twelve percent of patients with posttraumatic stress disorder were
found to have moderate to severe psychotic symptoms, although only 6 percent
had been diagnosed with a psychotic disorder.
In other words, the findings appeared to reflect that patients often had
signs and symptoms of multiple mental illnesses, even if they met criteria for
just one disorder.
"Two additional independent studies have confirmed these
findings," the researchers noted, "and support the feasibility and
utility of using dimensional measures of psychopathology in routine