Psychopathology: Description and classification

DSM-IV's strong empirical base has yielded an instrument with good to excel lent reliability and improved validity. Diagnostic reliability depends on b oth the clarity and validity of diagnostic criteria and the changeability o f disorders over time: The reliability of schizophrenic spectrum disorders, personality disorders, and some childhood and adolescent disorders remains problematic. Findings on diagnostic validity appear paradoxical: Attempts to validate schizophrenic spectrum disorders with neurobiological and genet ic-familial validators have been only modestly successful, whereas the trip artite personality trait model has differentiated a range of depressive and anxiety disorders. Research on comorbidity has identified several highly c omorbid disorders (substance-related disorders, personality disorders, depr ession, and anxiety) as well as some adverse consequences of comorbidity. T he advantages of dimensional approaches to diagnosis have largely been demo nstrated conceptually; ultimate conclusions about the strengths and weaknes ses of dimensional and syndromal methods await substantial additional empir ical research.