Limitations of the symptom-oriented approach to psychiatric research.

BACKGROUND: We critically reviewed the arguments of the symptom-oriented researchers who propose to replace syndromes and diagnostic categories with symptoms as units of analysis in psychiatric research. METHOD: Three central arguments were examined: (a) current diagnostic categories lack reliability and validity; (b) using diagnostic categories leads to misclassification and confounding; and (c) symptom-oriented theories are clearer, easier to test, and more likely to lead to an explanation of psychopathology. These arguments are based on three assumptions respectively: (a) symptoms have higher reliability and validity; (b) underlying pathological processes are symptom-specific; and (c) elucidation of the process of symptom development will lead to (and must precede) the discovery of the causes of syndromes. RESULTS: We found little evidence supporting these assumptions and arguments based on them. CONCLUSION: There are no clear advantages in replacing syndromes with symptoms as units of analysis for psychiatric research.