Classification in psychiatry: from a symptom based to a cause based model?

The assumption that eventually the classification in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM) will incorporate aspects of causation uncovered by research in neuroscience is examined in view of the National Institute of Mental Health's NIMH Research Domain Criteria (RDoC) project. I argue that significant advantages of maintaining the classification system, focussed on grouped descriptions of symptoms, are often undervalued or not considered. In this paper I will challenge the standard view that the transition from the purely symptom based approach is an inevitable and desirable change.