Staging in neuropsychiatry: a heuristic model for understanding, prevention and treatment.

The main mental disorders which develop and persist through adult life typically emerge during the critical developmental phase of adolescence and early adulthood, and are frequently associated with considerable associated distress and functional decline. Our current diagnostic system lacks validity and therapeutic utility, particularly for the early stages of these mental disorders, when symptoms are still evolving and may have not yet stabilised sufficiently to fit familiar or traditional syndromal criteria. Furthermore, there is often difficulty in distinguishing transient developmental or normative changes from the early symptoms of persistent and disabling mental illness. These factors point to the need for reform of our current diagnostic systems. The clinical staging model seeks to define the extent of progression of a disorder at a particular point in time and aims to differentiate early, milder clinical phenomena from those that accompany illness progression and chronicity. The staging framework allows clinicians to select treatments relevant to earlier stages of an illness, and to evaluate their effectiveness in preventing progression and producing remission or return to milder or earlier stages of disorder. For staging to be a valid approach, interventions in the early stages need to shown to be not only more effective but also safer than treatments delivered later in the course of illness. Staging may also allow a more efficient integration of our rapidly expanding knowledge of the biological, social and psychological vulnerability factors involved in development of mental illness into what may ultimately resemble a clinicopathological staging model.