Revisions of international classification systems for mental disorders have focused on improving the reliability of diagnostic criteria. However, the uncertain validity of the current diagnostic categories means that they do not always fulfil their key purposes, namely to guide treatment and predict outcomes. This is especially true when traditional diagnostic approaches are applied to adolescents and young adults with emerging illnesses. A clinical staging model, similar to those used in general medicine, could improve diagnosis in psychiatry and aid treatment decision-making, especially if applied to individuals aged about 15–25 years, which is the peak age range for the onset of severe mental disorders. Staging models may offer a new framework for the development of interventions with high benefit and low risk, and for research into neurobiological and psychosocial risk factors. However, this approach is not without controversy: some experts oppose its introduction, some argue that it represents a transdiagnostic model, and some suggest it is only viable if disorder-specific models are used.
• Gain awareness of some limitations of current approaches to psychiatric diagnosis
• Review the basic principles of clinical staging models used in general medicine
• Understand current research on the use of staging models in psychiatry, and attempts to apply these models to bipolar disorders