At what stage does staging become overly staged?

The refreshingly direct and straightforward commentary by Amad and Fovet (2021) makes a simple point, namely, that the current approach of pseudo-staging overlooks the complexity of psychiatric disorders. Crisply, they outline the inherent constraints that staging faces, specifically, its dependence on phenomenology, and the inherent heterogeneity and intrinsic capriciousness of psychiatric disorders.

In addition to these limitations, Amad and Fovet (2021) illustrate another major problem using the example of ‘stage 4’, which in the schema they describe is intended to capture severe, persistent or unremitting illness or treatment resistance. In essence, they point out that this stage is a concoction of severity, chronicity and treatment non-response – and that each of these facets of an illness are in fact separate constructs. Specifically, these aspects are governed by separate parameters, and although they may overlap, and at times even appear to be aligned, they are inherently distinct functions that cannot be easily combined. When examined, this point seems self-evident, but in practice, it is easily overlooked and is often forgotten in the staging literature. For example, treatment resistance of psychiatric disorders has been shown to be of limited usefulness and is operationally defunct. In the context of mood disorders, alternative paradigms that focus on treatment approach, such as channelling response, are arguably better for optimising management, than misleading descriptors such as treatment-resistant depression (TRD) (Malhi et al., 2020). Indeed, the creation of artificial phenotypes, such as difficult-to-treat depression (DTD) and TRD, likely compounds and complicates management in addition to diminishing hope.

We also agree with Amad and Fovet on the point that the primordial symptomatic soup, from which various syndromes are thought to emerge, may continue to flavour the subsequent evolution of psychiatric disorders, and furthermore, that transdiagnostic symptomatology is not limited to the pre-formative phase of psychiatric disorders. For example, irritability features strongly in many fully formed and established psychiatric illnesses and is a key and sometimes diagnostic feature for some (Bell et al., 2020). However, at the same time, there is undoubtedly some degree of transmutation as some symptoms fall away, others emerge and some coalesce to form evermore complex and sophisticated composites. This is useful, as it allows the enrichment of samples for longitudinal studies – based on the knowledge that traits and early symptoms are likely precursors to the later manifestation of disorders (Malhi et al., 2019). Nevertheless, this does not automatically lend itself to staging and in fact, if anything, argues against this possibility.

Conclusion

Like many others, we too subscribe to the need for longitudinal studies and the adoption of a perspective that allows for evolution and change. However, we remain critical of the drive for pseudo-staging, in which fictitious boundaries and steps engineer the fabrication of ‘stages’ that ultimately lack any pathophysiological anchor or meaningful translation into clinical practice. Thus, we argue it is time to consider whether staging is possible, and if so, to what extent we want psychiatric disorders and indeed our clinical practice to be staged.