Beyond DSM: Early stages of disorder pose predictable and modifiable risk for persistent disorder

To the Editor

In response to Professor Malhi’s discussion on the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 (Malhi, 2013), I wish to correct some significant inaccuracies. In his discussion of the at-risk concept, he is correct to say the project of identifying those at risk and manifesting early symptoms and signs of potentially serious disorders is of value because it paves the way for early intervention. This is why the paradigm has been so widely embraced around the world over the past 20 years. However, he goes on to wrongly assert that such a project is predicated on the assumption that those at risk of a disorder will invariably develop the illness. In fact, the concept of an at-risk syndrome, or, more accurately, an early, poorly differentiated stage of an actual disorder, is based on exactly the opposite scenario; namely, that only a subset (which must be a reasonably high proportion) of those with early, subthreshold symptoms will go on to develop the fully fledged illness. This is the whole point of the concept of risk syndromes, one which is well understood in medicine more generally. It is also important to say that the risk syndrome concept also means that the person has an immediate and a current need for care on the basis of the present symptoms, while the risk of worsening or progression underscores this need for care and careful monitoring. The staging model we have developed takes all these issues into account (McGorry et al., 2006).

Further, it is quite inaccurate to say that there are currently little or no data to allow actual prediction of a psychiatric illness on the basis of early symptoms, signs and additional risk factors. A recent high-quality meta-analysis, which included 2502 patients from 27 studies worldwide, has now clearly shown that we can predict that 36% of people defined by the psychosis risk syndrome or the ultra-high risk concept will develop a psychotic illness within 3 years (Fusar-Poli et al., 2012). This is a high predictive value, indicating a reasonable degree of specificity of the high-risk criteria for psychosis. The clinical value of the operational definition is further reinforced by the fact that, of those who do not make the transition to psychosis, the majority will have already developed or will develop another psychiatric disorder, mainly mood and anxiety disorders. So there is a clear need for care with reasonable yet still partial specificity for a future psychotic disorder. This means that a broader net than psychosis is required and the clinical staging model provides a solution to this by allowing broader outputs as well as inputs (Fusar-Poli et al., 2013; McGorry, 2013; McGorry and van Os, 2013).

With respect to interventions, it is simply not true to say that there is ‘even less evidence’ of which treatments are effective for those at risk. Two meta-analyses (Preti and Cella, 2010; Van Der Gaag et al., 2013) both show, on the basis of 10 randomised control trials with the ultra-high risk for psychosis concept, that treatment is very effective in reducing risk with the number needed to treat (NNT) between four and nine. This indicates real potency of treatment in reducing risk and also underscores the fact that cognitive behavioural treatment (CBT) is the most appropriate first-line treatment. This should defuse the controversy surrounding this issue, which has been fuelled by ideological currents and confused with disinformation (McGorry, 2012).

Finally, Professor Malhi is correct on one issue, which is that simply extrapolating treatments from established disorders to at-risk populations is not appropriate. This would result in overtreatment and once again the staging model and the data that exist suggest that simpler and safer treatments are sufficiently effective in these early stages of illness.