Precision Medicine for Psychiatry – The NIMH Research Domain Criteria (RDoC) project

In order to treat patients better, their conditions need to be better diagnosed so that they can be more effectively and appropriately treated.  Currently, diagnosis is based on the assessment of symptoms (which often fit poorly with available data and are shown to be highly heterogeneous) and the profile of an ‘average’ patient with mental health problems.  Clearly, greater precision in diagnosis is needed and one approach would be that adopted in other medical fields – that of precision medicine.

Not hubris but humility

The goal of RDoC is to develop, for research purposes, a number of ways of classifying mental disorders based on dimensions of observable behaviours and neurobiological measures. RDoC attempts to study the problems of mental illness independently from the classification systems currently used to group patients. As Professor Cuthbert is all too aware, where used so far, such an approach has so far failed to provide rapid advances in other fields of medicine including genetics and neuroscience. Therefore, the RDoC’ approach is being made cautiously and not with excessive hubris.

What RDoC seeks to do is to examine basic neurobiological mechanisms and their underlying pathologies to see whether there are common themes and pathologies that arise in what are currently classified as differing mental health disorders using a matrix approach.  For example, is the underlying cause of anhedonia the same in depressed and schizophrenia patients? This is the reverse of current approaches – where anhedonia is seen solely as a symptom of a particular disease and the underlying cause of the disease as a single condition is sought.

Countering criticism

Psychiatrists have been critical of such a systematic approach saying it ignores patients’ experiences and symptoms, is reductionist, it ignores environmental and developmental influences, pays no attention to aetiology and that it is not ready for the clinic yet. However, during his presentation, Professor Cuthbert countered all such objections bar one – he agreed that RDoC is not ready for the clinic. 

However, currently, that is not the main aim of the RDoC. Its principal aim right now is to allow the assessment of grant applications so that some standard practical approaches can be adopted into assigning funding to mental health research. Mention was also made that it is possibly being used in the future by regulatory agencies considering assessing approval applications for new therapy indications.

Attendees were invited to actively participate in RDoC and its associated activities.