The search for personalisation

Personalised medicine has become a bit of a topic du jour in the field of modern medicine, so naturally, with his expertise in neurobiology, Prof Vieta brought it to the forefront in his plenary.

“When we treat patients, we don’t treat averages”, Prof Vieta stressed, and then went onto explain how modern psychiatry needs to embrace a more comprehensive approach, beyond face-to-face diagnosing. This means using biomarkers, such as certain genes, or brain abnormalities, to tailor an individualised treatment approach for each patient.

Currently, psychiatry has only just about scratched the surface of personalised medicine with a more ‘categorised’ system, which Prof Vieta referred to as ‘stratified medicine’. More and more, bipolar patients are being stratified into different categories, whether it’s through neuroimaging, their predominant polarity (depressive vs. manic), or the presence of comorbidities. Well-known examples include patients who are divided between psychiatric and physical comorbidities.

Individualisation and DSM-5

What’s interesting to note is that the need for more individualisation is being reflected in the latest DSM-5 updates. Prof Vieta gave his audience a quick refresher on these important changes: particularly, the fact that bipolar has its own chapter and the inclusion of ‘mixed features’ as a specifier.

Prof Vieta went on to shed light on the link between structural changes to the brain and the incidence of bipolar I disorder, specifically looking at the default mode network, a network in the brain that is active when the brain is not focused on one particular thing.

Comorbidities and controversy

Adding a touch of controversy to his talk, Prof Vieta went on to question the reliability of anxiety disorders as a comobordity. Prof Vieta doesn’t believe all patients with bipolar I disorder who present with anxiety can truly be diagnosed with anxiety disorder – he prefers the term ‘anxiety distress’, which is highlighted as a specifier in the DSM-5 changes. Identifying this difference between comorbid anxiety disorder and simply anxiety symptoms could be critical to the treatment strategy.

Last, but certainly not least, Prof Vieta introduced the concept of the polarity index – a new way to show whether a treatment leans more toward an antidepressant or an antimanic. The bipolar index can be calculated by dividing the clinical number needed to treat (NNT) for mania by the NNT for depression. A polarity index of 1 indicates that the drug has a comparable efficacy in both mania and depression, whereas an index greater than 1 suggests that the treatment is better for mania, and vice versa.

How well this new concept will be embraced is obviously up in the air. However, Prof Vieta made a strong case for it – not all drugs should be used in all patients, when certain polarities may predominate over others.

The plenary came to a close with a quick round of questions. Within only the span of an hour, Prof Vieta had managed to deconstruct the classic view of bipolar disorder treatment. Sounding almost a little wistful, presenter Prof Antonio Panha asked, “Is the concept of bipolar disorder at an end?”