Dr Popović argued that personalised treatment was necessary to help ensure the successful treatment of patients with bipolar disorders. In support of this, she cited the often high relapse rates in the treatment of bipolar disorders. She noted that inadequate treatment was associated with increased rates of relapse in bipolar I disorder and that multiple episodes create a vulnerability to subsequent episodes, reducing the response to therapy.1
Dr Popović discussed a wide range of potential ways that patients could be stratified, in order for the best therapy to be selected. She discussed stratification by genetic markers but conceded that no tested, reproducible, clinically useful biomarkers had yet to be found in psychiatry.
She then took the audience through the benefits and problems of stratifying patients by different factors, including endophenotypic markers (“intermediate phenotypes standing between genes, gene products and clinical syndrome”), stage of disease, structural imaging and comorbidities
In the final part of her talk, Dr Popović presented recent research from her own group: stratification of treatment according to the predominant polarity of the patient. According to the British Association for Psychopharmacology (BAP) guidelines, when choosing a maintenance treatment for bipolar disorder, consideration should be given to whether patients are predominantly manic or predominantly depressed.2
The “Polarity Index” (PI) for bipolar treatments has been developed by Dr Popović’s group. It is a numeric expression of the efficacy profile of a given drug, calculated as the ratio of the number needed to treat (NNT) for prevention of depressive episodes to the NNT for mania episodes.3 In other words, drugs with a PI of 1 may have a similar antimanic and antidepressive potential, while those with a PI greater than one have stronger antimanic vs. antidepressive properties (and so on).
Dr Popović finished her lecture by listing the PI of several treatments for bipolar I depression, before showing early data confirming the usefulness of the PI approach when determining the optimal treatment for patients with bipolar disorders.3
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