Reading Between the… Diagnoses

Patients with bipolar disorder are often misdiagnosed with major depressive disorder (MDD) because of overlapping symptoms, as well as the subjective nature of psychiatric evaluation of patient self-reported information. Indeed, one third of bipolar patients remain misdiagnosed for over seven years (1). 

To address the issue, a research team from the University of Cambridge, UK, analyzed dried blood spots from individuals suffering from current depressive symptoms (2).

“We initially attempted to identify biomarkers of these conditions using proteomic profiling based on mass spectrometry; unfortunately, the signal was not strong enough,” says Sabine Bahn, Head of the Cambridge Centre for Neuropsychiatric Research and corresponding author. “We then turned to metabolomic profiling; we expected metabolites to be more stable in dried blood spots and provide a better signal than proteins, which they indeed did.” 

First, the samples were analyzed using a targeted mass spectrometry-based platform to measure the levels of 630 circulating metabolites. Next, the participants underwent a WHO validated diagnostic interview to determine whether they had BD so that correlations could be made with biomarker levels.

“We discovered a panel of 17 biomarkers that correctly detected 53 percent of patients with BD and 76 percent of patients with MDD in a group of 241 patients. These findings were then validated in a separate group of 30 patients,” says Jakub Tomasik, Senior Research Associate at the Cambridge Centre for Neuropsychiatric Research and principal author of the paper. “The biomarkers were especially useful in patients whose diagnoses based on self-reported symptoms were uncertain and those who underreported their symptoms.”

The researchers are planning a validation study to test the performance of the biomarker panel in a new group of patients with fresh dried blood samples.

“A blood biomarker test could provide a faster and more objective way to diagnose mood disorders,” says Bahn. “As such, it could substantially improve the diagnostic process, reducing the workload on physicians and helping select the right treatment early in the process.” 

Tomasik adds, “It would not only result in better outcomes in patients, but also contribute to more informed understanding of psychiatric disease and help reduce the stigma associated with psychiatric conditions.”

^{Image Credit: Cambridge Centre for Neuropsychiatric Research}