How to tell the difference between bipolar disorder and depression

Many patients with bipolar disorder, a debilitating mental condition that can take a person from the sluggishness of severe depression to super-human energy levels, are often misdiagnosed as having major depressive disorder, or MDD. But now as an alternative to reliance on patient interviews, scientists are closing in on an objective test that could help clinicians distinguish between the two—and provide better treatment. Their method appears in ACS' Journal of Proteome Research.

For many reasons, bipolar disorder is commonly mistaken for MDD. One reason is that the condition often first becomes noticeable when the patient has a bout of depression. And, as bipolar disorder only affects about 1 percent of the population worldwide, clinicians sometimes forget to ask about hypomania, a euphoric, hyperactive state that also characterizes the condition. Current diagnostic techniques involve structured interviews with patients, but these can be subjective and misleading. An accurate diagnosis, however, is crucial to quickly getting patients the treatment they need. So Peng Xie and colleagues set out to develop an objective way to tell the difference between MDD and bipolar disorder.

The researchers combined a couple of techniques—gas chromatography-mass spectrometry and nuclear magnetic resonance—to analyze urine metabolites in samples from patients who either had MDD or bipolar disorder. From these results, they identified a panel of six biomarkers with an 89 to 91 percent chance of predicting each disorder.