Diagnosis of a mental health disorder can be a challenge. There are no set bioanalytical tests, and many illnesses have similar symptoms, so misdiagnosis is common. To address this problem, researchers from Chongqing Medical University (China) have developed a new biomarker-based urine test that may have the potential to prevent the common misdiagnosis of bipolar disorder as major depressive disorder (MDD).
Bipolar disorder is often mistaken for MDD, partly because it is often first noticeable when the patient is suffering from a period of depression. Current diagnostic methods involve subjective and sometimes misleading techniques such as structured interviews. As bipolar disorder is comparatively rare, affecting less than 1% of the global population, clinicians can easily forget to ask about hypomania, a euphoric, hyperactive state that is characteristic of the condition.
The researchers took urine samples from patients who had been successfully diagnosed with bipolar disorder or MDD, and examined the metabolites present to determine if there were biomarkers suitable for differentiating between the two groups.
They created biomarker panels for all of the patients using a combination of GC-MS and NMR, and found that bipolar disorder patients had higher levels of 20 metabolites, with 14 significantly higher than in MDD patients. They were finally able to identify a panel of six specific biomarkers with a significant chance of predicting each disorder.
The team acknowledged that the study was limited by a small subject pool, all of whom came from the same hospital. They also suggested that future studies should involve the collection of different samples, such as cerebrospinal fluid and plasma, to ensure the same biomarker elevation is observed.
Correct diagnosis of patients is critical for both MDD and bipolar disorder in order to provide better and more precise treatment.
Source: Chen JJ, Zhou CJ, Liu Z. Divergent urinary metabolic phenotypes between major depressive disorder and bipolar disorder identified by a combined GC-MS and NMR spectroscopic metabonomic approach. J. Proteome Res. 7, 14(8), 3382–3389 (2015); Simple urine test may help differentiate between bipolar disorder and depression via biomarkers.