Today, on the Bipolar Burble Facebook page, someone posted a link to an article on The Health Magazine (a website) that had the headline: A Urine Test Can Distinguish Between Bipolar Disorder And Depression. The poster bought into this headline and felt that “people should know about this.”

Well, I can tell you that when someone claims to have found a urine test to distinguish between bipolar and depression, you should be very skeptical. Believe me, if this were a real thing, it wouldn’t just show up in some clickbait website, written by someone named “admin.” (Normally, these types of sites even steal the content they do have.)

Let’s look at the facts of the matter. Does a urine test to differentiate between depression and bipolar disorder really exist?

Biomarkers in Urine to Determine Depression or Bipolar

Many biomarkers in urine have been studied and have been found not to be able to properly distinguish between disorders. That said, it is thought that the right combination of biomarkers could be useful.

In the study referred to in the above article, 76 people with major depressive disorder and 43 people with bipolar disorder were used to identify different metabolites. Twenty different metabolites were identified that may be different those with bipolar versus those with depression.

Now, this is a very small group of people. Not only that but they have all been treated at the same hospital and were of the same ethnicity. This is the definition of a biased sample.

But let’s continue.

Which People with Bipolar or Depression Were Tested?

Some are claiming a urine test to differentiate between bipolar and depression exists. What's the science behind this and does this bipolar urine test exist?In blind trial (only) 50 people with major depressive disorder and 28 people with bipolar disorder were tested and their disorder was assigned based on the above metabolites. The results were not promising. The test could only identify 76% of those with major depressive disorder and 79% of those with bipolar disorder.

Let’s be clear: these numbers are not clinically significant. Remember, you have a 50% chance whether you look at metabolites or not. And even if these numbers were clinically significant, a much, much larger sample size would need to be used to show that anything useful could result from it.

Promise for a Urine Test that Differentiates Between Bipolar and Depression

All that said, researchers did further analysis of the data and found six metabolites that may be more promising. When they were used (in a data analysis, not a blind test) they had a 90% reliability in distinguishing between bipolar and depression. This is promising but is far, far from anything that resembles an actual test.

Does a Urine Test to Distinguish Between Bipolar and Depression Really Exist?

No, it doesn’t. A few years ago, someone claimed to have a blood test for schizophrenia, and it wasn’t real either and has since been discontinued..

Don’t believe headlines like this. Please, please read the whole piece critically, and if that doesn’t clarify things for you then go to the actual study because if you did, you would see that the final line of the study abstract was,

The identified urinary biomarkers can aid in the future development of an objective laboratory-based diagnostic test for distinguishing BD from MDD patients.

In other words, this is a tiny bit of groundwork that has been laid to possibly develop a test in the future.

And that’s where we are in most of the science of mental illness, in general. We’re in a place where there are certain theories that look promising but we really don’t know if, in fact, they are correct.

Remember, there are no easy bipolar/depression diagnostic tools right now. If there were, I would happily share them with you.

References

Chen et al, Divergent Urinary Metabolic Phenotypes between Major Depressive Disorder and Bipolar Disorder Identified by a Combined GC-MS and NMR Spectroscopic Metabonomic Approach. 2015.

The Health Magazine, A Urine Test Can Distinguish Between Bipolar Disorder And Depression. Retrieved July 31, 2016.

Image by Lab Science Career.