Hot on the heels of the Bipolar Burble’s post about the neurobiological evidence for major depressive disorder comes this: the first blood-based diagnostic aid for schizophrenia.
Um, what’s that again?
[At this time I’m forced to remind you that I am not a doctor or researcher and everything stated is my opinion or interpretation. Thanks.]
A Blood Test for Schizophrenia
A company VeriPsych, affiliated with Rules-Based Medicine Inc., is offering a blood test for schizophrenia. Or, more specifically, they are offering to test your blood and supply a likelihood that you have recent-onset schizophrenia.
VeriPsych and a Blood Test for Schizophrenia
The VeriPsych folks, through Rules-Based Medicine, apparently in conjunction with the US Military, ran a study to look for biomarkers of schizophrenia and then develop a test for them. (I should mention here the only thing VeriPsych appears to do, according to their web site, is offer this “diagnostic aid for schizophrenia.”)
Now, admittedly I am not a doctor or a researcher, but here’s what I make of the VeriPsych schizophrenia biomarkers study.
[FYI: Biomarker: a protein measured in blood whose concentration reflects the severity or presence of some disease state.]
Blood Test for Schizophrenia Research
Specifically: Validation of a Blood-Based Laboratory Test to Aid in the Confirmation of a Diagnosis of Schizophrenia by Emanuel Schwarz et al. Biomarker Insights 2010:5 39–47
The study was in two phases, in the first phase researchers looked for reproducible schizophrenia biomarkers and in the second phase, a test was developed to use these biomarkers to test for schizophrenia.
Phase One: Schizophrenia Biomarker Selection
- Assed 181 biomarkers
- Used 806 clinical samples
- Participants were in multiple countries, some from the US military
Initial assessment resulted in the finding of 22 biomarkers. These were retested in 63 subjects 3 months later and showed a correlation of 0.83 (83%).
Nine addition biomarkers were added for phase two due to known association with schizophrenia.
VeriPsych then did something odd: they included 20 biomarkers they felt indicated bipolar disorder, “to facilitate the future development of a test with differential diagnosis capability,” and to “enhance[d] the accuracy of VeriPsych.” (The former is from the research paper, the latter is from the website.)
Notes on Schizophrenia Biomarker Selection
This says to me they are really testing 31 biomarkers of schizophrenia, and 20 for “other reasons.” So when they claim to use a 51 biomarker test, that stretches the truth a little.
Also, the numbers on these seem to vary from the paper to the website making it difficult to deduce exactly how many biomarkers are used for each purpose. A spot on the website says: 36 identified and 15 added. Sorry, it’s just not clear.
Phase Two: Validation of Schizophrenia Biomarkers
- Phase two used 480 samples for biological test validation
- Biomarkers appear consistent for paranoid and nonparanoid schizophrenia
- Biomarkers test seems to work even after 4-6 weeks of antipsychotic treatment (85% accurate)
- Accuracy increases with chronic schizophrenia
- Appears (to me) to have more false-positives than false-negatives
- “Overall sensitivity of 83% and specificity of 83%”
Accuracy of Schizophrenia Blood Test?
There are some super-math algorithms and statistics going on here, but from what I can tell:
- You get a “score” from the blood test
- Depending on the score, you get a percent chance of having schizophrenia
- Some tests are inconclusive
Who Tested the Validity of These Results?
Good question. No one except the lab (Rules-Based Medicine) from what I can tell. This is not an FDA-approved test as it is a “laboratory-developed test.”
Laboratory-developed tests are:
- The activity of a single laboratory, not a traditional device manufacturer
- Not commercially marketed to other labs
- Wikipedia says: assays developed in the laboratory for internal use, or research use only, and not intended for diagnostic or medical use, and therefore treated differently by regulatory agencies; describes most current genetic testing.
So, Is This a Blood Test to Diagnose Schizophrenia?
No. It isn’t. This isn’t a blood test to diagnose schizophrenia. They mention this on their home page. This test is to, “aid a psychiatrist in the diagnosis of recent-onset schizophrenia.”
In other words, it’s a freaking guess with a number attached.
This test can’t tell you whether you have schizophrenia, it can provide a somewhat-accurate statistical likelihood. So how useful is that? You have an x% chance of schizophrenia plus-or-minus some variable. Based on one study by one company Does that sound useful? Actionable?
It doesn’t to me.
In Natasha Tracy’s Opinion:
This is a money-grab taking advantage of desperate mentally ill people.
I actually find this “diagnostic aid” blood test for schizophrenia to be bordering on unethical. VeriPsych can cover their ass with math and statistics and probabilities and legal-eze and I’m sure that makes it “OK,” but if you ask me, they are a hair’s breath away from lying. It feels irresponsible to me to hand out these kinds of results about a very serious illness based on one study. One. And there is so much math needed to make this model work that I would fall down dead if there wasn’t a mistake in there somewhere. Nobody gets it right the first time.
This test should be in a lab, used for further research and study, and not be used on the paying public.
(I have other reasons why I don’t like this test too, but as this has gone on long enough, I’ll save them for another day.)