Unfortunately, for around half of depressed patients, the first antidepressants prescribed do not work.
On top of that, around one-third of patients do not respond to any types of drugs (although psychological therapies may be useful).
At the moment, the only way to know is to try them and see what happens.
This means that many depressed people have to wait around three months to see if the drugs will work.
Then, if they don’t, it is another wait while a different form of medication is tried.
Now, though, scientists have found that some people with particular markers in their blood will not respond to antidepressants.
Professor Carmine Pariante, who led the study, said:
“This is the first time a blood test has been used to precisely predict, in two independent clinical groups of depressed patients, the response to a range of commonly prescribed antidepressants.
These results also confirm and extend the mounting evidence that high levels of inflammation induce a more severe form of depression, which is less likely to respond to common antidepressants.
This study moves us a step closer to providing personalised antidepressant treatment at the earliest signs of depression.”
The blood test focuses on two different types of biomarkers that measure blood inflammation.
Patients whose blood biomarkers were above a certain level had a 100% chance of not responding to the most common type of antidepressant medication.
Those below that level mostly responded positively.
Professor Pariante said:
“This study provides a clinically-suitable approach for personalising antidepressant therapy — patients who have blood inflammation above a certain threshold could be directed toward earlier access to more assertive antidepressant strategies, including the addition of other antidepressants or anti-inflammatory drugs.
It is really crucial now to carry out a clinical study comparing the current clinical practice in antidepressant prescription, based on trial-and-error, with our novel approach of ‘personalised psychiatry’, where the antidepressant treatment plan is guided by the blood test.”
The study was published in the journal Neuropsychopharmacology (Catteneo et al., 2016).
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