In an attempt to end the “trial and error” prescription of antidepressants, British scientists have conducted a small study that matches biological markers in the blood to the best treatments for depression.
“The study shows that we could use a blood-based ‘test’ to personalize the treatment of depression,” said Carmine Pariante, M.D., of King’s College London’s Institute of Psychiatry, who led the study.
Her team found that high levels of inflammation, which show up in biological markers in the blood, are part of the process that leads to depression, especially to forms of the disorder that do not respond well to mild or low-dose antidepressants.
“If a patient had high levels of inflammation, they could immediately begin with a more intensive treatment program, such as combining antidepressants or stepping up the doses,” said Pariante.
Although there are a variety of antidepressants on the market, it is widely accepted that many antidepressants work in only half of patients half of the time, and drugmakers are struggling to come up with a new effective medications.
The team set out to identify two types of biomarkers — the first ones (called predictors), which predict future response to antidepressants, and the second ones (called targets), which are targeted by antidepressants and change over the course of treatment.
The researchers said that in human cells, information from genes is transcribed into messenger RNA, or mRNA, before it becomes visible as a physical or biochemical sign. Therefore, the team monitored the patients’ mRNA before and after they were treated with one of two antidepressants — escitalopram or nortriptyline.
Escitalopram, sold under various brand names including Lexapro, Seroplex, Cipralex and made by generic drugmakers, is a serotonin reuptake inhibitor (SSRI). Nortriptyline, sold under the brand names Sensoval, Aventyl and others, is an older type of antidepressant known as a tricyclic.
After eight weeks of treatment, the participants who were not getting any better were those who had much higher levels of three inflammation markers before treatment began.
The results suggest that these three signals could identify patients who are least likely to respond to antidepressants, allowing doctors to consider a more personalized approach to treatment from the start, the researchers said.