Could a blood test predict if antidepressants will work for you?
By Ian Birch
If you have suffered from depression it is quite likely you will have tried more than one antidepressant before finding one that works for you. For many this process is one of trial and error.
Well for the first time, scientists believe they could be able to develop a blood test which predicts whether someone with depression will respond to antidepressants.
Loyola University Medical Centre in the USA has shown that it can predict whether depressed patients will respond to the relatively new antidepressant escitalopram – one of the most powerful on the market.
Their study shows that 85% of patients who had a higher than normal level of a blood protein called VEGF (vascular endolethial growth factor) responded to the drug – also known as Cipralex and Lexapro.
Escitalopram is an SSRI or selective serotonin reuptake inhibitor (sometimes also called “serotonin specific reuptake inhibitors) similar in chemical nature to fluoxetine (Prozac) and paraoxetine (Seroxat).
Scientists don’t know why SSRIs work in some patients but not in others. Some cite theories about imbalances in chemicals called neurotransmitters in the brain. Some recent scientists have said that there is a second possible mechanism by which it works in the brain. This is called neurogenesis and means helping to regenerate cells in parts of the brain that have atrophied during depression.
Now the Loyola University researchers say they support the regeneration theory and that if the finding is confirmed by further studies, it could lead to a blood test that would help physicians tailor treatment. If, for example, a patient had low levels of VEGF, the physician might skip SSRIs and try alternative classes of antidepressants, or alternative therapies, such as talking therapies or Transcranial Magnetic Stimulation (TMG).
It is hoped that one day a simple test will be available which will help prescribing doctors to tailor treatment to an individual’s brain rather than the trial-and-error approach which exists today.
