A Blood Test to Help Choose an Antidepressant

Choosing which antidepressant to take is not simple' it's almost like dating. You ask a lot of questions, such as am I nervous? How will I feel? And then, there's no way to know until you've tried it. But scientists may have found a way to cut through all that work with a simple blood test in particular, for people who need more aggressive treatment.

This study found that people whose blood tests showed inflammation had not been responsive to some common antidepressants. The new blood work measures two molecules that are markers of inflammation: macrophage migration inhibitory factor as well as interleukin-1beta. Even though inflammation is one of the body's immune responses to stress, it may be contributing to depression AND blocking antidepressants.

In fact, multiple studies now show an integration of our brain's response to depression with the body's immune system. For example people whose stress trigger more inflammation are more likely to suffer depression. And those who develop depression from childhood trauma are more sensitive to certain activators of inflammation.

What appears to be happening is the inflammatory signals outside the brain are transmitted into the brain, altering behavior. Once in the brain, the inflammation can affect pathways that influence neurotransmitters which regulate behavior, such as anxiety and depression.

So, if the markers of inflammation in the blood test are above a certain level, this is a clear indication that common antidepressants may not work. This can guide doctors to prescribe more effective antidepressants from the start.