In 2010, it was estimated that 1 in 10 Americans had depression and that antidepressants were the second most prescribed type of medication in the US. Contrary to popular belief, depression is probably not caused by the neurotransmitter deficiencies or imbalances we have been hearing about for years. While it is certain that biological factors are involved, they are likely not the ones we think.

George Slavich, a clinical psychologist at the University of California, Los Angeles, has spent years studying depression and has come to the conclusion that depression involves the body as well as the mind, but more importantly, that chronic inflammation is one of the major physiological causes of this condition.

Another researcher even suggests listing depression as an infectious disease, but not contagious. This author compares depression to a kind of allergic reaction to our modern world in view of the many pathogenic environmental factors that can cause inflammation.

It is certain that the scientific observations concerning vitamin D deficiency or the imbalance of the intestinal flora that favors depressive states remain valid, but that they would only be secondary to the inflammatory factors.

Dr. Kelly Brogan agrees. He argues that depressive symptoms are really just one of the manifestations of chronic inflammation.

According to him, the determining cause of this mood disturbance is exposure to dietary and environmental toxins, which are themselves the source of inflammation.

If from a psychological point of view these depressive symptoms are marked by a sad mood, sleep disorders or an inability to think or concentrate, biological markers such as cytokines or CRP levels (inflammatory messengers) are the physiological reflection.

For example, researchers have shown that depression, bipolar disorder and postpartum depression are directly associated with elevated cytokine levels and decreased cortisol. Remember that cortisol is a hormone that counteracts stress and reduces inflammation.

Until now, the diagnosis of depression has been based solely on subjective criteria. The measurement of these blood markers constitutes new and interesting potential diagnostic tools since they are directly correlated with this disease.

The advantage of this new approach is that it is obvious that if we intervene as soon as possible on the infection and on the inflammatory factors, we can avoid, prevent or even "cure" depression.