A new analysis of the cause of depression has seemingly upended what we know about this common condition and challenged the use of antidepressants. But it may also leave patients with more questions than answers as the science evolves.
A systematic umbrella review of 17 studies published in Molecular Psychology on July 20 looked at the decades-old theory that depression is caused by low serotonin, and found there was “no consistent evidence” of “an association between serotonin and depression.”
The theory that depression is caused by a chemical imbalance in the brain has been around since the 1960s. But for years, many experts have doubted this, feeling it oversimplified a complex condition.
“The serotonin theory is very old and has been very popular since the ’90s, when the pharmaceutical industry started promoting it,” said Dr. Joanna Moncrieff, a psychiatry professor at University College London and lead author of the study.
“But since about 2005, probably a bit before then, there’s been sort of rumours that actually the evidence isn’t very strong, or it’s inconsistent. Some studies are positive, some studies are negative, but no one’s really got that evidence together anywhere.”
