Joanna Moncrieff, MD, a psychiatry professor at University College London, and a team of five other top European researchers analyzed data from 361 existing studies worldwide about the relationship between serotonin levels and depression.
The researchers found “no convincing evidence that depression is associated with, or caused by, lower serotonin concentrations or activity. Most studies found no evidence of reduced serotonin activity in people with depression compared to people without, and methods to reduce serotonin availability … do not consistently lower the mood of volunteers.”