The idea that chronic depression is caused by a serotonin imbalance in the brain is widely accepted in society, but recent clinical studies have shown this to be wrong, according to this article from Quanta:
A literature review that appeared in Molecular Psychiatry in July was the latest and perhaps loudest death knell for the serotonin hypothesis, at least in its simplest form. An international team of scientists led by Joanna Moncrieff of University College London screened 361 papers from six areas of research and carefully evaluated 17 of them. They found no convincing evidence that lower levels of serotonin caused or were even associated with depression. People with depression didn’t reliably seem to have less serotonin activity than people without the disorder. Experiments in which researchers artificially lowered the serotonin levels of volunteers didn’t consistently cause depression. Genetic studies also seemed to rule out any connection between genes affecting serotonin levels and depression, even when the researchers tried to consider stress as a possible cofactor.
“If you were still of the opinion that it was simply a chemical imbalance of serotonin, then yeah, it’s pretty damning,” said Taylor Braund, a clinical neuroscientist and postdoctoral research fellow at the Black Dog Institute in Australia who was not involved in the new study. (“The black dog” was Winston Churchill’s term for his own dark moods, which some historians speculate were depression.)
That’s not to say drugs like fluoxetine (Prozac), citalopram, sertraline, or paroxetine don’t work but the reports of their high effectiveness for everyone is overstated. Maybe we should start with improving the harsh social environments we all live in and paying people more instead of cutting their wages.