For millions of people around the world, salvation from long periods of dark thoughts and oppressive feelings comes in pill form, with each dose doing its bit to ensure the balance of a humble neurotransmitter called Serotonin remains relatively undamaged.
Despite their popularity as a treatment for mood disorders, many of the mechanisms behind antidepressants are a black box. We don't know how they treat low moods.
Those guesses could be completely wrong, throwing into question whether depression is caused by a drop in the brain chemical serotonin.
There isn't enough evidence to support a link between the two variables, according to a new review.
Serotonin-based treatments may not be working on some other mechanism we don't know about. No one should abandon their medication without consulting their doctors. It's important to figure out what's really going on with so many people using these drugs.
It's hard to prove a negative according to the lead author of the book.
There is no evidence that depression is caused by lower levels or reduced activity of the brain chemical serotonin.
When a monoamine neurotransmitter called noradrenaline was proposed to be out of whack in people with depression, the beginnings of speculations that mood disorders arise from a chemical imbalance in the brain could be traced back further.
The monoamine hypothesis was formed because Serotonin was also seen as a monoamine.
The idea that depression is a relatively straightforward deficit in some kind of neurological happy juice was popular with the introduction of theSSRI antidepressants in the 1980's.
A huge increase in the use of antidepressants has been linked to the popularity of the chemical imbalance theory of depression.
One in six adults in England and two percent of teenagers have been prescribed an anti-depressant in the last year.
The hypothesis is accepted as fact. A simple fix can be sold for a profit.
Roughly one out of five people with depression seem to experience relief from their symptoms while on antidepressants, which is a good sign.
Eighty percent of the general public accepts that depression is a chemical imbalance.
The hypothesis has been on shaky ground since it took off in the 1990's, with study after study failing to support it.
In order to keep the hypothesis alive, Moncrieff and her team used terms related to meta-analysis investigations on depression and Serotonin to exclude those associated with other conditions.
The final calculation of each study's level of certainty was provided by independent reviewers.
There were 17 studies that made the cut, which included a genetic association study.
Serotonin's role in depression was not supported by the evidence. Serotonin levels in people with and without depression were not different. Huge studies didn't compare the genetics of the two drugs.
The studies that looked at the behavior of the neurotransmitter's receptors and its transporter were a little more supportive of the role it plays.
It seems that people who successfully take antidepressants may have lower levels of the brain chemical. The body compensates for changes in biochemistry over time.
Where do we go from here?
Studies like these remind us that there are differences in our body's functions that can't be boiled down to a single problem. Depression can be caused by a variety of factors and we have a lot of control over them.
According to Moncrieff, patients should not be told that depression is caused by a chemical imbalance or that antidepressants work by targeting the wrong parts of the brain.
Many of the included studies did not use direct measures of serotonin activity in the brain, something we're only recently technologically capable of doing.
We need to have honest conversations about how blind we are to the nature of chronic depression and the questions that persist over the benefits and costs of antidepressants.
It was published in a journal.
All Rights Reserved © 2024
