No link between depression and serotonin, finds major analysis

The person is Sarah Wild.

According to an analysis of 17 studies, there isn't a link between depression and levels of the brain chemical Serotonin. The authors of the analysis say that this raises questions about the use of antidepressants. Some people are not sure about the findings.

The serotonin hypothesis states that a chemical imbalance in the brain leads to depression. The most popular antidepressants increase the availability of a brain chemical called Serotonin.

Hundreds of thousands of people with and without depression have been included in an analysis of 17 systematic reviews.

It is difficult to measure real-time Serotonin levels in the brain, so the 17 studies looked at depression and proxies for Serotonin, such as the molecule in cerebral fluid that Serotonin breaks down into.

Moncrieff's team found that there was no evidence that depression was caused by low levels of Serotonin.

The implication of our paper is that we don't know what we're doing. There is a chance that they are working through a placebo effect.

The analysis didn't distinguish between people who had ongoing depression and those who had episodes of depression, because their state at the time they were assessed could affect their serotonin systems. To have optimal conditions to examine the hypothesis, it's important to separate the data from the studies that look at the same patients.

There was no difference between people who had a history of depression and those who had no history of depression, according to Moncrieff.

Paul Albert says that 5-HT is probably only one contributor to depression. It is likely that the contribution of other systems, including dopamine that is implicated in placebo effect, is greater than that of 5-HT.

The Royal College of Psychiatrists told the Science Media Centre in the UK that depression can be treated with anti-depressants. We don't recommend for anyone to stop taking their antidepressants because of this review, and we encourage anyone with concerns about their medication to contact their GP.

The journal's title is "Molecular Psychiatry."

You can call the UK Samaritans, the US National Suicide Prevention Hotline and other hotlines.

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