Not one mention of the word "thyroid"…
Scientists question widespread use of antidepressants after survey on serotonin
Millions of people take them, but there is ‘no clear evidence’ that chemical imbalance causes depression
Scientists have called into question the widespread use of antidepressants after a major review found “no clear evidence” that low serotonin levels are responsible for depression.
Prescriptions for antidepressants have risen dramatically since the 1990s, with one in six adults and 2% of teenagers in England now being prescribed them. Millions more people around the world regularly use antidepressants.
“Many people take antidepressants because they have been led to believe their depression has a biochemical cause, but this new research suggests this belief is not grounded in evidence,” said the study’s lead author, Joanna Moncrieff, a professor of psychiatry at University College London and consultant psychiatrist at North East London NHS foundation trust.
“It is always difficult to prove a negative, but I think we can safely say that after a vast amount of research conducted over several decades, there is no convincing evidence that depression is caused by serotonin abnormalities, particularly by lower levels or reduced activity of serotonin.
“Thousands of people suffer from side-effects of antidepressants, including the severe withdrawal effects that can occur when people try to stop them, yet prescription rates continue to rise. We believe this situation has been driven partly by the false belief that depression is due to a chemical imbalance. It is high time to inform the public that this belief is not grounded in science.”
Rest of newspaper article here:
theguardian.com/society/202...
This is the paper referred to above:
• Systematic Review
• Open Access
• Published: 20 July 2022
The serotonin theory of depression: a systematic umbrella review of the evidence
• Joanna Moncrieff,
• Ruth E. Cooper,
• Tom Stockmann,
• Simone Amendola,
• Michael P. Hengartner &
• Mark A. Horowitz
Molecular Psychiatry (2022)
Abstract
The serotonin hypothesis of depression is still influential. We aimed to synthesise and evaluate evidence on whether depression is associated with lowered serotonin concentration or activity in a systematic umbrella review of the principal relevant areas of research. PubMed, EMBASE and PsycINFO were searched using terms appropriate to each area of research, from their inception until December 2020. Systematic reviews, meta-analyses and large data-set analyses in the following areas were identified: serotonin and serotonin metabolite, 5-HIAA, concentrations in body fluids; serotonin 5-HT1A receptor binding; serotonin transporter (SERT) levels measured by imaging or at post-mortem; tryptophan depletion studies; SERT gene associations and SERT gene-environment interactions. Studies of depression associated with physical conditions and specific subtypes of depression (e.g. bipolar depression) were excluded. Two independent reviewers extracted the data and assessed the quality of included studies using the AMSTAR-2, an adapted AMSTAR-2, or the STREGA for a large genetic study. The certainty of study results was assessed using a modified version of the GRADE. We did not synthesise results of individual meta-analyses because they included overlapping studies. The review was registered with PROSPERO (CRD42020207203). 17 studies were included: 12 systematic reviews and meta-analyses, 1 collaborative meta-analysis, 1 meta-analysis of large cohort studies, 1 systematic review and narrative synthesis, 1 genetic association study and 1 umbrella review. Quality of reviews was variable with some genetic studies of high quality. Two meta-analyses of overlapping studies examining the serotonin metabolite, 5-HIAA, showed no association with depression (largest n= 1002). One meta-analysis of cohort studies of plasma serotonin showed no relationship with depression, and evidence that lowered serotonin concentration was associated with antidepressant use (n= 1869). Two meta-analyses of overlapping studies examining the 5-HT1A receptor (largest n= 561), and three meta-analyses of overlapping studies examining SERT binding (largest n= 1845) showed weak and inconsistent evidence of reduced binding in some areas, which would be consistent with increased synaptic availability of serotonin in people with depression, if this was the original, causal abnormaly. However, effects of prior antidepressant use were not reliably excluded. One meta-analysis of tryptophan depletion studies found no effect in most healthy volunteers (n= 566), but weak evidence of an effect in those with a family history of depression (n= 75). Another systematic review (n= 342) and a sample of ten subsequent studies (n= 407) found no effect in volunteers. No systematic review of tryptophan depletion studies has been performed since 2007. The two largest and highest quality studies of the SERT gene, one genetic association study (n= 115,257) and one collaborative meta-analysis (n= 43,165), revealed no evidence of an association with depression, or of an interaction between genotype, stress and depression. The main areas of serotonin research provide no consistent evidence of there being an association between serotonin and depression, and no support for the hypothesis that depression is caused by lowered serotonin activity or concentrations. Some evidence was consistent with the possibility that long-term antidepressant use reduces serotonin concentration.
Rest of paper open access here: