Skip to content
Back to the question

Evidence record

Is depression a chemical imbalance?

Every sentence on the exploration belongs to at least one claim below. Each says what kind of statement it is, what it rests on, what the evidence does not establish, and how far it was checked. Nothing here is a score, and none of it is a verdict on a belief or a theory.

Last checked 24 September 2026.

  • A judgement, not a fact: 18
  • Partly checked: 5
  • Source checked: 32
  • Presented as open: 4

If something here is wrong, misquoted, out of date or unfair, write to support@unknownoceans.com and give the claim number, which does not change.

What the question takes for granted

A scientific question about a popular explanation. It has two halves that are often run together: whether depression involves lowered serotonin, and whether drugs that act on serotonin help. The page keeps them apart and reports the dispute over the first.

  • There is a chemical balance for depression to depart from

    Contested

    The phrase assumes a known normal level of serotonin and a measurable departure from it. Critics of the phrase say neither has been established; defenders of a serotonin role argue for something narrower than a balance.

  • Depression is one condition

    Contested

    The diagnosis groups very different symptom profiles under one name, and whether they share a biology is exactly what is unknown.

  • Antidepressants do better than placebo in trials

    Established

    Established for acute treatment of adults with major depression in short trials, by a modest average margin. How large the benefit is, and for whom, is argued.

How the question is labelled

Claim: The explanation that outran the evidence

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s own title. It follows from claims 3 and 4: the serotonin account spread widely, and the evidence for it was never firm.

Claim 1 · checked 24 September 2026 · AI-assisted audit

Claim: Depression

Kind
Framing. Signposting. It asserts nothing a source could check.

The question

Claim: The serotonin account became common knowledge

Kind
Present-day figure. A count, survey or report finding, as the named source gives it.
Review
Partly checked. Only part of the source could be read. What was not read is listed.

What this does not establish

Rests on the review’s summary of two public surveys, one Australian and one American, which were not themselves read. It says nothing about other countries.

Later work looked for

Crossref, 2022 on, "chemical imbalance belief depression survey": nothing found that measures a change in public belief since.

Claim 3 · checked 24 September 2026 · AI-assisted audit

Claim: without ever having been established

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

The claim is about the lowered-serotonin account. Whether serotonin plays some part in depression is a separate question, argued in claims 23 and 24.

Claim 4 · checked 24 September 2026 · AI-assisted audit

Claim: The treatments built alongside it work anyway,

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

“Work” here means better than placebo, on average, over about eight weeks, in adults with major depression in trials. It is not a statement about any one person or about long-term use.

Later work looked for

Europe PMC and Crossref, 2019 on, "antidepressants placebo meta-analysis": the FDA patient-level analysis (Stone and others, 2022) finds the same small average advantage; nothing reverses it.

Claim 5 · checked 24 September 2026 · AI-assisted audit

Claim: which is the part worth understanding.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s judgement of where the interest lies, given claims 4 and 5.

Claim 6 · checked 24 September 2026 · AI-assisted audit

Claim: A systematic review of the evidence for lowered serotonin in depression found no consistent support for it.

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

  • Supports

    The serotonin theory of depression: a systematic umbrella review of the evidenceabstract, last sentences

    Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in people · Review of the field

    The source reads: 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.

  • Qualifies

    A leaky umbrella has little value: evidence clearly indicates the serotonin system is implicated in depressionabstract

    Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in people · Review of the field

    The source reads: We present reasons for why this conclusion is overstated, including methodological weaknesses in the review process, selective reporting of data, over-simplification, and errors in the interpretation of neuropsychopharmacological findings.

What this does not establish

One umbrella review, whose method and reading of the imaging and depletion studies were disputed in the same journal. The page reports that dispute in its first section.

Later work looked for

Crossref, 2022-07 on, "serotonin theory of depression umbrella review": replies by Jauhar and others (2023), Bartova and others (2023), Smith and others (2024) and a PET study by Erritzoe and others (2023, 17 patients) dispute it; page now reports the dispute.

Claim 7 · checked 24 September 2026 · AI-assisted audit

Claim: Separately, large analyses find antidepressants more effective than placebo by a modest margin.

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

Short-term trials of acute treatment. Averages across trials, not a prediction for a person.

Later work looked for

Europe PMC, 2019 on, "antidepressant placebo meta-analysis": nothing that changes the size or direction of the average effect.

Claim 8 · checked 24 September 2026 · AI-assisted audit

Claim: Both are true, and holding them together is the whole of the honest answer.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Follows from claims 7 and 8, which are about different things: a mechanism and an effect.

Other readings

Critics of the umbrella review would say the first half is overstated; see claim 23.

Claim 9 · checked 24 September 2026 · AI-assisted audit

Claim: A chemical imbalance is an explanation people can repeat,

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s reading of why the phrase spread.

Claim 10 · checked 24 September 2026 · AI-assisted audit

Claim: and for thirty years it was repeated in clinics, in advertising and in conversation.

Kind
Historical claim. A statement about the past that historical evidence can test.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

The advertising evidence is American: direct-to-consumer drug advertising is legal in few countries. “Thirty years” counts from the 1990s to the review in 2022.

Claim 11 · checked 24 September 2026 · AI-assisted audit

Claim: The research behind it was never as firm as the phrase,

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

Claim 12 · checked 24 September 2026 · AI-assisted audit

Claim: and the gap between the two has now been catalogued.

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

  • Supports

    The serotonin theory of depression: a systematic umbrella review of the evidenceIntroduction, third paragraph

    Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in people · Review of the field

    The source reads: Despite the fact that the serotonin theory of depression has been so influential, no comprehensive review has yet synthesised the relevant evidence.

What this does not establish

The catalogue is one review, and its reading is disputed (claim 23).

Claim 13 · checked 24 September 2026 · AI-assisted audit

What the evidence says

Claim: What the evidence says

Kind
Framing. Signposting. It asserts nothing a source could check.

The serotonin evidence, and the reply

Claim: The serotonin evidence, and the reply

Kind
Framing. Signposting. It asserts nothing a source could check.

Corrected

24 September 2026. Previously: “The serotonin evidence does not hold up” The heading took the umbrella review’s side while the passage reports a published reply that disputes it.

Claim: A 2022 umbrella review gathered the principal lines of research: serotonin and its main metabolite in body fluids, receptor and transporter measurements, tryptophan depletion studies, and genetic association work.

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

  • Supports

    The serotonin theory of depression: a systematic umbrella review of the evidenceabstract; Methods, third paragraph

    Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in people · Review of the field

    The source reads: 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

What this does not establish

The review excluded animal studies and depression in physical illness, and took at most the five most recent syntheses in each area.

Corrected

24 September 2026. Previously: “serotonin and its metabolites in body fluids” The review covers one metabolite, 5-HIAA, not several.

Claim 18 · checked 24 September 2026 · AI-assisted audit

Claim: It found no consistent evidence that depression is associated with lowered serotonin concentration or activity,

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

  • Supports

    The serotonin theory of depression: a systematic umbrella review of the evidenceabstract, last sentences

    Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in people · Review of the field

    The source reads: The main areas of serotonin research provide no consistent evidence of there being an association between serotonin and depression

  • Qualifies

    The serotonin theory of depression: a systematic umbrella review of the evidenceDiscussion, first paragraph

    Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in people · Review of the field

    The source reads: Weak evidence from some studies of serotonin 5-HT1A receptors and levels of SERT points towards a possible association between increased serotonin activity and depression.

    The weak signals the review did find point the other way, towards more serotonin activity, and may reflect past antidepressant use.

What this does not establish

Most of the included reviews were rated low quality, and most non-genetic studies could not exclude the effects of earlier antidepressant use.

Later work looked for

Crossref, 2022-07 on, "serotonin depression": the dispute noted at claim 7; nothing that establishes lowered serotonin.

Claim 19 · checked 24 September 2026 · AI-assisted audit

Claim: and the large genetic studies found no association between the serotonin transporter gene and depression.

Kind
Observation. Something measured or seen, as the named source reports it.
Review
Source checked. The cited passage was read, and it says this.

  • Supports

    The serotonin theory of depression: a systematic umbrella review of the evidenceabstract

    Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in people · Review of the field

    The source reads: 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.

What this does not establish

Read as reported in the umbrella review; the two genetic studies were not read themselves. Jauhar and colleagues note that single-gene studies are out of step with depression’s polygenic architecture.

Later work looked for

Crossref, 2019-06 on, "5-HTTLPR depression association": small studies only; nothing that overturns the two large null results.

Claim 20 · checked 24 September 2026 · AI-assisted audit

Claim: The review is not a demonstration that serotonin is irrelevant to mood.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The review asks a specific question about lowered serotonin, and the page keeps its conclusion to that question.

Claim 21 · checked 24 September 2026 · AI-assisted audit

Claim: Its case is that the specific claim people were told was not supported by the literature it was said to rest on.

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

  • Supports

    The serotonin theory of depression: a systematic umbrella review of the evidenceDiscussion, last paragraph

    Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in people · Review of the field

    The source reads: This review suggests that the huge research effort based on the serotonin hypothesis has not produced convincing evidence of a biochemical basis to depression.

Corrected

24 September 2026. Previously: “It is a demonstration that the specific claim people were told was not supported by the literature it was said to rest on.” One review, whose conclusion was disputed in the same journal, argues this rather than demonstrates it.

Claim 22 · checked 24 September 2026 · AI-assisted audit

Claim: A reply in the same journal from psychiatric researchers argued that it overstated that case, leaving out tryptophan depletion results in depressed people not taking antidepressants and misreading the imaging.

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

The reply concedes that several of the depletion studies came from one group and had wide confidence intervals. The umbrella review’s authors published a response in the same issue, which was not read.

Other readings

Moncrieff and colleagues hold that the depletion results in patients may reflect antidepressant use and that the imaging evidence is weak and inconsistent.

Later work looked for

Crossref, 2023 on, replies to the umbrella review: further letters on both sides (2024); nothing that settles it.

Corrected

24 September 2026. Previously: “” The page reported the umbrella review as settled. Its central conclusion was disputed in the same journal by researchers from departments of psychiatry; the disagreement is now reported, with who holds each side.

Claim 23 · checked 24 September 2026 · AI-assisted audit

Claim: What the reply defends is a role for serotonin in people vulnerable to or suffering from depression,

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

Corrected

24 September 2026. Previously: “” Added with claim 23, so the reader sees what the other side actually claims.

Claim 24 · checked 24 September 2026 · AI-assisted audit

Claim: a smaller claim than a chemical imbalance.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Follows from claim 24: a role for serotonin in some people, and a perturbed system, is less than a deficit that a drug corrects.

Other readings

The reply also cites a small PET study suggesting reduced serotonin release in depression, which would be closer to the older account if it were replicated.

Corrected

24 September 2026. Previously: “” Added with claim 23.

Claim 25 · checked 24 September 2026 · AI-assisted audit

The treatments are still better than placebo

Claim: The treatments are still better than placebo

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

In short trials of acute treatment in adults.

Later work looked for

Europe PMC, 2019 on, "antidepressant placebo meta-analysis": consistent with the FDA patient-level analysis of 2022.

Claim 26 · checked 24 September 2026 · AI-assisted audit

Claim: A 2018 network meta-analysis of 522 trials and 116,477 participants, covering 21 antidepressants, found all of them more effective than placebo in acute treatment of major depression in adults, with differences between drugs in efficacy and in how well they were tolerated.

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

The efficacy analysis itself drew on 432 of the 522 trials. Median treatment was eight weeks, 78 per cent of the studies were industry funded, and the certainty of evidence was rated moderate to very low.

Later work looked for

Europe PMC, 2019 on, "antidepressant placebo network meta-analysis": no larger synthesis that changes it.

Claim 27 · checked 24 September 2026 · AI-assisted audit

Claim: The margin is modest, and the paper says so itself.

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

Claim 28 · checked 24 September 2026 · AI-assisted audit

Claim: Odds of response ran from 1.37 to 2.13 times placebo depending on the drug, and the summary effect on symptom scores was 0.30 standard deviations, with a credible interval of 0.26 to 0.34.

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

“Response” means at least a halving of a rating-scale score. The odds ratios are for response against placebo, not a multiple of how much better people feel.

Later work looked for

Europe PMC, 2019 on: the FDA patient-level analysis (2022) reports a standardised mean difference of 0.24 in adults, in the same range.

Claim 29 · checked 24 September 2026 · AI-assisted audit

Claim: The usual reply is that an average hides the people who respond dramatically.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s characterisation of a common defence of the averages, which both variance analyses set out to test.

Claim 30 · checked 24 September 2026 · AI-assisted audit

Claim: That has been tested, by asking whether outcomes vary more on the drug than on placebo, and twice the extra variation was not there.

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Partly checked. Only part of the source could be read. What was not read is listed.

What this does not establish

Both analyses use trial-level summaries, 163 and 91 trials, and a spread that is no larger is compatible with large individual effects if drug and placebo responses are correlated. Maslej and colleagues say they cannot rule heterogeneity out. The second was read as an abstract only.

Later work looked for

Europe PMC, 2020 on, "antidepressant variability heterogeneity": a Bayesian re-analysis (Volkmann and others, 2020) agrees; the FDA patient-level analysis (Stone and others, 2022) reads the data differently, now reported in claim 32.

Claim 31 · checked 24 September 2026 · AI-assisted audit

Claim: A 2022 analysis of individual patients in trials submitted to the US Food and Drug Administration read the same kind of data differently: its model found three kinds of response, and put a large response at 24.5 per cent on the drug against 9.6 per cent on placebo.

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

The three kinds of response are components of a statistical mixture model, not groups anyone observed directly. The data include children, and the authors cannot fully exclude functional unblinding. It does not identify who the large responders are.

Later work looked for

Europe PMC, 2022 on, "antidepressant response distribution mixture model": nothing found that replicates or refutes it.

Corrected

24 September 2026. Previously: “” The page reported only the two variance analyses. A larger patient-level analysis of regulatory trials reaches a different reading of whether some people benefit substantially, and that disagreement belongs on the page.

Claim 32 · checked 24 September 2026 · AI-assisted audit

Claim: Outcomes do differ between people.

Kind
Observation. Something measured or seen, as the named source reports it.
Review
Source checked. The cited passage was read, and it says this.

Later work looked for

Not a finding later work could change; no search needed beyond claim 32.

Claim 33 · checked 24 September 2026 · AI-assisted audit

Claim: Whether the drug is what differs for some of them is still argued from the same trials.

Kind
Open question. Something the page says is not known.
Review
Presented as open. The page says this is unresolved, and the review found that it is.

Corrected

24 September 2026. Previously: “What the trials cannot show is that the drug is what differs.” The old wording implied the question was closed. The FDA patient-level analysis argues that the drug does make a large difference for a minority, so it is open.

Claim 34 · checked 24 September 2026 · AI-assisted audit

Claim: A drug that works is not evidence for the theory that inspired it.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s general point. Jauhar and colleagues argue the other way for this case, that SSRI efficacy lends the serotonin role some credibility.

  • Context

    The serotonin theory of depression: a systematic umbrella review of the evidenceIntroduction, second paragraph

    Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in people · Review of the field

    The source reads: It is often assumed that the effects of antidepressants demonstrate that depression must be at least partially caused by a brain-based chemical abnormality

Claim 35 · checked 24 September 2026 · AI-assisted audit

Claim: Aspirin was in use for more than seventy years before its mechanism was found in 1971.

Kind
Historical claim. A statement about the past that historical evidence can test.
Review
Partly checked. Only part of the source could be read. What was not read is listed.

What this does not establish

Vane’s paper was not read; its title and date come from the Crossref record. 1899 to 1971 is seventy-two years. “Its mechanism” is the principal one, blocking prostaglandin synthesis; more was learned later.

Corrected

24 September 2026. Previously: “Aspirin was in use for seventy years before its mechanism was found in 1971.” First marketed in 1899, its mechanism published in 1971: seventy-two years, so "more than seventy" rather than a round figure stated as exact.

Claim 36 · checked 24 September 2026 · AI-assisted audit

Claim: Two results that are both true

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Caption over claims 38 and 41.

Other readings

The first result is disputed by Jauhar and colleagues (claim 23).

Claim 37 · checked 24 September 2026 · AI-assisted audit

Claim: No consistent association between serotonin measures and depression.

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

The umbrella review’s finding; disputed (claim 23).

Claim 38 · checked 24 September 2026 · AI-assisted audit

Claim: The mechanism people were given is not established.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Follows from claims 4 and 19. Neither side of the dispute claims the lowered-serotonin account is established.

Claim 39 · checked 24 September 2026 · AI-assisted audit

Claim: The condition is not thereby explained away.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

A missing mechanism is not evidence that the condition is not real.

Claim 40 · checked 24 September 2026 · AI-assisted audit

Claim: Antidepressants outperform placebo across many trials, by a modest margin.

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

Short trials of acute treatment in adults.

Later work looked for

As claim 8.

Claim 41 · checked 24 September 2026 · AI-assisted audit

Claim: Something they do helps some people.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s reading of claims 41 and 32: an average advantage over placebo, concentrated by one analysis in a minority.

Claim 42 · checked 24 September 2026 · AI-assisted audit

Claim: What that is remains an open research question.

Kind
Open question. Something the page says is not known.
Review
Presented as open. The page says this is unresolved, and the review found that it is.

Claim 43 · checked 24 September 2026 · AI-assisted audit

Claim: Outcomes on antidepressants are no more variable than outcomes on placebo.

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Partly checked. Only part of the source could be read. What was not read is listed.

What this does not establish

As claim 31: trial-level variances, compatible with correlated individual effects. The second analysis was read as an abstract only.

Later work looked for

As claim 31.

Claim 44 · checked 24 September 2026 · AI-assisted audit

Claim: The defence usually made of the averages, that a few people respond dramatically, does not show up as extra spread.

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

The inference from spread to subgroups rests on assumptions the FDA patient-level analysis does not share.

Later work looked for

As claim 31.

Corrected

24 September 2026. Previously: “The defence usually made of the averages, that a few people respond dramatically, is not visible in the trials.” A patient-level analysis of regulatory trials finds large responses more common on the drug, so the defence is visible in the trials under another method. The row now says what the variance analyses show and no more.

Claim 45 · checked 24 September 2026 · AI-assisted audit

Claim: A patient-level analysis finds more large responses on the drug, so it is not ruled out.

Kind
Experimental result. What an experiment or trial found, under its own conditions. A result in animals, cells or a simulation is not a result in people.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

As claim 32: a mixture model, not observed groups.

Later work looked for

As claim 32.

Corrected

24 September 2026. Previously: “” Added with claim 32.

Claim 46 · checked 24 September 2026 · AI-assisted audit

Claim: Averages still do not describe a person.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Claim 47 · checked 24 September 2026 · AI-assisted audit

Claim: They are also most of what there is.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

No reliable predictor of individual response exists, so trial averages are the main evidence available.

Claim 48 · checked 24 September 2026 · AI-assisted audit

What might be happening

Claim: What might be happening

Kind
Framing. Signposting. It asserts nothing a source could check.

What the drugs are doing instead

Claim: What the drugs are doing instead

Kind
Framing. Signposting. It asserts nothing a source could check.

Claim: Candidate accounts include effects on neural plasticity, and early effects on how emotional and social information is processed rather than on mood directly.

Kind
Hypothesis. A proposed explanation, not an established one.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

The plasticity account rests largely on animal work; the review says it was characterised in animal models and set in context by human imaging and post-mortem studies. The emotional-processing account is from studies in people, many of them healthy volunteers.

Claim 50 · checked 24 September 2026 · AI-assisted audit

Claim: Neither is settled,

Kind
Open question. Something the page says is not known.
Review
Presented as open. The page says this is unresolved, and the review found that it is.

Claim 51 · checked 24 September 2026 · AI-assisted audit

Claim: and the review that sets them out argues they may be complementary rather than rival.

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

Claim 52 · checked 24 September 2026 · AI-assisted audit

Claim: Onset is also slower than the change in neurotransmitter levels,

Kind
Observation. Something measured or seen, as the named source reports it.
Review
Source checked. The cited passage was read, and it says this.

Later work looked for

Crossref, 2019 on, "antidepressant mechanism neuroplasticity emotional processing": rapid-acting agents such as ketamine are studied as exceptions; nothing changes the observation for monoamine drugs.

Claim 53 · checked 24 September 2026 · AI-assisted audit

Claim: which was an awkward fact for the original theory from early on.

Kind
Historical claim. A statement about the past that historical evidence can test.
Review
Source checked. The cited passage was read, and it says this.

“The original theory” is the monoamine account of how antidepressants act.

Claim 54 · checked 24 September 2026 · AI-assisted audit

Whether it is one thing

Claim: Whether it is one thing

Kind
Framing. Signposting. It asserts nothing a source could check.

Claim: Depression is defined by a list of symptoms, and the list can be satisfied many ways.

Kind
About a word. What a word in the original language means, or how it is translated.
Review
Source checked. The cited passage was read, and it says this.

The definition is the diagnostic one, in the DSM-5.

Claim 56 · checked 24 September 2026 · AI-assisted audit

Claim: Among 3,703 patients entering the STAR*D study there were 1,030 distinct symptom profiles, and about half of those profiles belonged to one patient each.

Kind
Observation. Something measured or seen, as the named source reports it.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

Profiles were built from twelve symptoms scored present or absent, which the authors call the conservative case. One American sample of outpatients. Half of the profiles is 13.5 per cent of the patients.

Later work looked for

Crossref, 2015-06 on, "unique symptom profiles depression heterogeneity": later work extends the theme; nothing that changes these counts.

Claim 57 · checked 24 September 2026 · AI-assisted audit

Claim: A category assembled that way may not correspond to a single biological state.

Kind
Hypothesis. A proposed explanation, not an established one.
Review
Source checked. The cited passage was read, and it says this.

What this does not establish

Different symptoms do not by themselves show different biology; the proposal is that they might.

Claim 58 · checked 24 September 2026 · AI-assisted audit

Claim: That would explain a literature full of effects that are real on average and inconsistent in detail, which is what this literature looks like.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Conditional on claim 58, and the authors offer it as a potential explanation.

Claim 59 · checked 24 September 2026 · AI-assisted audit

What is not understood

Claim: What is not understood

Kind
Framing. Signposting. It asserts nothing a source could check.

Claim: A treatment that works is not evidence for the story told about why.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Restates claim 35 as the interlude.

Claim 60 · checked 24 September 2026 · AI-assisted audit

What depression is

Claim: What depression is

Kind
Framing. Signposting. It asserts nothing a source could check.

Claim: There is no biological test for it.

Kind
What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review
Partly checked. Only part of the source could be read. What was not read is listed.

What this does not establish

The 2026 systematic review was read as an abstract only. The claim is about diagnosis: research biomarkers exist, none is used to diagnose.

Later work looked for

Crossref, 2020-06 on, "biomarkers major depressive disorder systematic review": the 2026 JAMA Psychiatry review still reports none; added as a source.

Claim 62 · checked 24 September 2026 · AI-assisted audit

Claim: A review of prospective biomarkers, across imaging, immune markers, neurotrophic factors and hormones, found none that predicted onset or recurrence once patients already diagnosed were set aside.

Kind
Observation. Something measured or seen, as the named source reports it.
Review
Source checked. The cited passage was read, and it says this.

  • Supports

    Prospective biomarkers of major depressive disorder: a systematic review and meta-analysisabstract

    Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in people · Meta-analysis

    The source reads: Only cortisol (N = 19, OR = 1.294, p = 0.024) showed a predictive effect on onset/relapse/recurrence of MDD, but not on time until MDD onset/relapse/recurrence. However, this effect disappeared when studies including participants with a baseline clinical diagnosis were removed from the analyses.

What this does not establish

Seventy-five prospective studies, most areas with too few for a meta-analysis; the authors note the null results may reflect small numbers. Absence of prospective evidence is not proof that no biomarker exists.

Later work looked for

Crossref, 2020-06 on, "prospective biomarkers major depressive disorder": no later synthesis finds a prospective predictor.

Claim 63 · checked 24 September 2026 · AI-assisted audit

Claim: Diagnosis is by description, treatment is by trial,

Kind
What scholars argue. A report of what specialists argue, or where they disagree.
Review
Source checked. The cited passage was read, and it says this.

Claim 64 · checked 24 September 2026 · AI-assisted audit

Claim: and the relationship between the experience, the brain and the circumstances a person is in is not understood.

Kind
Open question. Something the page says is not known.
Review
Presented as open. The page says this is unresolved, and the review found that it is.

Claim 65 · checked 24 September 2026 · AI-assisted audit

Claim: Saying so is not the same as doubting that the condition is real,

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

An unknown mechanism is not evidence against the condition.

Claim 66 · checked 24 September 2026 · AI-assisted audit

Claim: and the people who most need that distinction made carefully are the ones living with it.

Kind
This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review
A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s judgement. It gives no advice about treatment.

Claim 67 · checked 24 September 2026 · AI-assisted audit

What was read