How Reddit Citations Changed in Google AI Mode for High-Stakes Health and Medical Consumer Decisions

LLM Authority Index Research | Google AI Mode | Health and Medical | July-September 2026

Reddit remained a visible citation source in Google AI Mode for high-stakes health and medical questions throughout the July-September 2026 research window. Unlike the much sharper ChatGPT decline, however, Google AI Mode produced a mixed signal depending on the metric.

On the balanced 13-vertical July-to-September endpoint, Reddit citation-event share fell from 1.29% to 1.07%, a 16.7% relative decline. Reddit response citation coverage moved in the opposite direction, from 5.29% to 5.61%, an increase of 6.2%.

The full monthly platform slice shows the same divergence. Reddit event share declined steadily from 1.29% to 1.16% to 1.00%, while response coverage moved from 5.29% to 6.09% to 5.36%. Reddit ranked #7 in July, #8 in August and #7 in September.

The strict matched-prompt analysis is directionally negative. Among 328 matched Google AI Mode scenarios, Reddit remained cited in 18, disappeared in 22, newly appeared in 14, and was absent in 274. Matched coverage fell from 12.20% to 9.76%, down 20.0%. The exact two-sided McNemar p-value is approximately 0.243, so the matched loss-gain imbalance is not statistically significant at the conventional 0.05 threshold.

Answer Capsule

Reddit did not simply disappear from Google AI Mode health and medical answers between July and September 2026. Its citation intensity declined, while its aggregate response-level reach stayed roughly stable. On the balanced 13-vertical endpoint, Reddit citation-event share fell 16.7%, from 1.29% to 1.07%, but response citation coverage increased 6.2%, from 5.29% to 5.61%. In the strict matched panel, however, coverage fell from 12.20% to 9.76%, with 22 Reddit losses vs. 14 gains across 328 scenarios. The exact two-sided McNemar p-value is approximately 0.243, so the matched decline is directionally negative but not statistically significant at the 0.05 level.

Key Findings

• Reddit ranked #7 in July, #8 in August and #7 in September by Google AI Mode response citation coverage in the full health and medical slice.
• Full-panel Reddit citation-event share moved from 1.29% to 1.16% to 1.00%.
• Full-panel response citation coverage moved from 5.29% to 6.09% to 5.36%.
• On the balanced 13-vertical endpoint, Reddit event share fell from 1.29% to 1.07%, down 16.7%.
• Balanced response citation coverage increased from 5.29% to 5.61%, up 6.2%.
• The strict matched set contained 328 scenarios: 18 both, 22 losses, 14 gains, and 274 neither.
• Matched response coverage fell from 12.20% to 9.76%, down 20.0%.
• Reddit losses outnumbered gains 22 to 14, a 1.57-to-1 imbalance.
• The exact two-sided McNemar test gives p ≈ 0.243, so the matched loss-gain imbalance is not statistically significant at the 0.05 level.
• Among the 10 balanced verticals with measurable July Reddit event share, 7 declined and 3 increased.
• On response coverage, only 4 of those 10 declined, while 6 increased.
• The largest event-share declines were Online Therapy (-47.8%), STD Tests (-34.1%), IVF Clinics (-30.6%), Online Pharmacies (-25.0%), and Home Health Care (-16.7%).
• Weight Loss and Metabolic Health increased sharply, from 1.00% to 2.48% in event share and from 6.25% to 19.12% in response coverage.
• Hearing Aids also increased, with event share up 26.2% and response coverage up 91.5%.
• No single publisher replaced Reddit in the 22 matched loss scenarios. Verywell Mind, Choosing Therapy and Thervo each newly appeared in 18.2% of Reddit-loss scenarios.

Questions This Study Answers

• How did Reddit citation visibility change in Google AI Mode for high-stakes health and medical decisions from July to September 2026?
• Why do citation-event share, aggregate response coverage and matched response coverage tell different stories?
• Which health and medical verticals and replacement sources changed most as Reddit visibility shifted?

Why This Research Belongs in Daily AI Search Marketing Decisions

Article 53 isolates one source, Reddit, inside one surface, Google AI Mode, and one commercial decision family, Health and Medical. That narrow design makes the study useful for day-to-day AI search marketing because it separates measurements that can move in different directions:

1. How often does Reddit appear at least once in a response?
2. How much of the total visible citation inventory points to Reddit?
3. Does Reddit persist when the exact prompt and platform surface are held constant?

In the three-month Google AI Mode Health and Medical source study, Reddit ranked #7 overall at 5.56% response citation coverage. The frozen Article 53 child reconstruction shows monthly rank #7 in July, #8 in August and #7 in September, while full-panel response coverage moved from 5.29% to 6.09% to 5.36% and citation-event share fell from 1.29% to 1.16% to 1.00%.

The balanced 13-vertical endpoint is deliberately more nuanced than a simple decline story. Reddit citation-event share fell 16.7%, from 1.29% to 1.07%, while response citation coverage increased 6.2%, from 5.29% to 5.61%. That means Reddit appeared in roughly the same share of eligible AI Mode health responses, but accounted for a smaller portion of the total citation inventory.

The strict matched panel points in a different direction again. Among 328 exact prompt-plus-surface scenarios, Reddit produced 22 losses and 14 gains, a 1.57-to-1 loss-to-gain ratio, and matched coverage fell from 12.20% to 9.76%, down 20.0%. The exact two-sided McNemar test is p ≈ 0.243, so the observed matched imbalance is directionally negative but not statistically significant at the conventional 0.05 threshold.

For publishers, this is exactly why one AI visibility number is not enough. For healthcare brands and CMOs, it means AI Mode source strategy should track at least response coverage, citation-event share, matched persistence, rank, vertical mix and source replacement patterns separately.

The vertical audit reinforces that point. Among the 10 balanced verticals with measurable July Reddit event share, 7 declined and 3 increased. On response coverage, only 4 declined while 6 increased. Online Therapy lost 47.8% of event share, while Weight Loss and Metabolic Health gained 147.9% in event share and 205.9% in response coverage. Hearing Aids also increased materially. The category average therefore does not describe every health buying journey.

The platform comparison matters just as much. In the parent Health and Medical matched study, ChatGPT coverage fell 96.8%, Perplexity 100.0% on a much smaller base, Google AI Overviews 20.4%, Google AI Mode 20.0%, and Gemini 40.0%. Microsoft Copilot had no captured Reddit citations at either matched endpoint. A blended 'Reddit visibility in AI' score would erase these differences.

This result also belongs inside the broader Health and Medical Citation Authority Study. That study reports 61.3% median monthly Top 100 persistence, 25.8% median cross-platform Top 100 portability, and an approximate 35.5 percentage-point Persistence-Portability Gap. It also reports 20 domains appearing in all six platform Top 100 lists out of 290 distinct domains in the combined six-platform union.

The Google AI Mode Health source market has similar within-surface persistence: 66 domains remained in the monthly Top 100 across July, August and September, and median monthly Top 100 Jaccard similarity was 61.3%. The final Health child-study lists show AI Mode sharing 76 domains with Google AI Overviews, 54 with Gemini, 49 with Perplexity, 41 with ChatGPT and 38 with Microsoft Copilot.

Those are useful context measures, but Article 53 should not subtract one pairwise platform overlap from one temporal persistence statistic to manufacture a separate Persistence-Portability Gap. The comparison structures are different. The Persistence-Portability Gap framework is most useful here as a category-level interpretation: source authority can be more durable over time than transferable across engines, while one source can show different behavior depending on whether the metric is event share, aggregate coverage or matched persistence.

There is also a ranking-version distinction that should remain visible. The frozen Article 53 child reconstruction ranks Reddit #7, #8 and #7 by month. The later reconciled Article 25 source study ranks Reddit #7, #6 and #7. The three-month aggregate rank and coverage align, but the August rank differs because the two documents were produced from different stages of the source-ranking pipeline. Article 53 keeps its frozen monthly ranking series and labels the reconciled source-study version rather than silently replacing one with the other.

Health and Medical research also needs an additional guardrail. Citation visibility is separate from clinical quality, medical accuracy, safety, endorsement, brand mentions, recommendation rate, rank, sentiment, citation-recommendation coupling, and downstream business outcomes. This study measures the visible source layer around commercial high-stakes health decisions.

Commercial Action Matrix: What Publishers and CMOs Can Do With the Findings

Where Article 53 Fits in the High-Stakes Consumer Decisions Corpus

Article 53 is a child analysis of two parent studies:

• the Health and Medical Reddit decline study, which provides the balanced family endpoint and matched platform comparison; and
• the Google AI Mode Health and Medical source study, which provides the surrounding three-month AI Mode source market, including Reddit's #7 aggregate rank and 5.56% response coverage, 66 domains present in all three monthly Top 100s, and 61.3% median monthly Top 100 persistence.

The platform-level context comes from the overall Google AI Mode Top 100 study. The broader interpretation comes from the 2026 AI Citation Authority Study, the overall Reddit decline study, the cross-platform citation-overlap study, the citation-drift study, and the Persistence-Portability Gap framework. Those studies answer different questions and should not be collapsed into one visibility score.

What We Studied

This article is the Google AI Mode platform-specific extension of the broader LLM Authority Index study, Reddit's Decline in AI Citations for High-Stakes Health and Medical Consumer Decisions.

The underlying Google AI Mode Health and Medical source study contains:

The 14 source vertical labels are:

1. Addiction Treatment Centers
2. Assisted Living Facilities
3. Dental Implants
4. Fertility Clinics
5. Hearing Aids
6. Home Health Care
7. IVF Clinics
8. Medical Alert Systems
9. Mental Health Treatment Centers
10. Online Doctors
11. Online Pharmacies
12. Online Therapy
13. STD Tests
14. Weight Loss and Metabolic Health

Medical Alert Systems has no July source dataset in the frozen archive. It is included in the three-month source study but excluded from the balanced July-to-September endpoint. The remaining 13 verticals have observations at both endpoints.

The Core Finding: Reddit Lost Citation Intensity but Not Aggregate Response Reach

Questions This Section Answers

• Did Reddit decline on both primary Reddit metrics?
• How large was the balanced endpoint change?
• Why is this result more nuanced than the ChatGPT decline?

No. The two metrics moved in different directions on the balanced 13-vertical endpoint.

This divergence matters. Citation-event share asks what portion of all visible citation events pointed to Reddit. Response citation coverage asks how often Reddit appeared at least once in an eligible response.

The data suggests that Reddit appeared in roughly the same share of AI Mode health responses at the endpoint, but when it appeared, it accounted for a smaller share of the overall citation inventory. That is not the same pattern as the near-collapse measured in ChatGPT.

The broader all-platform Health and Medical parent study reported a 53.5% decline in Reddit citation-event share. Google AI Mode declined far less sharply than the family aggregate.

Reddit Event Share Fell Across All Three Months While Coverage Stayed Stable

Questions This Section Answers

• Was the event-share decline gradual across the quarter?
• Did response coverage decline at the same rate?
• Did Reddit lose meaningful rank inside Google AI Mode?

The full monthly platform slice shows a steady event-share decline but no comparable collapse in response coverage.

Reddit citation-event share declined each month, from 1.29% to 1.16% to 1.00%. Response coverage rose in August before returning close to the July level in September.

The full-panel July-to-September coverage change is only about +1.5%, from 5.29% to 5.36%. The balanced endpoint, which removes the September-only Medical Alert Systems vertical, produces a +6.2% coverage increase.

The rank remained relatively stable at #7, #8 and #7. That is a very different source-market story from the steep rank deterioration seen in some ChatGPT child studies.

The Matched-Prompt Test Is Negative but Not Statistically Significant

Questions This Section Answers

• Did Reddit decline when the same prompt and AI Mode surface were held constant?
• How many matched scenarios lost Reddit compared with gains?
• Was the loss-gain imbalance statistically significant?

The Article 30 Google AI Mode matched panel contains 328 scenarios:

Reddit losses outnumbered gains 22 to 14, a 1.57-to-1 imbalance.

Matched Reddit coverage fell from 12.20% to 9.76%, a 20.0% relative decline.

The exact two-sided McNemar test gives p ≈ 0.243. The matched direction is negative, but the observed loss-gain imbalance does not meet the conventional 0.05 threshold for statistical significance.

This matched result helps explain why aggregate coverage can look stable while matched coverage declines. The aggregate July and September panels are not identical prompt populations. When the comparison is restricted to the same prompt-plus-surface scenarios, Reddit is more likely to disappear than newly appear. The sample is still not large enough for that imbalance to be statistically strong under the exact test.

The Platform-Specific Vertical Audit Is Mixed, Not Uniformly Negative

Questions This Section Answers

• Did every health and medical vertical decline inside Google AI Mode?
• Which topics had the largest Reddit losses?
• Which topics moved strongly against the category-wide event-share trend?

The Google AI Mode vertical audit is notably mixed.

Among the 10 balanced verticals with measurable July Reddit event share, 7 declined and 3 increased. On response coverage, 4 declined and 6 increased.

The largest event-share declines were:

1. Online Therapy: down 47.8%.
2. STD Tests: down 34.1%.
3. IVF Clinics: down 30.6%.
4. Online Pharmacies: down 25.0%.
5. Home Health Care: down 16.7%.

Two verticals moved strongly against the category-wide event-share trend. Weight Loss and Metabolic Health increased from 1.00% to 2.48% in Reddit event share and from 6.25% to 19.12% in response coverage. The September base is larger than July but still materially smaller than some other health verticals, so the magnitude should be interpreted with sample size in mind.

Hearing Aids increased from 1.01% to 1.28% in event share and from 3.70% to 7.09% in response coverage.

Medical Alert Systems is not assigned a July zero. The frozen archive has no July source dataset for that vertical, so the missing month remains missing.

What Appeared When Reddit Disappeared?

Questions This Section Answers

• Did one source consistently replace Reddit?
• Which domains appeared most often in matched Reddit-loss scenarios?
• Does the evidence support a single replacement-source strategy?

No single source replaced Reddit across the 22 matched Google AI Mode scenarios where Reddit appeared in July but not September.

Verywell Mind, Choosing Therapy and Thervo were the most common newly appearing domains, each present in 18.2% of Reddit-loss scenarios.

The replacement mix spans mental-health publishers, therapy directories, provider sites, broad publishers and telehealth brands. That supports source redistribution, not a one-for-one transfer from Reddit to one dominant site.

For health brands, the operational lesson is to study the recurring source portfolio inside each prompt cluster rather than assume that one publisher is the replacement for Reddit.

Platform Differences: Google AI Mode Was Far More Stable Than ChatGPT

Questions This Section Answers

• Was the Reddit decline similar across AI platforms?
• How did Google AI Mode compare with ChatGPT and Google AI Overviews?
• Why should health teams report source visibility by platform?

The parent Health and Medical matched panel shows large platform differences:

Google AI Mode and Google AI Overviews were far more stable than ChatGPT in the matched health panel. ChatGPT recorded 30 losses and zero gains, while Google AI Mode recorded 22 losses and 14 gains.

The difference between the Google surfaces and ChatGPT is large enough that a single blended Reddit visibility KPI would be misleading. Healthcare brands, clinics, publishers, telehealth companies and consumer-health platforms should treat platform as a first-class reporting dimension.

What This Means for Health and Medical Brands and CMOs

Questions This Section Answers

• Should health brands interpret the result as a Reddit collapse?
• Which metrics should teams monitor next?
• How should source strategy respond to the mixed result?

1. Do not call this a Reddit collapse

Google AI Mode health data does not support that conclusion. Reddit's share of citation events declined, but aggregate response coverage stayed near its July level and increased slightly on the balanced endpoint.

2. Track event intensity and response reach separately

The two metrics diverged materially. Reporting only one would hide part of the source-market change.

3. Use matched prompts alongside aggregate panels

Matched coverage fell 20.0% even though aggregate balanced coverage increased 6.2%. That gap demonstrates why prompt-mix changes can affect a monthly aggregate.

4. Build a diversified third-party authority portfolio

Matched Reddit-loss scenarios redistributed across mental-health publishers, directories, provider sites and telehealth companies. There is no evidence of one universal replacement source.

5. Manage by vertical and prompt cluster

Online Therapy declined sharply while Weight Loss and Metabolic Health and Hearing Aids increased. Category-wide averages can conceal commercially important differences.

What This Means for Health and Medical Publishers

Google AI Mode's mixed Reddit result creates a different opportunity profile than a platform where Reddit disappears almost entirely.

A publisher can use this research to identify the health topics where Google AI Mode is changing citation intensity even when the number of responses citing Reddit remains stable. That can reveal where source-set depth is shifting before a large coverage change becomes visible.

For publishers selling advertising, research, sponsorship or data partnerships, a defensible commercial story can focus on:

• which health verticals cite the publisher;
• which high-intent prompt clusters produce citations;
• how event share and response coverage change separately;
• whether the publisher appears in Reddit-loss scenarios;
• whether visibility persists across Google AI Mode, Google AI Overviews, ChatGPT and other engines; and
• whether company mentions and recommendations move alongside source visibility.

The defensible claim is measured citation visibility, not that Google AI Mode trusts a publisher or that a citation caused a recommendation.

How This Study Relates to Prior Reddit and Health AI Research

Independent research is directionally consistent with a gradual Reddit decline in Google AI Mode, but the exact percentages are not directly comparable.

PromptWatch measured Reddit's share of Google AI Mode citations moving from about 2.22% in early July to 1.54% in mid-August 2026, a 30.5% relative decline. PromptWatch described the AI Mode movement as gradual rather than the abrupt break it observed in ChatGPT. Article 53 also shows a gradual decline in event share, 1.29% to 1.16% to 1.00%, while aggregate response coverage remained close to its July level. The magnitudes should not be merged because the prompt populations, dates, denominators and collection systems differ.

Ahrefs' September 2026 broad U.S. Google AI Mode leaderboard ranked Reddit #1 at 17.9% mention share, narrowly ahead of YouTube at 17.8%. That broad all-topic prominence can coexist with Reddit ranking #7 at 5.56% response coverage across this three-month Health and Medical source study. Ahrefs uses a broad U.S. query universe and a mention-share denominator, while Article 53 uses high-stakes commercial health prompts and reports response citation coverage plus citation-event share.

BrightEdge's healthcare citation study tracked ChatGPT, Google AI Mode and Google AI Overviews across 14 weeks from October 2025 through January 2026. For treatment queries, it reported Google AI Mode citations split across 17% elite hospitals, 15% government sources and 46% other sources, and measured materially higher citation volatility on AI Mode than on ChatGPT. That source-type and volatility study uses a different period and methodology, but it reinforces the need to treat AI Mode as its own health source environment.

Tinuiti's Q3 2026 research reports more than 13x growth in google.com's share of AI Mode citations during 2026 and says Google is increasingly citing its own surfaces, particularly in AI Mode. Tinuiti also reports most tracked AI platforms at or near Q3 highs in overall social citation share, with Perplexity as a notable exception. That broader social-source movement can coexist with a Reddit-specific decline because the social category and one social domain are different measurements.

Taken together, the outside research strengthens the case for measurement discipline, not a universal Reddit or healthcare-source narrative. The defensible comparison is direction, platform specificity, intent, source role and methodology, not decimal-point equivalence across unrelated panels.

How This Study Is Different

This study narrows the broader Reddit health trend research to one platform, one high-stakes commercial family and one fixed three-month window.

It combines:

1. a 4,158-response Google AI Mode health and medical source slice;
2. a balanced 13-vertical July-to-September endpoint;
3. a 328-scenario matched prompt-plus-surface test;
4. both citation-event share and response citation coverage;
5. a fresh 14-vertical platform-specific audit, with Medical Alert Systems explicitly identified as missing in July; and
6. a matched Reddit-loss source redistribution audit.

The narrow question is: did Reddit become less important as a visible Google AI Mode citation source for consequential health and medical consumer decisions, and does the answer change depending on whether importance is measured by citation intensity or response reach?

Why AI Citation Studies Can Disagree

Two well-executed studies can report different Reddit trends without either one necessarily being wrong.

Query population

Health and medical commercial questions are not representative of the entire web. Reddit's role can differ in software, travel, entertainment, troubleshooting and general informational queries.

Platform surface

Google AI Mode can behave differently from Google AI Overviews, ChatGPT, Gemini, Perplexity or Microsoft Copilot.

Denominator

Citation-event share and response citation coverage answer different questions. This article is a direct example: event share declined while balanced response coverage increased.

Aggregate versus matched panels

Aggregate monthly coverage stayed roughly stable, while matched coverage fell 20.0%. Changing prompt composition can therefore affect the headline monthly rate even when the same-prompt comparison moves in another direction.

Time window

A short product change and a three-month endpoint comparison answer different questions.

Missing versus zero

Medical Alert Systems has no July source dataset. That missing month is not converted into a measured zero.

Prompt weighting

This study does not weight prompts by search volume, patient volume, media spend, treatment value, conversion probability or revenue.

Domain and infrastructure handling

Domains are consolidated at the registrable-domain level. Article 25 reported that no additional infrastructure domains were removed from this specific public Google AI Mode health Top 100 under the frozen category-slice rule set.

The useful conclusion is not that one universal Reddit citation percentage exists. Citation visibility is conditional on platform, category, prompt set, time period, denominator and collection method.

Verticals Covered

The Google AI Mode Health and Medical source study covers 14 vertical labels:

• Addiction Treatment Centers
• Assisted Living Facilities
• Dental Implants
• Fertility Clinics
• Hearing Aids
• Home Health Care
• IVF Clinics
• Medical Alert Systems
• Mental Health Treatment Centers
• Online Doctors
• Online Pharmacies
• Online Therapy
• STD Tests
• Weight Loss and Metabolic Health

Thirteen are present in both July and September. Medical Alert Systems is present later in the quarter but has no July source dataset in the frozen corpus.

Methodology

Source archive

This study uses the frozen July-September 2026 LLM Authority Index archive underlying the Health and Medical citation-source study and the parent Health and Medical Reddit decline study.

Eligibility

A record is eligible when it is:

• in July, August or September 2026;
• assigned to the Google AI Mode platform family;
• associated with the Health and Medical family; and
• not explicitly marked as an extraction failure.

Exact-repeat anti-double-counting

An observation is treated as an exact analytical repeat when all of the following match:

• report month;
• exact raw platform/source surface;
• normalized prompt text; and
• exact set of original citation URLs.

One analytical record is retained while source-dataset memberships are preserved for vertical analysis.

Prompt normalization

Prompt text is normalized with Unicode NFKC normalization, case folding, whitespace collapse and trimming.

Domain normalization

Citation URLs are parsed to hostname, lowercased, stripped of a leading www., and consolidated to registrable domain using Public Suffix List logic.

Reddit identification

Reddit is identified at the registrable-domain level as reddit.com.

Citation-event share

Reddit citation-event share = Reddit citation events / all eligible public citation events

A response can contribute more than one Reddit citation event if multiple eligible Reddit URLs appear.

Response citation coverage

Reddit response citation coverage = eligible responses citing Reddit at least once / all eligible responses

Reddit counts no more than once per response for this metric.

Balanced endpoint

The headline July-to-September endpoint excludes Medical Alert Systems because the frozen archive contains no July dataset for that vertical. The other 13 verticals are present at both endpoints.

Matched prompt-plus-surface test

The matched panel requires the same normalized prompt and Google AI Mode surface in July and September, with exactly one eligible observation at each endpoint after exact-repeat handling. The panel contains 328 scenarios.

Replacement-source audit

For matched scenarios where Reddit appeared in July but not September, the analysis identifies registrable domains present in September but absent from the paired July citation set. Newly appearing domains can co-occur and should not be interpreted as proven substitutes for Reddit.

Limitations

1. The study covers one frozen three-month research window and should not be treated as a permanent platform rule.
2. Prompt sets are research panels, not search-volume-weighted market-share samples.
3. Visible citation does not prove recommendation causality, hidden retrieval influence or training-data use.
4. The study measures captured public-facing sources and cannot observe every internal retrieval step.
5. Vertical labels are source dataset labels and are not necessarily statistically independent clinical markets.
6. Some verticals have low Reddit event counts, which makes relative percentage changes volatile.
7. Medical Alert Systems has no July source dataset and is excluded from the balanced endpoint.
8. The matched loss-gain imbalance is not statistically significant at the conventional 0.05 level.
9. Newly appearing September domains are descriptive co-occurrences, not proven substitutes for Reddit.
10. Platform behavior can change after the research window.

Commercial Disclosure

LLM Authority Index is affiliated with CiteWorks Studio and related AI-search research and services. This research is designed to document observed AI citation behavior. Commercial relationships do not alter the frozen source corpus, eligibility rules, matching logic or published denominators.

No company can purchase a ranking, recommendation, score or position in this study. Citation visibility should not be interpreted as an endorsement by LLM Authority Index or by the AI platform being measured.

References

1. LLM Authority Index. The 2026 AI Citation Authority Study: Which Websites Does AI Cite for High-Stakes Decisions? https://llmauthorityindex.com/resources/research/2026-ai-citation-authority-study-high-stakes-consumer-decisions
2. LLM Authority Index. The Most-Cited Websites in AI for High-Stakes Health and Medical Consumer Decisions. https://llmauthorityindex.com/resources/research/most-cited-websites-ai-health-medical-high-stakes-consumer-decisions
3. LLM Authority Index. Reddit's Decline in AI Citations for High-Stakes Health and Medical Consumer Decisions. https://llmauthorityindex.com/resources/research/reddit-ai-citation-decline-health-medical-high-stakes-consumer-decisions
4. LLM Authority Index. The 100 Most-Cited Websites in Google AI Mode for High-Stakes Health and Medical Consumer Decisions. https://llmauthorityindex.com/resources/research/top-100-google-ai-mode-citations-health-medical-high-stakes-consumer-decisions
5. LLM Authority Index. The Persistence-Portability Gap: Why AI Citation Authority Persists Over Time but Fragments Across Platforms. https://llmauthorityindex.com/resources/measurement/persistence-portability-gap
6. PromptWatch. Why Did ChatGPT Stop Citing Reddit? Inside the August 2026 Citation Collapse. https://promptwatch.com/blog/chatgpt-stop-citing-reddit
7. Ahrefs. The 50 Most-Cited Websites in Google AI Mode (September 2026). https://ahrefs.com/blog/most-cited-domains-ai-mode/
8. BrightEdge. Healthcare AI Citations: How ChatGPT and Google Define Trust Differently. https://www.brightedge.com/resources/weekly-ai-search-insights/healthcare-ai-citations-chatgpt-vs-google-trust
9. Tinuiti. AI Citation Trends Report Q3 2026. https://tinuiti.com/research-insights/research/ai-citation-trends-report/

Related LLM Authority Index Research

Corpus foundation and measurement framework

• 2026 AI Citation Authority Study
• Overall Reddit Citation Decline Study
• Cross-Platform Citation Overlap Study
• AI Citation Drift Study
• Overall Google AI Mode Top 100 Study
• Persistence-Portability Gap Framework

Health and Medical source-market branch

• All-Platform Health and Medical Citation Authority Study
• Google AI Overviews Health and Medical Citation Sources
• Google AI Mode Health and Medical Citation Sources
• ChatGPT Health and Medical Citation Sources
• Perplexity Health and Medical Citation Sources
• Gemini Health and Medical Citation Sources
• Microsoft Copilot Health and Medical Citation Sources

Health and Medical Reddit-trend branch

• Health and Medical Reddit Decline Parent Study
• Google AI Overviews Reddit Trend
• Google AI Mode Reddit Trend
• ChatGPT Reddit Trend
• Perplexity Reddit Trend
• Gemini Reddit Trend
• Microsoft Copilot Reddit Trend

Article 53 is the Google AI Mode x Health and Medical x Reddit intersection study. The source-market branch explains the surrounding publisher, provider and specialist ecosystem, the Reddit parent study supplies the balanced family decline framework, and the five sibling Reddit studies show how the same source behaved on the other platform families.