# ChatGPT, Google AI Overviews split on health authority sources

Published: 2026-08-31T20:19:06.843Z · Source: BrightEdge Blog (https://www.brightedge.com/resources/weekly-ai-search-insights/ai-overviews-chatgpt-authority-health-finance)
Source date: 2026-08-31
Flags: BrightEdge study — vendor-published
Entities: ai-overviews, chatgpt

ChatGPT's top five cited domains for health questions are all government agencies or hospital systems, with YouTube absent from its top ten, while Google AI Overviews' YouTube citations run 1.8x above their June level and outrank clinical sources, according to a BrightEdge analysis using its AI Hyper Cube citation tracking. For finance questions, BrightEdge found Google AI Overviews concentrates citations in a single leading source (51% of tracked prompts) far more than ChatGPT, whose top five sources run 19%, 15%, 14%, 14%, and 11% and include the smaller valuation platform SimplyWall.st.

Why it matters: The two engines are applying different definitions of authority to the same YMYL categories, so a source's realistic shot at citation depends on which engine it's optimizing for, not just what it publishes.

## What this answers

**Does ChatGPT cite YouTube for health questions?**

No, per BrightEdge — ChatGPT's top five cited domains for health queries are all government agencies or hospital systems, and YouTube doesn't appear in its top ten. Google AI Overviews shows the opposite pattern, with YouTube citations running 1.8x above their June level and outranking clinical sources.

**Is citation concentration the same across AI engines for finance questions?**

No — BrightEdge found Google AI Overviews' top finance source appears in 51% of tracked prompts versus 18% for its fifth-ranked source, while ChatGPT spreads citations more evenly (19%, 15%, 14%, 14%, 11%) and includes a smaller platform, SimplyWall.st, in its top five.


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