2026-08-07 — Opened (ben-steer)

• Opened as a dedicated child thread of mh-evidence-watch, seeded from the EBP digital/AI-science research crawl. Distinct from meta-ai-csam-ads (platform/ad-system liability) — this thread tracks the evidence fight over whether social media causally harms adolescent mental health, not a specific platform-liability incident. (EBP digital/AI-science crawl, 2026-08-07) ⟨steer 2026-08-07⟩

2026-08-07 — Four months on, still no published reply to the Haidt-camp rebuttal

• Checked three separate ways — the SAGE journal page itself, a Platformer piece on the Haidt/Odgers fight, and general search — Vuorre, Przybylski, and Odgers have not published a reply to the April 11, 2026 rebuttal (below). The fight is currently one-sided in publication terms: Haidt’s camp has thrown the most recent punch and it sits unanswered. (SAGE, Platformer) (wave: mh-q08) ⟨daily 2026-08-07⟩

2026-08-03 — A new matched-comparison US study also lands null on school phone bans

• The first US study to test school phone bans’ effect on youth mental health with a causal matched-comparison design (states whose pre-ban trends match the treated states) found no evidence bans reduced screentime or improved any of eight psychological wellbeing measures. Preliminary — only three states have enough post-ban data yet — but a genuine methodological upgrade that lands in the same place as the existing null studies below. (ProMarket) (wave: mh-q08) ⟨daily 2026-08-07⟩

2026-06 — US age-verification litigation becomes a genuine circuit split, trending toward the Supreme Court

• Appellate courts are increasingly letting state social-media age-verification laws take effect pending appeal, reversing what had been a clean string of NetChoice trial-court wins. Ohio’s under-16 parental-consent law was revived by a fractured Sixth Circuit panel in June 2026; Mississippi’s law is live in the real world after the Supreme Court declined to block it at the emergency-relief stage (Justice Kavanaugh nonetheless called it “likely unconstitutional”); Florida’s preliminary injunction was stayed by the Eleventh Circuit in November 2025, with March 2026 arguments pressing NetChoice on standing rather than accepting a blanket First Amendment theory. Legal observers expect the Supreme Court will ultimately have to set the boundary — a track running only loosely coupled to the causality debate itself. (Bloomberg Law, BiometricUpdate) (wave: mh-q08) ⟨daily 2026-08-07⟩

2026-06 — Australia doubles penalties and expands enforcement power; evasion holds near 85%

• Legislation introduced in June 2026 doubles the maximum penalty for platform non-compliance from roughly $34M to roughly $68M USD, and would give the eSafety Commissioner power to compel platforms’ internal documents. The regulator opened investigations into five platforms (Facebook, Instagram, Snapchat, TikTok, YouTube) in March 2026; a compliance review found platforms letting minors retry failed age-checks repeatedly. More than 5 million accounts have been deactivated or restricted since the ban took effect, yet independent tracking still found roughly 85% of under-16s accessing banned platforms three months in — the government’s answer to weak enforcement so far has been harder penalties, not a reassessment, and still no wellbeing outcome data either direction. (Fortune, JURIST) (wave: mh-q08) ⟨daily 2026-08-07⟩

2026-06 — Australia’s under-16 ban: ~80% still accessing banned platforms at 3 months

• About three months after Australia’s under-16 social-media ban took effect (the world’s first), roughly 8 in 10 Australian under-16s were still accessing banned platforms, with about 1 in 5 creating fake over-16 accounts and roughly 10% using private browsing or VPNs to evade — despite the government’s own pre-launch lab trial finding age-verification tech “private, robust and effective.” An independent early academic assessment (University of Newcastle) found “insufficient evidence of any substantive early effects.” (The National) ⟨steer 2026-08-07⟩

2026 — A large within-person UK panel study also lands null on social media and mental health

• A random-intercept cross-lagged panel study of 25,629 Greater Manchester adolescents across three annual waves — a design built specifically to separate stable between-person differences from actual within-person change, the main methodological weakness skeptics point to in most existing correlational work — found no evidence that social media time or gaming frequency predicted later internalizing symptoms for either sex. The single strongest new causal design surfaced this pass, and it reinforces the skeptic camp with better methodology than most of the pro-causation literature currently has behind it. (Journal of Public Health / Oxford Academic) (wave: mh-q08) ⟨daily 2026-08-07⟩

2026 — A fresh rebuttal shows the fight is still live, not settling

• A 2026 paper (Sigaud, Rausch, McClean & Haidt) directly rebuts Vuorre and Przybylski’s cross-national null-effect analyses (below) on conceptual/methodological grounds — meaning both camps are still publishing new critiques of each other’s flagship evidence as of this year, not converging. Month of publication not specified in the underlying crawl. (SAGE) ⟨steer 2026-08-07⟩

2025-12 — Australia’s under-16 social media ban takes effect

• Australia’s under-16 social-media ban took effect December 10, 2025 — the world’s first national law of its kind, and the single most important live test of whether legislation can fix what the causality debate can’t resolve. ⟨steer 2026-08-07⟩

2025 — The youth mental-health trend line is more ambiguous than either camp’s framing suggests

• CDC’s own YRBS trend report shows “early signs that adolescent mental health is getting better” from 2021 to 2023 — a tentative reversal, not a continuation, of the decade-long worsening narrative (self-reported major depressive episodes among 12-17-year-olds reportedly fell from a 2021 peak of 20.8% to 15.4% by 2024). The UK tells the opposite story: NHS England’s 2025 Mental Health Survey found 25.8% of 16-24-year-olds affected by a common mental disorder, up from 18.9% in 2014 (36.1% among young women) — a real, sourced, ongoing worsening trend diverging from the tentative US signal. Neither the pro- nor anti-causation camp’s public framing currently reflects this divergence; CDC’s next YRBS wave (2025 data) is the concrete milestone to watch. (CDC YRBS) (wave: mh-q08) ⟨daily 2026-08-07⟩

2025-02 — School phone bans: real academic gains, null mental-health effects

• A 91-school England study found a 6.4% test-score increase after phone bans, concentrated among low-income students, plus improved attendance — but the same UK data found no association with wellbeing, anxiety, depression, or sleep. In-school phone use fell about 30 minutes a day, but total use outside school compensated, so overall exposure barely moved even where in-school behavior clearly did — the academic and mental-health claims are being cited as one finding when the evidence says they’re two separate ones. (ScienceDaily) ⟨steer 2026-08-07⟩

2025 — NBER: no clear wellbeing improvement from school phone bans

• A companion NBER working paper (w35181) on school smartphone bans found no clear reduction in screentime or improvement in psychological wellbeing from the policy — corroborating the null mental-health finding above from a separate dataset. Exact month within 2025/2026 not specified in the underlying crawl. (NBER) ⟨steer 2026-08-07⟩

2025 — Sapien Labs: n≈28,000, earlier smartphone age correlates with worse adult wellbeing

• Sapien Labs’ Global Mind Project (n=27,969, ages 18-24, using 2023 survey data) finds earlier first-smartphone age strongly correlates with worse adult mental wellbeing, especially on a “Social Self” dimension, with suicidal-ideation, aggression, and derealization items all elevated in the early-smartphone group — consistent across world regions, and the effect is stronger in females. Large-N and cross-cultural, but still self-report and correlational, and run by an advocacy-adjacent tracking organization rather than an independent academic RCT — flag carried forward from the source crawl. (Sapien Labs) ⟨steer 2026-08-07⟩

2024 — ABCD Study: no evidence of drastic tech-linked change

• The Adolescent Brain Cognitive Development (ABCD) Study — the largest US longitudinal youth brain-development study — found no evidence of drastic changes associated with digital-technology use, a heavyweight null/small-effect data point on the skeptic side of the debate. (Nature) ⟨steer 2026-08-07⟩

2023 — Vuorre & Przybylski: 72-country study finds no evidence of widespread harm

• A 72-country study of Facebook adoption (n=946,798, 2008-2019 data) found no evidence of widespread psychological harm from social-media penetration, and small positive associations for younger users — though the associations were small and didn’t clear pre-registered credibility thresholds in every analysis. A companion piece extended the analysis into Clinical Psychological Science in 2024. This is the flagship evidence the 2026 rebuttal above directly challenges. (Royal Society Open Science) ⟨steer 2026-08-07⟩

← Backstory