{"data":{"event":{"id":"eae32afc-ab1c-4818-82df-021892fc625b","slug":"neda-tessa-harmful-diet-advice","title":"NEDA disables Tessa after the chatbot gives diet advice to people with eating disorders","short_summary":"On 30 May 2023 the National Eating Disorders Association took down Tessa after users showed it recommending calorie restriction and weekly weight loss, contrary to eating-disorder care.","full_description":"NEDA had been pivoting from a human helpline toward the chatbot. Tessa originated as a more scripted prevention program; NEDA later said a vendor change allowed unconstrained generative replies. The bot was withdrawn. Population-level clinical harm was not epidemiologically measured; the incident is a documented unsafe-advice event in a high-risk population.","ledger_type":"harm","primary_domain_id":"c09546b6-10f8-48df-8347-0c1979416464","event_status":"verified","event_date":"2023-05-30T00:00:00.000Z","discovery_date":"2023-05-30T00:00:00.000Z","first_published_date":"2023-05-30T00:00:00.000Z","last_reviewed_date":"2023-05-30T00:00:00.000Z","geographic_scope":"United States (national helpline users)","affected_population":"People seeking eating-disorder help from NEDA, including users who received diet advice","base_impact_tier":2,"base_score":"3.00","attribution_multiplier":"0.4500","evidence_multiplier":"0.7000","realization_multiplier":"0.7000","durability_multiplier":"0.3000","current_event_score":"0.119100","confidence_level":"high","score_explanation":"Harmful clinical advice to a vulnerable group is notable (tier 2). Shared attribution with vendor and NEDA process failures. Multiple independent user logs plus NEDA admission. Realization is unsafe advice and service disruption. Transient after shutdown.","methodology_version_id":"d7881163-fb23-4e71-8625-bac1a8662c0f","original_methodology_version_id":"d7881163-fb23-4e71-8625-bac1a8662c0f","published_at":"2023-05-30T00:00:00.000Z","created_at":"2026-09-13T20:47:20.075Z","updated_at":"2026-09-13T20:47:20.075Z","flags":[],"domain_name":"Medicine & Health","domain_slug":"medicine-health","methodology_version":"0.1"},"contributions":[{"id":"841256d4-e5fe-4d6e-b044-0e964f5359b5","event_id":"eae32afc-ab1c-4818-82df-021892fc625b","model_id":"2539d286-76c3-4aaf-b49f-505aadaa9f19","role_description":"Chatbot that produced weight-loss and calorie-restriction advice.","attribution_multiplier":"0.4500","credit_share":"0.6000","contribution_score":"0.119100","attribution_rationale":"Generative or loosened replies produced the harmful content; NEDA deployed it to a clinical population.","attribution_confidence":"medium","first_used_date":"2022-02-01T00:00:00.000Z","model_version_if_known":null,"review_status":"approved","created_at":"2026-09-13T20:47:20.075Z","model_slug":"tessa","model_name":"Tessa","identity_class":"named_release","is_internal":false,"family_name":"Cass chatbot","family_slug":"neda-cass-chatbot","organization_name":"National Eating Disorders Association","organization_slug":"neda"}],"sources":[{"id":"788e103e-aa2a-411d-a356-2fd7642916e6","event_id":"eae32afc-ab1c-4818-82df-021892fc625b","url":"https://www.nbcnews.com/tech/neda-pulls-chatbot-eating-advice-rcna87231","canonical_url":"https://www.nbcnews.com/tech/neda-pulls-chatbot-eating-advice-rcna87231","source_type":"journalism","publisher":"NBC News","author":null,"publication_date":"2023-05-31T00:00:00.000Z","retrieved_at":"2026-09-13T20:47:20.075Z","title":"National Eating Disorders Association pulls chatbot","excerpt":null,"content_hash":null,"source_reliability_class":"medium","is_primary_source":false,"is_independent":true,"is_peer_reviewed":false,"archived_url":null,"created_at":"2026-09-13T20:47:20.075Z"},{"id":"586b2b7a-f9be-47a9-a8d1-ad69f8821ddb","event_id":"eae32afc-ab1c-4818-82df-021892fc625b","url":"https://www.npr.org/sections/health-shots/2023/06/08/1180838096/an-eating-disorders-chatbot-offered-dieting-advice-raising-fears-about-ai-in-hea","canonical_url":"https://www.npr.org/sections/health-shots/2023/06/08/1180838096/an-eating-disorders-chatbot-offered-dieting-advice-raising-fears-about-ai-in-hea","source_type":"journalism","publisher":"NPR","author":null,"publication_date":"2023-06-08T00:00:00.000Z","retrieved_at":"2026-09-13T20:47:20.075Z","title":"Chatbot that offered bad advice for eating disorders taken down","excerpt":null,"content_hash":null,"source_reliability_class":"medium","is_primary_source":false,"is_independent":true,"is_peer_reviewed":false,"archived_url":null,"created_at":"2026-09-13T20:47:20.075Z"}],"claims":[{"id":"7259f6a5-d428-440d-8830-df21366b86a2","event_id":"eae32afc-ab1c-4818-82df-021892fc625b","claim_text":"Tessa gave calorie-restriction and weight-loss advice to users seeking eating-disorder support and was taken down.","claim_type":"outcome","claim_status":"supported","confidence_score":null,"created_at":"2026-09-13T20:47:20.075Z","updated_at":"2026-09-13T20:47:20.075Z"}],"revisions":[{"id":"d59cd04d-0081-49c0-b1a9-609526131c81","event_id":"eae32afc-ab1c-4818-82df-021892fc625b","model_id":null,"previous_score":"0.000000","new_score":"0.119100","previous_factors":{},"new_factors":{"evidence":0.7,"base_score":3,"durability":0.3,"attribution":0.45,"realization":0.7},"change_reason":"Initial adjudicated seed score under methodology 0.1.","trigger_type":"seed","trigger_source_ids":null,"reviewer_id":null,"review_status":"published","created_at":"2026-09-13T20:47:20.075Z"}],"secondary":[{"name":"Computer Science","slug":"computer-science"}]},"methodology_version":"0.1"}