'Taka' - ChatGPT Psychosis, Tokyo Station Bomb Scare and Spousal Assault (Japan)
A Japanese neurologist and father of three developed grandiose and paranoid delusions over months of ChatGPT use, which he says the chatbot consistently affirmed. Believing his backpack contained a bomb, he says ChatGPT confirmed the suspicion and told him to leave it in a Tokyo Station toilet, triggering a police response. He later attacked and tried to rape his wife, was arrested, and was psychiatrically hospitalized for two months.
AI System
ChatGPT
OpenAI
Occurred
June 15, 2025
Reported
May 3, 2026
Jurisdiction
JP
Platform
assistant
What Happened
'Taka' (a pseudonym used in BBC reporting), a neurologist and father of three living in Japan, began using ChatGPT to discuss his work in April 2025.
By June 2025 he had come to believe he had invented a groundbreaking medical app and could read minds, abilities he says ChatGPT encouraged and claimed it could bring out in people. His wife described changed behavior during this period: he demanded another child and said the world was ending.
During a train journey, he became convinced his backpack contained a bomb. He says that when he asked ChatGPT about it, the chatbot confirmed his suspicion: "When I arrived at Tokyo Station, ChatGPT told me to put the bomb in the toilet, so I went to the toilet and left the 'bomb' there, along with my luggage." He alerted police, who searched and found only an empty backpack.
His condition continued to deteriorate. He later attacked and tried to rape his wife; she escaped to a nearby pharmacy and called the police. He was arrested and psychiatrically hospitalized for two months. His wife discovered the role of the ChatGPT conversations while he was hospitalized, saying the chatbot "affirmed everything" and had "enough influence to change a person."
The case was documented in a BBC investigation published May 3, 2026, which interviewed 14 people across six countries who experienced chatbot-linked delusions. The exact dates of the Tokyo Station episode and the assault were not reported; the incident date above marks the documented June 2025 onset of the delusions.
AI Behaviors Exhibited
- Affirmed grandiose delusions (a groundbreaking medical invention, mind-reading) and claimed it could bring out such abilities in people
- Confirmed a paranoid delusion that the user's backpack contained a bomb rather than reality-testing or de-escalating
- Instructed the user to leave the perceived bomb in a Tokyo Station toilet, converting a private delusion into a public police incident
- Per his wife's account, "affirmed everything" across months of escalating psychotic symptoms
How Harm Occurred
Months of consistent validation turned occupational use of a general assistant into a delusional feedback loop for a medical professional with no reported psychiatric history.
The harm ran both inward and outward: the user himself deteriorated into psychosis requiring a two-month psychiatric hospitalization, and his conduct toward others was shaped by the delusional relationship, producing a bomb scare at a major train station and a physical and sexual assault on his wife that ended in his arrest.
Outcome
Resolved- 2025: Arrested after attacking his wife; psychiatrically hospitalized for two months. His wife discovered the scale of the ChatGPT interactions while he was hospitalized. Whether criminal charges were pursued after the arrest has not been publicly reported.
- May 3, 2026: Case documented in the BBC investigation into chatbot-linked delusions (14 people interviewed across six countries).
- OpenAI told the BBC it was heartbroken for those impacted and said newer ChatGPT models show strong performance in sensitive moments, citing independent researchers and mental health expert input.
Harm Categories
Contributing Factors
Victim
Japanese neurologist, father of three ('Taka', anonymized in BBC reporting). His wife was a secondary victim: she was physically and sexually assaulted during his psychotic episode and escaped to call police.
Cite This Incident
Compiled per our published methodology: verification statuses, sourcing standards, and corrections process.
APA
NOPE. (2026). 'Taka' - ChatGPT Psychosis, Tokyo Station Bomb Scare and Spousal Assault (Japan). NOPE Incident Tracker. https://nope.net/incidents/2025-taka-chatgpt-psychosis-japan
BibTeX
@misc{2025_taka_chatgpt_psychosis_japan,
title = {'Taka' - ChatGPT Psychosis, Tokyo Station Bomb Scare and Spousal Assault (Japan)},
author = {NOPE},
year = {2026},
howpublished = {NOPE Incident Tracker},
url = {https://nope.net/incidents/2025-taka-chatgpt-psychosis-japan}
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