Rare Bromide Poisoning Caused Hallucinations and Paranoia in a Seattle Man
The patient: A 60-year-old man living in Seattle
The symptoms: The man developed intense paranoia, along with auditory and visual hallucinations. He was also extremely thirsty but became afraid to drink water offered by other people.
What happened next: The man went to an emergency department because he believed his neighbor had poisoned him. Doctors checked his vital signs and performed a neurological examination, but the initial assessment did not reveal any obvious problems.
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Doctors First Suspected a Chloride Imbalance
Blood tests showed that the man’s chloride levels were far above the normal range. This finding initially suggested hyperchloremia, a condition in which chloride ions accumulate in the blood. Hyperchloremia commonly develops because of dehydration or excessive salt consumption.
However, additional testing showed that the apparent chloride increase did not tell the whole story. The man’s blood contained an excess of negative electrical charge, suggesting that another negatively charged substance was interfering with the laboratory test.
In true hyperchloremia, the body usually compensates for extra negatively charged chloride ions by reducing bicarbonate, another negatively charged ion produced by the body. This process helps maintain the blood’s electrical balance.
In this case, the blood was more negatively charged than expected. Doctors concluded that a different negative ion had accumulated too quickly for the body to compensate.
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The Diagnosis: Pseudohyperchloremia and Bromide Poisoning
The diagnosis: After consulting poison control specialists, the doctors diagnosed the man with pseudohyperchloremia. This occurs when a blood test mistakenly identifies another negatively charged ion as chloride, making chloride levels appear abnormally high while concealing the true cause.
A known cause of pseudohyperchloremia is a high concentration of salicylate, the active ingredient in aspirin. However, tests showed that aspirin was not responsible for the man’s symptoms.
Doctors then considered bromide, a negatively charged form of bromine. Bromine sits directly below chlorine on the periodic table, so bromide and chloride ions have similar sizes, charges and chemical properties. As a result, bromide can sometimes interfere with chloride laboratory tests, as described in previous reports.
The man’s bromide concentration was approximately 230 times higher than normal. Doctors diagnosed him with bromide poisoning, also known as bromism. This rare form of poisoning can cause neurological symptoms, including confusion, paranoia, hallucinations and other changes in mental state.
High doses of aspirin can sometimes cause pseudohyperchloremia because chloride tests detect salicylate in the blood. In this case, however, aspirin was not the source of the abnormal test result.
(Image credit: boonchai wedmakawand via Getty Images)
How the Patient Was Treated
The treatment: The patient spent three weeks in the hospital while doctors monitored his health and gradually restored his electrolyte balance. Because his paranoia led him to try to leave, he was temporarily held in the hospital involuntarily. Doctors also prescribed daily doses of risperidone, an antipsychotic medication.
His hallucinations and paranoia eventually improved. He was gradually taken off the medication and discharged from the hospital. His condition remained stable during a follow-up evaluation two weeks later.
How a Salt Substitute Led to Bromism
What makes the case unique: After recovering, the man told doctors that he had been searching for a healthier alternative to table salt, or sodium chloride. He consulted ChatGPT, which suggested replacing sodium chloride with sodium bromide. The man followed that advice and used sodium bromide for approximately three months.
Bromide-containing medicines were once widely used to treat problems such as headaches and upset stomach. They eventually fell out of favor after doctors linked bromide exposure to a significant number of psychiatric hospital admissions. In the early 20th century, bromide poisoning reportedly accounted for 8% of admissions to psychiatric hospitals.
Because bromide ions resemble chloride ions, they can take over some of chloride’s functions in the body. Chloride helps regulate electrical activity in the brain by moving through chloride channels in neurons. Bromide can also pass through these channels, potentially disrupting normal brain activity and causing neurological symptoms.
Doctors Warn Against Using AI for Medical Advice
Bromide poisoning is uncommon today, so doctors may not immediately consider bromism when a patient develops hallucinations, paranoia or confusion. However, bromide supplements and salts can be purchased online, creating a potential risk of accidental poisoning. The doctors described the case in a case report.
The doctors later asked ChatGPT about removing chloride from the diet. The chatbot again suggested bromide salt as an alternative and did not provide an adequate warning about the dangers of consuming excessive bromide.
The case authors said that bromism should be considered during psychological evaluations when patients present with unexplained paranoia, hallucinations or other neurological symptoms. They also emphasized the potential dangers of relying on AI chatbots for medical advice.
Live Science contacted OpenAI, the developer of ChatGPT, about the case and is awaiting comment. OpenAI’s service terms state: “You should always verify the information provided by ChatGPT for Healthcare and exercise independent professional judgment in decision-making about a patient without relying primarily or solely on the output.”
(Live Science first covered this case when it was published in 2025. At that time, an OpenAI spokesperson said the company’s safety teams were working to reduce risks associated with its services and train its products to encourage users to seek professional advice.)
This article is for informational purposes only and is not meant to offer medical advice.
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Source: www.livescience.com