Countless shelves line the basement walls of the University of Odense in Denmark, home to the world’s largest brain.
There are 9,479 organs, all removed from the corpses of psychiatric patients between the 1940s and the 1980s.
Preserved in formalin in large white containers labeled with numbers, the collection was the life work of renowned Danish psychologist Erik Stromgren.
Starting in 1945, it was “a kind of experimental research,” Jesper Vaczy Kragh, a historian of mental illness, explained to AFP.
Stromgren and his colleagues believed that “maybe they can find out where mental illness resides, or they think they can find answers in the brain”.

The brains were collected after autopsies on the bodies of people who had volunteered at mental institutions in Denmark.
Neither the deceased nor their families were asked for permission.
“These were public hospitals, and there were no outsiders asking questions about what was going on in public institutions,” he said.
At that time, patients’ rights were not a priority.
In fact, people believe that it is necessary to protect these people, a researcher from the University of Copenhagen said.
Between 1929 and 1967, the law required that volunteers in mental hospitals be locked up.
Until 1989, they needed a special dispensation to marry.
Denmark considered that people who were “mentally ill,” as they were called at the time, “were a burden to society (and believed that) if we allowed them to have children, we would release them . . . he said.
Back then, every Dane who died was operated on, said pathologist Martin Wirenfeldt Nielsen, who heads the collection.
“It was just part of the culture back then, the autopsy was just another medical procedure,” Nielsen said.
Changes in post-mortem procedures and a growing awareness of patient rights heralded the end of new additions in 1982.
Then there was a long and difficult argument about what to do.
The State Ethics Council in Denmark eventually ruled that it should be kept and used for scientific research.
Unlocking hidden secrets
The collection, originally located in Aarhus in western Denmark, was moved to Odense in 2018.
Research related to the collection, over the years, has involved a variety of illnesses, including dementia, schizophrenia, bipolar disorder, and depression.

“The debate has settled, and (people are now) saying, ‘Well, this is really interesting and useful scientific research if you want to know more about mental illness’,” said the group’s director.
Some brains belonged to people suffering from mental illness and brain diseases.
“Because most of these patients were admitted for maybe half their lives, or their whole lives, they would have had other brain diseases, such as strokes, epilepsy or brain tumors,” he added.
Four research projects are currently using the collection.
“If it’s not used, it doesn’t help,” says the former head of the country’s health agency, Knud Kristensen.
“Now we have it, we have to use it,” he said, lamenting the lack of funding for research.

Biologist Susana Aznar, a Parkinson’s specialist who works at a research hospital in Copenhagen, is using the collection as part of her group’s research.
He said the brain is unique because it helps scientists see the effects of modern medicine.
“They were not treated with the drugs we have now,” he said.
The brains of patients today can be changed by the drugs they receive.
When Aznar’s team compares this with the brain from the tissues, “we can see if these changes can be treated with drugs,” he said.
© Agence France-Presse