Every weekend was an adventure for Julie Tanny when she was a young girl.

Her father, Charles, made sure of it, surprising his three children with trips and visits to the amusement park. His warmth radiated physically, too, when he would rub his children’s ice-cold feet back to life after a skate at their backyard rink in Montreal.

Everything changed in the winter of 1957. A tooth filling gone awry spurred an excruciating neurological condition that stumped five of his doctors. They referred him to the Allan Memorial Institute, a psychiatric hospital at McGill University in Montreal, where he was admitted for three months of treatment.

When Ms. Tanny’s father was released, the man who came home was distant, irate, confused and physically abusive. He did not remember that he owned a snowblower business. He was barely able to recognize his family.

It was as though his brain had been reprogrammed.

As Ms. Tanny would later learn, it largely was. Her father had unknowingly become a patient of Dr. Donald Ewen Cameron, a psychiatrist running a secret mind-control experiment claimed to be funded by the Central Intelligence Agency as part of a Cold War-era program known as MK-ULTRA.

“He was like a shell of what he was before,” Ms. Tanny, a retired wholesale jeweler, said. “He was just a completely different person.”

Ms. Tanny, 70, is the lead plaintiff in a class-action lawsuit filed in 2019 against the institutions linked to the experiment and the Canadian and United States governments. About 400 people, mostly families of former patients who were treated at the clinic between 1948 and 1964, have joined the effort, she said.

But their legal battle was recently dealt a setback. A Quebec judge approved a request by the United States to dismiss the case against it, arguing that foreign states are immune from the jurisdiction of Canadian courts. The ruling was upheld in the province’s court of appeal.

Two weeks ago, the Supreme Court of Canada rejected a request for appeal, meaning that the case against the United States is dismissed but will proceed against the Canadian government, McGill University Health Center and its associated Royal Victoria Hospital.

Dr. Cameron’s experiments included intensive electroshock therapy, drug-induced comas, sensory deprivation and a regimen of powerful medications to alter nerve function, according to the claim. These methods led to the erasure of thoughts and changed behavior patterns, rendering patients childlike. Some had to relearn how to use the bathroom after losing the ability to control their bladders.

Some patients, according to the claim, were forced to listen up to 500,000 times to a looped audio tape of phrases intended to rewire their brains: “You are selfish” or “My mother hates me” or “You are lovable.”

The families of patients argue that these treatments were a form of psychological torture that the patients did not consent to.

The fallout of Dr. Cameron’s experiments shattered the lives of families and traumatized patients, said Jeff Orenstein, the class-action lawyer.

“They just came out sort of robots, robotlike,” he said.

The United States and Canadian governments compensated some victims as the extent of the “Montreal Experiments” came to light, but their families were not, the claim said. Ms. Tanny’s father received 100,000 Canadian dollars, an amount she said hardly reflected the true cost of his mental, and then physical, lapse.

He had two massive heart attacks, which Ms. Tanny believes were a direct aftermath of the electroshock therapy, and a stroke that left him debilitated. He required round-the-clock care, and Ms. Tanny’s brother abandoned his young career in law to take over their father’s business.

“I paid the price for those experiments my whole life,” she told me from her home in Montreal.

Neither government nor the hospitals or McGill University has formally apologized for their participation, the claim says.

The case has been widely covered in Canada, but most families of victims are still reluctant to speak publicly about it, Ms. Tanny said. Others have detailed harrowing stories of abuse, cycling between foster homes after losing parents to the experiment and having to fight for answers.

Ms. Tanny decided to file the action after reading, in 2017, about the case of another daughter of a brainwashing patient, who quietly reached a settlement with the government.

Ms. Tanny’s father died in 1993. After his stroke at the age of 60, he couldn’t write, speak or walk for the remaining 18 years of his life, she said.

For her, one of the most harrowing parts of the legacy of the Montreal Experiments is thinking of how much was lost: happy family lives, careers, relationships.

“We didn’t really realize our full potential, with either taking care of a parent that was ill or suffering the repercussions for traumatic changes at home,” she said. “Imagine a father who doesn’t know who you are.”


Vjosa Isai is a reporter and researcher for The New York Times in Toronto.


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