Shattered by Montreal Mind-Control Experiments, but Undeterred in a Suit

The C.I.A. headquarters in Langley, Va. A class-action lawsuit claims the agency funded life-altering psychiatric experiments in Montreal.Credit…Doug Mills/The New York Times

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.