Anna Chancellor, who plays Vanessa's mother, had previously played Eva Green's mother in The Dreamers.
Eva Green did not shave her head for this episode, it was all special effects and makeup.
This is the first time we flashback to Vanessa's time in the Banning Clinic. It is later revisited in the season three episode "A Blade of Grass."
YouTuber Diane Jennings played Nurse Ruth, she said that most of her footage ended up on the cutting room floor.
In 1888 Dr. Gottlieb Burkhardt pioneered psychosurgery by removing parts of the cerebral cortex of six psychiatric patients. At that time the idea that malfunctions (without traumatic injury) of particular parts of the brain could cause mental disorders was relatively new. Over the decades, psychosurgery became more respected and more common. Also arguably more brutal. By the 1940s prefrontal lobotomy was a standard psychiatric treatment for difficult patients. A Dr. Freeman developed the transorbital lobotomy which required only a modified icepick and a mallet. He performed over 3400 lobotomies before being banned from ever doing any surgery. Subsequently, the lobotomy has been seen as a symbol of medical inhumanity.