In specialised wards called mother-and-baby units, doctors treat postpartum psychosis while allowing women to keep caring for their children. The blood dripping from the bathroom faucet was the first sign that something was wrong. A few days later, Alexandra Hardie saw cockroaches scuttle from beneath the bed.

Soon, she noticed spiders crawling up the wall. One day in May 2016, four months after giving birth to her first child, Hardie began shouting that the devil was in the room. She became so agitated that she smashed a bottle of red wine on the floor of her Edinburgh, Scotland, apartment.

Her husband, James, called 999, Britain’s emergency number. He pinned his wife, who was threatening to harm herself, to the floor to prevent her from grabbing a kitchen knife. A few hours later, James Hardie was driving his wife and infant daughter to a specialised psychiatric ward , where Alexandra Hardie would remain for nearly six months as a team of psychiatrists, nurses, therapists and social workers treated her for postpartum psychosis, a psychiatric disorder that can cause hallucinations and delusional thoughts, often centred on a woman’s child.

This rare condition is thought to be caused by a combination of genetics, sleep deprivation and biological changes after childbirth..