The disorder that stops people loving their family

Media playback is unsupported on your machine

Media captionDuring one bout, Sarah remembers do with her sides in 2D

For people living with depersonalisation disorder the world sees preposterous, as if through a haze or fog – or even in 2D. One in 100 people is thought to have the condition, but professionals are warning it is not included in any GP training.

“Relationships you know you value deeply lose their essential character, ” Sarah tells the BBC’s Victoria Derbyshire programme.

“You know you love your family, but you know it academically – rather than detecting it in the normal way.”

Sarah is an actress. She’s used to playing roles and projecting emotion. Yet for long pulls of her own adult life, she herself has been emotionally numb – unable to feel.

This is the result of a little-known mental-health condition called depersonalisation disorder.