Have you ever watched 'Sybil' 1970s movie?

This tale of child abuse and and its deep psychological scars, based on a true story, follows Sybil (Sally Field), an introverted student living alone in New York City who suffers from multiple personality disorder. Haunted by nightmares of her past, Sybil starts seeing a psychiatrist named Dr. Cornelia B. Wilbur (Joanne Woodward). When Dr. Wilbur discovers Sybil has over a dozen different personalities, she becomes obsessed with uncovering her patient's tortured childhood in order to heal her.

I watched it years ago and it disturbed me greatly. It still does.

Careful if you decide to watch it, could be triggering.