So she turned to social media. “I’m having a really hard time right now,” Anna — who asked to be identified by a pseudonym — posted on Facebook. “Is there anyone I can call and talk to until I feel better?”

Almost immediately, three people responded with offers to talk. They were friends she had met playing Quidditch, a sport based on the Harry Potter fantasy books, and she kept in touch with them online. Anna talked to two of them until she was able to fall asleep.

“I used to be very shy about posting personal stuff on Facebook because I didn’t want people judging me,” said Anna, 26. “But that night, I was in such a bad place; I was desperate, and I thought anything would help.”