Student Molly Russell used an anonymous Twitter account to ask celebrities and influencers for help, according to an investigation.
The 14-year-old tweeted American actress Lili Reinhart and YouTube star Salice Rose, with one saying, “I can’t take it anymore.”
Molly’s father, Ian Russell, was questioned on the messages from the witness stand on Thursday, where he said, “I think social media helped kill my daughter.”
He said that messages sent to high-profile figures were “particularly popular on Twitter”.
Mr Russell told Coroner’s Court in North London that malicious and “normal” online content would be “confused” in a 14-year-old’s mind.
Family attorney Oliver Sanders KC was asked what his views were on the effect of Molly’s access to “harmless” content on social media platforms, such as fashion and pop music posts.
I believe social media helped kill my daughter.
Mr. Russell told the inquiry that “digital technology can be brilliant,” but the difference between the two types of content “would be very blurry” for his daughter.
Providing evidence on the stand on Thursday, Mr. Russell said, “I believe social media helped kill my daughter.
“I think there is still too much of that content and I believe there is a lack of transparency.
“Children shouldn’t be on a platform that poses a risk to their life.”
Mr. Russell was taken through tweets to celebrities in which his daughter said she “just can’t make it”.
A tweet, sent to Mrs. Reinhart by Molly, read in court on Thursday, said: “I can’t take it anymore.
“I need to contact someone, I just can’t do it.”
Mr. Russell said: “It’s exactly that kind of message … that was particularly popular on Twitter.
“On the Twitter platform… he reached out to celebrities with thousands or millions of followers who wouldn’t even notice a small tweet from someone like Molly.
“He would never have had an answer.”
Other tweets, directed to YouTuber Ms Rose, said: “I can’t take it anymore. I give up.”
Another said, “I don’t fit into this world. Everyone is better off without me. “
The court was told that these tweets had been sent a few months before the teenager’s death.
Mr. Russell said the student appeared to have “returned to her normal self” shortly before she died.
The 59-year-old said her daughter seemed “excited” about things to come and that in the two months before her death she thought the “transition phase she was going through was over”.
The investigation, which is expected to last up to two weeks, continues.