The charity said it saw a 14% increase in calls about the topic over 2017 and 2018 compared with the previous years. The youngest caller was 10 years old.
Mental health issues, bullying and social media are all contributing towards a growing number of young people struggling with feelings of isolation and loneliness, according to Childline.
The vast majority of callers, 80%, were girls and some children pointed to the “harmful effects” of social media by comparing themselves to others online and felt “increasingly isolated” by seeing people they thought were friends socialise without them.
One unnamed teenage boy told Childline: “Recently I’ve been feeling really isolated and alone. I see all my friends having a good time on social media and it gets me down, I feel like no one cares enough to invite me.
“My mood is getting worse and now I’m just upset all the time and can’t stop crying. It’s affecting my school work and my mood swings are uncontrollable, it’s like everything is falling apart. I just don’t want to feel alone anymore.”
Another 12-year-old child told the charity: “I feel really sad and like I’m being neglected. My Mum got married recently and ever since she doesn’t take notice of me. Sometimes I feel like she would prefer it if I wasn’t there.
“I have tried to speak to her about it, but she just tells me I’m being silly and jealous. It never used to be like this; I feel really lonely and hurt.”
Childline founder, Dame Esther Rantzen, said loneliness needed to be taken seriously because it is “potentially damaging to children’s physical and mental health.”
“The crucial question is what is causing this rise among the young?” she said. “Are we all too busy to make space and time for our children? Is it that we have lost the habit of eating together? Or is it the illusion created by social networks that everyone else is liked, popular and enjoying a far more exciting life so they feel lonelier than ever?
“Whatever the reason it’s crucial that young people know they can always contact Childline to speak to someone who will listen and care about them.”
The NSPCC advises parents who struggle to get their children to open up to try to start conversations at a time when you won’t be interrupted, such as in the car or on a walk; not to overreact if the child says something that is upsettingas it may put them off talking to you, and to ensure you take in what your child is telling you, to show you value their feelings and opinions.
HuffPost UK spoke to experts last year who set out eight steps for parents who are worried their child is lonely.
Children can contact Childline for free and confidential support anytime on 0800 1111, www.childline.org.uk or by downloading the ‘For Me’ app from the app store.