It was after several weeks of unanswered messages to an old friend that Andrew, 53, finally decided to call the police. Jimmy, his friend of 40 years, had not been in touch since Andrew had messaged to say he was unable to spend Jimmy’s birthday with him due to work commitments. Andrew hadn’t thought much of the radio silence at first, but then it struck him that something might be up.

“I thought, ‘This is a bit weird,’” Andrew tells me, shaking his head. “Then I was scared that something had happened to him, that he’d died or was in some terrible black hole. There was no one else I could call to say, ‘Have you seen him?’ He’d moved to a new town where he didn’t know anyone.

“Eventually I emailed him and said, ‘Look, if you’ve cut me out of your life, I understand, and fair enough, that’s your choice, but I’m executor of your will, you must let me know if you’re OK or I’m going to have to call the police. I don’t know how I’m going to find you. You could be in a ditch.’ And I said, ‘I love you, I care about you.’”

Andrew told Jimmy that the police were overstretched as it was, without looking for “stupid sods” like him, and asked for just one word from him to say that he was OK. Nothing. So Andrew called the police, fearing the worst. But when they went round to his house, Jimmy was fine. He had simply decided to cut Andrew out of his life.

“We’d been through so much together,” Andrew says. “All the punctuation marks of life: best man at my wedding, we carried each other’s parents’ coffins. We’ve been there for each other’s heartbreaks. We’ve been friends through puberty, through first relationships, through failing exams, university. To lose that overnight feels like having a limb cut off.”

I’ve asked Andrew about his friendship breakup , or friend dumping (frumping, perhaps? We don’t have a language for the experience yet), because the same thing recently happened to me. A friend of almost a decade decided to cut me out last year. She said she “needed time” after a silly argument on WhatsApp that, to my mind, wasn’t worth falling out over, and rebuffed all my attempts to get in contact, as well as an apology (not reciprocated). When she finally responded to me, it was to say that we hadn’t been that close anyway. When I tried to rescue the friendship to no avail, and realised it was over, I was stunned by how much it hurt. Why don’t people talk about this?

“I was devastated,” says Patricia, 61, who “broke up” with a friend of 17 years after an argument on Patricia’s birthday six years ago. “They say you shouldn’t cry on your birthday, and it’s true: your birthday is when people ought to be nice to you. Her anger towards me came out of the blue.” The friend had been snappy and distant. “I said to her, ‘I value your friendship. Why are you treating me like this?’ And she said: ‘Your friends find you hard work.’ Which was awful. If she’d said, ‘I find you hard work’, I could have dealt with it, but suddenly dragging in other people and implying they’d been talking about me was so hurtful. I was terribly upset. I went for a walk. It was sleeting and I was crying. I just howled.”

Having close friendships is linked to better health, yet one in eight adults have no close friends at all

A Finnish study in 2016 found that men and women make more and more friends until the age of 25, when the numbers begin falling rapidly and continue to fall throughout the rest of a person’s life. Factors such as moving house or falling in love can act as catalysts – one Oxford study found that falling in love can cost you two close friends. Having close friendships is consistently linked to better physical and mental health yet, according to Relate, one in eight adults have no close friends at all. Friendships end frequently – Utrecht University sociologist Gerald Mollenhorst asked 604 adults about their friendships, and returned to interview them seven years later. Most had replaced half of their friends, and only 30% of the subjects’ close friends remained close. We know conceptually that you can’t hang on to all the same friends throughout your life, or maintain the same number of friendships when things such as work and children get in the way, yet losing a friend can still come as a shock.

‘He was best man at my wedding, we carried each other’s parents’ coffins. We’ve been there for each other’s heartbreaks.’ Photograph: Franck Allais

“If a sexual relationship breaks down, there’s punctuation there,” Andrew says. “That’s a full stop. You stop having sex, you stop living together, if that’s what you’ve been doing. There’s all this protocol, painful as it is. But there’s none of that when friendships stop because there’s nothing to disentangle. So you’re left alone, and you have to fill in the gaps yourself, replaying all of those conversations you’ve had. Things you might have done or said that landed as a slight on this person. Or were there signs?”

Technology has made it even easier to dump friends. “Ghosting” – simply ceasing to communicate with a person without explaining why – allows people to avoid difficult conversations and simply phase a friend out of their life.

Face-to-face screaming rows don’t tend to happen. It’s very easy to break up via text message

“I think it’s a lot to do with how we communicate now,” says Marianne, 46. “Face-to-face screaming rows don’t tend to happen. It’s very easy to break up via text message, which is what happened to me. We’d been friends for 20 years.”

Marianne was unemployed at the time and, by her own admission, volatile (like all the other people I speak to, she has spent a long time picking over what she may have done wrong). Her friend was a very high earner, while Marianne was going through a very low period after losing her job. “She sent me a platitudinous text. I sent her a really cross text – this had obviously been building up – saying, ‘I don’t think you really understand the situation.’ I was really sensitive. I said, ‘Is it a status thing, because all your friends are really successful?’

“She said, ‘I’m sorry you feel that way.’ And I said, ‘Can we talk about it?’ Nothing. And I sent texts, maybe an email, over the next couple of months, and… This is the most petty thing, she unfollowed me on LinkedIn.” The end of the friendship devastated Marianne. “I dreamed about her. Still do, sometimes,” she smiles sadly. “As the years pass, I think about her on my birthday, on her birthday. When my mother died. Those are the worst times.

“I sent her a text message in July 2015 on the 10th anniversary of 7/7, because we had known someone who died, just saying, ‘I was thinking about you today.’ And I got a ‘thanks’. That was it.”

‘It’s the grief of knowing you’re not going to see or speak to that person again.’ Photograph: Franck Allais

“When it comes to friendship breakups, I think there’s no real difference emotionally between them and the breakup of a serious relationship, or potentially even the death of someone,” says Dave, 32, who has lost two friends, one of a decade, another of 15 years. “For me, the emotional impact has been the same. It’s the grief of knowing you’re not going to see or speak to that person again; the adjustment to a new reality in which that person is no longer a part of your life.”

It’s no wonder it hurts so much. “We choose our friends, firstly, whereas with family we can’t choose them,” says Weekend’s advice columnist Annalisa Barbieri, to whom I recount the whole sorry tale of my frumping (it’s not going to catch on, is it?). “Because we choose them, we tend to go for things we really like in people, or that we need. And therefore, when they end, it’s more catastrophic.”

It is bad enough to have a friendship end after all those years, I say, but when you’re dumped and there is no real reason given, it can be even worse. “It’s the not knowing,” she agrees. “It’s like when a boyfriend doesn’t ring you. The pain is easier to cope with when you’re not left endlessly analysing.”

Dave finds it easier to understand the loss of one friend than the other. “The person in question was having a rough time, and had decided I was not a good enough friend to him. There were a lot of mental health issues bound up in that, which made it in some ways easier – you can’t hold something against someone when they can’t control it – but that didn’t make it any less painful. The other was someone who dated a mutual friend, and when they broke up decided they didn’t want to see the friends who knew both of the people involved. That one I was less impressed with.”

***

Liz Pryor is the author of What Did I Do Wrong? What to Do When You Don’t Know Why the Friendship Is Over. Her emphasis is on female friendships, which she says are the ones overwhelmingly affected by this phenomenon, though she estimates that around 10% of men experience it, too. “It’s devastating to lose a historical friendship – anything over two years, where you really did rely upon each other emotionally,” she says. “There’s the receiver and there is the dumper. The two points of view are so incredibly opposed. The girl who is dumped says, ‘It was out of nowhere, I had no idea.’ But when you talk to the person on the other side, that person typically says they have been accumulating things that have been bothering them over time.”

Women tend not to call out their friends on the things that bother them, but when it’s a partner we don’t hesitate

Often, the reason cited for ending a friendship seems trivial. “What you learn is, it’s of course never that one single event,” Pryor says. “That straw is just the last straw for one person, and the first straw for the poor person who is being dumped, because they have no idea.”

Long-running friendships are so multilayered and complex that boiling them down to one factor for the breakup is pretty much impossible. Maybe that is why some people choose just to cut and run, rather than untangle it all. Pryor says that women tend not to call out their friends on the things that bother them, while when it’s a partner hurting us or pissing us off in some way, we don’t hesitate. This is certainly true of my experience with my friend. I never spoke to her directly about the things she did that hurt me, and I suspect that she did the same with me.

“The dumper claims that it is the kinder thing to do to you, which is really twisted,” Pryor adds. “That’s cruelly devastating. We expect to be dumped by lovers – society prepares us – but not by our friends.”

As well as the heartbreak, there is also the embarrassment. I ask Marianne why she thinks it isn’t talked about more, and her answer resonates: “I don’t tell anybody who doesn’t know me well about it. My boyfriend doesn’t know. It’s about not wanting to put people off.”

“It’s a stigma,” Patricia says. “You worry that other people will think there’s something wrong with you. When your friends are picking holes in you, you don’t think, ‘Maybe it’s my choice of friends that’s led to this.’ You start to think, ‘Maybe this means that I’m a horrible person.’”

Patricia realises now that, in fact, this was not the case at all. “Other friends have been really supportive. They can play a really strong part. It can bring you closer.”

‘It’s a stigma. You worry that other people will think there’s something wrong with you.’ Photograph: Franck Allais

There tends to follow a lot of doubt and self-criticism. I worried for weeks that I was a bad friend, and am struck by the way the people I speak to focus on their own faults. Patricia calls herself tactless, Marianne recriminatory. Andrew wonders if he secretly enjoyed being the emotionally resilient one in the friendship, there to dispense advice, while his friend struggled. “I think taking some agency is really important,” he says. “You can’t just say, ‘It’s their fault because I’m perfect.’ It’s really disabling not to claim any responsibility for anything.”

For my own part, I have certainly found that talking about it has helped me come to terms with the end of my friendship. “At the end of the day, all interaction with people comes down to communication,” Barbieri says. “If you can’t communicate with them, you can only ever do your bit. Imagine you are going to visit someone in prison and there is that heavy glass between you. You can only go up to the glass. That’s the only bit you have control over. Beyond the glass is their 50% of it.”

I take comfort in the fact that I have tried my utmost to make things right – I have gone up to the glass. I resolve to focus on the great friendships that I do have, and vow never to be like this towards someone myself. “It’s never the right thing to leave a person you have loved and cared about wondering for the rest of their lives what happened,” Pryor says. “We have a duty to honour the incredible impact and value of our friendships. I say the same thing about friendship as I do about marriage. The best thing you can do is put your focus on the kind of wife you want to be, as opposed to the kind of husband you wish he were.”

“I think we should be a bit kinder to each other,” Marianne says, sadly. “We are very self-centred. The fact that we keep hurting people shows that we think life is going to last for ever. But what if the world ended? Why throw away a friendship?”

When friendships end: how to minimise the pain

Look at the big picture

Try to understand what has happened, including looking at your own behaviour, but do not descend into self-loathing. “Consider the possibility that there is a reason that has nothing to do with you,” life advice expert Liz Pryor says. She cites examples of people who have found out years later that something entirely unknown had been going on in their friend’s life at the time, which influenced the split.

Talk about it

Consider therapy if you are struggling to cope. Talking about it can really help. The British Association for Counselling and Psychotherapy can recommend counsellors.

Try to take control of the situation

If you are the one who has been dumped, and you feel there is nothing more you can do to salvage the friendship, it can help to call time on it yourself. Annalisa Barbieri suggests saying, “This is the last email I am going to send you”, as it can make you feel in control. If they do not want to communicate, you can’t make them.

Focus on acceptance

Sometimes, people move on, and historic friendships can become incompatible. Perhaps you remind your ex-friend of a former life from which they are trying to distance themselves. Be honest with yourself, and ask why you were friends with that person in the first place. What were you getting out of it? Was it all on their terms?

Be open

If you are doing the dumping, be more forthcoming. “I cannot tell you the hurt feelings that come from not saying anything. I know it’s uncomfortable,” Pryor says, “but you have to accept that you are ending something that another person is a part of.”

• Some names have been changed.

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