I chose my first friend not because she was kind, funny or interesting, but because she was blonde. Our eyes locked on the first day of Junior Infants, two practically phosphorescent fair heads turning in tandem, and an unspoken pact was made. We later discovered a mutual love of horses and Play-Doh so, naturally, we became best friends. 

When you're that young, friends are easy to spot and actually easier to maintain. Play nice, don't hit, make them laugh and for the love of God, don’t rat them out – basic schoolyard rules. As you grow up, of course, things get complicated. The rules change as people change, not to mention how we keep in touch itself, until you find yourself like Grandpa Simpson ranting about how you used to be "with it" until "they changed what 'it’ was". 

Dramatically reimagined
Friendships has been dramatically reimagined over the years, but not when it comes to the "why" of it all. "From an evolutionary perspective, we needed to be part of a group to survive so that desire to be part of a group and have social connections is very deeply engrained", explains Aisling Leonard-Curtain, chartered psychologist, co-director of Act Now Purposeful Living.

What's changed instead is the "how". Technology has come to play a major role in how we keep in touch, too. There’s the Twitter mutuals who like each other’s tweets and send jokes over DMs, but who have never met; the childhood friends who only ever hear each other’s laugh over voice messages; the family who keep up their weekly movie nights over Netflix Party, despite living in separate cities. 

And in this chasm between what we thought friendship was and what we discover it can be, another variation can come into focus, one you might have felt lurking around the edges, or even festering the centre: the toxic friendship. 

It's hard to put into words what a toxic friendship is, but there are a few key points. Leonard-Curtain says she'd consider a friendship toxic if it feels "quite one-sided", where "one side is not getting their needs met". 

"It can vary from one friend feeling their needs don't get spoken about, to something quite emotionally abusive where one friend is pointing out aspects of the other friend that are hard for them to look at, constantly pulling the other person down."

Of course, no one enters into a toxic friendship by choice. "The challenge with toxic relationships is that these things shift and change over time, so usually a friendship doesn't start off at that level of toxicity but it often gradually increases over time", Leonard-Curtain says. She compares them to "lobsters when they're being cooked". 

"If you put a lobster into a pot of boiling water they will jump out of it, save themselves. The way lobsters are cooked, the water is boiled slowly and when it’s done in that way the lobster won’t jump out. It can be a little like that with toxic friendships."

Boundaries are pushed over time, she explains, until the relationship feels "unbalanced". Those schoolyard rules – no hitting, playing nice – can become distorted and stretched to the point where you're not sure if someone's playing nice or not, or what kind of jabs you're being thrown. 

Photo: Getty

"Sometimes it can be that the other person changes but sometimes it can be that we actually change", Leonard-Curtain explains. "It could be that the two friends started in the same place but then one friend is in an unhappy intimate relationship or in an unhappy workplace and that's shifted how they relate to their friends."

And those schoolyard rules are hard to shake, too. Very often, we don't even rat out our most toxic friends. 

This, Leonard-Curtain says, is often tied up in our own histories and how we deal with confrontation. "One person's history may have got to the point where it's like, 'just keep it in’", she says. "We hear these things like 'if you don’t have anything good to say, don’t say anything at all’ and there’s something to that, that’s held too rigidly as a rule, and can lead to us staying in some toxic relationships."

"We're very passive as people. If you look at it on a national level, we try to stay out of wars and that’s wonderful, there’s loads of benefits to that, but sometimes people don’t actually say what they’re thinking and we may be passive-aggressive with people … instead of giving things a chance to change."

But also, there's a stigma to it. While many of us don't think twice about detailing the missteps and hurts of a broken romantic relationship, airing our dirty friendship laundry feels shameful for many of us. 

"Sometimes with friendships we feel like we're being disloyal for talking about friendships. I think people are almost afraid of airing their dirty laundry or saying anything negative about anybody else, particularly friends. 

"There can sometimes be this fear of 'will people judge me? If they think this is going on in my life will they think I caused this?’ There can be shame about being part of a toxic friendship."

This stigma is slowly lifting, Leonard-Curtain says. "I think people didn't have a name for what this was", she says, while cautioning that people shouldn't rush to "spring clean" their friend groups. 

"No friendship is perfect. We will inevitably feel worse after spending time with some friends and that's normal. Just because we have one or a few challenging interactions doesn’t mean it’s toxic."

Photo: Getty

How to deal with a toxic friend
So how do you cure yourself of a toxic friendship? She suggests starting with a discussion about their behaviour, speaking with awareness and compassion, being specific about your concerns about how they've treated you. 

"Try to isolate the action that was challenging and how that impacted you. Say 'when you do this, I notice that's challenging for me. Is that something you're willing to do differently?’"

If confrontation isn't something you're comfortable with, Leonard-Curtain suggests writing down what you want to say first, or write a letter you won't send to the friend about what you're feeling. "When something is highly emotional we go into 'emotional mind' where our problem solving ability to stay grounded becomes affected." 

A key difference between toxic friendships and a toxic romantic relationship is that very often you'll be enmeshed with the friend in a larger group or workplace. If this is the case, Leonard-Curtain cautions that you don't "self-isolate" or pull back from the friend group, or you'll lose contact with possible supports. 

In more extreme toxic friendships, of course, even broaching the topic of how you're treated might not be possible. In these cases, Leonard-Curtain says, you might have no choice but to "ghost". "If the relationship is really toxic, it may be the only option in terms of safeguarding our safety."

But what if it's you?
People change for all sorts of reasons, and it's not impossible that we can slip up ourselves and pick up some bad habits. What if you're the one dumped by a friend? 

"The first thing is to build compassion for yourself", Leonard-Curtain says. "If this is a one-off basis, there might be specific details around that."

"But if you’re noticing that this is happening with a few different people and it’s happened in close enough succession, maybe grounding yourself and saying 'is there anything I do that might be contributing to this challenge in my life? When I’m with friends, do I make enough space for them as I take up myself? The words and tone I use, might they be challenging?’" 

"It's really challenging if any other person has cut off friendship. Even if we weren't getting much out of the friendship either, we may still feel it as a personal slight because that’s part of the evolutionary perspective", she adds.

"Because we needed to be part of a group to survive, we can find being cut off really hard."