Studies have shown having frenemy relationships can actually damage your health

• Studies have found that having "frenemies" may be damaging to our mental and physical health.
• Frenemy encounters can raise blood pressure and are linked to long-term depression, studies found.

It's no surprise that we categorize our relationships as either good or bad or that we tend to focus our energy on nurturing connections that generate positive feelings and avoid people to whom we have negative reactions.

But some relationships exist in a gray area, ones that aren't purely bad or good but contain elements of both. Yes, I'm talking about "frenemies." And recent research has found an unexpected twist: These may be the most damaging relationships of all to both our mental and our physical health, affecting our blood pressure and our likelihood of depression, among other issues.

Angela Ficken, a Boston psychotherapist specializing in anxiety, describes frenemies as connections that appear friendly on the surface but have dwelling beneath them negative feelings, jealousy, competition, and even harmful actions, such as one person spreading the other's personal information or secrets or taking deliberate actions to damage their self-esteem or reputation.

A toxic friendship at work left me on the edge

I experienced a relationship like this with a work friend I made at a new job. At first, she was a lifeline, showing me the ropes of the workplace and offering invaluable advice on everything from dealing with managers to finding the best lunch spots. We shared weekly lunches and happy hours for a whole year, creating a seemingly strong bond.

Things took a turn, however, when I mentioned my interest in applying for a more senior role. Instead of providing genuine support, she offered a backhanded compliment, observing how much I was growing in my role, with the insinuation that I might not be qualified for the next step. Then, without telling me, she applied for the very same position despite having the same training and years of experience as me.

Despite this awkward incident, we maintained the appearance of friendship at work. But the constant unease of not knowing whether she would help or hinder me left me on edge. It's precisely this discomfort in predicting someone's behavior that makes "frenemy" relationships so harmful.

Why frenemies can be hazardous to our health

Our brains are wired to handle clear threats: natural disasters, armed robbers, saber-toothed tigers (hey, I don't know what you deal with in your day-to-day). When we come up against anything that gets our adrenaline pumping, fight-or-flight mode kicks in until we're safe again.

But an uncertain situation that brings up both negative and positive emotions, such as one involving a frenemy, can also trigger our adrenaline-stress response. It puts us in a prolonged state of hypervigilance, and being on high alert like this as we try to discern whether we'll be embraced or harmed is not only mentally and physically exhausting but also may have lasting negative health effects. One study found that the more ambivalent relationships people had, the higher their blood pressure climbed over a 10-month period. Having a higher number of "frenemies" in your network is also linked to a higher, long-term likelihood of depression.

Surprisingly, studies have found that encounters with people who evoke mixed emotions lead to higher blood pressure and heart rates than encounters with those whom we have purely negative feelings toward. In short, we're worse off after interacting with a frenemy than with someone we consider an actual enemy, according to the findings.

The mental and emotional cost of these relationships

Why, though, do frenemies take such a toll on us? Do we react to them because of our history with them or because of their actions in the moment? In other words, is it who they are or what they do? The answer, researchers have found, is both.

Even in the most positive relationships, emotional ambiguity can take a toll, like the coach who praises you during practice but leaves you on the bench during the game. This is not to say we should ditch all relationships where we've ever had a negative interaction. (No one would stay married or keep a job very long.) However, we can be aware of the effects that mixed feedback and behavior can have on us and behave accordingly.

Ambivalent relationships have been linked not only to negative health outcomes but also to feelings of depression and a reduced ability to cope with stress effectively. In light of this, Ficken says that the harmful effects of frenemy-type relationships on mental and emotional well-being usually outweigh any benefits.

She recommended addressing and, if necessary, extricating oneself from such relationships. Reducing interaction frequency with frenemies, seeking supportive and uplifting friendships, and focusing on personal growth are essential steps, Ficken said. For particularly challenging relationships, seeking guidance from a therapist or counselor can provide valuable perspective and support.

Avoiding frenemies in real life — and online — is key

Much of this advice also applies to "hate follows," online connections that thrive on negativity. It's stressful and emotionally draining for your brain to wrestle with the conflicting emotions of someone following you on social media only to criticize you, Ficken said. Unlike the real world, however, we can easily filter or block content from hate followers. Ficken recommended doing this, along with practicing an occasional digital detox to recharge and regain perspective. This break can help you refocus on the real-world connections and activities that bring you joy.

In the end, the adage of keeping your friends close and your enemies closer may need a reevaluation.