Have you ever noticed your teen picking up a friend’s traits, habits, or worries? This is sometimes called peer contagion in teens: the way emotions and behaviors spread through friendship groups. Usually, this happens without anyone realizing it, but when it negatively impacts behaviors, it can be hard to know what to do.
To help you better understand peer contagion, this page explores:
“Peer contagion” describes how people’s thoughts, feelings, and behaviors influence each other, often without anyone realizing it.[1]
The word “contagion” might make you think of catching a cold or flu. But in this case, it’s emotions and behaviors that can be passed on.
For example, imagine if your teen’s friends regularly compare their appearances or talk about how much better they’d look if they lost weight. After a while, your teen might start judging their own appearance more harshly, too.
Or, perhaps their friends start making fun of someone at school. Your teen doesn’t particularly dislike the classmate, but they may laugh along because they don’t want to become the next target.
In both situations, friends affect how your teen feels or behaves without directly telling them what to do. Unlike peer pressure, this influence doesn’t have to be deliberate.
Friendships matter at any age, but they become particularly important during adolescence.
Several factors may contribute to this, including:
Yet, this doesn’t mean adolescents can’t think for themselves. But when fitting in matters so much, certain behaviors may start to feel more “normal” or appealing through negative peer influence.
Here are some examples of how your teen might pick up their friends’ behaviors or emotions:
Sometimes, one friend sets an example that others want to follow. If someone in your teen’s group starts vaping, for instance, then your teen might become curious or try it themselves to fit in.[1]
Sometimes, emotions can spread between friends. So, if one teenager feels anxious about an exam and talks with their friends about everything that could go wrong, the entire group may start feeling more nervous about the test.
According to social contagion psychology, adolescent group behavior can make certain actions start to seem normal, even when they aren’t. It’s simply that when more people do something, it may appear to be more acceptable.
But not every teen will copy their friends’ behavior or “catch” their feelings. How strongly an adolescent is swayed by their peers may depend on factors such as their:[1][3]
Peer contagion can affect how teens feel about themselves, others, and the world around them. The following sections consider the impact of peer influence on mental health.
Talking about your worries can be helpful, but it could also turn into a cycle of rumination. By discussing the same worries and “what ifs” over and over, a teen may end up feeling more anxious and stressed, rather than reassured.
Appearance can feel especially important during puberty, as bodies are changing. If friends regularly compare their looks or weight, they may become more critical of themselves or might consider unhealthy ways to change their appearance, such as overexercising or extreme dieting.
Further, research backs up this concept, as it shows that friends and peers can influence a teen’s body image, exercise, and dieting behaviors, including disordered eating.[1]
If a friendship group becomes stuck focusing on hopelessness, worthlessness, or negative thoughts, it could reinforce low mood and rumination.[1][4] However, this doesn’t mean teens cause each other’s depression simply by talking about difficult feelings. Further, repetitive negative thinking may affect some friendship groups more than others.[1][4]
Friends can also play a role in encouraging risky behaviors, including substance use or self-harm, particularly when these behaviors are treated as “normal” by friends.
Additionally, being exposed to suicidal behavior may increase the risk amongst others, while having aggressive friends may make teens more likely to become aggressive themselves through peer reinforcement.[1][5][6]
Mission Prep is here to help you or your loved one take the next steps towards an improved mental well-being.
It can be worrying if your teen’s mood or behavior seems to change around their friends. You may even feel tempted to stop them from hanging out together. But unless there’s an immediate safety concern, it might be more helpful to understand what’s happening and support your teen to make their own decisions.
Here are some ideas you could start with:
But sometimes, talking things through isn’t enough. If they’re being bullied, taking risks that put them in danger, or experiencing worsening mental health, additional support may be beneficial.
Peer contagion isn’t a diagnosis, and changes in your teen’s behavior or mood may stem from several different causes. But it isn’t always easy to know when your teen might benefit from some extra support.
You might consider reaching out to a mental health professional if your teen:[7][8]
If you notice these changes persist, get worse, or interfere with daily life, professional support, such as therapy, may help your teen work through what’s happening. Therapy offers teens a confidential, no-judgment space to explore:
However, the right therapeutic approach depends on your teen’s needs and circumstances.
For instance, cognitive behavioral therapy (CBT) can help adolescents understand how their thoughts, feelings, and actions affect one another, challenge unhelpful beliefs, and practice responding differently to peer pressure.
Alternatively, interpersonal therapy (IPT) focuses on how relationships and life changes affect mood. It may help teens:
Ultimately, the aim is to help teenagers make their own decisions, build healthier relationships, and ask for support when they need it. Therapy can be one part of that process.
If your teen is having thoughts of suicide, treat this as a medical emergency. Call or text 988 Suicide & Crisis Lifeline, call 911, or take them to your nearest emergency room for support.
Mission Prep provides treatment for teens experiencing various mental health conditions. Mental Health support is a phone call away – call 866-901-4047 to learn about your treatment options.
See our residences in Southern California’s Los Angeles & San Diego areas.
Take a look at our Minneapolis-St. Paul area homes in Hennepin County.
View our facilities in Loudoun County, VA within the DC metro area.
Your teen’s friends may influence how they think, feel, and behave, sometimes in ways that are hard to spot at first. But peer contagion doesn’t automatically mean your teen will follow the crowd. However, if you’re concerned about changes in their mood, behavior, or safety, you don’t have to figure everything out alone.
At Mission Prep Teen Treatment, we offer tailored treatment programs to help your teen work through friendship difficulties, manage tough emotions, and develop confidence in their own decisions. With the right support, they can learn to build healthier relationships while still feeling like they belong.
Whether your teen could benefit from residential treatment at one of our locations or something more flexible, like an outpatient mental health program delivered virtually, to treat their mental health concerns, our team can help.
Mission Prep Teen Treatment accepts insurance and is in-network with most major providers. We are happy to help you check your insurance coverage for mental health care.
Learn about our admissions process online or call 866-901-4047 to speak with a caring member of our team who can answer any questions you might have. Reach out for a free, no-obligation conversation.
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