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15 Red Flags in Teenage Behavior

Reading Time: 8 minutes

Teens are going through significant changes during adolescence. Hormonal shifts, social pressures, and emotional growth all impact teens’ moods and how they act. Consequently, it can be hard for parents to tell the difference between typical teenage behavior and warning signs of possible mental health disorders. But being able to recognize red flags in teenage behavior is an essential skill for parents.

In this article, we’ll look at the 15 most common warning signs of teen mental health issues. Knowing what to watch for can help teens get the care they need before serious mental illness develops. If parents suspect mental health conditions in their teenagers, an assessment with a doctor or mental health professional is the next step.

Key Takeaways

  • It can be hard to tell the difference between typical teen behavior and red flags in teenage behavior that might indicate a mental health condition.
  • Disruption in sleep patterns, slipping grades, lack of interest in things they used to enjoy, and self-medicating with substances are all warning signs of possible mental health issues.
  • Low self-esteem, isolation, hopelessness, and worthlessness could be indications of severe depression.
  • If you’re seeing any of the 15 signs below in your teen, an assessment with a mental health professional is the next step.

The Top 15 Red Flags in Teenage Behavior: What Parents Should Look For

Here are 15 of the most common signs that a young adult is struggling with a mental health challenge.

#1: Problems with Sleep and Fatigue

If a teen is demonstrating irregular sleep patterns, it might be a warning sign. Excessive sleeping, sleeping during the day, or not getting enough sleep can be red flags in teenage behavior. Teens who struggle with sleep can be especially moody. They may seem “off.”

Here are a few common signs to watch for that might indicate that your teen is not getting enough sleep.

  • Having trouble waking up most mornings
  • Irritability and mood swings
  • Falling asleep easily during the day
  • Trouble concentrating or poor academic performance
  • Sleeping very late on weekends
  • Hyperactivity and nervousness
  • Aggressive behavior

#2: Slipping Grades

Another red flag in teenage behavior is poor academic performance. If a teen usually is a straight-A student and starts getting Cs and Ds, something might be wrong. Family members should be on the lookout for a teen’s slipping grades.

Numerous factors can impact teens’ academic performance—factors that have nothing to do with their intellectual abilities. They might be experiencing anxiety that prevents them from focusing, or depression that makes them tired and unmotivated. In addition, being bullied at school is another reason for slipping grades.

#3: Lack of Interest in Activities They Used to Enjoy

One of the warning signs that something is wrong is if a teen no longer shows interest in things they used to take pleasure from. Those might be spending time with friends, playing an instrument or making art, or doing physical activities like hiking or sports. An overall lack of joy and engagement with life is a red flag that parents should pay attention to. It could be a sign of depression, lack of motivation, or avoidance behaviors.

#4: Poor Self-Care

Teens are learning how to take care of themselves. So poor grooming can be normal behavior for adolescents. But if a teen stops doing things like brushing their teeth, taking regular showers, or dressing properly, it could be an indication that something is wrong.

A messy room can be another aspect of poor self-care. Teens with messy rooms, particularly if the messiness is extreme, may be struggling with a mental health disorder, such as anxiety , ADHD, or depression. Letting your room get messy can be an expression of the feeling that nothing matters, so why bother trying to keep things neat?

#5: Self-Medicating with Drugs and Alcohol

One of the warning signs that a teen may be having mental health issues is if they are using drugs or alcohol to self-medicate. Substance abuse can start early and is a serious mental health problem that needs to be addressed as soon as possible. Early intervention for substance abuse is vital in making sure that drug or alcohol use doesn’t get worse. Getting a teen who is self-medicating with drugs or alcohol into treatment early can prevent further issues as they get older.

Some signs of substance abuse include:

  • Bloodshot or watery eyes
  • Poor hygiene and diminished personal appearance
  • Smell of smoke on breath or clothes
  • Extreme moodiness
  • Irritability
  • Difficulty staying focused, causing problems in school
  • Secretive behavior, hiding in their room
  • Sleeping more than usual, staying in bed all day

#6: Excessive Moodiness

Moodiness can be considered typical teenage behavior, but excessive moodiness could mean there’s an underlying mental illness. For example, bipolar disorder is a mood disorder that can cause big mood swings.

If parents notice their teens’ moods are up and down and all over the place, it could mean that there’s a mental health condition underneath those mood swings.

Here are three criteria that can help both parents and mental health professionals distinguish between moodiness and mental health disorders:

  1. Intensity or severity: Is the intensity of the moodiness interfering with a teen’s everyday life, including family life, social activities, and school?
  2. Duration (length of time): Is the moodiness ongoing, or does it only crop up now and then? When it does arise, how long does it last—hours, days, or weeks?
  3. Domains, or situations: Does a teen’s moodiness persist in all situations, including with friends, or is it just with parents, or just at school? 

The answers to these questions can help determine the extent of the problem and whether moodiness is a red flag behavior or more typical teen behavior.


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#7: Changes in Eating Behavior, Weight Loss, and Obsessive Body Image Concerns

Many teenagers become obsessed with their weight and have poor body image during adolescence. A change in eating habits could indicate an eating disorder, which is a very serious mental health condition that needs to be addressed as soon as the warning signs appear. If parents notice their teen has a change in eating patterns and/or is losing a lot of weight, they should seek professional help immediately.

#8: Anger and Aggression

We’ve already established that teens can be moody, but if a teen starts acting aggressively or demonstrates extreme anger, these could be warning signs that something else is going on. Increased anger and aggression are red flags in teenage behavior and should be taken seriously.

Common triggers for teen anger include feeling disrespected, inadequate, or misunderstood by parents. But not all anger is a natural part of growing up. Anger can often be a secondary emotion that masks other painful emotions, such as grief, shame, or guilt. Teens who are angry and aggressive might be disguising low self-esteem, self-loathing, depression, and other mental health issues.

#9: Self-Isolating and Withdrawal

Excessive isolation is a red flag in teenage behavior. If a teen is isolating or withdrawn, they could be dealing with depression, and possibly thoughts of suicide. Seeking professional help is critical in making sure that the teen is safe. Depression and suicidal ideation are serious mental health concerns that should be handled with treatment from a mental health professional.

Moreover, teens who withdraw from parents and spend much of their time in their room may be interacting with peers on social media. While this type of connection can have benefits, there are also numerous negative effects of social media, including the risk of tech addiction. Parents who notice this red flag in teenage behavior may need to investigate what their teen is doing online and find ways to engage them in family activities.

#10: Low Self-Esteem

If a teen is demonstrating low self-esteem, it could mean that they’re dealing with depression. Research shows that low teen self-esteem is the strongest predictor of depression in adolescents. Poor self-esteem is an underlying issue in most mental health and co-occurring disorders, including PTSD, anxiety, substance abuse, and eating disorders. 

If a teen demonstrates low self-esteem, parents should talk to them about what’s going on and possibly seek professional help. Parents and caregivers can also help foster self-esteem in teens. Here are five approaches for how to build self-esteem and instill confidence in teens.

#11: Expressing Hopelessness or Worthlessness

Expressing feelings of hopelessness or worthlessness could be a red flag for serious depression and possibly thoughts of suicide or self-harm. If a teen is expressing that they feel hopeless or worthless, they should be taken seriously and brought to a mental health professional to help them work through what could be despair and depression.

#12: Paranoia and Excessive Secrecy

A certain amount of teenage secrecy is a natural part of growing up and developing independence and a life that’s separate from their parents. However, if a teen is being excessively secretive or demanding a lot of privacy, it could be a red flag that something is wrong. They may be hiding substance abuse or suffering from what’s known as smiling depression. This is a form of depression in which the person shows a positive face to the world but is suffering inside.

Moreover, some teens develop an intense fear that shows up as paranoia. Because adolescents are so aware of what others are thinking about them, they can be particularly vulnerable to paranoia.  Paranoia in adolescence is linked with various mental health issues, including anxiety, self-harm, and PTSD. Or it can be a sign of a serious mental illness, such as schizophrenia or other psychotic disorders. If parents notice that their teen is acting paranoid, they should seek mental health treatment immediately.

#13: Self-Harm

Self-harm is a teenage behavior that should be taken very seriously. Teens use self-harm, such as cutting, as an unhealthy coping mechanism to deal with difficult emotions and release feelings of pain, tension, and anxiety. Usually, there are underlying mental health concerns when a teen is harming themselves. These need to be addressed with the help of mental health professionals and understanding parents.

Some signs of self-harm include:

  • Unexplained cuts, scratches, bruises or other wounds, often on the wrists, arms, thighs, or torso
  • Wearing clothes that cover up the skin, such as long sleeves or long pants, even in hot weather
  • Blood stains on bedding, clothing, towels, or tissues
  • Having sharp objects in their possession, including razors, safety pins, nail scissors, knives, needles, shards of glass, or bottle caps
  • Spending long periods of time alone, often in the bathroom or bedroom

#14: Abandoning Friends

Similar to the red flag behavior of not showing interest in activities they used to enjoy, abandoning friends is another red flag for parents to watch out for. If a teen suddenly stops hanging out with their friends, that could be an indication that they’re struggling internally with something they don’t know how to express. If they feel really depressed or anxious, for example, they may pull away from their friends for fear of being rejected or misunderstood. Furthermore, suddenly forming a new friend group can be a sign of substance abuse or other risky behavior.

#15: Extreme Worry and Anxiety

Everyone gets worried and anxious from time to time, but if a teen demonstrates constant worry and anxiety that’s out of proportion to the situation, parents should take it seriously. Anxiety can be debilitating and stop teens from engaging in activities they used to enjoy, spending time with their friends, and getting enough sleep. Excessive worrying can keep teens up at night and affect their performance at school. It can make them irritable or aggressive when underneath it all they’re scared and anxious.

Assessment for Red Flags in Teenage Behavior

A full evaluation with a physician or mental health expert is the best and most effective way of determining whether red flags in teenage behavior are indications of a teen mental health disorder. An assessment can take place in an ER, a doctor’s office, an outpatient treatment center, or a therapist’s office. The provider will ask the teen and parents questions about their behaviors, feelings, and past health history. They may take blood tests or do a physical examination to rule out any medical issues that could be catalyzing symptoms of mental illness. Following the examination, the provider will typically give a probable diagnosis and recommend options for care.

When teens and families come to Newport Academy, we do a full assessment that informs a treatment plan tailored to meet their unique needs. We look at the whole person when we work with a teen, not just the presenting problem or reason they’re coming in for treatment. Moreover, we will recommend options for treatment, including the appropriate level of care and type of program. If Newport isn’t the right fit for a teen, we can recommend another program that we’ve personally vetted.

Mental Health Treatment at Newport Academy

At Newport Academy, we work with teens who are struggling with depression, anxiety, substance abuse, eating disorders, suicidal ideation, and trauma. We serve clients ages 12–18, in both residential and outpatient locations nationwide. In our specialized treatment programs, teens build authentic connections with themselves, their peers, and their families, and replace maladaptive teenage behavior with healthy coping strategies.

Contact us today to schedule a mental health assessment at no charge and learn more about our integrated approach to teen mental health treatment.

Frequently Asked Questions

How do I know if my teenager needs counseling?

If your teen demonstrates any of the aforementioned red flags in teenage behavior, they may need counseling or treatment. Talk to your teen if you notice if something seems off. Sadness, extreme moodiness or worry, disordered eating, and thoughts of suicide are serious warning signs that should be treated with help from a mental health professional.

What is typical 13-year-old behavior?

Thirteen-year-olds are just entering the teen years. During early adolescence, they are likely feeling awkward in their changing bodies and self-conscious around their peers. Therefore, many 13-year-olds spend more time obsessing about the way they look, worrying about what their friends think of them, and navigating peer pressure. Because of the significant changes they are experiencing, some level of moodiness and irritability is to be expected.

What is normal 16-year-old behavior?

By the time a teen is 16, they’ve started building their identity and separating from their parents. At this stage of adolescence, it’s not unusual for 16-year-olds to be less inclined to spend time with their parents and more time with their friends. However, they may also be engaging in risky behaviors, as they’re brains and impulse control are not fully developed. Parents need to stay connected and maintain open communication even as teens get older.


Aust N Z J Psychiatry. 2021 Dec; 55(12): 1166–1177.

Front Psychol. 2019; 10: 565.