The Teen Brain: Understanding Your Teenager's Development

Of all the stages of a child’s development, the teenage years can be some of the most exciting and transformative. Change can also bring uncertainty and newness, which may make these years tumultuous for both teens and their parents. 

Below, we’ll review the three main stages of a teenager’s development. Each stage can present unique challenges related to puberty and mental health but can also create opportunities for teens and parents to connect through shared goals, challenges, and accomplishments. Keep reading to learn more about teenage development and how you can support your child through these important years.

Defining the teenage years 

While some resources use the terms adolescent and teen interchangeably, early adolescents may not technically be teens. Therefore, some children may undergo many of the physical changes associated with the teen years before they turn 13.

Although the teenage years generally span from the ages of 13 to 17, every child’s timing of puberty differs slightly due to a number of factors. These may include a child’s nutritional status, place of origin, emotional well-being, and physical health conditions.

What are the stages of teenage development? 

Noting the distinction between adolescents and teens, most experts divide teenage development into three distinct stages. 

1. Early adolescence 

As noted above, early adolescence may begin around age 10, before a child technically enters their teenage years. However, the main signs of early adolescence often continue through age 13. Around this age, the most common signs of development include: 

• The appearance of underarm and pubic hair
• Enlargement of the sexual organs in people assigned male at birth
• Breast development and the first menstrual period in teens assigned female at birth

During this initial stage of development, young teens undergo bodily changes at varying rates. For example, some teens with a gynecological reproductive system may not experience their first period until age 16, while others begin menstruating around age 10 or even earlier.

In most cases, these variations are normal and expected. Still, a teen may have questions and feel self-conscious about their changing body. During this stage, it can be important for parents to stay in touch with their child’s doctor and other health professionals who can answer questions and offer resources to both teens and their parents. 

2. Middle adolescence

From the ages of approximately 14 to 17, many teens—sometimes referred to as “middle adolescents”—continue to experience the physical changes of puberty. In those with an androgynal reproductive system, these shifts may include a lower voice, growth spurts, and acne. Teens with a gynecological reproductive system may have regular periods, and their other bodily changes may be nearly complete.

Still, there is plenty of room for physical, emotional, and psychosocial growth throughout this stage. According to the Centers for Disease Control and Prevention, teens ages 15 to 17 are learning how to think, feel, and interact with others, both romantically and platonically. They may explore intimate relationships and sexual activity for the first time, establish a new peer group, and pursue more independence from their families.

During these years, some teens develop meaningful friendships that endure well beyond adolescence. However, they may also experience social upheaval and navigate conflicts with their parents and other authority figures. While these challenges are surmountable, they can create tension and uncertainty as teens question their social circles, identities, and values.

In some cases, a teen’s social and emotional difficulties may be related to mental health conditions, which tend to emerge during adolescence. According to the National Institutes of Health, ongoing changes in the teenage brain can increase the likelihood of anxiety, depression, eating disorders, bipolar disorder, and other mental health conditions. 

With this fact in mind, parents can be helpful by answering their teen’s questions about mental illness, their family's mental health history, and substance use, which some teens may observe among peers or via social media. 

3. Late adolescence

As teens reach physical and reproductive maturity, many begin preparing for their adult lives. By the age of 18, most teens have reached their full adult height and may have a solid sense of their values and identity, as well as improved impulse control.

At age 18, teens may have a clearer idea of their goals and the ability to make more thoughtful, informed decisions. However, because the brain continues to develop well into early adulthood, roughly until a person’s mid-to-late 20s, an 18-year-old’s brain is typically still learning and rewiring. Research shows that adults think with the prefrontal cortex—the rational part of the brain—while teens process information with the amygdala, the emotional region of the brain. 

As their children’s brains develop, parents can be useful by continuing to model healthy and rational decision-making, particularly as late teens make their first “big” choices. At this phase of life, teens may be choosing whether to attend college, accept a job offer, or live on their own, among other decisions. 

As you evaluate these choices with your child, you may establish a more adult relationship with each other and discuss more mature topics.

How to support your children through the stages of development

Whether your child is just entering their teenage years or approaching adulthood, you may be searching for ways to support their development physically, emotionally, and socially. The following four tips may promote healthy growth and development as well as stronger bonds between parents and their teens. 

1. Encourage a healthy relationship with food and exercise for your teenager's mental health

Throughout the teenage years, many young people begin to establish routines and habits related to food and physical fitness. As an adult, you can model healthy behaviors, such as regular physical activity and a balanced diet, and encourage your teen to form their own healthy routines. 

At the same time, many teens struggle with body image and may express concerns about their changing bodies. Parents can help teens develop a balanced, peaceful relationship with food and exercise by encouraging an “all foods fit” model, which typically avoids labels of “good” and “bad” in reference to specific foods. 

2. Respect their independence while understanding your teenager’s development and social media

As teens gain exposure to new ideas, places, and people, they may begin spending more time with friends and less time with their families. While this independence tends to be a normal part of adolescence, you may worry about your child’s ability to navigate the world on their own. With social media's added influence, teens may be further exposed to external pressures and comparisons, making it even more important for parents to stay involved.

It can be useful to note that many teens emerge from this exploratory phase with a clearer understanding of themselves, the world, and other people. In the meantime, parents can honor their teen’s self-reliance but remain available as a safe, consistent presence. If you notice any warning signs of mental health challenges in your teen, it may be time to step in and discuss your concerns with your teen and/or their primary care doctor. 

3. Learn more about adolescent psychiatry and its impact on child brain development

Some researchers devote their entire careers to the study of adolescent psychiatry. This is an invaluable field of study, given the number of environmental, social, genetic, and other biological factors that can affect a teenager’s brain and cognitive development. 

Parents and other adults can learn more about the teenage brain by speaking to a psychiatrist in person or online. Today, there are numerous online resources and active studies of the adolescent brain, including the Adolescent Brain Cognitive Development (ABCD) study: the biggest long-term study of brain development and child health in the U.S. 

Interested parents can consult the ABCD study website for updates, articles, podcasts on medical news, and other resources. This information may help parents understand their children on a deeper level and get them help should they display any mental health concerns. 

4. Consult a professional therapist for guidance in supporting your children

To supplement their self-education, many parents consult with a licensed therapist for an additional layer of support and empathy. The adolescent years can be difficult for both parents and teens, but therapists can offer tangible strategies and compassionate advice for fostering a strong, supportive parent-teen relationship.

How online therapy can be useful for parents

Navigating the teen years can be challenging and complex, but having a professional in whom to confide may make the process less stressful. Although parenting is often time-consuming, online therapy platforms like BetterHelp may provide an easier, more convenient way to get support. Sessions can be scheduled according to your availability, and you can connect with your therapist from anywhere using video chats, phone calls, or in-app messaging. Whether you’re seeking parenting tips or you’d like to know how to care for your mental health while raising children, online therapy can meet your preferences and needs. 

If your teen is interested in counseling services, TeenCounseling offers online therapy to those aged 13-19.

The efficacy of online therapy

A growing body of research shows that online interventions can be as effective as in-person therapy. The literature on online therapy includes a 2020 study of an online psychosocial group intervention for parents of children with a chronic illness. The researchers recruited 73 parents who were at a higher risk of anxiety, depression, and other psychosocial challenges due to their children’s medical needs. After six weeks of 90-minute sessions, parents reported fewer symptoms of anxiety and depression and stronger coping skills. This study illustrates the value of online psychological interventions, particularly when applied to the unique challenges of parenting.