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Stages of Adolescence

3 stages adolescence

Recognizing the Three Major Stages of Adolescence

Raising teenagers is tough. They used to be this tiny little baby that needed you for everything. Any problems that arose could be quickly solved with a bandaid and a kiss or a trip to the ice cream shop.

Now everything is different. That little baby has started to grow up and wants a lot more independence than they used to.

If your teen is struggling, it can be hard to know how to help. It can be difficult to know what changes in your teen are normal parts of adolescent development and what might be potential signs of trouble.

If your teen is struggling with behavioral health issues, they are not alone. According to the Substance Abuse and Mental Health Services Administration, from 2016-2019, an annual average of 314,000 people ages 12-17 who experienced a major depressive episode received treatment in Texas. Whether your teen is suffering from depression or another behavioral health issue, it’s important to know what typical adolescence looks like so you can tell if your teen needs additional support.

Early Adolescence (10-13 Years Old)

This is usually when puberty begins, although it can start earlier in some cases. During this period, children often have growth spurts and typically begin to experience sexual interest. Most girls begin to develop breasts during this period, and both girls and boys begin to grow body hair on their legs, armpits, and genitals. It is also during this time that most girls get their first menstrual cycle.

In terms of behavior, kids in this stage typically struggle with abstract thought (concepts) and may have a worldview that lacks complexity. This is also when they begin to develop their deeper sense of morality, or the difference between right and wrong, but still tend to think of things in fairly black-and-white terms. They are often self-conscious and afraid of judgment due to the changes they are experiencing. However, extreme anxiety could be a sign of mental illness.

During this period, children typically begin to expand their intellectual interests and desire more privacy than they did previously. As part of this need for privacy, they may begin to push boundaries and try to fight any limitations that are set on them.

Middle Adolescence (14-17 Years Old)

Puberty continues and often finishes during this stage of development. Girls typically reach their adult height during this stage, while boys will continue to get taller. This is also the part of development when boys experience changes in their voice, like cracking and deepening. Girls typically have regular menstrual cycles by this period in development.

Children ages 14 through 17 also typically begin to experiment with romantic and sexual attraction. This can be a very difficult phase for children who do not feel like they have the support of their families or who are questioning their sexuality. A common part of sexual curiosity during this stage is masturbation and sometimes even sexual activity with a partner.

Teens at this age often are busy developing their own social networks and trying to distance themselves from their families. It is normal for teens at this stage to want to spend more time with their friends than they do with their families. This also tends to be the age where susceptibility to peer pressure peaks and kids continue to be self-conscious about the changes they are experiencing. While some teen anxiety and fear are normal, an extreme level may point to a developing mental illness.

This is often when teens develop more in-depth reasoning skills and long-term thinking skills, although they may still struggle to use these skills at the moment and give in to impulsive behavior. This may be when your teen begins planning for the future. This is also usually when teens develop a more complex style of moral reasoning.

Late Adolescence and Early Adulthood (18-21 Years Old)

By the time they reach late adolescence and early adulthood, most physical changes are complete. By this age, most people have reached their adult height and completed puberty.

Instead, most of the changes that take place at this stage are cognitive (involving thinking and reasoning) and behavioral.

The brain actually does not finish developing until a person is in their mid-20s. However, by the time most people are 18 through 21 years of age, they have rational thinking skills and the ability to overcome impulse with logic. They can typically delay gratification (rewards), make plans for the future, and understand how their actions will affect their future selves.

At this point in their lives, many people have a fairly stable sense of self and morality, which makes them less susceptible to peer pressure. This is also when their romantic relationships and friendships begin to stabilize. During this period, people also form an “adult relationship” with their parents where they see them less as authority figures and more as equals with whom they can share information and get advice.

The early 20s are also a period where people begin to show symptoms of serious mental illnesses, like schizophrenia.

Signs Your Teen May Need Help

The National Alliance on Mental Illness has a list of potentially concerning behavior to be aware of when researching how to help your child, including the following:

  • Changes in school performance and trouble concentrating
  • Excessive fear, worry, sadness, disobedience, or aggression
  • Avoiding peers and social events
  • Changes in sleeping habits and appearing tired
  • Using/hiding alcohol or drugs
  • Thinking about suicide
  • Intense fear of weight gain or concern with appearance

Treatment at SUN Houston

At SUN Houston, we have an excellent teen counseling program if you’re looking for a child psychologist. We understand that adolescents are going through a significant and formative period of their lives and that their treatment must reflect their individual needs.

Mental health therapy for adolescents is approached differently than for adults for several reasons, including:

  • Teens and adolescents are physically and mentally still developing
  • Academic programs are included to provide structure
  • Family support is key, especially for aftercare and ongoing treatment
  • Teens may or may not be willing participants during the initial assessment

Call SUN Houston Today

Is your teen struggling with behavioral health problems, like mental illness or substance use? We can help your child overcome their struggles. Take the first step and call us today at (713) 796-2273.



What are the behaviors of each stage of adolescence?

People in early and middle adolescence are often impulsive and may think about the world in black-and-white terms while struggling to see things from other people’s perspectives. By late adolescence and early adulthood, most people gain more emotional maturity, as well as individuality and a developed moral compass.

What are the three major areas of development in adolescence?

The three major stages of adolescence are early adolescence from ages 10 through 13, middle adolescence from ages 14 through 17, and late adolescence from ages 18 through 21.

What happens during the adolescent stage?

During adolescence, people go through a lot of physical and emotional changes. Their bodies develop, and they gain increased mental reasoning and thinking skills. Adolescence is essentially the stage of growth between early childhood and adulthood.

What are the major development stages of adolescence?

The three major developmental stages of adolescence include early adolescence from ages 10 through 13, middle adolescence from ages 14 through 17, and late adolescence from ages 18 through 21.

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