Physical Development in Adolescence

If they had to describe the most awkward time of their lives, many people would probably describe adolescence. Our bodies change rapidly during the teen years, and it's difficult to trust our emotions. What's important to remember during this uncomfortable time is that we are not alone, our feelings are valid, and this will not last forever.

• What is physical development in adolescence?
• What are the stages of physical development in adolescence for both biological sexes?
• How does physical development in adolescence impact mental health?
• What is the process of physical development in adolescence in the brain?
• What factors affect physical development in adolescence in healthy or unhealthy ways?

Meaning of Physical Development in Adolescence

When adolescence begins, we start experiencing growth spurts, brain development, and surges in hormones. All physical changes during the teen years are collectively referred to as puberty.

As the pituitary hormones start increasing, they stimulate other glands to cause changes in primary and secondary sex characteristics. The first refers to the physical organs involved in reproduction, like the penis, testes, vagina, and ovaries. Secondary sex characteristics involve physical changes that aren't linked to reproduction, like voice tone, pubic hair, breast growth, and height.

These hormonal changes often result in major fluctuations in mood and behavior. Even though everyone goes through puberty at some point, the timing is different depending on a person's gender, culture, and other environmental or genetic factors. Everyone's experience of puberty is also as unique as they are. Those who start puberty early (9-11 years old) have a different experience than those who start changing much later (14-15 years old).

The Stages of Physical Development in Adolescence

Puberty is a different experience depending on your biological sex. Girls generally reach puberty between 8 and 13 years old. For boys, this time typically begins between the age of 9.5 and 14. Notice that boys tend to develop physically a little bit later than girls.

Puberty for Girls

Puberty for girls often starts with their first period or menstrual cycle, called menarche. Girls can start getting their period as young as eight years old, or they may not start menstruating until they are 16. The start and symptoms of menarche are influenced by genetic and environmental factors, nutrition, physical activity, socioeconomic and health status.

Periods aren't the only change for girls, though. Breast development also happens during adolescence, and pubic and armpit hair starts to grow. Acne is also a common experience as well as weight gain in the hips, butt, and chest. This weight gain is normal and healthy. The female body naturally tends to carry more fat tissue than the male body. However, these changes can be hard for teen girls and negatively impact their self-esteem.

Fig. 1 Acne during adolescence, freepik.com

Puberty for Boys

Puberty for boys often starts with spermarche: the production of sperm and first ejaculation. This usually begins around age 11-15. Once spermarche starts, boys might have "wet dreams" - when semen (the wet substance containing sperm) is produced and emitted while asleep. The testicles and penis get larger and pubic hairs start to grow. Boys also begin to grow facial hair and armpit hair. Their voices become deeper by dropping in tone, sometimes very suddenly. Acne and excessive body odor are also common.

Examples of How Physical Development in Adolescence Impacts Mental Health

The timing of physical development in adolescence can significantly impact self-esteem. For boys, early maturation could mean that they are stronger, more athletic, or taller than everyone else their age. This can lead to popularity, self-assurance, and confidence. It can also increase the risk of engaging in premature sexual activity, alcohol use, and delinquency, though.

Premature sexual activity is associated with many risks, including unprotected sex, sexually-transmitted diseases, unwanted pregnancies, and abortions. It can also contribute to difficulties in school, relationship struggles, delinquency, drug use, lower self-esteem, and suicide risk. The idea is for the teen to wait until they are old enough to protect themselves, understand the risks and reduce the risks, and choose their sexual partners without coercion.

Girls who mature early may face different challenges than boys. The natural weight gain in teen girls, particularly in the waist, hips, and belly area, can contribute to feeling self-conscious and insecure. Teen girls experience an increased risk of developing eating disorders. Those who experience puberty early may socialize with older adolescents instead of girls their age, and they experience teasing and sexual harassment. Early-onset of puberty also increases the risk of developing anxiety or depression in girls.

Fig. 2 Teen girls and eating disorders, freepik.com

Transgender or Non-Binary Adolescents

While puberty and physical development in adolescence is a stressful experience for most teens, transgender or non-binary teens face unique challenges. They are often already experiencing distress over gender incongruence. Puberty can add to the psychological strain and well-being of these teens and increase their risk of depression and suicidal ideation.

Medical options like puberty suppression may help extend the time before someone begins puberty so that they can clarify their gender identity. Even though impression treatments are reversible, they can cause side effects. Many physicians worry that puberty suppressing treatments may affect physical development in adolescence and negatively interfere with gender expression. Either way, non-binary and transgender teens, in particular, can benefit from family support and counseling during puberty.

The Process of Physical Development in the Brain

Changes in primary and secondary sex characteristics are not the only changes during adolescence. The brain also changes. In fact, the pituitary hormones that start puberty are activated by the brain's hypothalamus.

The adolescent brain is forming new neural connections while pruning away connections that are used very little. Connections also become faster as they grow in complexity. The brain streamlines its networks to promote greater communication between different brain regions.

More and faster connections in the adolescent brain cause improvements in impulse control, long-term planning, and judgment compared to children. Compared to adults, however, the adolescent frontal lobe is still developing, all the way up until around age 25. As the brain develops, adolescents experience an increase in dopamine.

A frontal lobe that hasn't reached maturity yet, increased dopamine activity, and hormonal surges help explain common teen behaviors like drug use, reward-seeking, risk-taking, and aggression. Even though adolescents and adults have a similar ability to understand risks, adolescents often pay more attention to the reward and have more difficulties controlling their impulses fully maturely.

Factors Affecting Physical Development in Adolescence

Several factors can affect physical development in adolescence. A few major factors are drug and alcohol use, stress, and overall health and nutrition.

Teen Alcohol Use

Alcohol use during adolescence can cause long-term brain damage and impact behavior and brain development. The frontal and temporal lobes, cerebellum, hippocampus, and pre-frontal cortex areas of the brain are especially vulnerable to the effects of alcohol, and they are particularly important to mature brain development. Heavy drinking in adolescence can cause memory and learning difficulties, likely due to damage to the hippocampus.

Heavy alcohol use in adolescence damages the frontal lobe, which controls judgment, self-regulation, problem-solving, reasoning, and impulse control. This is why heavy alcohol use during adolescence predicts alcohol dependence later in life. Being an adolescent is stressful for many of us; the drastic physical and hormonal changes make life harder and impact mood. It makes sense that adolescents would be drawn to drug use as a coping mechanism for social and sexual maturation stress.

Teen Stress

Stress can harm a person at any stage of life. For teens, it can affect physical development. Research shows that stress impacts the brain's ability to create new connections and mature. During adolescence, it can also contribute to developing mental health concerns like depression and anxiety. The changes occurring in physical development in adolescence alone are stressful. Those changes also make it harder for adolescents to cope with stress. Teen girls may experience higher stress levels than teen boys, but for both, a strong parent-teen bond can act as a buffer against stress.

Teen Health and Nutrition

Nutrition is so important for physical development in adolescence, and it can influence eating habits later in life. Teens often need to be taught how to eat healthy, though. Many of the foods they are drawn to are unhealthy. Since teens tend to struggle with impulse control, making healthy lifestyle and food choices can be challenging. Adolescents may choose food based on taste or emotions over nutritional value.

Adolescents may not feel the need to eat due to negative body image or other factors. Food choice or undereating can cause deficits in essential nutrients that promote physical development, such as calcium, protein, potassium, iron, and fiber. Physical activity and healthy sleeping habits play a significant role in physical development in adolescence. Regular exercise can also be an effective way to reduce stress, and getting enough sleep at night can help reduce irritability and moodiness.

Fig.3 Teens and physical activity, freepik.com