UCLA CDA Co-Executive Directors, Adriana Galván and Andrew Fuligni, spoke with PBS NewsHour’s William Brangham about why sleep is so important to youth mental health.
How Teenagers’ Lack of Sleep is Taking a Toll on Their Mental Health
How Teenagers’ Lack of Sleep is Taking a Toll on Their Mental Health
Additional Resources
This fact sheet gives an overview of adolescent brain development and explains how access to resources, opportunities, and meaningful relationships during adolescence can build connections within our brains and with the world around us that support us into adulthood.
Brain development during adolescence is fundamentally a story of connections.
Around age 9 or 10, hormonal changes kick off a period of intense learning and development, when brain cells form, strengthen, and streamline connections in response to our experiences more rapidly than in any period of life after early childhood.
Activity increases especially in the brain networks that propel us to explore the world, learn from our mistakes, and connect with others in new ways. In turn, these new experiences prompt our brain cells to connect with other neurons in ways that help us adapt to new events and new information. These neural connections become stronger the more we use them, while unused connections are pruned away, helping the brain become more efficient at acquiring and mastering new skills and new ways of thinking.
This brain-building learning happens through direct experiences in our environments and interactive, responsive relationships—with our families and peers, in our classrooms and neighborhoods, in community activities, and even online. The resources, opportunities, and experiences we as adults provide in and out of school can help young people’s brains build the extensive networks of connections that will manage the complex knowledge and behaviors needed to navigate adulthood.
Learning by Exploring the World Around Us
One of the networks that changes significantly with the increase in hormones and dopamine at the beginning of puberty is the “reward system” in our brain. Heightened activity in this system increases the feeling of reward we get from exploring the world, taking risks, and learning from the results.
Meanwhile, the network of brain regions that make up the “social brain” also changes during adolescence. These changes help us tune into social and emotional cues, like facial expressions or social rejection and approval, and increase our desire to earn respect and contribute to others. It also enables us to learn the nuances of changing social contexts in ways that help prepare us for adult relationships.
The prefrontal cortex (the region of the brain that orchestrates critical thinking and behavioral control) undergoes its most rapid period of development during adolescence. It builds on many other systems within the brain to manage our responses to the flood of new information and intensifying emotions. Engaging with other people and our environment and learning from our successes and our mistakes, known as “action-based learning,” helps shape the prefrontal cortex by strengthening the connections within it and between it and other brain networks. We learn through repeated practice—which includes trying and sometimes failing—what is adaptive and appropriate in different situations and how to guide our behavior accordingly, in ways that equip us to pursue new forward-looking goals.
When adults provide youth with opportunities to try new things, to practice navigating emotions, and to learn from failures along the way, it helps build the brain connections that we all need to grow into healthy, thriving adults.
Policies, Experiences, and Mindsets Shape the Connecting Brain
Although we can continue to learn new skills and behaviors as adults, the adaptability of the brain during adolescence means that these connections are much more likely to form quickly in response to experiences. The extent of these changes make the adolescent years a critical window when investments in the right policies and programs for youth can shape long-term positive development.
Likewise, this makes the adolescent years a time when negative experiences including racism, other forms of discrimination, poverty, or abuse can create steeper hills for young people to climb toward a healthy adulthood. When adults ensure that all young people, especially those who have experienced earlier adversity, have what they need along their journey, they can build the skills and capacities they need to thrive as adults. This includes opportunities to explore and take healthy risks, to connect with and contribute to those around us, to make decisions and learn from the outcomes, to develop a healthy sense of identity, and to rely on support from parents or other caring adults.
Understanding how and why the brain develops during adolescence lets us provide the support young people need to build healthy connections—in their world and within their brains—that will help our youth and our communities thrive.
This roundup provides an overview of the new research into adolescent development, including how neighborhoods affect sleep, the link between prosocial behavior and school performance, the role of location in racial discrimination, and the impact of specific types of adversity on brain development.
In this Research Roundup, we provide an overview of recent research about adolescent development that highlights how neighborhoods affect sleep, the link between prosocial behavior and school performance, the differences in perceived racial discrimination across locations in the United States, and the impact of specific types of adversity on adolescent brain development.
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- The impact of neighborhood disadvantage on sleep changes between childhood and adolescence
- The link between helping behaviors and school performance during adolescence across cultures
- Effects of location on adolescents’ experiences of racial discrimination in the United States
- The effects of different types of adverse childhood experiences on adolescent brain development
The impact of neighborhood disadvantage on sleep changes between childhood and adolescence
(Sleep Health, May 2025)
Sufficient and restful sleep is essential to healthy adolescent development. Research has found that people who live in economically disadvantaged neighborhoods sleep less and experience more sleep disturbances on average. However, few studies have examined whether these associations between neighborhood disadvantage and sleep change between childhood and adolescence. In this study, Thomas Fuller-Rowell and colleagues investigated the relationship between neighborhood economic disadvantage and sleep in childhood and adolescence. The researchers examined the sleep patterns of 339 youth during childhood (average age about 10 years old) and again in a subset of 167 of the same youth when they were adolescents (average age just over 17 years old). At each timepoint, participants wore wrist monitors for seven consecutive nights. Researchers found that sleep patterns changed between childhood and adolescence: Participants slept fewer hours in adolescence, but also had more efficient sleep compared to when they were younger—meaning that they spent more time actually sleeping between falling asleep and waking with fewer “long wake episodes” in which they were awake for five minutes or longer in the night.
However, the sleep quality of youth residing in neighborhoods with greater socioeconomic disadvantage improved less as they got older compared to youth in neighborhoods with more resources. Researchers also found racial disparities in these patterns–Black children who lived in highly economically disadvantaged neighborhoods experienced less decrease in long-wake episodes between childhood and adolescence. Together, these findings highlight how childhood neighborhoods and racial inequities may shape sleep outcomes as youth progress from childhood to adolescence.
Why this is important: This research provides important insights into how sleep patterns change as youth transition from childhood into adolescence and also sheds light on how neighborhood disadvantage may impact adolescent sleep–which is critical to physical and mental health during this formative period of development.
The link between helping behaviors and school performance during adolescence across cultures
(Applied Developmental Science, May 2025)
Studies have found that prosocial behavior—voluntary actions intended to benefit other people, such as helping or sharing—is associated with a range of beneficial outcomes during adolescence. In this study of 884 adolescents from six countries (Colombia, Italy, Jordan, the Philippines, Thailand, and the United States), Flavia Cirimele and colleagues examined associations between prosocial behavior and school performance over three time points, spanning from when participants were 10 to 16 years old. They found that youth who reported higher levels of prosocial behavior tended to perform better in school (averaged across reading, math, social studies, and science performance) across time. They also found that at time points when an adolescent reported being more prosocial than usual, they also performed better in school than usual. These effects remained after adjusting for differences in the socioeconomic status of their countries of residence. Together, these findings suggest that, across countries with diverse cultures and economic landscapes, prosocial behaviors and educational achievement are interrelated during adolescence.
Why this is important: By studying a large sample of adolescents from countries throughout the world, this research showcases a connection between prosocial behavior and school performance during adolescence across diverse cultural and national contexts. These patterns suggest that prosocial behaviors and academic achievement may benefit each other and support healthy development.
Effects of location on adolescents’ experiences of racial discrimination in the United States
(Journal of Adolescent Health, July 2025)
Research has found that youth experience increasing messaging about race as they enter adolescence and that young people are particularly susceptible to the negative effects of perceived racial discrimination during this stage. Using longitudinal data from over 4,000 youth in the Adolescent Brain Cognitive Development (ABCD) Study, Christopher Fields and colleagues investigated how levels of perceived discrimination changed between the ages of 10 to 14 and examined whether these patterns differed based on neighborhood or state-level factors. At three time points, participants reported whether they had experienced discrimination or unfair treatment based on their race, ethnicity, or skin color in the past year. The researchers found that non-Hispanic Black, Asian American and Pacific Islander, and multiracial youth reported experiencing significantly increasing rates of discrimination over time, while non-Hispanic White and Native American youth reported that their experiences of discrimination decreased. Additionally, Hispanic youth with immigrant backgrounds reported experiencing more discrimination. Youth living in areas with highly segregated, economically disadvantaged Black households and in states with high anti-Black bias reported greater discrimination, suggesting that structural racism at neighborhood and state level in part shapes experiences of discrimination during adolescence.
Why this is important: We know that discrimination negatively impacts well-being during adolescence. By showing how perceived discrimination increases for young people across multiple racial groups throughout the United States, this work emphasizes the importance of efforts at the community and state levels to decrease adolescents’ experiences of discrimination.
The effects of different types of adverse childhood experiences on adolescent brain development
(Translational Psychiatry, May 2025)
Adverse childhood experiences (ACEs) have been found to have lasting effects on the brain. However, it is unclear how different types of adversity uniquely affect the developing brain. In this study, Yumeng Yang and colleagues examined how different forms of adversity related to brain development in a sample of 5,885 adolescents from the ABCD Study over four years, beginning when participants were between 9 and 10 years old. Using functional magnetic resonance imaging (fMRI), the researchers examined functional connectivity, the process by which different brain regions work together and communicate via networks in the brain. The researchers examined whether different forms of adversity predicted differences in how these networks developed during early adolescence. They looked at the effects of both interpersonal adversity (caregiving disruptions, caregiver mental health challenges, maltreatment, and interpersonal trauma) and socioeconomic adversity (low family socioeconomic status, community violence, neighborhood trauma, and neighborhood poverty). Adolescents who had experienced both categories of adversity–more unpredictable or disrupted caregiving, as well as living in high-poverty neighborhoods–showed accelerated development in brain networks that support emotion regulation and executive functioning. The earlier maturation of these networks was associated with decreased performance on cognitive tasks. Together, these findings suggest that the adolescent brain may adapt to stress by accelerating brain development in ways that can negatively affect aspects of cognition.
Why this matters: During adolescence, connections between regions of the brain mature rapidly, enabling our brains to work more efficiently as we develop and learn about the world around us. By demonstrating how adversity may alter this developmental process, this work provides further evidence that stable, supportive caregiving environments and resourced neighborhoods are essential for healthy adolescent brain development. Policies that support consistent and reliable caregiving and provide resources to disadvantaged neighborhoods may be especially effective in supporting adolescents who have experienced adversity.
Six Insights to Support Adolescents’ Fundamental Need to Contribute to Others
Science Spotlight | Education | Community Engagement | Mental Health | Out-of-School Time
This spotlight provides research-based insights into how opportunities to contribute and to have those contributions recognized can build autonomy, agency, and a healthy sense of purpose during adolescence.
Adolescence is an important time for contributing to others. During the developmental period between childhood and adulthood, we forge our sense of who we are and how we want to contribute to the world. Throughout our adolescent years, our physical, cognitive, and emotional capabilities mature in ways that allow us to contribute to our friends, family, schools, and broader community in deeper, more meaningful ways than when we were younger.
Opportunities to contribute, to reflect on the meaning of our contributions, and to have our contributions recognized can build our autonomy, agency, and identity and support our sense of purpose—the forward-looking feeling that our lives are directed and significant. All of these are important to positive development during adolescence, helping us navigate adversity and set and achieve goals in ways that can impact us into adulthood.
Brain and Behavioral Development Makes Adolescence a Key Period for Contribution
One of the important developmental tasks of our adolescent years is learning who we are and how we can contribute to the world around us. Contribution becomes especially important during our adolescent years—the beginning of puberty, around 9 or 10 years old, initiates a series of interacting changes in our bodies, social lives, and within our brains that make us particularly sensitive to our social environments as we continue to build and refine our cognitive and social abilities.
During adolescence, our sensitivity to social interactions increases and combines with other developmental changes including a growing ability to consider the needs and perspectives of others, motivation to explore and pursue new experiences,6 and a new desire to create meaningful relationships and feel respected by others.
Neural Systems Underlying Contribution
Research has highlighted a network of brain regions that support our emotional and social responses when we contribute to others.
The ventral striatum, which is active in how we process rewards, matures relatively early in adolescence. High levels of activity in the ventral striatum are associated with greater tendency for contributing behavior and a heightened ability to understand the perspectives of others. The temporoparietal junction and the medial prefrontal cortex, which continue to develop into our early 20s, are also involved in contributing to others, supporting cognitive functions such as memory and attention as well as sociability.
Opportunities to Contribute During Adolescence Support Physical and Mental Well-Being While Strengthening Our Communities
Creating opportunities for adolescents to engage with and contribute to the broader community can help foster social and emotional skills, cultivate positive relationships, shape identity, promote civic engagement, and impact well-being across physical, cognitive, social, and emotional domains.
Social and emotional development
Research suggests that contribution, service to others, and other prosocial activities play an important role in adolescents’ social and emotional development. Opportunities to contribute and to see contribution modeled by others can increase young people’s empathy and compassion, two essential skills for building positive and meaningful social relationships. Indeed, adolescents who engage in helping behaviors more frequently tend to have stronger relationships with their peers and are also more likely to be accepted and popular among their peers.
Mental and physical health
Research has linked contributing in adolescence to lower rates of depression as well as to decreases in depressive symptoms over time. For example, one study found that young people tend to experience higher positive moods on days they engage in helping activities. Another study showed that an intervention that assigned youth to perform acts of kindness for others increased positive affect and decreased stress in adolescents who tend to be more altruistic.
Contributing may also support physical health. Volunteering and other forms of contribution have been linked to lower inflammatory markers, cholesterol levels, and body mass index, and may reduce the negative effects of stress on health outcomes.
Adolescents with higher levels of depression show especially strong associations between prosocial (positive or helpful) behavior and positive mood, suggesting that interventions that support contributing might be especially effective for adolescents who are depressed. The positive impact of volunteering on adolescents’ depressive symptoms has even spurred experts to argue that volunteering should be incorporated into existing treatments for adolescent depression.
Social identity formation and belonging
Contributing within a community involves navigating new social environments and working with diverse groups of people towards a common goal. This process can help young people gain a deeper understanding of their role in society. Recognizing (and being recognized for) the impact of their actions on others can help young people feel a sense of purpose and self-efficacy, improve self-esteem, and boost a positive sense of identity.
Contribution can also help youth feel a sense of belonging and connectedness, increasing their motivation to improve society and enhancing their sense of civic responsibility. Research suggests that the skills young people learn from contributing support academic and career success, as contribution has been linked to better academic performance in adolescents. In addition, more civic engagement (including volunteering, voting, and activism) in adolescence is linked to higher income and education level in adulthood.
Educational outcomes
Incorporating contribution into classrooms and school curricula can help support positive development in adolescence. For example, a school-based intervention for middle school students that provides activities, conversations, and lessons about prosocial behavior was shown to increase helping behavior and decrease aggression40 and increase students’ grades by the end of middle school.
INSIGHT: Adolescents with higher levels of depression show especially strong associations between prosocial (positive or helpful) behavior and positive mood, suggesting that interventions that support contributing might be especially effective for adolescents who are depressed. The positive impact of volunteering on adolescents’ depressive symptoms has even spurred experts to argue that volunteering should be incorporated into existing treatments for adolescent depression.
An after-school program called Youth Empowerment Solutions (YES) was designed to promote middle school students’ positive behaviors despite institutional disadvantages (such as racism) they might have faced. The goals of the program included providing students with opportunities to learn about African history and African-American contributions to U.S. history, and to work to prevent youth violence and make other positive changes in their community. After completing the YES program, the young people involved were more likely to show helping behaviors toward others and less likely to engage in verbal or physical aggression. These benefits continued over the following year and were especially strong for Black youth, highlighting the potential for fostering positive youth development through programs that help youth develop confidence in themselves, think critically about their community, and become involved in community change efforts.
- Values Alignment: Contribution is most impactful when it aligns with a young person’s interests, values, and skills. Conversely, a mismatch between contributing activities and a young person’s interests, values, and skills may lead to stress and negative outcomes.
- Agency: Youth should have agency or a role in choosing the type of service, its parameters, and its evaluation.
- Impact: Adult facilitators should ensure that the project has a real impact, even if the impact is only on an individual person. Youth will discern if they are simply doing “busy work.”
- Reflection: To reap positive developmental impacts from service and attach meaning to the experience, youth should be given opportunities to reflect through discussion, journaling, or other outlets–either individually or with peers.
- Challenge: Youth develop a sense of efficacy through opportunities that challenge them to stretch themselves or otherwise extend some effort in attainable ways as they contribute to others.
- Connection: Social connections are important for adolescents and can encourage youth to contribute to others. Research has shown that adolescents’ (but not adults’) real-world helping is guided by their friends’ prosocial moral values. And when youth provide emotional support to their family, they are more likely to support their friends the next day, and vice versa.