Key facts

Globally, one in seven 10-19-year-olds experiences a mental disorder, accounting for 15% of the global burden of disease in this age group.

Depression, anxiety and behavioural disorders are among the leading causes of illness and disability among adolescents.

Suicide is the third leading cause of death among those aged 15–29 years old.

The consequences of failing to address adolescent mental health conditions extend to adulthood, impairing both physical and mental health and limiting opportunities to lead fulfilling lives as adults.

Introduction

One in six people are aged 10–19 years. Adolescence is a unique and formative time. Physical, emotional and social changes, including exposure to poverty, abuse, or violence, can make adolescents vulnerable to mental health problems. Protecting adolescents from adversity, promoting socio-emotional learning and psychological well-being, and ensuring access to mental health care are critical for their health and well-being during adolescence and adulthood.

Globally, it is estimated that one in seven (14.3%) of 10–19-year-olds experience mental health conditions (1), yet these remain largely unrecognized and untreated.

Adolescents with mental health conditions are particularly vulnerable to social exclusion, discrimination, stigma (affecting readiness to seek help), educational difficulties, risk-taking behaviours, physical ill-health and human rights violations.

Mental health determinants

Adolescence is a crucial period for developing social and emotional habits important for mental well-being. These include adopting healthy sleep patterns; exercising regularly; developing coping, problem-solving, and interpersonal skills; and learning to manage emotions. Protective and supportive environments in the family, at school and in the wider community are important.

Multiple factors affect mental health. The more risk factors adolescents are exposed to, the greater the potential impact on their mental health. Factors that can contribute to stress during adolescence include exposure to adversity, pressure to conform with peers and exploration of identity. Media influence and gender norms can exacerbate the disparity between an adolescent’s lived reality and their perceptions or aspirations for the future. Other important determinants include the quality of their home life and relationships with peers. Violence (especially sexual violence and bullying), harsh parenting and severe and socioeconomic problems are recognized risks to mental health.

Some adolescents are at greater risk of mental health conditions due to their living conditions, stigma, discrimination or exclusion, or lack of access to quality support and services. These include adolescents living in humanitarian and fragile settings; adolescents with chronic illness, autism spectrum disorder, an intellectual disability or other neurological condition; pregnant adolescents, adolescent parents, or those in early or forced marriages; orphans; and adolescents from minority ethnic or sexual backgrounds or other discriminated groups.

Emotional disorders

Emotional disorders are common among adolescents. Anxiety disorders (which may involve panic or excessive worry) are the most prevalent in this age group and are more common among older than among younger adolescents. It is estimated that 4.1% of 10–14-year-olds and 5.3% of 15–19-year-olds experience an anxiety disorder (1). Depression is estimated to occur among 1.3% of adolescents aged 10–14 years, and 3.4% of 15–19-year-olds (1). Depression and anxiety share some of the same symptoms, including rapid and unexpected changes in mood.

Anxiety and depressive disorders can profoundly affect school attendance and schoolwork. Social withdrawal can exacerbate isolation and loneliness. Depression can lead to suicide.

Behavioural disorders

Behavioural disorders are more common among younger adolescents than older adolescents. Attention deficit hyperactivity disorder (ADHD), characterized by difficulty paying attention and/or excessive activity and acting without regard to consequences, occurs among 2.7% of 10–14-year-olds and 2.2% of 15–19-year-olds (1). Conduct disorder (involving symptoms of destructive or challenging behaviour) occurs among 3.3% of 10–14-year-olds and 1.8% of 15–19-year-olds (1). Behavioural disorders can affect adolescents’ education and increases the risk of criminal behaviour.

Eating disorders

Eating disorders, such as anorexia nervosa and bulimia nervosa, commonly emerge during adolescence and young adulthood. Eating disorders involve abnormal eating behaviour and preoccupation with food, accompanied in most instances by concerns about body weight and shape. Girls are more commonly affected than boys. Eating disorders can affect physical health and often co-exist with depression, anxiety and substance use disorders. They occur in an estimated 0.1% of 10–14-year-olds and 0.4% of 15–19-year-olds (1). They are associated with suicide. Anorexia nervosa can lead to premature death, often due to medical complications or suicide, and has higher mortality than any other mental disorder.

Psychosis

Conditions that include symptoms of psychosis most commonly emerge in late adolescence or early adulthood. Symptoms can include hallucinations or delusions. These experiences can impair an adolescent’s ability to participate in daily life and education and often lead to stigma or human rights violations. Schizophrenia occurs in 0.1% of 15–19-year-olds (1).

Suicide and self-harm

Suicide is the third leading cause of death in older adolescents and young adults (15–29 years) (2). Risk factors for suicide are multifaceted, and include harmful use of alcohol, abuse in childhood, stigma against help-seeking, barriers to accessing care and access to means of suicide. Digital media, like any other media, can play a significant role in either enhancing or weakening suicide prevention efforts.

Risk-taking behaviours

Many risk-taking behaviours for health, such as substance use or sexual risk-taking, start during adolescence. Risk-taking behaviours can be an unhelpful strategy to cope with emotional difficulties and can severely impact an adolescent’s mental and physical well-being.

Young people are especially vulnerable to developing harmful substance use patterns that can persist across the lifespan. In 2019, the prevalence of alcohol use among 15–19-year-olds was high worldwide (22%) with very few gender differences, and showing an increase in consumption in some regions (3).

The use of tobacco and cannabis are additional concerns. Many adult smokers had their first cigarette prior to the age of 18 years. In 2022, the prevalence of cannabis use among adolescents was higher than that of adults globally (5.5 per cent compared with 4.4 per cent, respectively) (4).

Perpetration of violence is a risk-taking behaviour that can increase the likelihood of low educational attainment, injury, involvement with crime or death. Interpersonal violence was ranked among the leading causes of death of older adolescents in 2021 (1).

Promotion and prevention

Mental health promotion and prevention interventions aim to strengthen an individual’s capacity to regulate emotions, enhance alternatives to risk-taking behaviours, build resilience for managing difficult situations and adversity, and promote supportive social environments and social networks.

These programmes require a multi-level approach with varied delivery platforms – for example, digital media, health or social care settings, schools or the community – and varied strategies to reach adolescents, particularly the most vulnerable.

Early detection and treatment

It is crucial to address the needs of adolescents with mental health conditions. Avoiding institutionalization and over-medicalization, prioritizing non-pharmacological approaches, and respecting the rights of children in line with the United Nations Convention on the Rights of the Child and other human rights instruments are key for adolescents’ mental health.

WHO response

WHO works on strategies, programmes and tools to assist governments in responding to the health needs of adolescents.

For example, the Helping Adolescents Thrive (HAT) Initiative is a joint WHO-UNICEF effort to strengthen policies and programmes for the mental health of adolescents. More specifically, the efforts made through the Initiative are to promote mental health and prevent mental health conditions. They are also intended to help prevent self-harm and other risk behaviours, such as harmful use of alcohol and drugs, that have a negative impact on the mental – and physical – health of young people.

WHO has also developed a module on Child and Adolescent Mental and Behavioural Disorders as part of the mhGAP Intervention Guide 2.0. This Guide provides evidence-based clinical protocols for the assessment and management of a range of mental health conditions in non-specialized care settings.

Furthermore, WHO is developing and testing scalable psychological interventions to address emotional disorders of adolescents, and guidance on mental health services for adolescents.

WHO’s Regional Office for the Eastern Mediterranean has developed a mental health training package for educators for improved understanding of the importance of mental health in the school setting and to guide the implementation of strategies to promote, protect and restore mental health among their students. It includes training manuals and materials to help scale up the number of schools promoting mental health.

(1) 2021 Global Burden of Disease (GBD) [online database]. Seattle: Institute for Health Metrics and Evaluation; 2024 (https://vizhub.healthdata.org/gbd-results/, accessed 13 August 2025).

(2) WHO Global Health Estimates 2000-2021

(3) Global status report on alcohol and health and treatment of substance use disorders. Geneva: World Health Organization; 2024.

(4) World Drug Report. Geneva: UNODC; 2024

Emotional struggles and poor impulse control might help explain the link between overeating and later challenges, with social and parental pressures ramping up the risk for girls.

Picky eating, however, revealed no predictive value for later mental health issues.

Clinical relevance: New study finds that early childhood eating habits might predict anxiety, hyperactivity, and impulsivity in adolescence.

Mealtime for families with young kids can be a roller coaster. But those seemingly trivial battles – whether it’s about the vegetables or eating too much – can loom large later on.

According to a new study out of Canada, overeating patterns in early childhood – especially among girls – can augur anxiety, hyperactivity, and impulsivity by the time those kids hit adolescence.

The research, published in BMC Pediatrics, followed more than 2,000 children in Quebec from their time as toddlers to their teens. The researchers identified trends that suggest that overeating in young children could serve as an early behavioral marker of mental-health challenges, particularly those linked to attention deficit hyperactivity disorder (ADHD).

By contrast, picky eating – every parent’s frustration – doesn’t seem to mean much in terms of foreshadowing future issues.

From A Toddler’s Table to A Teenager’s Brain

The researchers tracked participants from age 2.5 to 6 and reassessed them at 15. Mothers reported their children’s eating behaviors during the preschool years, while teenagers later completed standardized assessments of mental health.

The researchers identified three distinct “trajectories” of overeating:

Early-onset overeating (14.1%) – Children who started eating excessively as toddlers.

Late-onset overeating (24.3%) – Children whose overeating habits emerged closer to kindergarten age.

Never-displayed overeating (61.6%) – The majority who showed no persistent overeating.

Picky eating, however, followed a different pattern:

High level (7.1%) – Kids who exhibit repeatedly selective behavior at mealtime.

Mid-level (37.4%) – Children with moderate, yet consistent, pickiness.

Low level (55.5%) – Children generally unfussy about food.

Unlike overeating, picky eating habits tended to remain stable over time.

“Occasional overeating is normal, but if a child frequently overeats, it can be a sign of emotional struggles,” senior author Linda Booij, Professor in McGill’s Department of Psychiatry and clinician-scientist at the Douglas Eating Disorders Continuum and Research Centre, explained. “The answer isn’t restriction. In fact, strict control can make things worse and even increase the risk of disordered eating. Instead, parents and caregivers should also pay attention to children’s emotional well-being.”

What the Teen Years Revealed

Years later, when those same participants turned 15, researchers questioned them for symptoms of anxiety, depression, ADHD, conduct disorder, and social issues. What they uncovered was a clear fracture between the sexes.

Teen girls who’d shown overeating behaviors as kids appeared to be more likely to report anxiety, hyperactivity, and impulsivity as adolescents. Boys, on the other hand, displayed no such connection.

Additionally, picky eating didn’t seem to show any significant tie to later mental health symptoms. This finding echoes earlier research suggesting that pickiness might be more of a nuisance than any real harbinger of later psychiatric problems. Although the researchers insisted that it can overlap with conditions such as autism spectrum disorder in some cases.

Why Overeating? Why Not Pickiness?

The authors point to two potential explanations. First, children who overeat may struggle with inhibitory control, making it harder for them to regulate their impulses, generally speaking. Second, emotion dysregulation – turning to food as a comfort – might connect overeating to anxiety or ADHD symptoms later in life.

The sex differences raise additional questions. Why would girls, but not boys, show this connection?

“It could be that parents may sometimes monitor girls’ eating more closely than boys’, and restrictive environments could be linked to increased risk of disordered eating later in life. The social context around girls’ eating habits may partly explain why overeating is linked with later difficulties for them,” she said.

The findings complicate some lingering misconceptions about childhood eating. While we tend frame overeating as the path to obesity, we tend to classify pickiness as a dietary red flag. This study suggests that the psychological dimension of overeating – especially for girls – might demand more scrutiny.

Caveats

The study’s strength lies in its duration – and scale. Even so, the authors warn against drawing gross generalizations from the data. The mothers reported the eating behaviors were reported by mothers, subjecting to the data to potential bias – conscious or otherwise.

And the questionnaire the authors relied on was a short one, which might have limited just how well it could distinguish between types of eating behaviors.

Finally, even though the team relied on a large community-based sample, the effect sizes they identified appeared to be relatively modest.

Future research, the authors advise, should include clinical populations, more nuanced measures of eating, and earlier assessments of mental health.

No Time To Panic

The authors reiterate that, of course, not every child who overeats will go on to develop ADHD or anxiety. Most participants who displayed overeating behaviors never reported any major problems later on. But the patterns do leave some breadcrumbs for pediatricians, teachers, and parents to follow.

Most parents, and even some psychiatric professionals, are quick to dismiss childhood eating issues as fleeting. But this study underscores their potential as windows – if sometimes foggy ones – into long-term psychological health. For parents, it’s less about making them finish the broccoli and more about observing patterns, listening to what they’re saying, and paying attention to behaviors that might suggest that something more than an appetite is at work.

Further Reading

New Insights Into Eating Disorders

Could Biology Explain Why Girls Are More Prone to Depression?

Nutrition Labels May Harm Those With Eating Disorders

As students return to the classroom this fall, parents are once again navigating the balance between employing technology for learning and helping their children develop healthy screen time habits. While digital tools have become essential in education, pediatric neurologists warn that excessive screen time—especially unstructured or recreational use—can have long-term negative effects on a developing brain.

The Cedars-Sinai Newsroom recently spoke with Jane Tavyev Asher, MD, director of the Division of Pediatric Neurology at Cedars-Sinai Guerin Children’s, about how screens affect children and teens differently depending on their age, and what parents can do to set healthy boundaries for screen time.

What is the recommended amount of screen time for children in different age groups?

Before the COVID-19 pandemic, the American Academy of Pediatrics had fairly strict guidelines: no screen time at all for children under age 2, and minimal exposure for ages 2 to 5. Ideally, screen time should be under an hour a day. For ages 5 to 11 and older, less than two hours per day.

Since the pandemic shifted much of our education and social lives online, we’ve had to adapt those guidelines a bit. Still, research continues to support limiting screen time to less than two hours a day for older children as well. Exceeding that amount has been associated with increased risks of anxiety, depression and other emotional challenges.

How can excessive screen time affect young children’s developing brains?

The general consensus among developmental pediatricians is that children under age 3 should have little to no screen exposure. That’s because their brains are in a critical stage of development, with key processes like myelination, the biological process that speeds up the nerve transmission to the brain, and neural pathway formation actively taking place.

When a young brain is exposed to too much screen time, it can overstimulate the visual cortex—the part of the brain that processes images—at the expense of the auditory cortex, which is vital for developing social skills and language. Ideally, we want their early learning to be grounded in real-world, interactive face-to-face experiences—not passive viewing.

How does screen time via social media impact brain development in teenagers?

Adolescence is a time when the brain is deeply focused on social development and seeking acceptance from peers. Before social media, that feedback loop was limited to in-person interactions with a small group of peers. But now, through apps and platforms, teens are exposed to a constant, amplified stream of approval or disapproval on a much larger scale.

That amplification can be harmful. It places undue stress on the adolescent brain, increasing the risk of social anxiety, low self-esteem and even depression.

Does the type of screen make a difference?

Yes, the type of screen can make a difference. A lot of what’s called “educational content” is often just labeled that way for marketing purposes, without clear evidence that it’s truly educational. Watching content on a TV screen is generally safer—it’s farther from the eyes and doesn’t strain the neck or vision as much as phones or tablets.

Also, the platform matters. Streaming services like YouTube often auto-play endless content using algorithms to keep kids hooked. There’s no clear stopping point. In contrast, traditional TV typically airs for a set duration, which naturally limits screen time and reduces the risk of overconsumption.

How does screen-based learning in school affect brain development?

We’ve found that when students read something from a book, they tend to retain the information better than when they read the same content on a screen. We don’t fully understand why that is, but it does suggest that traditional learning methods still hold an important place.

That said, screens can be very helpful when used purposefully. For example, watching a video demonstration of a complex science experiment can be far more effective than trying to imagine it from a textbook. In classroom settings, it’s best when screens are used collectively, as part of a group lesson with discussion led by the teacher, rather than having each student isolate on their own individual device.

Are some children more vulnerable than others to the negative effects of too much screen time?

Yes, certain children are especially sensitive. Children with attention-deficit hyperactivity disorder, or ADHD, symptoms can become overstimulated by video games and may struggle even more with attention. Similarly, children experiencing anxiety or depression, or children who face social challenges may be more prone to negative effects from screen exposure, especially if they’re using it as an escape or replacement for in-person interaction.

In these cases, screen time should be monitored closely, and alternative, healthy outlets should be prioritized.

What are some practical tips for parents to set healthy screen time limits?

One of the most beneficial things parents can do is to ensure their children get at least two hours of physical activity each day, ideally outside. This supports not only their physical health but also their energy levels, focus and even vision.

Another important tip is to delay giving your child a smartphone for as long as possible. There’s a movement called “Wait Until 8th” that encourages parents to hold off until at least after eighth grade. The longer you can wait, the more time your child has to build a strong foundation of social and emotional development without the added pressures of smartphone use.

Read more on the Cedars-Sinai Blog: Does My Child Need Growth Hormone Therapy?

It’s typically between the ages of nine and twelve that our cute, cuddly little children, once so willing to climb into our laps and share their secrets, suddenly want little or nothing to do with us. A child in preadolescence is not the same person they were just a year or two ago. They have changed—physically, cognitively, emotionally, and socially. They’re developing new independence and may even want to see how far they can push limits set by parents.

What they may not know is that they need you as much as ever, because a strong parent-child relationship now can set the stage for a much less turbulent adolescence. But it won’t be easy, because you as a parent need to respect your child’s need for greater autonomy in order to forge a successful relationship with this “updated” version of your kid.

We asked some experts for parenting tips to help you keep the channels of communication open between you and your pre-teen—and have a smoother transition into the teen years.

1. Don’t feel rejected by their newfound independence

It’s appropriate for kids this age to start turning away from their parents and relying more and more on friends, but parents can take their pre-teen’s withdrawal as rejection. “All too often parents personalize some of the distance that occurs and misinterpret it as a willful refusal or maybe oppositional behavior,” says Catherine Steiner-Adair, a Harvard psychologist, schools consultant, and author of The Big Disconnect.

Beware of trying to force information out of a resistant tween. “This is a time when children really start to have secrets from us,” says Dr. Steiner-Adair, “and parents who have a low tolerance for that transition — they want to know everything — can alienate their children by being too inquisitive.”

2. Set aside special time with your child

It’s often tough to get pre-teens to open up and talk. Laura Kirmayer, a clinical psychologist, suggests establishing a special period of one-on-one time once or twice a week that you spend with your tween, where you’re providing undivided attention ,and you’re not working or texting at the same time,

In doing this you’re not only improving your relationship, you’re also teaching interpersonal skills that are going to be crucial in the future. “That quality time is really key,” Dr. Kirmayer says, “and it’s something that we might overlook because our kids might be saying they don’t want it and be pulling away. And we might unintentionally collude with that tendency.”

3. Try the indirect approach

When they were younger you could ask direct questions. How was school? How did you do on the test? Now, the direct approach — carpet-bombing them with questions about school and their day — doesn’t work. Suddenly that feels overwhelming and intrusive. And it’s going to backfire.

If anything, says Dr. Kirmayer, you have to take the opposite approach and position yourself as mostly just a listener: “If you actually just sit down, without questions, and just listen, you’re more likely to get the information about your child’s life that you’re wanting.” Dr. Kirmayer says this approach gives kids the message that “this is a place where they can come and talk, and they have permission to say anything that they’re thinking or feeling.” Sometimes you’ll be able to help and give advice—but don’t try to step in and solve all their problems. Other times you’ll just be there to empathize with how hard it is to deal with whatever they’re going through.

4. Don’t be overly judgmental

“At this age your children are watching you very astutely to hear how judgmental you are,” advises Dr. Steiner-Adair. “They are taking their cues on how you talk about other people’s children, especially children that get into trouble — how that girl dresses, or that boy has good manners or bad manners. And they are watching and deciding whether you are harsh or critical or judgmental.”

She gives the example of the parent who says, “‘I can’t believe they posted this picture on Facebook! If we were their parents we’d be mortified.’ Or ‘I can’t believe they sent that YouTube video around!’ They are commenting on behaviors that need commenting on, but the intensity and the rigidity of their judgment is what backfires.”

5. Watch what they watch with them.

Beginning in middle school, watching the stuff that your child wants to watch with them and being able to laugh at it and talk about it is an important way to connect and to be able to discuss subjects that would otherwise be taboo. “Don’t get too intense in how you critique the values,” says Dr. Steiner-Adair.

It’s our job as parents, she adds, to help both boys and girls recognize how the media instills the gender code — the barrage of cultural messages that tell kids what it “means” to be a boy or a girl—and to help them identify when something crosses the line from teasing to mean. But tread lightly and use humor.

6. Don’t be afraid to start conversations about sex and drugs

The unfortunate reality is that kids are starting to experiment with drugs and alcohol as early as 9 or 10. And according to Dr. Kirmayer, “Sexual development is a big part of this age, and it’s when we first start to see eating disorders arise, so these are key years for us to be building a strong foundation and giving them developmentally appropriate information.” Dr. Kirmayer suggests providing your tween with information and resources on sexuality without the pressure of a big “talk.”

She recommends books like The Boy’s Body Book (by Kelli Dunham) and, for girls, The Care and Keeping of You (by Valarie Schaefer) to introduce sexual development and Ten Talks Parents Must Have With Their Children About Drugs and Choices (by Dominic Cappello) to bring up the subject of drugs.

“They are going to be exposed to this stuff through their peer group,” she says. “You want to provide them with information that is accurate, but you want to do it in a way that isn’t overwhelming. Let them have the book on their bookshelf so that they can look through it and come to you with questions.” Dr. Steiner-Adair’s book The Big Disconnect also offers scripts and advice about how to talk to your children about sex.

7. Don’t overreact

Dr. Steiner-Adair warns against being the mom or dad who, in a bad situation, makes things worse. She gives this example: “Your child comes in crying; they weren’t invited to a sleepover. They see a photo of it on Instagram or Snapchat. The parent says, ‘Oh my god, I can’t believe you weren’t invited! That’s horrible! I’m going to call the mother.’” The crazy parent amplifies the drama, throwing fuel on the pre-adolescent’s already hyper-reactive flame. They make their kids more upset.

8. Don’t be “clueless” either

At the other extreme, don’t be a parent who “just ignores stuff,” says Dr. Steiner-Adair. You risk seeming oblivious or unconcerned to kids.

When a teenager is caught hosting a party with alcohol, the clueless parent might say, “‘Oh, that’s just kids getting drunk at a 10th grade party.’ So kids watch their older siblings getting away with everything without consequences and they think, ‘Great, why would I tell them anything? Why would I turn to them?’”

9. Encourage sports for girls

Girls’ self-esteem peaks at the tender age of 9 and then drops off from there, but research shows girls who play on teams have higher self-esteem. Girls on sports teams also tend to do better academically and have fewer body image issues.

Anea Bogue, creator of an empowerment program for girls called REALgirl, notes, “There’s a very common correlation, in my experience, between girls who play team sports and girls who suffer less with low self-esteem because they are looking within and to other girls for their value, as opposed to looking to boys for validation.”

10. Nurture your boy’s emotional side

“One of the really hard things for boys at this age is that the messages from the culture about their capacity for love, real friendships, and relationships are so harmful to them,” says Dr. Steiner-Adair. “They say that anything to do with real feelings — love, sadness, vulnerability — is girly, therefore bad.”

At the very least parents should do everything they can to encourage boys to be sensitive and vulnerable at home, while at the same time acknowledging the reality that those traits might not go over well at school. “You can tell him,” Dr. Steiner-Adair explains, “that at 15 or 16, when he wants to have a girlfriend, this is going to serve him really well.”

Finding just the right balance with your tween probably won’t be the easiest parenting job you’ve ever had. It will take some trial and error, but keeping the channels of communication open during these years is well worth the work you’ll have to put in.

If you develop trust with pre-teens you can offer them a safe place to come back to no matter what happens in the new world they’re inhabiting, and in doing that you’ll also be setting the stage for a smoother adolescence.

This surprised Zeitzer and his colleagues, who thought it would be healthier to live in alignment with one’s “chronotype,” the sleep patterns a person naturally tends toward. In their study, participants who went to bed late had higher risks of depression, anxiety and other mental health disorders, no matter whether going to bed late aligned with their natural sleep preferences.

Zeitzer thinks this could be partly a result of what people are doing late at night, and how poor-decision hangovers could be bad for mental health.

“There is a theory called ‘mind after midnight,’ which is this idea that after midnight, your brain makes choices it wouldn’t make at noon,” he said. “Late at night, there are fewer social guardrails because everyone else is asleep, and you’ve been awake for 16 hours, so the cumulative experiences and stress of the day can change your decision-making processes.”

There is a theory called ‘mind after midnight,’ which is this idea that after midnight, your brain makes choices it wouldn’t make at noon.

— Jamie Zeitzer

Which came first, the depression or the insomnia?

Because sleep and mental health are so intertwined, teasing out cause and effect between the two can be tricky. In other fields, scientists often turn to animal studies where they can manipulate the animals’ biology or environments. But similar tactics for studying mental health can fall short, Zeitzer said. There aren’t great animal replicas of most human mental health conditions, and assessing mood in a lab rat is difficult. Instead, researchers often trace the sequence of events. Which came first, the sleep disruption or the depression? Even that might not always indicate that the first caused the second.

“One of the theories is that you have some underlying disruption of the brain where at a lower level of disruption, you get sleep problems. And at a higher level of disruption, you get disruption of emotion,” Zeitzer said. “You see the sleep one first, but it’s really the same process.”

To complicate the picture further, the issues can compound and amplify each other, resulting in a vicious cycle where mental health problems exacerbate sleep problems, which further exacerbate sleep disruptions. In the clinic, sleep specialists observe which symptoms seem to dominate a person’s experience.

“Does it look like the insomnia has taken on enough of a life of its own that it would be helpful to treat independently? Does it look like it’s sticking around even when other things are getting better?” asked Norah Simpson, PhD, a clinical professor of psychiatry and behavioral sciences. “Those would make me think it’s something we need to address.”

(Adobe Stock/Eugenio Marongiu)

Not all sleepers were created equal

In the U.S., 16% of employed people are shift workers, meaning their work hours fall outside the typical 9-to-5. Of those, 6% work evenings and 4% work overnight. The rest work irregular shifts — think on-call doctors and nurses who swap between working days and overnight. Shift work is also associated with depression, anxiety and other psychiatric conditions.

Getting the best sleep possible is especially challenging for these people. So someone switching from an overnight shift to a day schedule, for example, might want to limit their light exposure after their shift, take a few-hour nap when they get home, then stay up until nighttime to return to a regular schedule as soon as possible.

“We’re still really leveraging those two underlying systems, the circadian rhythm and the sleep drive,” Simpson said.

And then there are teenagers. When puberty hits, there’s a natural shift in circadian rhythms; melatonin production in teens is delayed by about two hours compared with that of younger children and adults. But teens need just as much, if not more, sleep than adults do.

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Some school districts have shifted start times later in recognition of this biological change. But many remain on an early morning schedule, and sports teams and other extracurriculars often have morning practices or meetings, requiring even earlier rising.

Mental health in teens has worsened since before the pandemic, and symptoms of depression among high schoolers jumped to even higher levels since 2020. Some of this may be a result of a rise in chronic sleep deprivation — up to 80% of teens aren’t getting the recommended amount of sleep. Unfortunately, the pressures of school and extracurricular activities keep sustainable solutions to the combined sleep and mental health crisis out of reach for many.

“The question becomes, if your kid is sleeping until 2 in the afternoon on the weekend, is that OK?” Zeitzer asked. “Frankly, they need that sleep. That is not an ideal sleep pattern. But not getting enough sleep overall is worse.”

(Adobe Stock/Forewer)

Improving the sleep-mental health relationship

For people who want to take steps to improve their mental health through better sleep, Stanford Medicine researchers offer tips for achieving or maintaining good sleep hygiene:

Avoid caffeine and other stimulants after early afternoon.

Avoid alcohol before bedtime — it can reduce the quality of sleep and cause more frequent sleep interruptions.

Keep the bedroom a comfortable and soothing environment.

Try to go to bed and wake up at the same time every day, even on weekends. Maintaining a consistent sleep schedule is healthier than trying to weekend-warrior your sleep.

Avoid screen time before bed. Apps are designed to keep you awake and can displace sleep.

If you can’t sleep, don’t panic. You can’t force sleep when it is not happening. It is better to let go of the struggle and pick up a book and read until you are sleepy.

If sleep issues are lasting weeks or months, it could be time to see a sleep specialist. The problem could be a chronic condition such as sleep apnea, circadian rhythm disorder, narcolepsy or chronic insomnia.

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Cognitive behavior therapy is the gold-standard treatment for treating insomnia; it teaches patients behavioral changes to regulate the two biological systems involved in sleep: the circadian system and the sleep drive system.

The latter works much like natural hunger. People need to build up enough “sleep hunger” so they can get to sleep at night. That means avoiding long naps during the day. CBT practitioners also work with patients to address anxiety around sleep and insomnia.

“We work on decoupling the connection between the bed and arousing feelings. When someone has insomnia, they are so aroused and anxious, it prevents them from being able to fall asleep,” Goldstein-Piekarski said. “By decoupling those experiences, to re-pair sleep with the bed, you can more easily fall asleep.”