Teen mental health conditions, actually understood.

Approximately 20.3 percent of U.S. adolescents — more than 5.3 million teens aged 12 to 17 — have a current diagnosed mental or behavioral health condition, according to 2023 federal data. Nearly half of all adolescents (49.5 percent) will experience a mental health disorder at some point during their teen years. The conditions in this library are not rare. They are the conditions families bring to clinicians every day.

The conditions library is organized into six clusters that reflect how conditions actually present in adolescents — and how families actually search for help. Each cluster's hub page covers the category in depth, with subpages on specific subtypes and treatments. Some clusters are fully built; some are still in production. We say which is which, on the cluster cards below.

If your teen is in immediate crisis — talking about suicide, unable to function, or in any acute danger — call or text 988, or go to your nearest emergency department. The rest of this page assumes the situation has more time to think through.

How common are mental health conditions in teens, actually?

The numbers are worth knowing, because they affect how families understand what they're seeing — and because most of the data Hartley parents encounter online is from sources with something to sell.

Per the 2023 National Survey of Children's Health, published in October 2024 by the U.S. Health Resources and Services Administration:

• 20.3 percent of U.S. adolescents aged 12 to 17 had a current diagnosed mental or behavioral health condition in 2023 — more than 5.3 million teens.
• Anxiety was the most common, at 16.1 percent. Depression was second at 8.4 percent. Behavior or conduct problems were third at 6.3 percent.
• Diagnosed conditions among adolescents have increased 35 percent since 2016. Diagnosed anxiety has increased 61 percent. Depression has increased 45 percent.
• Female adolescents have substantially higher rates of diagnosed anxiety (20.1 percent vs 12.3 percent for males) and depression (10.9 percent vs 6.0 percent). Males have higher rates of behavior and conduct problems (8.2 percent vs 4.3 percent).

Those are the numbers for current diagnosis. Lifetime prevalence — the share of adolescents who experience a disorder at some point during their teen years — is much higher. NIMH estimates that 49.5 percent of adolescents will experience a mental health disorder during adolescence. The CDC's Youth Risk Behavior Survey for 2023 found that 40 percent of high schoolers reported persistent feelings of sadness or hopelessness in the past year.

Disparities matter:

• LGBTQ+ adolescents report substantially higher rates: 66 percent of LGBTQ+ young people aged 13–24 reported recent symptoms of anxiety in 2023, per Trevor Project data, and 53 percent reported recent depression symptoms.
• Adolescent suicide remains a leading cause of death in U.S. adolescents. In 2023, 20 percent of high schoolers reported seriously considering suicide, and 9 percent reported attempting suicide in the past year (CDC).
• Native American adolescents have suicide rates roughly 3.5 times the national average (Center for Native American Youth).

One more statistic worth knowing: of adolescents with a mental health condition, only about 50 percent receive treatment in any given year (NAMI). The treatment gap is real, and it widens by income and geography.

Why teen conditions don't fit clean categories

{CLINICAL REVIEW NEEDED}: Adolescent mental health conditions don't typically present as one clean diagnosis. Comorbidity — the co-occurrence of multiple conditions in one person — is the rule, not the exception.

A few of the most common patterns:

• Anxiety and depression co-occur in an estimated 30 to 50 percent of adolescent cases. The conditions reinforce each other; treating one without the other often produces incomplete improvement.
• Eating disorders frequently co-occur with anxiety, obsessive-compulsive disorder, depression, or trauma. Treating an eating disorder without addressing the underlying anxiety often produces relapse.
• Trauma can present as anxiety, depression, conduct problems, dissociation, or substance use — depending on the teen, the type of trauma, and the developmental stage at which it occurred.
• Neurodivergence — autism spectrum, ADHD, learning differences — is associated with elevated rates of anxiety and depression. Many neurodivergent teens are first identified through their secondary anxiety or depression rather than the underlying neurodevelopmental condition.
• Substance use in adolescents is rarely just substance use. It's frequently a coping strategy for an underlying condition that hasn't been addressed.

This is why diagnostic labels matter — and where they fail. They matter because they direct treatment: CBT for anxiety is different from family-based treatment for an eating disorder. They fail when families or clinicians try to fit a complex teen into one box, missing the comorbidities that affect treatment direction and outcomes.

The implication for parents: a thorough evaluation by a child mental health professional — ideally one with specific adolescent training — matters more than self-diagnosis from a checklist or symptom search. The same constellation of symptoms can reflect different underlying conditions in different teens.

Why teen mental health looks different from adult mental health

{CLINICAL REVIEW NEEDED}: A few patterns make adolescent presentation different from adult presentation, and worth understanding for parents:

Physical symptoms predominate. Adolescents — particularly with anxiety and depression — often experience their condition primarily as physical symptoms: stomach pain, headaches, fatigue, sleep disruption, appetite changes. The verbal acknowledgment of mood that adults tend to report comes later, if at all.

Avoidance is the core behavior. Adult mental health conditions often show up as visible distress. Adolescent conditions often show up as withdrawal — from school, from social events, from previously-enjoyed activities, from family. The avoidance is what makes the condition self-perpetuating.

Irritability often replaces sadness. Major depression in adolescents may present primarily as irritability rather than the lowered mood adults more commonly report. Parents often interpret this as moodiness or attitude problems rather than depression.

Some conditions are systematically missed. Autism in girls, ADHD in girls, anxiety in academically-successful teens, depression in teens who are still functioning at school — these patterns get missed for years. Recognition often comes only when the teen reaches a breaking point. Earlier recognition is better.

Developmental context matters. Some level of moodiness, worry, self-consciousness, and identity exploration is developmentally typical in adolescence. The clinical question is whether what's happening exceeds what's developmentally expected and produces functional impairment. That judgment requires clinical training.

How Hartley organizes this library

A few notes on the editorial logic behind this library:

We organize by how parents actually search. The clusters above reflect the categories families use when trying to understand what's happening with their teen — not the technical taxonomy a clinician might use. Within each cluster, the deep articles are organized by specific subtypes and treatment approaches.

We publish slowly. Hartley aims to be the publication that matters when families are at decision points, which means we'd rather have one carefully-reviewed article than ten generic ones. Each article is researched against current AACAP, NIMH, CDC, and peer-reviewed sources, then reviewed by a licensed clinician before publication. Articles include the date of last review and the date of next scheduled review.

We don't pretend to be complete. Mental health is large. Hartley covers the conditions most commonly seen in adolescents and the questions families most commonly ask. We don't try to be the comprehensive textbook reference. For more specialized presentations, we link out to the appropriate authoritative sources.

We don't refer to treatment programs. Hartley is a publication, not a directory or referral service. We don't accept payment from treatment programs. We do investigative reporting on the industry. Read the disclosures page for the full funding statement.

We update regularly. Mental health research changes. Statistics get refreshed annually. Treatment evidence shifts as new RCTs publish. Each article is on a quarterly review cycle, with the next scheduled review visible in the byline.

What to do if you're starting today

If you've read this far and you're trying to figure out a concrete next step:

1. Start with your teen's pediatrician. Most pediatricians can do an initial mental health screening using validated tools (PHQ-9, GAD-7, SCARED) and refer to a child mental health professional. This is also typically required to access insurance-covered care.
2. Read the cluster that seems most relevant. If you're recognizing a specific pattern — anxiety, depression, eating concerns, substance use, trauma, neurodivergence — start with that cluster's hub page. The anxiety cluster is the most fully built right now and may be useful even if your teen's primary concern is something else, since anxiety co-occurs with most other conditions.
3. Consider whether the question is "diagnosis" or "treatment." If you're trying to understand what's happening, the conditions library is the right starting point. If you're past diagnosis and trying to figure out next steps, the parent's guide to teen mental health treatment and levels of care guide are more useful.
4. If you're in a crisis right now, use the crisis resources at the top of every page, or call or text 988.

Most adolescent mental health conditions respond to evidence-based treatment, especially when treatment begins early. The biggest predictor of outcome is whether treatment is evidence-based, sustained for an adequate duration, and matched to the specific condition (or conditions). The information here is to help families ask better questions of clinicians — not to replace them.

Common questions parents ask