Adolescent medicine

• Adolescence runs from 10 to 19 years: a stretch of rapid physical, cognitive and social change in which patterns of eating, sleep, substance use, activity and sexual behaviour are being set for life.
• Good care meets the adolescent alone for at least part of every visit, assures confidentiality, and uses a structured psychosocial history such as HEADSS. ^[5]
• Mental health problems affect about one in seven adolescents worldwide, and common disorders begin in these years; suicide is the third leading cause of death among 15 to 29 year olds. ^[2]
• Eating disorders are more common in girls; binge eating, self-induced vomiting, laxative misuse, depression, substance use and pregnancy risk often travel together.
• Think in systems: the teenager, the family, the peers, school and the wider social world, and hand over to adult services deliberately rather than letting the relationship fade away.

By the end of this page you should be able to:

1. Explain the developmental and legal basis for confidentiality and for consent during adolescence, and state when confidentiality must be broken.
2. Take a HEADSS history and turn it into a risk and protective summary.
3. Screen for and respond to substance use with a brief intervention and a clear referral pathway.
4. Recognise anorexia nervosa, bulimia nervosa and binge eating disorder in adolescents, assess physical risk, and know the principal treatments and when to refer.
5. Counsel on contraception and sexual health in a non-judgemental, developmentally appropriate way.
6. Choose a first response to low mood, anxiety and self-harm and know the warning signs for suicide.
7. Plan a transition from paediatric to adult services using a named worker and a timetable.

Adolescent medicine is not a collection of small-adult problems. It is the care of people whose bodies, brains and social worlds are changing quickly, and whose doctor must be teacher, ally and safety net at once. In most countries adolescence is defined as 10 to 19 years ^[1], and there are about 1.3 billion adolescents worldwide, one sixth of the global population, with about 1.1 million dying each year ^[1]. Many of these deaths are preventable: road traffic injuries, suicide and interpersonal violence lead the list, and for older adolescent girls pregnancy complications and unsafe abortion are leading causes of death ^[1].

A medical student meeting the topic for the first time should hold two ideas together. First, the biological story: puberty, growth and sexual maturation happen on a fixed timetable that varies between individuals, and cognitive development (in particular the move from concrete to abstract thinking) determines whether a young person can weigh consequences, understand a diagnosis and give informed consent ^[5]. Second, the social story: peers replace parents as the reference point, identity is negotiated, authority is tested, and risk taking is common and partly developmental rather than simply reckless ^[5]. An adolescent's belief in personal invulnerability helps explain substance experimentation, unsafe sex, poor adherence and dangerous driving ^[5]. Treat these as expected developmental tasks, not moral failures, and the clinical relationship becomes workable.

The practical shape of a good adolescent consultation is consistent across cultures: see the young person alone as well as with the parent; keep the parent involved but make clear that the adolescent is the centre of the visit; be empathetic, respectful and non-judgemental, especially about substances, sex and mental health; communicate at the young person's developmental level; and assure confidentiality in every setting ^[5]. These skills take practice and are worth acquiring deliberately, because they underpin every section of this page.

Confidentiality is not a courtesy in adolescent care; it is the condition that makes honest history-taking possible. Many adolescents delay or avoid care for contraception, sexually transmitted infection, substance use, pregnancy and mental health problems when they believe a parent will be told ^[5]. The World Health Organization lists lack of confidentiality among the barriers that stop adolescents getting the care they need ^[1], and low-resource as well as high-resource services benefit from a clear, stated confidentiality policy that everyone on the team understands ^[1].

Practical points that matter in the room ^[5]:

• see the young person by themselves and with the parent, and say so at the outset
• assure confidentiality in all clinical settings, including reception, pharmacy, telephone calls and electronic records ^[5]
• ask whether the young person wants a parent present for any part of the visit
• record what confidentiality was offered and what was disclosed, so the next clinician is not starting blind

Confidentiality is not absolute. It is ethical and legal in most jurisdictions to break it when there is a serious risk to the young person or to others, including self-harm or suicide risk, child abuse or neglect, an immediate safeguarding concern, or another person at serious risk. Before breaking it, tell the adolescent what you are going to do and why, and involve them in how the disclosure is made where it is safe to do so. When in doubt, talk to a senior clinician and to the local safeguarding lead rather than guessing.

Consent is not a form signed once; it is a conversation that changes as the young person develops. Key ideas:

• Parental consent is the default early in adolescence, with the young person increasingly involved in explanations and decisions as they mature.
• Shared decision making is the norm in mid-adolescence: explain options in the young person's developmental language, check understanding, and negotiate a plan.
• Autonomous consent is realistic only when the young person can think abstractly about future consequences, weigh risks and benefits, and understand that they can withdraw consent; these capacities develop through mid to late adolescence and are not signalled by a birthday ^[5].
• Best-interests decisions are needed when capacity is lacking, usually made with parents and, where required, under the relevant legal framework for compulsory treatment.

Capacity is task-specific: a 15 year old may be able to consent to a simple treatment but not to a risky, irreversible one. Document capacity for significant decisions.

For contraception, sexual health testing, mental health treatment and substance use interventions, take consent after a private conversation with the adolescent, with the limits of confidentiality explained. If parents are involved, keep what is confidential confidential unless the young person agrees otherwise or a mandatory safeguarding duty applies.

HEADSS is a structured psychosocial history designed for adolescents ^[5]. It is not an interrogation; it is a map of the young person's home, school, peer world, mood, substance use, sexuality, trauma and sleep, gathered in an order that builds trust. It is used in every setting, from a brief screening to a full consultation, and can be shortened to the items that matter today.

Ask few enough questions to get honest answers: a blunt opener such as "Tell me about home" works better than six closed questions. Move from safer to more sensitive topics, and save suicide and self-harm for last so that the relationship is already in place. Always ask the sensitive items alone, without a parent in the room. Finish by summarising what you heard and what you are going to do, and ask whether they want anything else raised.

A HEADSS history only matters if it changes the plan. After it, write a one-paragraph risk and protective summary: the strengths (relationships, activities, goals, supportive adult), the current risks (substance use, sexual risk, low mood, self-harm, abuse, school failure), and the one or two priorities for today. For a reminder of how to open and close, see the communication principles above; practice and supervision improve these skills markedly ^[5]. Use local referral lists for mental health, substance use and sexual health services and make a clear plan rather than vague advice to "talk to someone".

Sensitive questions land better when they are routine: normalise the question ("I ask all teenagers about mood and about alcohol"), keep a neutral tone, avoid judgemental wording, and thank the young person for answering. If you cannot cover everything in one visit, say so, prioritise safety, and arrange a follow-up. Confidentiality plus genuine interest usually elicits more information than a perfect questionnaire.

Globally, in 2019 the prevalence of alcohol use among 15 to 19 year olds was high at 22%, with few gender differences and rising use in some regions ^[2]. In 2022 cannabis use among adolescents (5.5%) was higher than among adults (4.4%) ^[2]. Most adult smokers start before 18, and adolescent substance patterns predict adult patterns ^[2]. Substance use and mental health problems, sexually transmitted infection risk and unplanned pregnancy often cluster in the same young person.

Adolescent reward systems mature before the systems that inhibit risk and weigh consequences, which is part of why experimentation is common and sustained use is dangerous ^[5]. Legal substances (alcohol, nicotine vapes) are the commonest first substances; they deserve the same prevention and brief intervention as illegal ones.

Make substance use part of routine care from early adolescence onward rather than a one-off lecture. A short, validated screener (for example the CRAFFT questionnaire) helps identify risky use; a positive or high score, or any use in a younger adolescent, drives a deeper assessment. From the clinical conversation alone you can usually stratify:

• no use: praise and reinforce, revisit annually
• experimental or occasional use: brief advice about risks, sleep, accidents and the law, with a safety message about never drinking and driving or getting into a car with a driver who has used substances
• risky or heavy use, or use with harm: a brief motivational intervention, a plan for reduction, involvement of a trusted adult if safe and appropriate, and referral

Brief intervention works best when it is non-judgemental, uses open questions, affirms strengths, and colludes with the adolescent's own goals rather than lecturing. Keep it short and end with one or two agreed SMART goals and a follow-up date.

Refer to specialist substance use services when there is dependence, withdrawal risk, injecting drug use, psychotic symptoms, co-occurring mental illness or eating disorder, safeguarding concerns, or failed brief intervention. In younger adolescents and in pregnancy, refer earlier and more readily. Harm reduction (not driving after drinking, not using alone, naloxone availability for opioid use) should be offered where complete abstinence is not yet achievable, alongside realistic advice about potency, adulterants and overdose risk.

Eating disorders usually begin in adolescence and young adulthood. Anorexia nervosa involves restrictive eating with low body weight and intense fear of weight gain; bulimia nervosa involves binge eating followed by compensatory behaviours such as vomiting or excessive exercise; binge eating disorder involves binge episodes without regular compensation. All can occur at any body weight, and all share body image preoccupation and secrecy. Eating disorders affect an estimated 0.1% of 10 to 14 year olds and 0.4% of 15 to 19 year olds globally, and are more common in girls than boys ^[2]. Anorexia nervosa has the highest mortality of any mental disorder, often from medical complications or suicide ^[2]. Eating disorders are also associated with depression, anxiety, substance use and deliberate self-harm ^[2].

Risk is highest in young people between 13 and 17 years of age ^[3]. Because the early signs are easily missed, consider an eating disorder in any adolescent with:

• rapid or unexplained weight change, or weight loss while claiming to eat well
• rigid or ritualised eating, cutting out whole food groups, or eating alone
• compensatory behaviour: vomiting, laxatives or diuretics, excessive exercise, food restriction before or after meals
• body image distortion, fear of weight gain, or unusual interest in recipes, cooking or food rules despite not eating
• menstrual disturbance, delayed puberty or faltering growth in younger adolescents
• unexplained gastrointestinal symptoms, syncope, palpitations, dizziness, or poor concentration
• excessive exercise or a sports or performance setting with pressure (dance, gymnastics, wrestling, distance running, modelling, fashion)

The first assessment should be structured and unhurried: history of eating, exercise and compensatory behaviour; weight, height and (in younger adolescents) pubertal stage; mental state, suicidality and substance use; and medical complications. Useful blood tests when physical risk is a concern include full blood count, urea and electrolytes, liver function, glucose, thyroid function, bone profile and (in sexually active females) a pregnancy test, with an electrocardiogram where indicated ^[3]. Do not use screening tools such as SCOFF as the sole means of deciding whether someone has an eating disorder ^[3]. Do not use a single measure such as body mass index, weight or duration of illness to decide whether to offer treatment ^[3].

When an eating disorder is suspected, refer immediately to a community-based, age-appropriate eating disorder service; early treatment matters most for those who are severely underweight or emaciated ^[3]. Services work as multidisciplinary teams with medical, psychological and dietetic input.

Evidence-based psychological treatments are family-based for adolescents with anorexia nervosa, with cognitive behavioural therapy and family therapy for bulimia nervosa ^[3]. Medication is not offered as the sole treatment for any eating disorder ^[3]. Supervision of meals, nutritionally adequate refeeding, weight restoration and physical health monitoring (including bone health in prolonged underweight) are part of the package, as is supporting families who are frightened and grieving ^[3].

Comorbid medical conditions need parallel attention: eating disorders with diabetes require coordinated care, insulin misuse must be addressed within psychological treatment, and eating disorders coexist with substance use, depression and anxiety ^[3]. Children and young people with delayed growth or puberty need specialist paediatric or endocrine advice ^[3]. Bone mineral density is considered after 1 year of underweight in children and young people and after 2 years in adults (earlier with bone pain or fractures) ^[3].

Pregnancy complicates eating disorders and needs dedicated support, including advice on conception, weight and nutrition, and a nominated professional for pregnancy and postnatal monitoring ^[3]. Services must also plan the move from children's to adults' eating disorder services, because transition is a high-risk period ^[3].

In settings without an eating-disorder service, prioritise medical safety and stabilisation, screen for suicide, refeed carefully to avoid refeeding syndrome, set up regular weighing and monitoring with a clear medical lead, and involve the family in supporting regular eating. Keep copies of the guideline recommendations above with the clinical record so that the plan is explicit.

The American Academy of Pediatrics recommends that pediatricians provide contraceptive care for adolescents, with counselling skills that support optimal reproductive health ^[6]. Sexual and reproductive health is part of routine adolescent care, best delivered in a confidential, non-judgemental visit that explains options and their practicalities, including how to use methods correctly, side effects, what to do after unprotected sex, and when to seek help.

Sexual and reproductive needs vary with age, maturity and culture; the task is to protect health and autonomy while respecting family context. Ask about sexual activity privately, in a normalising way, and avoid assumptions about orientation or gender. Useful early questions: "Some young people your age have started having sex, some haven't. Have you?" and "If you were to become pregnant, how would you feel about it?"

Confidentiality, discussed earlier, is especially important here: adolescents value confidentiality and may assume that parents would disapprove, even where the real gap between adolescent and parental attitudes is smaller than expected ^[5]. Try to involve a supportive adult with the young person's consent, and be clear about the limits.

Rather than memorising an effectiveness league table, work from a harm-reduction principle and offer the most effective methods first, while respecting informed choice. A standard counselling sequence:

1. Long-acting reversible contraception (copper or hormonal intrauterine device, implant): highly effective, user-independent, but needs a trained provider for insertion and removal.
2. Short-acting hormonal contraception (combined pill, progestogen-only pill, patch, ring, injection): effective when used correctly, and they can help heavy or painful periods, acne and polycystic ovary syndrome.
3. Barrier methods (external and internal condoms): the only methods that also reduce sexually transmitted infection risk; essential for every sexually active adolescent.
4. Emergency contraception (levonorgestrel, ulipristal, copper intrauterine device): should be offered after unprotected sex with a clear time limit, and emergency contraception should not be used as the regular method.
5. Fertility-awareness methods: realistic only for adolescents who are able to plan and track with support.

Always provide condoms alongside any method when pregnancy or infection protection is needed. Screen for contraindications on religious, medical and psychological grounds, and follow local guidance on medical eligibility (for example the UK Medical Eligibility Criteria and the equivalent national criteria). Do not prescribe without checking interactions with antibiotics, antiepileptic drugs and other medicines the adolescent takes.

• Offer pregnancy testing when there is a missed period, for any sexual activity, and on request.
• Screen for sexually transmitted infections according to local guidance, routinely for sexually active adolescents, with chlamydia and gonorrhoea testing where prevalence is high, HIV and syphilis testing where risk or background prevalence indicates, and human papillomavirus vaccination for eligible ages.
• Use universal precautions, test after new partners or symptoms, and treat partners too.
• Discuss consent, coercion, online sharing of intimate images, and respectful relationships; ask about exploitation directly.
• Offer hepatitis B vaccination and, where available, pre-exposure prophylaxis for HIV.

Pelvic examination should be avoided in adolescents unless there are symptoms or a medical indication; cervical screening begins at the local recommended age.

Globally, about one in seven adolescents aged 10 to 19 experiences a mental disorder, and mental disorders account for about 15% of the global burden of disease in this age group ^[2]. Anxiety disorders affect an estimated 4.1% of 10 to 14 year olds and 5.3% of 15 to 19 year olds; depression affects about 1.3% and 3.4% respectively; attention deficit hyperactivity disorder affects about 2.7% and 2.2%, conduct disorder about 3.3% and 1.8% ^[2]. Schizophrenia emerges in 0.1% of 15 to 19 year olds ^[2]. Anorexia nervosa and bulimia nervosa commonly begin in adolescence and young adulthood, with anorexia carrying the highest mortality of any mental disorder ^[2].

Suicide is the third leading cause of death among 15 to 29 year olds ^[2], with risk factors that include harmful use of alcohol, childhood adversity, stigma against help-seeking, barriers to care and access to means of suicide. Early recognition and a safe environment matter more than any single scale.

Adolescent mental health problems often present physically: abdominal pain, headache, fatigue, insomnia, menstrual disturbance, poor concentration, school refusal and risky behaviour. Low mood that does not respond to reassurance, persistent irritability, and withdrawal from friends or activities are the classic pointers. Many adolescents see only their general practitioner and never a mental health clinician, so primary care must be ready to assess and to refer.

Anxiety is the commonest condition and tends to show as physical anxiety, school avoidance, reassurance seeking and somatic complaints. Depression ranges from irritability and anhedonia to self-harm. Difficulties with attention and impulse control (attention deficit hyperactivity disorder) become more obvious when academic demands rise. Disruptive behaviour and aggression often signal trauma, learning difficulty or family stress rather than deliberate defiance. Psychosis is rare but important, and any hallucination or delusion in an adolescent warrants careful specialist assessment.

A stepped approach works:

1. Ask directly about mood, sleep, enjoyment, concentration and appetite.
2. Screen for self-harm, suicidal thoughts, plans, intent and past attempts.
3. Ask about substances, physical health, medication and chronic illness.
4. Consider trauma, abuse and bullying.
5. Ask the family about changes they have noticed.

If there is suicidal intent, a plan or means, or significant self-harm, do not manage alone: remove or reduce access to means, involve a responsible adult with the adolescent's consent where safe, contact the family, and arrange same-day specialist review. Never promise to keep suicidal thoughts secret.

• Most adolescents with mild depression or anxiety respond to psychosocial support: stable routine, sleep, activity, school engagement, problem solving and brief cognitive behavioural or interpersonal approaches.
• Moderate to severe depression, anxiety with impairment, or self-harm needs a specialist assessment; medication is considered by clinicians with adolescent experience, usually alongside psychological treatment, with careful monitoring for suicidal ideation.
• Attention and behaviour difficulties need assessment for coexisting learning, language, hearing and trauma difficulties; school-based adjustments matter as much as clinic care.
• Family involvement helps outcomes, with the adolescent's preferences respected and capacity considered.
• Keep the adolescent in school or education where possible: the classroom is part of recovery.

When specialist services are unavailable, a trained non-specialist can deliver evidence-based brief psychological interventions, school and community workers can provide support, and telehealth can bridge distance. A local safety plan (warning signs, coping steps, trusted contacts, professional contacts, means reduction) should be written together with the adolescent and shared with a supportive adult. Keep follow-up short and reliable: adolescents disengage quickly after a negative first experience.

Transition is the deliberate, planned movement of a young person from child to adult health and social care services. It is not the day the referral letter is sent. A good transition begins early and leaves the young person (and the new team) prepared.

NICE recommends planning from year 9, around age 13 or 14, at the latest, and never basing the point of transfer on a rigid age threshold; it should happen at a time of relative stability ^[4]. Practice should be developmentally appropriate and strengths based, with person-centred goals reviewed regularly ^[4]. A single named worker coordinates support and supports the young person for a minimum of 6 months before and after transfer, arranging joint or overlapping appointments so that an adult-services clinician meets the young person before transfer ^[4].

Core elements of a good transition ^[4]:

• start a transition register of young people who may need adult services
• hold an annual (or more frequent) review meeting involving the young person, carers, practitioners and the general practitioner
• write a transition plan that includes education and employment, community inclusion, health and wellbeing, and independent living
• a practitioner from adult services meets the young person before transfer, with joint or overlapping appointments ^[4]
• the young person sees the same practitioner in adult services for the first two attended appointments after transfer ^[4]
• involve parents and carers as the young person wishes, respecting capacity
• carry out a gap analysis for young people who will not meet adult service thresholds, so they are not lost ^[4]

The named worker hands over to someone in adult services and leaves a contingency plan if they move roles. For complex specialties, consider a coordinated clinic or a single physician taking a coordinating role. Gaps between children's and adults' mental health services are a common and high-risk example; plan these explicitly because many adolescents with chronic conditions lose follow-up in the early twenties.

Adolescents with long-term conditions such as asthma, diabetes, epilepsy, inflammatory bowel disease, cystic fibrosis, congenital heart disease, sickle cell disease or juvenile arthritis need a longer and more structured handover. Begin teaching self-management early, with an assessment of the young person's ability to manage the condition, self-confidence and readiness to move. Arrange a readiness assessment well before the age of transfer, and make the first adult appointment feel like a continuation, not a new beginning.

Adolescent health services can be delivered everywhere if the principles hold. Practical priorities:

• train all front-line staff in the HEADSS questions and in confidentiality; a five-minute psychosocial screen is better than none
• use a dedicated adolescent clinic time or separate space, even for a short weekly session, so that privacy exists
• keep confidential records, including electronic ones, physically and digitally separated from those of parents
• involve community health workers and school nurses, who often see adolescents first
• integrate sexual and reproductive health, mental health and substance screening into immunisation and other existing contacts
• use task sharing: nurses and trained community workers deliver brief interventions, with clear referral criteria
• keep basic supplies (pregnancy and sexually transmitted infection tests, contraceptives, iron and folic acid, oral rehydration salts) reliably stocked
• address safeguarding and exploitation, including female genital mutilation, early marriage and child labour, as routine health issues rather than as separate programmes

• Anticipatory guidance and screening
• Child abuse and neglect
• Autism, ADHD and developmental delay
• Contraception (general)
• Sexual health and sexually transmitted infections
• Mental health disorders of children and adolescents
• Transition clinics and young adult health services
• Nutrition and eating disorder services