L21 Psychological Medicine Adolescence and emerging adulthood

Overview

The lecture covers development across adolescence and emerging adulthood, treating both as life stages of simultaneous diverse development, competence and vulnerability. It begins with the social changes that made emerging adulthood recognisable as a distinct stage, then sets out the developmental tasks of each stage (the ten tasks of adolescence; the tasks of young adulthood), then works through growth domain by domain — physical (puberty, brain, peak young-adult physiology), cognitive, social and emotional. The emotional domain leads into the emergence of mental health difficulties, supported by New Zealand population data and the Dunedin study finding that most young-adult disorder began in adolescence. The final part converts all of this into practice: how to assess a young person, what principles should shape assessment and intervention, and the red flags to pursue in adolescents and in young adults.

Framing: objectives, curriculum links and whakatauki

Learning objectives:

1. Understand developmental tasks and growth across domains of function in adolescence and in emerging adulthood.
2. Understand these life stages as periods of diverse development, competence and vulnerability.
3. Recognise risk indicators or red flags to pursue in assessment.

Curriculum links: ELM2 Psychological Medicine Block Module (Childhood; Depression, Drug & Alcohol Disorders); ELM3 RDA/RCA (Suicide & Self Harm); Integrated Case 17 – Mood Disorder (ELM3); EPE Unit 8: Child Development.

Whakatauki: Ta te tamariki tana mahi wawahi tahā — “It is the job of the children to smash the calabash.” The calabash was a valuable tool for transporting food and water and for heating water; here it is a metaphor for rules and regulations, which children and adolescents may from time to time over-step in order to develop.

Emerging adulthood as a new life stage

Emerging adulthood is recognised as a new life stage because of social changes:

• Later ages of marriage and parenthood
• Longer and more widespread education
• Birth control, fewer children
• Tolerance of premarital sexuality, cohabitation
• Changes in gender role attitudes

Supporting data — median age of marriage or civil union in New Zealand, 1961–2019 (Stats NZ):

• Male: about 24.5 years in 1961, dipping to roughly 23.5 around 1969–1973, then rising steadily from the mid-1970s to about 32.5 years by around 2006–2007, plateauing at roughly 32–32.5 through 2019.
• Female: about 21.7 years in 1961, dipping slightly to about 21.3 around 1967–1973, then rising steadily to about 30.5 around 2005–2007, plateauing at roughly 30–31 through 2019.
• The male line stays consistently above the female line by roughly 2–3 years throughout.
• Message: median age at marriage/civil union has risen markedly since the early 1970s for both sexes.

Developmental tasks of adolescence

The ten tasks of adolescence (MIT “Raising Teens”), each with what it involves:

Task	What it involves
Adjust to sexually maturing bodies and feelings	Establish healthy behaviours; sexual identity; relationship skills
Develop and apply abstract thinking skills	Understand and coordinate abstract ideas; hypothesise; plan ahead; metacognition; construct philosophies
Develop and apply new perspective on human relationships	Develop empathy and use it in conflict resolution
Develop and apply new coping skills (decision making, problem solving, conflict resolution)	Future orientation; sophisticated reasoning; risk taking to serve goals
Identify meaningful moral standards, values and belief systems	Complex understanding of morality, justice and caring for others; question childhood beliefs; adopt personally meaningful values, religious views and belief systems to guide decisions and behaviour
Understand and express more complex emotional experiences	Identify and communicate complex emotions; understand others’ emotions and abstract emotional constructs
Form friendships that are mutually close and supportive	Peers play powerful roles in providing support and connection; friendships based on sharing ideas/feelings, trust and understanding
Establish key aspects of identity	An identity reflecting both a sense of individuality and connection to valued people and groups
Meet the demands of increasingly mature roles and responsibilities	Acquire skills and manage multiple demands to prepare for employment; meet expectations regarding commitment to family, community and citizenship
Renegotiate relationships with adults in parenting roles	Adults and teens working together to negotiate a relationship balancing autonomy and ongoing connection

Note that risk taking appears here as a developmental task in service of goals, not only as a problem behaviour.

Developmental tasks of young adulthood

• Achieve autonomy
• Establish identity
• Develop emotional stability
• Establish career
• Finding intimacy
• Become part of group
• Establish a residence and manage household
• Become parents and raise children
• Marital/relationship adjustments

Physical development: puberty

	Female	Male
Beginning of puberty	8 to 13 years	9.5 to 14 years
First pubertal change	Breast development	Enlargement of the testicles
Next changes	Pubic hair development shortly after breast development	Penis enlargement begins approximately 1 year after the testicles begin enlarging
Pubic hair	—	13.5 years
Hair under the arms	12 years	Underarm and facial hair, voice change and acne at 15 years
Menstrual periods	10 to 16.5 years	—
Nocturnal emissions (“wet dreams”)	—	14 years

Physical development: the adolescent brain

Adolescence is framed as “a second window of opportunity” (UNICEF Office of Research–Innocenti):

• Early adolescence is a time of rapid learning and brain development. These changes include increases in sensation-seeking, motivation for social relations, and sensitivity to social evaluation.
• It is a period of both vulnerability and opportunity: puberty initiates intense learning and brain development, which lead to structural remodelling and neural re-configuration of key brain systems. It is a crucial time to invest in adolescents.
• Two windows of opportunity are marked on the age timeline (0 to 16): the first at ages 0–3 and the second at ages 9–14.
• Surrounding domains illustrated: social groups, communication, alcohol, education, sport, sensation.

Transcript flag (slide 12)

No content on this slide beyond the title “The adolescent brain” and the image caption “THE TEEN BRAIN / Fig. 1” — the graphic appears to be a placeholder/thumbnail (likely for a video or animation shown in class); the highlighted brain region is unlabelled so cannot be identified.

Physical development in young adulthood

20s–30s: peak physical development

• Reproductive system, motor ability, strength, lung capacity
• Peak substance use, STDs
• Highest rates of death by unintentional injury, suicide, homicide
• Lifestyle encourages poor nutrition, lack of sleep, high stress

Mid-late 30s: emergence of early signs of aging

• Immune system, response time, recovery from exertion

Peak physical capacity and peak risk coincide in the 20s–30s: the same period holds peak reproductive and physical function alongside peak substance use, peak STDs, and the highest rates of death by unintentional injury, suicide and homicide.

Cognitive development

Cognitive changes across adolescence and young adulthood:

• Complex thinking
• Abstract concepts — examples given: social issues, politics, philosophy
• Goal oriented
• Question / hypothesise / test / analyse

Social development

Social domains of change across adolescence and young adulthood (no hierarchy implied):

• Identity development
• Peer relationships, referencing, conformity
• Changing roles/relationships within family
• Developing value system
• Becoming future focused
• Romantic and sexual relationships
• Risk-taking/antisocial behaviour

Emotional development

• Self regulation
• Extended range and intensity of emotional experience
• Emergence of mental health difficulties

Mental health in adolescence and emerging adulthood

Conditions that emerge in this period:

• Depression
• Anxiety
• Non suicidal self injury
• Suicide
• Psychosis
• Substance use
• Personality Disorder

New Zealand data (2018 Mental Health Monitor and 2018/19 New Zealand Health Survey):

• 1 in 5 adults aged 15 years and over are diagnosed with a mood and/or anxiety disorder (Ministry of Health, 2019).
• Mental distress is highest amongst young people (15 to 24-year-olds).
• It is more common for individuals to be aware of close friends having mental distress than those they live with, work with, or their neighbours.
• The proportion of New Zealanders with high levels of mental distress is trending upwards over time.
• A greater proportion of younger people fall into higher/more severe categories on anxiety and mental distress measures than older age groups (25–64 and 65+).
• A lower proportion of young people report coping with everyday stresses than older age groups.
• 15 to 17-year-olds and 18 to 24-year-olds are more likely than older age groups to report long term psychological conditions that affect their everyday activities and socialising.

Awareness of mental distress in self and others (lifetime experience, 2018; more than one option could be selected): know someone or self 78%; close friend 49%; worked with 35%; lived with 32%; self 32%; neighbour 20%.

Long-term outcomes — Dunedin Multidisciplinary Health and Development Study (Newman, Moffitt, Caspi et al., 1996). Of adults diagnosed with a disorder at age 21 years:

• 74% had already been diagnosed in adolescence
• 26% were diagnosed for the first time at 21

Most young-adult psychiatric disorder has its onset in adolescence — 74% of those diagnosed at 21 were already diagnosed as adolescents. Adolescence is therefore the key window for detection and intervention.

Assessment

Five assessment principles:

• Assess broadly — multi modal, multi informant
• Promote autonomy in the patient
• Recognise competence and the limits of developmental stages
• Consent and confidentiality
• Assess substance use, mental health, social media use, lifestyle, stress, risky behaviour

Implications for assessment and intervention:

• Know the research on risk and protective factors, and developmental pathways
• Consider these factors in the life of this young person
• Avoid a deterministic approach, i.e. the view that particular outcomes are inevitable

Red flags

Adolescents:

• Worried or anxious
• Having trouble sleeping
• No interest in activities
• Changing peer groups
• Socially withdrawn
• Drug, alcohol, tobacco use
• Excessive food or exercise
• Trouble with the law
• Suicidal thoughts

Young adults:

• Major changes in behavior or personality
• Irritability, moodiness, or grumpiness
• Frequent anger or aggression
• Risky behaviors (drug use, promiscuity, etc.)
• Difficulties with sleep
• Avoidance and withdrawal from others
• Self-harm and/or suicidal thoughts

Self-test

1. List the social changes that led to emerging adulthood being recognised as a new life stage.
2. Describe what the New Zealand median age at marriage/civil union data (1961–2019) shows for each sex, including the gap between them.
3. Explain the whakatauki “Ta te tamariki tana mahi wawahi tahā” and what the calabash stands for.
4. List five of the ten tasks of adolescence.
5. List the remaining five tasks of adolescence.
6. Describe what the task “develop and apply new coping skills” involves.
7. Explain how risk taking is framed within the ten tasks of adolescence.
8. List the developmental tasks of young adulthood.
9. State the age range for the beginning of puberty in females and in males, and the first pubertal change in each.
10. State the ages given for menstrual periods in females and for nocturnal emissions in males.
11. Describe the sequence and timing of male pubertal changes from first change through to voice change and acne.
12. Explain why early adolescence is described as a “second window of opportunity,” and state the ages of both windows.
13. List the three changes said to increase during early adolescent brain development.
14. List the four cognitive changes of adolescence and young adulthood, with the examples given for abstract concepts.
15. List the seven social domains of change in adolescence and young adulthood.
16. List the three emotional domains of change in adolescence and young adulthood.
17. Describe physical development in the 20s–30s, including both the peaks and the risks.
18. State what changes in the mid-late 30s.
19. List the mental health difficulties said to emerge in adolescence and emerging adulthood.
20. State the proportion of New Zealand adults aged 15+ diagnosed with a mood and/or anxiety disorder, and which age group has the highest mental distress.
21. Explain what the Dunedin study finding on adults diagnosed at 21 implies for clinical practice.
22. List the five assessment principles for a young person.
23. Explain what “avoid a deterministic approach” means and why it matters.
24. List the nine red flags in adolescents.
25. List the seven red flags in young adults.
26. Distinguish the adolescent red flag list from the young adult red flag list, naming items unique to each.
27. A 15-year-old is brought in by a parent who reports he has stopped playing football, has a new group of friends, is not sleeping, and is drinking. Identify the red flags present and state how the lecture says the assessment should be conducted.
28. A 22-year-old presents with irritability, aggression, withdrawal from friends and recent risky drug use. Explain, using the lecture’s data, why her adolescent history should be taken and why her outcome should not be treated as inevitable.
29. Explain how the lecture’s characterisation of adolescence as a period of both competence and vulnerability is supported by the brain development and the mental health content.

Answers

Reveal answers

1. Later ages of marriage and parenthood; longer and more widespread education; birth control and fewer children; tolerance of premarital sexuality and cohabitation; changes in gender role attitudes.
2. Male median age was about 24.5 years in 1961, dipped to about 23.5 around 1969–1973, then rose steadily from the mid-1970s to about 32.5 by 2006–2007 and plateaued at roughly 32–32.5 through 2019. Female was about 21.7 in 1961, dipped to about 21.3 around 1967–1973, rose to about 30.5 by 2005–2007 and plateaued at roughly 30–31 through 2019. The male line stays about 2–3 years above the female line throughout.
3. “It is the job of the children to smash the calabash.” The calabash was a valuable tool for transporting food and water and for heating water; it is a metaphor for rules and regulations, which children and adolescents may over-step from time to time in order to develop.
4. Any five of: adjust to sexually maturing bodies and feelings; develop and apply abstract thinking skills; develop and apply a new perspective on human relationships; develop and apply new coping skills; identify meaningful moral standards, values and belief systems; understand and express more complex emotional experiences; form mutually close and supportive friendships; establish key aspects of identity; meet the demands of increasingly mature roles and responsibilities; renegotiate relationships with adults in parenting roles.
5. The five not given in the previous answer, from the same list of ten.
6. Coping skills in decision making, problem solving and conflict resolution — involving future orientation, sophisticated reasoning, and risk taking to serve goals.
7. As part of a developmental task: risk taking in the service of goals, alongside future orientation and sophisticated reasoning, rather than purely as problem behaviour (though risk-taking/antisocial behaviour also appears as a social domain of change).
8. Achieve autonomy; establish identity; develop emotional stability; establish career; finding intimacy; become part of a group; establish a residence and manage household; become parents and raise children; marital/relationship adjustments.
9. Females: puberty begins 8 to 13 years, first change is breast development. Males: puberty begins 9.5 to 14 years, first change is enlargement of the testicles.
10. Menstrual periods 10 to 16.5 years; nocturnal emissions at 14 years.
11. Testicular enlargement first (from 9.5–14 years); penis enlargement about 1 year after the testicles begin enlarging; pubic hair at 13.5 years; nocturnal emissions at 14 years; underarm and facial hair, voice change and acne at 15 years.
12. Because puberty initiates intense learning and brain development, leading to structural remodelling and neural re-configuration of key brain systems, making it a period of both vulnerability and opportunity and a crucial time to invest in adolescents. The first window is ages 0–3; the second is ages 9–14.
13. Sensation-seeking; motivation for social relations; sensitivity to social evaluation.
14. Complex thinking; abstract concepts (examples: social issues, politics, philosophy); goal oriented; question/hypothesise/test/analyse.
15. Identity development; peer relationships, referencing and conformity; changing roles/relationships within family; developing value system; becoming future focused; romantic and sexual relationships; risk-taking/antisocial behaviour.
16. Self regulation; extended range and intensity of emotional experience; emergence of mental health difficulties.
17. Peak physical development of the reproductive system, motor ability, strength and lung capacity; alongside peak substance use and STDs, the highest rates of death by unintentional injury, suicide and homicide, and a lifestyle that encourages poor nutrition, lack of sleep and high stress.
18. Early signs of aging emerge: immune system, response time, and recovery from exertion.
19. Depression; anxiety; non suicidal self injury; suicide; psychosis; substance use; personality disorder.
20. 1 in 5 adults aged 15 years and over are diagnosed with a mood and/or anxiety disorder; mental distress is highest amongst 15 to 24-year-olds.
21. 74% of adults diagnosed with a disorder at 21 had already been diagnosed in adolescence (only 26% were diagnosed for the first time at 21), so most young-adult psychiatric disorder has its onset in adolescence — making adolescence the key window for detection and intervention, and making adolescent history essential when assessing a young adult.
22. Assess broadly (multi modal, multi informant); promote autonomy in the patient; recognise competence and the limits of developmental stages; consent and confidentiality; assess substance use, mental health, social media use, lifestyle, stress and risky behaviour.
23. It means not taking the view that particular outcomes are inevitable. It sits alongside knowing the research on risk and protective factors and developmental pathways, and considering those factors in the life of this particular young person — so that risk factors inform rather than dictate the formulation.
24. Worried or anxious; having trouble sleeping; no interest in activities; changing peer groups; socially withdrawn; drug, alcohol, tobacco use; excessive food or exercise; trouble with the law; suicidal thoughts.
25. Major changes in behavior or personality; irritability, moodiness or grumpiness; frequent anger or aggression; risky behaviors (drug use, promiscuity, etc.); difficulties with sleep; avoidance and withdrawal from others; self-harm and/or suicidal thoughts.
26. Both include sleep difficulty, withdrawal/avoidance, substance or risky behaviour, and suicidal thoughts (self-harm and/or suicidal thoughts in young adults). Unique to adolescents: worried or anxious, no interest in activities, changing peer groups, excessive food or exercise, trouble with the law. Unique to young adults: major changes in behavior or personality, irritability/moodiness/grumpiness, frequent anger or aggression, self-harm.
27. Red flags present: no interest in activities, changing peer groups, trouble sleeping, and drug/alcohol/tobacco use. Assessment should be broad — multi modal and multi informant — while promoting his autonomy, recognising the competence and limits of his developmental stage, addressing consent and confidentiality, and specifically assessing substance use, mental health, social media use, lifestyle, stress and risky behaviour.
28. Her presentation matches the young-adult red flags (major behaviour change, irritability, anger/aggression, risky behaviour including drug use, withdrawal). The Dunedin study found 74% of those diagnosed at 21 had already been diagnosed in adolescence, so an adolescent history is likely to be informative. At the same time, the lecture requires knowing risk and protective factors and considering them in the life of this young person while avoiding a deterministic approach — the view that particular outcomes are inevitable.
29. Competence: adolescence brings abstract and complex thinking, goal orientation, hypothesis testing and analysis, empathy and conflict resolution, complex moral reasoning, and identity formation, and the 20s–30s are the peak of physical function. Vulnerability: puberty drives structural remodelling with increased sensation-seeking and sensitivity to social evaluation; mental distress is highest in 15 to 24-year-olds and trending upwards; most mental health disorders emerge in this period; and the 20s–30s carry peak substance use and STDs and the highest rates of death by unintentional injury, suicide and homicide.