ADOLESCENT BRAIN DEVELOPMENT: A PERIOD OF VULNERABILITIES OPPORTUNITIES Ronald E Dahl, M.D. Staunton Professor of Psyc

1. ADOLESCENT BRAIN DEVELOPMENT: A PERIOD OF VULNERABILITIES & OPPORTUNITIES Ronald E Dahl, M.D.Staunton Professor of Psychiatry and Pediatrics University of Pittsburgh

3. Morbidity & Mortality in Adolescence: Primary sources of death/disability are related to problems with control of behavior and emotion Increasing rates of accidents, suicide, homicide, depression, alcohol & substance use, violence, reckless behaviors, eating disorders, health problems related to risky sexual behaviors� High rates of risk-taking, sensation-seeking, and erratic (emotionally-influenced) decisions Behavior with long-term health consequences

4. Probability of Smoking Initiation Onset of alcohol and other substances Onset of initial depression episode More than 50% of HIV risk Rates of accidents related to violence and reckless behavior

7. Adolescence as a Developmental Period of Unique Risks (& Opportunities) Gene/Environment/Development interactions Reward Neurocircuitry: changes at puberty? emotional and motivational influences on decision making? Adolescence as a crucial time for developing self-regulatory capacities (decision-making skills)

8. Overview of General Model Early adolescence as a period of brain development that creates unique vulnerabilities (and opportunities) for some kinds of emotional-motivational learning. Onset of puberty: Activational effects on drives, motivation, and emotions Versus gradual emergence of cognitive control Relevance of: Earlier timing of puberty Scaffolding/social support Social policy and intervention

10. Puberty & The Balance of Adolescence PUBERTY: rapid physical, endocrine, and affective changes (EARLY) Versus the gradual (LATE) development of affect regulation and maturation of cognitive/self-control skills (progress slowly and continue long after puberty is over)

11. Adolescence Youth are heated by Nature as drunken men by wine. --Aristotle I would that there were no age between ten and twenty three�for there is nothing in between but getting wenches with child, wronging the ancientry, stealing, fighting� --Shakespeare (The Winter�s Tale; Act III)

12. The Tinderbox in the Teen-age Brain As illustrated by Romeo and Juliet (and hundreds of other stories, dramas, and movies) adolescence has been recognized throughout human history as a time when surging emotions have a particularly dramatic capacity to influence decisions and behavior.

13. Scientific Questions: What is the empirical evidence that adolescents are �heated by Nature�? Role of biology? Specific hormones of puberty? Role of intensifying emotions? Specific neurobehavioral underpinnings to adolescent-onset motivational tendencies for: risk-taking and/or sensation-seeking? status-seeking? emotional and motivational changes at puberty?

14. Defining Adolescence: Conceptual Issues

15. Adolescence: That awkward period between sexual maturation and the attainment of adult status in society. The transition from �child� status (requires some adult monitoring) to �adult� self-responsibility for one�s behavior in the absence of adult supervision; Interposed with physical and neurobehavioral changes of puberty

19. Herman-Giddens et al 1997:17,000 Girls in US Pediatric Practices: % w Breast/Pubic Hair Development at Tanner 2 or above

21. Puberty, Marriage, and Adult Roles in Contemporary Society (United States) Average age of menarche is now age 12; average age of first marriage for females is 26. Not simply changing attitudes about marriage� Many adult social roles�starting careers, owning a home, choosing to become parents�are now occurring a decade or more after puberty. These changes have advantages and costs (create vulnerabilities). ADOLESCENCE HAS EXPANDED from a 2-4 year interval in traditional societies to an 8-15 year interval in contemporary society.

22. Puberty: Changes in Motivation/Emotion Strongest direct links to puberty: changes in romantic motivation, sexual interest, emotional intensity, sleep/arousal regulation, appetite, and risk for affective disorders A general increase in risk taking, novelty seeking, sensation seeking (status seeking). Animal studies also show behavioral changes and alterations in social motivation in adolescent period (Spear 2000); many examples of species-specific changes (e.g. play fighting in rats takes on �stakes� Pellis 2004)

23. Human Puberty: Igniting Passions in the Developing Brain Profound changes in romantic interest, motivation, emotional intensity Intensification of many types of goal-directed behavior, including intense motivation for long-term and abstract goals (particularly those related to social-status) Relatively understudied aspect of adolescent development (neurobehavioral changes in emotion and motivation)

24. In contrast to these early affective changes directly linked to puberty: Most measures of cognitive development correlate with age and experience (not sexual maturation): planning, logic, reasoning, inhibitory control; problem-solving skills; capacity for understanding long-term consequences of behavior These maturational capacities continue to develop long after puberty is over� Brain development?

26. Hypothesis regarding affective development: Starting the engines with an unskilled driver Earlier (historically) timing of puberty results in several years with a sexually-mature body and sexually-activated brain circuits (�igniting passions�) Yet with relatively immature neurobehavioral systems necessary for cognitive-control and affect regulation Predict: increased risk for disorders of self-control; difficulties navigating social-emotional situations

31. Sleep/Arousal Regulation: Example To Illustrate Key Features:Brain/Behavior/Context Interactions Some developmental changes in sleep regulation are biologic and linked to puberty Some changes in sleep regulation linked to social & environmental influences, habits, and patterns Spiraling interactions between these domains can lead to vulnerability and spiral into serious clinical problems

32. Adolescent Sleep: Pubertal Changes Shift in biologic timing systems�physiologic change in tendency to prefer to stay up late/sleep-in late Related to changes in circadian system more �owl�-like tendencies Lee et al animal model in O. degus� Pubertal increases in daytime sleepiness Probably an increase need for sleep during puberty and adolescence

33. Social factors contributing to LATE bedtimes/sleep onset times: Peers and social activities Greater freedom to self-select bedtimes Access to light and stimulating activities Stress/anxiety or excitement ? difficulty falling asleep Major circadian shift on weekends/vacation Work, Sports, Homework, Projects, meds...

34. The School-Sleep Squeeze Despite average school night bedtimes of 11:30 pm in high school seniors, the average wake-up time on school days is 6:15 am. Greater than 10% of US high school students must get up before 5:30 am to catch buses More than 15 % of high school students report averaging 6 or less hours of sleep per night on school days (need 8 or more)

35. Consequences of Insufficient Sleep in Adolescents Sleepiness, Tiredness Difficulties with focused attention Irritability, Emotional lability Difficulties with affect regulation & cognitive-emotional integration Direct effects on learning, memory consolidation Increase use of caffeine, stimulants

36. A Small Biological Change Leading to a Spiral of Negative Effects Late night/erratic schedules ? Sleep Deprivation ? erodes mood and motivation ? greater stress and affective problems ? interferes further w sleep/arousal regulation ? greater difficulty falling asleep Social context that amplifies the biologic change ? a descending spiral

37. Analogous Spiral in Emotion Regulation/Cognitive Control? Achieving a more mechanistic understanding of emotion regulation�

39. Yet, These Affective Changes in Adolescence May Create Unique Maturational Opportunities Establishing new links between more complex ways of thinking and new emotional/motivational experiences Development of brain systems underpinning higher levels of cognitive-emotional integration Opportunities for early intervention/prevention in identified high-risk samples �Igniting passions� can be sculpted by positive learning experiences:

40. Brain/Behavior/Social-Context Interactions: Positive SPIRALS Igniting Passions: Sports Literature/Arts/Music Science/Medicine Politics Caring for others Larger Purpose Changing the world in positive ways

41. Conclusions Early adolescence appears to be a natural time of motivational learning�a time of igniting passions in ways that create vulnerability for developing destructive versions�addiction, reckless behavior, and emotional disorders. Yet, also opportunities to align these passions to healthy long-term goals. Compelling neuroscientific questions about mechanisms in ways that can inform early intervention in high-risk populations and to promote social policies that can contribute to healthy development in youth.