Adolescent Brain Development: A Period of Vulnerabilities and Opportunities Ronald E Dahl, M'D' Stau

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Adolescent Brain Development A Period of
Vulnerabilities and OpportunitiesRonald E Dahl,
M.D.Staunton Professor of Psychiatry and
Pediatrics University of Pittsburgh
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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

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Tipping Points and Spirals in Development?
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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-contro
  l skills (progress slowly and continue long after
  puberty is over)

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Herman-Giddens et al 199717,000 Girls in US
Pediatric Practices w Breast/Pubic Hair
Development at Tanner 2 or above
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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)

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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

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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

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REGULATORY CONTROL
AFFECTIVE LOAD
These effects increase sharply at puberty
(relatively early)
Influence of peers, media, music, etc.
Social stress and conflicts
Pubertal drives and emotions
Cognitive-control and decision skills
Social support
Family/Parent/ adult control

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REGULATORY CONTROL
AFFECTIVE LOAD
External controls on behavior usually diminish
across adolescence
Improvements occur slowly across adolescence
(relatively late)
These effects increase sharply at puberty
(relatively early)
Variable
Influence of peers, media, music, etc.
Social stress and conflicts
Pubertal drives and emotions
Cognitive-control and decision skills
Social support
Family/Parent/ adult control

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Sleep/Arousal Regulation Example To Illustrate
Key FeaturesBrain/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

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Adolescent Sleep Pubertal Changes

• Shift in biologic timing systemsphysiologic
  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

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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...

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The School-Sleep Squeeze

• Despite average school night bedtimes of 1130 pm
  in high school seniors, the average wake-up time
  on school days is 615 am.
• Greater than 10 of US high school students must
  get up before 530 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)

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Circadian (Biological Clock) Factors

• During summers, vacations, and weekends,
  adolescent sleep/wake schedules are phase delayed
  (e.g. 3 am - noon)
• Circadian advance requires slow, steady changes
  (students often partially-adapted to school
  schedules)
• Delayed circadian phase contributes to difficulty
  falling asleep, difficulty waking

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Contributing Factors/Vicious Cycle

• Catch-up sleep on week-ends pushes circadian
  system to further delay
• Use of stimulants (caffeine and nicotine) can
  contribute to DFA
• Full time students working greater than 20
  hours/week with significant sleep sx
• Stress and conflict contribute to emotional
  arousal and further DFA

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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
• Synergistic effects with alcohol

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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

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SLEEP DEPRIVATION IN ADOLESCENCTS AND PREVENTION

• Understanding physiology provides insights that
  inform early intervention (including behavioral
  and social policy focused on sleep)
• INDIVIDUAL DIFFERENCES (e.g. need for sleep
  vulnerability to affective challenges etc)
• Sleep deprivation itself may be contribute to
  affective challenges in adolescence, especially
  in some high-risk youth and may provide
  opportunities for prevention efforts

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Analogous Spiral in Affect Regulation/Cognitive
Control?
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Negative spirals
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Yet, These Affective Changes in Adolescence
Appear to Create a Maturational Period of
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

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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

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THANK YOU