adolescent brain development dr alex hassett senior consultant (camhs) managercamhs practice...

Adolescent Brain Development Adolescent Brain Development

Dr Alex HassettDr Alex Hassett

Senior Consultant (CAMHS)Senior Consultant (CAMHS)

ManagerManager CAMHS Practice Improvement ProgrammeCAMHS Practice Improvement Programme

Brain developmentBrain development

Brain CircuitryBrain Circuitry• NEURON — specialized cell designed to

transmit information to other nerve cells and muscles

• Each neuron consists of a cell body, axon, and dendrite

• Axon – an electricity conducting fiber that carries information away from the cell body

• Dendrite – receives messages from other neurons

• Synapse – contact point where one neuron “communicates” with another neuron

Brain CircuitryBrain Circuitry

• Neurons “communicate” by transmitting electrical impulses along their axons

• Axons send messages across a synapse to the receiving dendrite of the target neuron

OVERPRODUCTION AND PRUNINGOVERPRODUCTION AND PRUNING• Brain development occurs in 2 basic stages–

growth spurts/overproduction of neurons and pruning

• Critical phases: in utero 0-3 years overproduction

10-13 years • Overproduction results in significant increase

in the number of neurons and synapses• Exuberant growth during these 3 phases gives

the brain enormous potential

PRUNINGPRUNING

• These 3 critical phases are quickly followed by a process in which the brain prunes and organises its neural pathways

• LEARNING is a process of creating and strengthening frequently used synapses (brain discards unused synapses)

• Brain keeps only the most efficient and “strong” synapses

• Experience determines which synapses flourish and which are pruned away

PRUNINGPRUNING

• “USE IT OR LOSE IT”– Reading, sports, music, video games, x-box, hanging out—whatever a child/teen is doing—these are the neural synapses that will be retained

• How children/teens spend their time is CRUCIAL to brain development since their activities guide the structure of the brain

Defining adolescenceDefining adolescence

• Defined in different ways• Not just puberty• Adolescence is the transition from childhood to

adulthood. From dependence to independence• No distinct beginning and end but roughly 10-20

years of age • Adolescence is a transitional process not a stage

Summary of Tasks of AdolescentsSummary of Tasks of Adolescents

Cope with physical changesEstablish sexual identity/sexual orientationEstablishing an identity Establishing autonomy Prepare to live independentlySeparate and develop new relationships with family of originDevelop moral codeEstablish peer relationshipsEstablish intimate relationships

Ruth Talbot, YoungMinds

THE ADOLESCENT BRAINTHE ADOLESCENT BRAIN

Adolescent brains are different to adultsAdolescent brains are different to adults

They may look like adults, they may behave like adults, they may even come to the same

conclusions as adults but what is going on in their brain is different

Teenage brains are a work in progress

DISPARITIES OF ADOLESCENCEDISPARITIES OF ADOLESCENCE

• Adolescence is a TRANSITIONAL period during which a child is becoming, but is not yet, an adult

• Adolescent brains are far less developed than we previously believed

• Normal adolescent development includes conflict, facing insecurities, creating an identity, mood swings, self-absorption, etc.

ADOLESCENT BRAIN DEVELOPMENTADOLESCENT BRAIN DEVELOPMENT

• Underdevelopment of the frontal lobe/prefrontal cortex make adolescents more prone to “behave emotionally or with ‘gut’ reactions”

• Adolescents tend to use an alternative part of the brain– the AMYGDALA (emotions) rather than the prefrontal cortex (reasoning) to process information

• Amygdala and limbic system tend to dominate the prefrontal cortex functions– this results in a decrease in reasoned thinking and an increase in impulsiveness

• Because of immature brains, adolescents do not handle social pressure, instinctual urges, and other stresses the way adults do

• A major part of adolescence is learning how to assess risk and consequences — adolescents are not yet skilled at these tasks



• To appreciate consequences of risky behaviour, one has to have the ability to think through potential outcomes and understand the permanence of consequences, due to an immature prefrontal cortex, teens are not skilled at doing this

• Teens do not take information, organise it, and understand it in the same way that adults do—they have to learn how to do this


• Important to understand that teens often fail to heed common sense or adult warnings because they simply may not be able to understand and/or accept reasons that seem logical and reasonable to adults

• NEVER assume that you and a teen are having the same understanding of a conversation


• With experience, teens are able to temper their instinctive ‘gut’ reaction with more rational, reasoned responses—they are able to “apply the brakes” to emotional responses. During this time of development, teens need adult mentors and role-models who demonstrate how to make good decisions and how to control emotions

ADOLESCENT BRAIN DEVELOPMENTADOLESCENT BRAIN DEVELOPMENT• Adolescents are not very skilled at distinguishing the

subtlety of facial expression (excitement, anger, fear, sadness, etc.)—results in a lot of miscues—leads to lack of communication and inappropriate behavior

• Differences in processing, organization, and responding to information/events leads to misperceptions and misunderstanding verbal and non-verbal cues


Adolescence involves the maturation of self-regulation of behavior and emotions—teens need to learn how to navigate complex social situations under conditions of strong emotions – such as social anxieties, romantic relationships, academic pressures, desires for immediate gratification vs. long term goals, moral dilemmas, and success/failure

• Adolescent brain is neuroplastic undergoing specific and significant remodelling

• Grey matter white matter • Process of fine tuning brain developments• Use it or lose it• Adolescence and young adulthood is a time of

great potential for change and development

New research on brain development during New research on brain development during adolescenceadolescence

Changes in levels of gray matterChanges in levels of gray matter

Key findingsKey findings

• Experience plays an important role in determining connections made

• The types of brain activities engaged in during adolescence probably have a significant impact on what cognitive abilities people will have for the rest of their lives

• Over or under stimulation of certain responses can lead to mis-communication between different areas of the brain

IMPACT OF NEGATIVE LIFE IMPACT OF NEGATIVE LIFE EXPERIENCE ON BRAIN EXPERIENCE ON BRAIN

DEVELOPMENT AND DEVELOPMENT AND FUNCTIONINGFUNCTIONING

Negative life events (risk factors):Home

School

Other Environmental Factors e.g. poverty, toxic waste sites, natural disasters

SchoolPersistent bullying

Social isolation

Conflictual relationships with teaching staff

Exclusion

Impact of ongoing stressImpact of ongoing stress

SCARS THAT WON’T HEALSCARS THAT WON’T HEAL

• Growing evidence of altered brain development and functioning as the result of negative life events and experiences

• Our interactions with the world “organise our brain’s development” and shapes the person we become

• Brain will develop to respond to a positive or a negative environment

SCARS THAT WON’T HEALSCARS THAT WON’T HEAL

• Chronic stress, and neglect sensitize certain neural pathways and over-develop certain regions of the brain (limbic region) involved in anxiety and fear. This often results in the under-development of other regions of the brain (frontal lobe)

• Chronic stress from fear, violence, abuse, hunger, pain, etc. focuses the brain’s resources on survival and other areas of the brain are not “available” for learning social and cognitive skills

BRAIN’S RESPONSE TO THREATBRAIN’S RESPONSE TO THREAT

• Brain is uniquely designed to mobilize the body in response to threat—all body response—fight or flight

• Neurochemical systems cause a cascade of changes in attention, impulse control, sleep patterns, and fine motor control

• Chronic activation of the neural pathways involved in fear creates “memories” which shape a person’s perception of and response to the environment—indelible perception of the world

NEUROBIOLOGY OF ABUSENEUROBIOLOGY OF ABUSE

• Neural systems that are chronically activated by threat can change in permanent ways:

-- Altering number of synapses -- Changing dendritic density -- Inhibit development of neurons -- Alter neurotransmitter receptors -- Change gross structure and volume of

the hippocampus

SummaryIt appears that aggressive, submissive, and

frustration behaviors may become structurally encoded.

If relationships are negative, threatening, and/or fear inducing, the lower brain responses become dominant and the cognitive regulating structures do not develop to their full capacity; consequently, an individual may not develop the cognitive ability to control emotions or behavior.


• Prefrontal Cortex is still underdeveloped• Executive functioning, controlling and

coordinating thought and behaviour, directing attention and thinking about future consequences, are limited

• This impacts on aptitudes such as response inhibition, emotional regulation, analysing problems and planning


• Response to rewards is different – respond less to small rewards, have bigger response to larger rewards but soon have no impact

• Risk taking and exploration of new activities• Reward centre in overdrive coupled with

planning regions that are not fully functional could make an adolescent an entirely different creature to an adult when it comes to seeking pleasure


• Mentalisation or perspective taking capacity dips during puberty.

• Ability to empathise teenagers hardly use the area of the brain that is involved in thinking about other people’s emotions and thought when considering a course of action – less able to imagine emotional reactions and to read the emotions of other which can led to misunderstandings and over reactions

• The ability to hold in mind an intention to carry out an action at a future time also dips

• Mismatch between emotional and cognitive regulatory modes– Results in powerful emotional responses (e.g.

urges for sexual behaviour, independence and the formation of social bonds) which they cannot easily regulate, contextualise, create plans about or inhibit.

• Too much, too young– Self-restraint in the face

of emotional experience– Required to make

decision and have high degree of agency

Brains are developing!Expectations may prove to be too much for them

STRES

SED

OUT!

STRES

SED

OUT!

STRUGGLING!

STRUGGLING!

What is criticalWhat is critical

• Brain of young people particularly in infancy and in adolescence is very malleable

• Experience both positive and negative plays a crucial role

• Neural systems that are chronically activated by threat can change in permanent ways

Increased risk-Increased risk-taking in taking in

adolescence is adolescence is normative, normative, biologically biologically driven and driven and inevitableinevitable

Adaptive role of adolescenceAdaptive role of adolescence

• A biological wedge is naturally driven between parents and adolescents to aid their transition from dependence to independence.

• These changes compel adolescents to explore the deeper end of the gene pool and acquire the skills competence and confidence necessary to survive on their own

• You need to engage in high-risk behaviour to leave your village and find a mate

• At the same time as risk taking soars hormones kick in for adolescents to find sexual partners

Sexual Maturation

Peer Relationship

Risk and Exploration

Conflict with authority

Resistance to authority

INDEPENDENCEINDEPENDENCE

AdolescentsAdolescentsNormal Adolescents Adolescent Turmoil Disturbance

Struggle for autonomy Acting out Major disturbance

Establish peer relationships Fighting Bullying

Exploration of sexuality Promiscuity Unplanned early pregnancy/ prostitution/ sexual abuse

Emotional stress Self consciousness, loss of confidence

Depressive illness/ anxiety/neurosis

Challenging authority Minor acts of delinquency Persistent law breaking

Concern about body shape Dietary chaos Eating disorder

Exploration, experimentation

Risk taking Self harm

adolescent brain development dr alex hassett senior consultant (camhs) managercamhs practice...

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