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The Developing Brain & Youth High Risk Behaviors: Updates, Barriers & Opportunities for Interventions. Yifrah Kaminer MD, MBA Alcohol Research Center UConn Health Center, Farmington, CT Latest December 17, 2008.
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The Developing Brain & Youth High Risk Behaviors: Updates, Barriers & Opportunities for Interventions Yifrah Kaminer MD, MBA Alcohol Research Center UConn Health Center, Farmington, CT Latest December 17, 2008
The Developing Brain & Youth High Risk Behaviors Why Don’t They Get it?Or,Why Don’t We Get It (Right)?
Objectives • Accept that youths are not mini adults. they are evolving and are more vulnerable than they believe & know • Clarify adolescent elevated risk for high-risk behavior with an emphasis on Driving, substance (ab)use from a scientific developmental perspective • Place clinicians, parents, educators, public health professionals, policy makers, and youth on the same page • Improve: 1) Knowledge Base that will lead to 2) IncreasedPublic Awareness and conclude with 3) Political Will: Engagement of community stake-holders and politicians in order to convince them that it is a crucial step towards the goal of reducing youth mass casualties • Discuss implications of findings on future directions in prevention and public health policy
The High-Risk Maturational Gap: The Take Home Message • Youth reach Intellectual maturation around age 16 HOWEVER • They reach Emotional maturation ONLY around age 25
Linkage Between Internet and Other Media Violence With Serious Violent Behavior by Youth • Exposures to violence in the media, both online and off-line, were associated with significantly elevated odds for concurrently reporting aggression and seriously violent behavior (in Japan and the USA). Anderson CA et al. (2008); Ybarra ML (2008)
Watching Sex on TV Predict Teen Pregnancy • Teens exposed to high level of television sexual content (90th) percentile were twice as likely to experience a pregnancy in the subsequent 3 years, compared with those with lower levels of exposure (10th percentile).Chandra et al (2008)
The Minimum Drinking Age Debate • Initiated by founder of “Choose Responsibility” that focuses on Responsible Drinking (RD) and increasing awareness of the harms associated with alcohol use. • Supporters of a Minimum Legal Drinking Age of 18 argue that: 1) it should be consistent with other legal rights, 2) Youth can and should be taught RD., 3) that MLDA-21 is unrealistic and leads to underground dangerous drinking. • Supporters of MLDA-21 are concerned with “trickle down” effect • The strongest support of MLDA-21 is associated with data that 25,000 have been saved since it was established in 1984.Barnett (2008)
Extended Adolescence in Western Societies • Hormonal surges that lead to puberty are beginning earlier than in previous decades • The maturational gap is wider in Western societies compared to traditional societies • In traditional societies there is a shorter 2-to 4-year gap between the onset of puberty and the taking on of adult roles. Schlegel & Barry (1999)
Adolescent Maturation • Although maturation is progressive, it is not uniform in speed or timing and individual differences are the rule, rather than the exception. Moss (2008) • There are periods of rapid transition, reorganization, spurts of growth, alternating with periods of consolidation • Exposure to stress and substances during critical periods of development have behavioral consequences and may increase liability to disorders if the mismatch between capacities and demands is too severe for compensatory physiological responses and behaviors that in time may affect brain structures. Lenroot & Giedd (2006)
Adolescent High-Risk Behaviors Occur in a Developmental Context • Biological-Puberty: hormonal, brain neuro-anatomical and neuro-transmitters interchanges • Circadian rhythm: circadian shift and school schedule are causing youth sleep deprivation (6-7 instead of the necessary 8-9 hours of sleep necessary for optimal function) • Emotional-Affective: emotional lability and dysregulation • Cognitive: information processing, executive functioning • Behavioral: novelty seeking, risk taking, impulsivity • Social: increased conflicts with parents/adults, increased peer interactions and influence, and forming intimate relations
Adolescence is a Developmental Phase With Specific Functional Purposes Prepare youth for adult roles • Improve: separation individuation, industrialization, relationship with peers and intimate others • However, often done by trial and error (not internalizing well the experience, wisdom and codes of elders of the tribe/society) • Narcissistic defenses such as omnipotence-invulnerability, devaluation of the elders and societal/legal codes (unless it suits them) Leads often to imbalance between needs and wants and may result with problems and dire consequences
Why Didn’t Life problems Hit Me When I was a Teenager and Knew Everything? (a bumper sticker)
Childhood Vs. Adolescence Mortality • Compared with children , teens show improvements in strength, reaction time, reasoning capabilities, and immune function • Overall morbidity and mortality rates soar X4-5 folds between childhood and adolescence/young adulthood • In 2003, about 7,000 U.S. children aged 5-14 years died of all causes. Compared to 33,500 youth aged 15-24 years Dahl, (2008)
U.S.A. Youth Mortality From Top 3 Preventable Causes- 2004 CDC Data • Vehicles accidents ages 16-19= *4767 *41% associated with alcohol/substance use; 23%BAC>0.08g/dl; 74% of drinkers were unrestrained *30% of teens rode with a driver who has been drinking in past month -Persons aged 15-24 represent 14% of the US pop., account for 30% of costs of injuries • Homicides = 5570 between the ages of 10-24 • Suicide = 4599 between the ages of 10-24 -17% of high schoolers seriously considered attempting and 8.4% attempted suicide in 2005)
High Risk Behaviors in Youth • Driving in general and driving under the influence in particular (52 fold increase for an accident) • Impulsive aggression (IA): Deliberate yet nonpremeditated acts • Suicidal behavior: Linked to IA commonly an uninhibited impulse to act on self-directed anger • Sexual behavior: Precocious, coercive/traumatic, unprotected (STDs and pregnancy) • Substance use and gambling • Gang and illegal activity including school bullying
Social Forces in (Pre) Adolescence • Curiosity • Social desirability/acceptance (Cool factor) • Social norms • Social pressure?
Einstein’s: Mass-Energy equivalence E=MC2 Applies to Youth Networking?
Puberty • Hormones have been implicated in behavioral changes during adolescence • Puberty means Youth “on Steroids”: 18 fold increase in Male Testosterone level 8 fold increase in Female Estradiol level • Hormonal changes affect: motivation circuits, response to stress, increased sensitivity to novel sexual, social & aggression stimuli
Puberty and the Adolescent Brain • Adolescence is a period of brain structural and functional changes • Pruning (reduction) nerve connections (synapses) • Myelinization increases by 100% • Limbic System: early development of arousal pathways of the 4 Fs (feeding, fighting, fleeing and sex) • Puberty increases susceptibility to stress • Executive cognitive functions (ECF) develop
Executive Cognitive Functions (ECF) “The individual ability to carry out “higher-order” cognitive processes such as strategic goal planning, abstracting, working memory, attentional control, thinking flexibility, self-monitoring, and the ability to use feedback when regulating behavior” Giancola & Moss, (1998)
Brain Neuroimaging “More than any previously available neurobiological technique or research tool, imaging offers the opportunity to define the neural systems that mediate the genetic and environmental determinants of brain development with their cognitive, emotional, and behavior consequences”. Gerber & Peterson, (2008) Both structural and functional changes are involved in the maturation process
http://www.brainchannels.com/evolution/evolutionmedia/halfbrain.jpg
The Importance of the Frontal & Pre-Frontal Brain for Development • Thinking skills: Identify, prioritize, problem solving and integrate • Executive Functions (EF): language-processing, emotion regulation, cognitive flexibility, & social skills • Youth dysregulate: affect, cognitive process, impulses, and self perception • Emotional development (i.e., maturation) “meets” cognitive development only around age 26 • The pivotal questions is how to proactively address triggers before the emergency sets in? Green & Ablon, (2006)
Prefrontal INHIBITION Midbrain raphe projections to motivational circuitry including VT, NA, amygdala, hippocampus areas Prefrontal ACTION Mesolimbic: Ventral tegmental (VT) area- Nucleus accumbens (NA) Reward pathways Pleasure Reinforcing behaviors Catecholaminergic Neurotransmission Serotonin (5-HT) Dopamine .
Dopamine-Serotonin Ratio • Ratio of Dopamine metabolite to 5-HT metabolite suggest a high rate of DA to 5-HT turnover • These findings indicate that adolescents may be characterized by greater activity in promotivational dopamine systems than in inhibitory serotonin systems • Relatively low levels of mesolimbic DA activity in youth may contribute to risk taking and seeking rewarding stimuli (boredom effect?) • Hormonal changes contribute to promotivational functioning of dopamine systems
Dopamine Mesocortical Pathway Basal ganglia Nucleus accumbens • Attention • Arousal • Concentration • Other cognitive fxns Ventral tegmental area
I AmBored: “I Am The Chairman of The Bored”(Iggy Pop) • A Biological explanation for Boredom Based on a primates model. During adolescence Dopaminergic activity migrates from the limbic system to the pre frontal cortex, leaving the limbic system with a relatively lower levels of Dopamine then before. This might explain sensation seeking, X-treme activities etc. • Romer & Walker (2007)
Impulsivity An innate trait for rapid response (Consider Latency Period) to internal or external stimuli REGARDLESS of potential negative consequences Swan (2001)
Cognitive Aspects of Impulsivity • Inability to delay immediate gratification • Distractibility: inability to maintain task oriented attention • Disinhibition: inability to restrain behavior as expected based on social norms and constraints
Evolutionary Approaches to Impulsivity • Risk Aversiveness Versus Impulsivity (over vs. under estimated harm) • It has been argued that impulsive symptoms can be understood in adaptive evolutionary terms • Particular environments favor “Response Ready” individuals (e.g., hyper vigilant, quick to respond) over “Problem Solvers” • Fairbanks LA et al. (2004) ; Williams J, Taylor E (2007)
Biological Basis of Impulsivity • A deficiency of central serotonin the chief inhibitory substrate (5-HT =hydroxytryptamine) is associated with greater impulsivity • This includes outward and self directed violence, suicide, fire setting, pathological gambling, binge eating • Frontal lobe lesions in humans are correlated with impulsive behaviors • Conversely, pro-serotonergic agents decrease social aggression and impulsivity
Neurobehavioral Disinhibition (ND) • ND is a trait derived from using measures of ECF, affect modulation, and behavioral control, discriminates youth at high and average risk for substance use disorders and significantly predicts the SUD between late childhood and young adulthood. • Deficits in frontal activation in youth with high amounts of ND, suggesting a possible developmental delay of executive processes in high-risk youth Tarter et al. (2003/4)
Youth Substance Use and SUD: Definitions Occasional Use- in social setting Regular Use - on a weekly or more regular basis Misuse - Emergence of pattern of use Abuse -Misuse with impairment in one or more domains within a 12-month period Dependence -Pervasive pattern of use with associatedimpairment, inability to control use, use despite consequences, tolerance, and physiological symptoms Substance Use Disorders -Abuse & dependence
Causality “After this, therefore, because of this = Fallacy of misplaced connectedness” Tarter (2008)
Liability • The individual tendency to develop or contract the disease= susceptibility Falconer (1965) • No diagnosis captures the liabilty. The common traits are: sensation seeking, temperament, negative affectivity, and externalizing disorders (Transmissible Liability Index-TLI) • The capacity to maintain self regulatory capacity under stress is crucial. Inability may increase risk for SUD • There is a common genetic vulnerability to develop dependence to all drugs (PCP 100%; Stimulants 73%; Cannabis 67%; Sedatives 81%, and heroin/opiates 30%). Tarter (2008)
Deficient Response Modulation (DRM):Youth Response to Drugs • One factor that characterizes youth who experience SU-related problems, is the difficulty considering negative consequences specifically in the presence of a well established, competing reward • Increased sensitivity to reward is associated with use (e.g., getting “high”,) that are salient to developmental increase in thrill-seeking & need for peer approval • Decreased sensitivity to negative consequences (e.g., “hangovers”, others disapproval, punishment) • The rewards aspects of SU are often more proximal to the decision to use than are the negatives Justus (2008)
Drug Use Conditioned Reinforcement • Reinforcing effects of drugs are repeatedly paired with environmental stimuli (e.g., sight, smell, use situations) • Social situation = become a “cue” exposure leading to a stimulation for drug use or relapse • Nicotine availability=drug reinforcement • Social cues= conditioned reinforcement • Pairing the two creates even stronger urge to smoke
Drugs and The Adolescent Pre-Frontal Cortex • Drugs exert persistent neurobiological effects that extend beyond the midbrain centers of pleasure and reward to disrupt the function of the frontal cortex where risks and benefits are weighed and decisions are made • More specifically, the site of control over Motivation, behavior, and Inhibitions of behaviors • The developing adolescent brain is more sensitive to drug effects. Delaying onset from age 14 to 21 is associated with 7-and 5-fold increase for binge drinking and SUD respectively. Chambers et al. (2003) Exposure to nicotine >addictive than in adulthood
Social Stressors Affect Neurobiology(Expression of Heterogeneity) • In experiments with young monkeys in isolation the dominant animal has shown changes in expression of receptors compared to subordinate • The dominant monkeys did not abuse cocaine >placebo while the subordinate did! • The addicted brain manifests loss of control even when the behavior is not pleasurable any more Impulsive Compulsive Behavior Volkov N (2006)
The Utilitarian View • A 19th century Consequentialist thinking that places the moral worth of an action in its consequences or outcomes and emphasizes the good of the total society (“greatest good for the greatest numbers”, as opposed to benefits accruing by individuals or a group of individuals. • Measurement is quantitative by adding up the positive aspects and contrast them with the negative ones • Jeremy Bentham’s (1784-1832) “An introduction to the Principles of Morals and Legislation” • Cost-benefit analysis is based on a utilitarian application (David Stewart, 1998)
Rights and Duties • How should we balance our duties with our obligations to the community • Are there cases when individual rights should be sacrificed or restricted for the sake of a greater good? (e.g., CT Gun Control; 1st amendment vs. Hate Speech) • Sense and sensibility: driving at 16, enlisting at 18, and drinking legal age at 21?
Contextual Features that Promote Positive Outcomes for Youth 1. Physical & psychological safety 2. Appropriate structure 3. Supportive relationships 4. Opportunities for belonging 5. Positive social norms 6. Support for efficacy and mattering 7. Opportunities for skill building 8. Integration of family, school , and community Eccles & Gootman, (2002)
Parental Role in AUD Prevention: Supervisory Neglect • Among community subjects ages 14-17, those with inadequate supervision were significantly more likely to drink alcohol, to have AUD, to develop AUD later and less likely to be free of AUD symptoms over 1-year follow-up. • Family structure was not significantly correlated with supervision group ( e.g., single vs. 2-parent family) • Complementary to adolescents’ pursuit of independence parental supervision remains critical to their development • Consistent, emphatic, and authoritative parental style generates best outcomes. Clark DB (2005)