Slide 1:The Developing Brain, Adolescence and Vulnerability to Drug Abuse Teaching Resource from The Mentor Foundation Prepared by Ken Winters, Ph.D. Scientific Advisor, Mentor Foundation Professor, Dept. of Psychiatry, University of Minnesota Copyright © 2008 The Mentor Foundation


Acknowledgements :This work was prepared by Ken Winters, Ph.D. Scientific Advisor, Mentor Foundation Professor, Dept. of Psychiatry, University of Minnesota Support for this work was provided by the Archie and Bertha Walker Foundation, RKMC Private Foundation, and the Mentor Foundation. The author expresses gratitude to these colleagues whose work and consultation significantly contributed to the development of this presentation: Jay Giedd, National Institute on Mental Health (USA) Jeff Lee, Mentor Foundation (UK) Tom McClellan, Treatment Research Institute (USA) Linda Spear, SUNY at Binghamton (USA) Susan Tapert, University of California – San Diego (USA) Acknowledgements


Slide 3:New insights about: Risk taking by teenagers How teenagers may be highly vulnerable to drug abuse Emerging Science:Teen Brains Are Still “Under Construction”


Slide 4:Emerging Science:Brain Imaging New insights because: 1990’s information explosion due to the development of brain imaging techniques (e.g., CT, PET and MRI).


Slide 5:Adolescence is a period of profound brain maturation. We thought brain development was complete by adolescence We now know… maturation is not complete until about age 25! What Have We Learnt? Source: Giedd, 2004.


Slide 6:Rate of Change Brain Development Source: Tapert & Schweinsburg, 2005


Slide 7:Brain Development When the pruning is complete, the brain is faster and more efficient. But… during the pruning process, the brain is not functioning optimally. Source: Giedd, 2004.


Slide 8:Brain Development Maturation Occurs from Back to Front of the Brain Images of Brain Development in Healthy Youth (Ages 5 – 20) Blue represents maturing of brain areas Source: Gogtay, Giedd, et al., 2004. Copyright © 2004 The National Academy of Sciences, USA Gogtay, N., Giedd, J.N., et al. (2004) Dynamic mapping of human cortical development during childhood through early adulthood Proceedings of the National Academy of Sciences, 101 (21), 8174 – 8179


Slide 9:Implications of Arrested Development: Adolescent Behaviour Earlier development of the back of the brain and later development of the front of the brain …


Slide 10:Earlier development of the back of the brain and later development of the front of the brain … Preference for physical activity Less than optimal planning and judgment More risky, impulsive behaviours Minimal consideration of negative consequences Implications of Arrested Development: Adolescent Behaviour


Slide 11:Implications of Arrested Development: Drug Abuse Vulnerability Research question addressed by scientists: 4 lines of evidence


Slide 12:Implications of Arrested Development: Drug Abuse Vulnerability Research question addressed by scientists: Epidemiological data


Slide 13:Drug use starts early and peaks in the teen years Evidence from surveys


Slide 14:Addiction is a Developmental Disease Starts in Adolescence and Childhood Source: NIAAA National Epidemiologic Survey on Alcohol & Related Conditions, 2003.


Slide 15:Age (years) % lower rates with older recent users Source: Winters & Lee, 2008 Percentages of Past Year Alcohol Use Disorder Among Those with a Recent Onset (Prior 2 Years) of Alcohol use (N = 4058)


Slide 16:Implications of Arrested Development: Drug Abuse Vulnerability Research question addressed by scientists: Survey data Adolescent rats are less sensitive to the sedative and motor impairment effects of intoxication.


Slide 17:Direct evidence can not obtained from human adolescents for ethical reasons. Much of what is known about alcohol susceptibility is from adolescent rat studies. Comparing adolescent and adult rats, both having no prior exposure to alcohol and matched on temperament…. Adolescent rats are less sensitive to the sedative and motor impairment effects of intoxication. more drinking before “signals to stop” Susceptibility to Alcohol Source: Spear, 2002


Slide 18:Adolescent rats are more sensitive to the social disinhibition effects of alcohol compared to adults. These studies suggest that adolescent rats derive greater “social comfort” from intoxication than adult rats. Social Disinhibition Source: Spear, 2002


Slide 19:Implications of Arrested Development: Drug Abuse Vulnerability Research question addressed by scientists: Survey data Adolescent rats are less sensitive to the sedative and motor impairment effects of intoxication. Adolescent rats are more sensitive to the social disinhibition effects of alcohol. 2 and 3 may contribute to binge drinking and increased risk to alcohol dependence.


Slide 20:Implications of Arrested Development: Drug Abuse Vulnerability Research question addressed by scientists: Survey data Adolescent rats are less sensitive to the sedative and motor impairment effects of intoxication. Adolescent rats are more sensitive to the social disinhibition effects of alcohol.


Slide 21:Implications of Arrested Development: Drug Abuse Vulnerability Research question addressed by scientists: Survey data Adolescent rats are less sensitive to the sedative and motor impairment effects of intoxication. Adolescent rats are more sensitive to the social disinhibition effects of alcohol. Alcohol produces greater cognitive disruptions in adolescents.


Slide 22:Animal Data: Alcohol’s Effects Source: Spear, 2002 When exposed to alcohol, adolescent rats, compared to adult rats, reveal more… Disruption in memory Impairment of neurotransmission in hippocampus and cortex


Slide 23:Human Data: Alcohol’s Effects Source: Tapert & Schweinsburg, 2005 The hippocampus encodes new information into memory. Adolescents with a history of alcohol use disorder have a smaller hippocampus volume (on average, by about 10%).


Slide 24:MRI: Hippocampal Size Left hippocampal smaller in AUD (alcohol use disordered) teens compared to healthy teens by about 10%.


Slide 25:Verbal information Nonverbal information Retention Rate % Human Data: Alcohol’s Effects Source: Brown et al., 2000 An average of 10% less memory in the alcohol dependent youth compared to the healthy youth.


Slide 26:Expect impulsivity, poor judgment, emotionality “On second thought…” not in the repertoire Parents must use their judgment to protect teens Parents must anticipate - teens need help with this Less than optimal planning and judgment Drugs, particularly alcohol, have different and more significant effects on teenagers Drug experimentation is normal But… can be dangerous Summary


Slide 27:Take Home for Parents Promote activities that capitalize on the strengths of the developing brain Assist your child with challenges that require planning Reinforce their seeking advice from you and other adults Educate about risk taking and negative consequences Never underestimate drug effects on developing brain Tolerate “oops” behaviors common during the teens


Slide 28:Brown, S.A., Tapert, S.F., Granholm, E., & Delis, D.C. (2000). Neurocognitive functioning of adolescents: Effects of protracted alcohol use. Alcoholism: Clinical and Experimental Research, 242, 164-171. Clark, D. B., Kirisci, L., & Tarter, R. E. (1998). Adolescent versus adult onset and the development of substance use disorders in males. Drug and Alcohol Dependence, 49, 115-121. Giedd. J. N. (2004). Structural magnetic resonance imaging of the adolescent brain. Annals of the New York Academy of Sciences, 1021, 77-85. Gogtay, N., Giedd, J.N., et al. (2004). Dynamic mapping of human cortical development during childhood through early adulthood. Proceedings of the National Academy of Sciences, 101 (21), 8174 – 8179. Grant, B.F., Dawson, D., et al. (2004). The 12-month prevalence and trends in DSM-IV alcohol abuse and dependence: United States, 1991-1992 and 2001-2002. Drug and Alcohol Dependence, 74, 223-234. Johnston, L. D., O’Malley, P. M., & Bachman, J. G. (2006). Monitoring the Future national survey results on drug use, 1975-2005. Bethesda, MD: National Institute on Drug Abuse. Spear, L. P. (2002). Alcohol’s effects on adolescents. Alcohol Health and Research World, 26(4), 287-291. Tapert, S. & Schweinsburg, A.D. (2005). The human adolescent brain and alcohol use disorders (pp 177-197). In M. Galanter (Ed.), Recent developments in alcoholism: Vol XVII. Washington D.C.: American Psychiatric Press. Winters, K.C., & Lee, S. (2008). Likelihood of developing an alcohol and cannabis use disorder during youth: Association with recent use and age. Drug and Alcohol Dependence, 92, 239-247. References


Slide 29:Suggested Reading Dahl, R.E. & Spear, L.P. (Eds.) (2004). Adolescent brain development: vulnerabilities and opportunities. NY, NY: Annals of the New York Academy of Sciences, Volume 1021. Dubuc, B. (n.d.). The brain from top to bottom. Retrieved September 1, 2004, from McGill University Web site: http://www.thebrain.mcgill.ca/flash/index_d.html# Nestler, E. J., & Malenka, R. C. (2004, March). The addicted brain. Scientific American, 290 (3), 78-85. Wallis, C. (2004, May 10). What makes teens tick? Time, 163, 57-65. U.S. News & World Report. (Special Issue, 2005). Mysteries of the teen years. Author.


Slide 30:Contact Ken Winters, Ph.D.winte001@umn.edu Visit www.mentorfoundation.org Mentor’s site for more prevention information Comments or Questions?