Medicinal Marijuana and the Developing Adolescent Brain

Transcription

1 Medicinal Marijuana and the Developing Adolescent Brain John R. Knight, MD Associate Professor of Pediatrics Harvard Medical School Associate in Medicine & Psychiatry Children s Hospital Chair in Developmental Medicine Boston Children s Hospital Sion Kim Harris, PhD & Sarah Copelas, BA assisted in developing slides. Julie & Jeffrey Johnson Julie and Jeffrey Johnson were born 3 years apart. Jeffrey could always make Julie smile. He taught Julie to love running. But then Jeffrey started getting high. He called Julie late one night sounding despondent and they talked for 3 hours. The next morning their Dad found Jeffrey dead. He was 19 years old. 2 1

2 The Teen Brain What s going on in there? Copyright :JRKnight MD; CeASAR, Children s Hospital Boston, All i h d Leading Causes of Death, U.S. Ages 15 24, 2010 Other 28% Suicides 16% Homicides 15% Unintentional Injuries 41% Source: CDC National Vital Statistics Reports, Vol. 61, No. 4, May 8, 2013 Motor vehicle crashes 61% Poisoning 26% Other 13% Alcohol/drugs are a major contributor! 2

3 judgment, impulse control FRONT DEVELOPMENT BACK Copyright :JRKnight MD; CeASAR, Children s Hospital Boston, All i ht d The Golden Window The human brain cal growth and development continues through the mid 20 s Birth Giving Birth 3

4 Genes Environment Brain Development Copyright :JRKnight MD; CeASAR, Children s Hospital Boston, All rights reserved. Epigenes Copyright :JRKnight MD; CeASAR, Children s Hospital Boston, All rights reserved. 4

5 Volkow ND et al., Adverse Health Effects of Marijuana Use. New England Journal of Medicine 2014;370: Copyright 2009 John R Knight MD, Center for Adolescent Substance Abuse Research, Children s Hospital Boston; All rights reserved. THC Acute Effects on Brain Function Cerebrum Cingulate Gyrus Basal Ganglia judgment Hippocampus VTA Cerebellum 10 5

6 Adverse Effects of Short-Term Use and Long-Term or Heavy Use of Marijuana. Immediate: impaired motor coordination (driving skills and increasing risk of injury), impaired short term memory (difficulty learning and retaining information), altered judgment (increasing risky sexual behaviors, pregnancy and STI transmission), paranoia and psychosis Lifetime: brain damage: psychiatric d/o s, addictive d/o s (5x greater risk with early onset of use), altered development, decreased cognitive impairment (lower IQ) Volkow ND et al. N Engl J Med 2014;370: As THC content increases, we see more adverse effects: Paranoia Anxiety and panic Hallucinations Hyperemesis Erratic mood swings Aggressive behavior Source: National Drug Abuse Warning Network,

7 TOP: Increases over Time in the Potency of Tetrahydrocannabinol (THC) in Marijuana BOTTOM: Number of Emergency Department Visits Involving Marijuana, Cocaine, or Heroin. Volkow ND et al. N Engl J Med 2014;370: Level of Confidence in the Evidence for Adverse Effects of Marijuana on Health and Well- Being. Volkow ND et al. N Engl J Med 2014;370:

8 Marijuana and Driving Studies of performance show that THC impairs attention, working memory, coordination, reaction time, and visual perception Source: Castle D, Solowij N. Acute and subacute psychomimetic effects of cannabis in humans. In: Castle D, Murray R, eds. Marijuana and Madness. Cambridge, UK: Cambridge University Press; 2004: JOY rewards behaviors needed for survival (e.g., work resulting in food, reproduction) Drugs are a counterfeit for well earned rewards. Risk of Addiction The Brain s Reward Pathway 8

9 The Limbic System Part of primitive lizard brain Stores memories of rewards: food, sex, alcohol and drugs Responsible for powerful cravings Younger Age of First MJ Use Increases Risk of MJ Disorder 20 % with MJ Disorder Data Source: SAMHSA Age at First Use of MJ 9

10 Number of People Aged 12+ Receiving Drug Abuse Treatment in Past Year (2011) Marijuana Cocaine Pain meds Stimulants Heroin Hallucinogens Tranquilizers Source: Substance Abuse and Mental Health Services Administration. (2010). Results from the 2009 National Survey on Drug Use and Health: Volume I. Summary of National Findings (Office of Applied Studies, NSDUH Series H-38A, HHS Publication No. SMA Findings). Rockville, MD. Marijuana is especially addictive for teens 88% of all substance abuse treatment admissions for those years old involved marijuana Source: Data from the Treatment Episodes Data Set (TEDS), SAMHSA,

11 Risk of Mental Illness Human Brain White Matter Connectivity Studies on MJ Use and Psychosis Moore TH, Zammit S, Lingford-Hughes A, et al. Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review. Lancet. Jul ;370(9584):

12 Studies on MJ Use and Depression Moore TH, Zammit S, Lingford-Hughes A, et al. Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review. Lancet. Jul ;370(9584):

13 THC Harms Brain Connectivity This bundle of axons (connecting fibers) is one of the brain s communication super highways. Source: Yücel M, Zalesky et al. White-matter abnormalities in adolescents with long-term inhalant and cannabis use: a diffusion magnetic resonance imaging study. J Psychiatry Neurosci Nov;35(6): The Brain s Information Superhighway: Myelinated axons = White Matter Tracts Source: Gordon J. Harris, PhD

14 THC and Cognitive Decline Meier MH, Caspi A, Ambler A, et al. Persistent cannabis users show neuropsychological decline from childhood to midlife. Proc Natl Acad Sci U S A. Oct ;109(40):E Use of Marijuana in Relation to Perceived Risk and Daily Use of Tobacco Cigarettes or Marijuana among U.S. Students in Grade 12, Volkow ND et al. N Engl J Med 2014;370: Johnston LD, O Malley PM, Miech RA, et al. Monitoring the Future: national survey results on drug use, overview, key findings on adolescent drug use. Ann Arbor: Institute for Social Research, University of Michigan, 2014 ( 14

15 Percent of 12 th Graders Reporting Using Substance in Lifetime, Marijuana Source: National Monitoring the Future Survey, 2013 Perceived Risk of Harm and Marijuana Use, U.S. 12 th graders: Perceived risk is at a nearly historic low! 39.5% 22.7% Source: National Monitoring the Future Survey,

16 Julie Johnson with her The Falmouth Road Race 31 Summary & Recommendations 16