# Presentation: 534675

## BRAIN RESEARCHTHE EFFECTS OF ALCOHOL ON THE ADOLESCENT BRAIN

**Ken Winters, Ph.D.**
**Department of Psychiatry**
**University of Minnesota**
- _[winte001@umn.edu](mailto:winte001@umn.edu)_
**CSAP’s Western CAPT **
**Audio Teleconference**
**March 18, 2004**

## 1. Developmental Issues

**1. Developmental Issues**

## Alcohol Use by Youth

**Alcohol Use**

**Youth alcohol use occurs on a continuum**
**Most youth have used some alcohol**

**Alcohol Use by Youth**

**7 million teens binge drink at least once a month**

## Trends in prevalence of drugs for 12th graders: 1994 to 2001

**	****  ****	****30-Day****           ****	**
**  **_**Year**_**	**** ****	**_**Alcohol %**_**    ****	**
**  **
**  ****1994****	****   ****	****50.1****	****	****	****	**
**  ****1995****	****   ****	****51.3****	****	****	****	****	**
**  ****1996****	****   ****	****50.8****	****	****	****	****	**
**  ****1997****	****  ****	****52.7****	****	****	****	****	****          **
**  ****1998****	****   ****	****52.0****	****	****	****	**
**  ****1999****	****	****51.0****	****	****	****	**
** **
**  ****2000****	****	****50.0****	****	****	****	**
**  ****2001****	****	****49.8**
**	****	****	**

***MTFS*****, 1975-2001**

## Long-Term, Heavy Use of Alcohol

**Significant shrinking of the brain**
**50% - 75% show **_**cognitive impairment**_
**Effects **_**remain**_** even after detoxification & abstinence**
**Alcohol dementia is 2****nd-****leading **_**cause**_** of adult dementia**** **** **

## 2. Adolescence and the 

**2. Adolescence and the **
**Brain**

**1. Developmental Issues**

## The Adolescent Brain is Still Developing

**During adolescence, the brain is undergoing dramatic transformations**
**In some brain regions, over 50 % of neuronal connections are lost**
**Some new connections are formed**
**Net effect is pruning (a loss of neurons)**

## Adolescent Brain Changes

**These brain changes are relevant to adolescent behavior**
**Prefrontal cortex (PFC)**** is pruned; not fully developed until mid-20’s**
**Amygdala (and n.a.)**** show less pruning and tend to dominate the PFC**

**judgment**

**reward**
**system**

**amygdala**

**nucleus**
**accumbens**

**prefrontal**
**cortex**

## This imbalance leads to...  planned thinking   impulsiveness   self-control   risk-takingmore “hot” talking, less “cool” talking

**PFC**

**amygdala**

**I like to use drugs!! **

## In the presence of stress...

**amygdala**

**In the presence of stress...**

**I hate school; I am going to skip classes and get drunk **

## GOOD NEWS!

**amygdala**

**GOOD NEWS!**
**The pruning of the PFC neurons produces a more efficient PFC by young adulthood**

**I am planning for the future**

## 2. Adolescence and the 

**2. Adolescence and the **
**Brain**

**3. Brain and Alcohol**

**1. Developmental Issues**

**Is addiction a **
**brain disorder?**

## From “Oops” to Dependence

## “Oops Phenomenon”

**First use to “**_**FEEL GOOD**_**”**
**Some continue to compulsively use because of the reinforcing effects (e.g., to “**_**FEEL NORMAL**_**”)**
_**Changes**_** occur in the “reward system” that promote continued use**

## Reward System

**The reward system is responsible for seeking **_**natural**_** rewards that have survival value**
**seeking food, water,  sex, and nurturing**
**Dopamine is this system’s primary neurotransmitter**

**reward**

## Drugs Hijack the Brain’s Reward Circuitry

**Immediate effect of drug use is an **_**increase**_** in dopamine**
**Continued use of drugs **_**reduces**_** the brain’s dopamine production.**
**Because dopamine is part of the  reward system, the brain is “fooled” that the drug has survival value for the organism.**
**The reward system responds with “drug seeking behaviors”**
**Craving occurs and, eventually, dependence.**

**reward**

## Evidence

_**Animal Studies**_**: **
** ****electrodes attached to “Reward Circuit”**
** ****animals press lever to receive stimuli to brain**
** ****they continue until collapse from exhaustion**
_**Behavioral Genetics Studies**_**:**
-  **heredity plays a role**
**identical twins: > chance of becoming alcoholics than fraternal twins**
**adoptive children of alcoholics: > chance of becoming alcoholic;**
**	****even true when raised by non-alcoholic parents**
**further research needed by gender**

## 2. Adolescence and the 

**2. Adolescence and the **
**Brain**

**3. Brain and Alcohol**

**4. Youth, Brain**
**and Alcohol**

**Are adolescents **
**more susceptible to**
**alcohol than adults?**

**1. Developmental Issues**

**Is addiction a **
**brain disorder?**

## Are adolescents more susceptible to alcohol than adults?

**Adult studies suggest that the areas of the adolescent brain that are remodeled are sensitive to the effects of alcohol**

**Difficult scientifically and ethically to study adolescent sensitivity to alcohol**

**amygdala**

**nucleus**
**accumbens**

**prefrontal**
**cortex**

## Are adolescents more susceptible to alcohol than adults?

**Animal models can be easily used to explore this issue**
**Role of psychosocial factors can not be studied**

## Are adolescents more susceptible to alcohol than adults?

**1.  Adolescent rats are **_**less**_** sensitive to effects of intoxication and **_**less**_** sensitive to the “hangover” that follows use**

## Are adolescents more susceptible to alcohol than adults?

**2.  Adolescent rats are **_**more**_** sensitive to the social disinhibition induced by alcohol use**

**Wanna look**
**for some cheese**
** ****with me?**

**Sure!**

## Are adolescents more susceptible to alcohol than adults?

**3.  Adolescent drunk rats perform worse on memory tasks than adult drunk rats**

**Ugh??**

**disrupts the hippocampus**
**brain damage in the PRF**

**converts information to memory**

**planned**
**thinking**

## Supporting Human Studies

**1.  Reduced sensitivity to intoxication**
** **
**3.  Greater adverse effects to cognitive functioning**

## Survey Data Suggest that Adolescents Are More Sensitive to Alcohol

**Monitoring the Future, 2001**

## Alcohol’s Effects

** ****Adolescents with a history of extensive use....**
** **
**Hippocampus (50%)**
**brain activity during memory tasks**
**brain activation when shown alcohol images**

**converts information to memory**

**trigger for relapse**

**(Brown, 2002; Wuethrich, 2001)**

## Are adolescents more susceptible to alcohol than adults?

**Hyperexcitability issue**

## Are adolescents more susceptible to alcohol than adults?

**4.****  Hyperexcitability issue**
**Alcohol **_**relieves**_** hyperexcitability state**
**Relief is temporary;  continued seeking of alcohol is reinforced**
**Hyperexcitability is a key characteristic of  conduct disorders, ADHD & other impulsive behaviors**
**Found in non-alcoholic relatives - suggests **_**inheritance**_** of brain wave patterns**

## Are adolescents more susceptible to alcohol than adults?

**Reduced sensitivity to intoxication**
**Increased sensitivity to social disinhibitions**
**Greater adverse effects to cognitive functioning**
**Medicates “excitability”**

**Most certainly YES**

## References

**Leshner A. Oops.  **_**How casual drug use leads to addiction**_**.  National Institute on Drug Abuse web site: www.drugabuse.gov/Published_Articles/Oops.html**
**	****September, 2000. **_** **_
**National Institute on Alcohol Abuse and Alcoholism.  **_**Imaging and Alcoholism:  A Window on the Brain**_**.  **
***	******Alcohol Alert***** No. 47, April 2000.  **
**National Institute on Alcohol Abuse and Alcoholism.  **_**Tenth Special Report to the U.S. Congress on Alcohol and Health**_**, NIH Pub. No. 00-1583, 2000.**
**National Institute on drug Abuse.  **_**Principles of drug addiction treatment: A research-based guide**_**.  **
**	****No. 99-4180, 1999.**

## Thank You!