MH



The study of human social life, groups and
societies
Deals with your environment, friends, life
issues
More of the risk of taking drugs



Addiction is a primary, chronic disease of
brain reward, motivation, memory and related
circuitry
Changes in the brain resulting in a
compulsive need to use drugs
Depends on two main biological factors:
1. Effects of drugs on the individual
2. Biological status of the individual (inherited
characteristics)






Made up of billions of neurons
They pass messages back and forth to different
systems
These networks regulate what we feel, think and
do
Neurotransmitters-chemicals that carry
messages between neurons
Receptors-bind with certain neurotransmitters
Sending a message:
◦
◦
◦
◦
◦
Neurotransmitter released
Jumps synapse
Attaches to receptor
Causes changes in receiving brain cell
Message delivered


When we participate in life-sustaining activities
our brain treats it with a pleasurable “reward”
The brain releases dopamine as a reward
◦ Dopamine is a neurotransmitter present in regions of the
brain that regulate movement, emotion, cognition,
motivation and feelings of pleasure



Drugs interfere the way nerve cells normally
communicate
Drugs can target the reward system with
dopamine
Drugs release 2-10 times more dopamine than
natural rewards do and can last longer

Drugs such as, heroin and marijuana, can
activate neurons because their chemical
structures mimic that of a natural
neurotransmitter
◦ Attaches to receptor and activates nerve cell in an
unnatural way
◦ Abnormal messages are transmitted

Drugs such as, cocaine and amphetamine, can
cause nerve cells to release abnormally large
amounts of natural neurotransmitters or prevent
the normal recycling of these chemicals
◦ Produce a greatly
amplified message
◦ Disrupts communication
channels

Prefrontal Cortex
◦
◦
◦
◦


a “pleasure centre”
Develops during adolescence
While developing there is a chemical imbalance
Substance use during this time can impair future
decision making and other functions
A person who starts drinking at age 13 has a
43% chance of becoming an alcoholic
A person who starts drinking at age 21 has a
10% chance of becoming an alcoholic





Account for 40%-60% of the likelihood of
developing an addiction
There are multiple genes that control various
aspects of the biological response to drugs or the
physiological predisposition to become an abuser
Genetic factors don’t ensure addiction, just as
lack of them don’t prevent addiction
Certain genes make it harder for a user to stop
using drugs
Diversity of molecular components involved in
addiction
◦ Neurotransmitters
◦ Desensitization of targets for many drugs



How researchers proved that addiction is
hereditary
Constructed from large families with
addiction problems
Shows recurring traits



Scientists have found more than 80 of these
genes
Each of these genes contain clustered single
nucleotide polymorphisms that display
significant allele frequency differences
between abusers and non-abusers
Implicated with many cellular functions,
including adhesion
◦ Establish and maintain neuronal connections of
significance to addiction’s “memory” function

Genetic factors contribute to alcohol preference

When bred to lack a certain gene:
◦ Smaller doses of alcohol affected mice with genetic factors
more than ones without
◦ Maybe due to inherited differences in the mesocorticolimbic
dopamine system – inherited increase response to this
system (when exposed to alcohol)
◦ Different levels of activity in other neurotransmitter system
that moderate activity in the mesocorticolimbic dopamine
system
◦ Cannabinoid receptor gene-reduced reward response to
morphine
◦ Serotonin receptor gene-more attracted to alcohol and
cocaine
◦ B2 subunits nicotinic cholinergic receptors-reduced reward
response to cocaine
◦ Lower levels of neurpeptide Y-drink more alcohol
◦ Higher levels of neurpeptide-tend to abstain from alcohol
◦ Creb gene-less likely to develop morphine addiction
◦ Defective Per2 gen-drink 3X more alcohol

Treatment of addiction genes
◦ Modify activity
◦ Transform them-reduce likelihood of addiction
◦ Signals and pathways in the brain-returned to normal

Creating tamper-resistant drugs
◦ When crushed, chewed or cut, release naltrexone which
absorbs the morphine
◦ When dissolved-gel-like substance forms, which makes
it impossible to inject
◦ Tamper-resistant oxycontin is already being produced

Creating a vaccine
◦ Prevents addictive substances from ever reaching the
brain
◦ Opioid vaccine is being produced
◦ A vaccine for drugs such as heroin and cocaine is the
target












Defining Sociology. (2005). In The British Sociological Association. Retrieved April 25, 2012,
from www.sociology.org.uk/as4def.doc
Definition of Addiction. (2011, April 19). In American Society of Addiction Medicine. Retrieved
April 25, 2012, from http://www.asam.org/for-the-public/definition-of-addiction
Drugs, Brains, and Behavior: The Science of Addiction. (2010, August). In National Institute on
Drug Abuse. Retrieved April 25, 2012, from http://www.drugabuse.gov/publications/scienceaddiction/drugs-brain
Genetic Science Learning Center. (2012). Genetics is an important factor in Addiction. In The
University of Utah. Retrieved April 25, 2012, from
http://learn.genetics.utah.edu/content/addiction/genetics/
Grucza, R. J. (2006). Co-Occurring Risk Factors for Alcohol Dependence and Habitual Smoking.
Alcohol Research & Health, 29(3), 172-178.
Liu Q-R, Drgon T, Johnson C, Walther D, Hess J, Uhl GR. 2006. Addiction Molecular Genetics:
639,401 SNP Whole Genome Association Identifies Many “Cell Adhesion” Genes. Am J Med
Genet Part B 141B:918–925.
Nestler, Eric J., and David Landsman. "Learning about addiction from the genome." Nature
2001. Web. 9 May 2012.
<http://www.nature.com/nature/journal/v409/n6822/full/409834a0.html#top>.
Nurnberger, J. (2007). SEEKING THE CONNECTIONS: ALCOHOLISM AND OUR GENES. Scientific
American, 296(4), 46-53.
The Pleasure Centers (n.d.). In The Brain From the Bottom to the Top. Retrieved April 25, 2012,
from http://thebrain.mcgill.ca/flash/i/i_03/i_03_cr/i_03_cr_que/i_03_cr_que.html
U.S. Congress, Mice of Technology Assessment, BioZogicaZ Components of
Substance Abuse and Addiction, OTA-BP-BBS-1 17
Woods, T. L. (2010). Opioid abuse and dependence: Treatment review and future options.
(cover story). Formulary, 45(9), 284-291.





http://www.parentingclan.com/talking-teendrugs-alcohol.html
http://www.drugabuse.gov/publications/science
-addiction/drugs-brain
http://learn.genetics.utah.edu/content/addiction
/genetics/
http://thebrain.mcgill.ca/flash/i/i_03/i_03_cr/i_
03_cr_que/i_03_cr_que.html
http://m.drugabuse.gov/publications/teachingpackets/brain-actions-cocaine-opiatesmarijuana/section-iii-introduction-to-drugsabuse-cocaine-opiat-1