2. chemicals  Drugs are chemicals.  They work in the brain by tapping into the brain's communication system and interfering with the way nerve cells normally send, receive, and process information.  Different drugs—because of their chemical structures—work differently.

3.  Marijuana and heroin, activate neurons because their chemical structure mimics that of a natural neurotransmitter. › these drugs can “fool” receptors, can lock onto them, and can activate the nerve cells. › Problem = don't work the same way as a natural neurotransmitter, - neurons wind up sending abnormal messages through the brain.  Cocaine and amphetamine, cause nerve cells to release excessive amounts of natural neurotransmitters or prevent the normal recycling of these brain chemicals. › This leads to an exaggerated message in the brain, ultimately wreaking havoc on the communication channels. › The difference in effect is like the difference between someone whispering in your ear versus someone shouting in a microphone.

4.  All drugs of abuse—nicotine, cocaine, marijuana, and others— affect the brain’s “reward” circuit. › Normally, the reward circuit responds to pleasure by releasing the neurotransmitter dopamine  creates feelings of pleasure, and tells the brain that this is something important › Hippcampus/amygdala!  Drugs hijack this system, causing unusually large amounts of dopamine to flood the system. › Sometimes, this lasts for a long time compared to what happens when a natural reward stimulates dopamine. › This flood of dopamine is what causes the “high” or euphoria associated with drug abuse.

5.  When drugs are taken, they can release up to 10 times the amount of dopamine that natural rewards do!  This dwarfs the affects of naturally rewarding behavior …  Such a powerful reward STROGNLY motivates people to take drugs again and again… › Scientists say that drug abuse is something people can LEARN to do very, very, well…

6.  Most people feel sick from the toxic chemicals found in most drugs… › In fact, some neurons will die from the toxicity of some chemicals found in drugs  HOWEVER, the brain starts changing immediately to the unnatural flood of neurotransmitters…

7.  The brains ability to activate pleasure circuits changes…it needs more dopamine to create the same affect  Without high amounts of dopamine released, a person will feel flat, lifeless, and depressed.  Now the person needs drugs just to bring dopamine levels up to normal. Larger amounts of the drug are needed to create a dopamine flood, or “high”

8.  These brain changes drive a person to seek out and use drugs compulsively, despite negative consequences such as stealing, losing friends, family problems, or other physical or mental problems brought on by drug abuse---  —this is ADDICTION !!!

10. 1. Stimulation 2. Tolerance 3. Dependence 4. Withdrawal 5. Relapse

11. 1. What is addiction? 2. What kind of drugs can you become addicted to? 3. What makes a person more likely to become addicted to drugs? 4. Why does the drug become “more important?” 5. Can a person quit drugs?

12.  Anyone Can Become Addicted to Drugs  http://www.youtube. com/watch?v=SY2lu GTX7Dk http://www.youtube. com/watch?v=SY2lu GTX7Dk http://www.youtube. com/watch?v=SY2lu GTX7Dk  Why Are Drugs So Hard to Quit  http://www.youtube. com/watch?v=zV6zK mt7S5E http://www.youtube. com/watch?v=zV6zK mt7S5E http://www.youtube. com/watch?v=zV6zK mt7S5E

13. drug  NO…can’t predict how many times a person must use a drug before becoming addicted…  Genetics and environment play a huge role