1. C 2. Drug addiction changes the structure and chemistry of the brain. 3. Drug antagonism occurs when each drug’s effect is canceled out or reduced by the other. Drug synergism occurs when drugs interact to produce effects greater than those that each drug would produce alone. 4. The drug cross the placenta, the membrane separating the baby’s blood from the mother’s blood.

5. It is a crime to produce, possess, transport, or sell illegal drugs, such as methamphetamine or marijuana. In addition, many drug abusers commit other crimes, such as theft to support their drug habit. Section C 7. Sample answer: Examples of social risk factors are associating with peers who use drugs, having role models that use drugs, and feeling competitive pressure to use drugs. Examples of social protective factors are having strong social bonds to school and other community institutions, associating with peers who are drug free, and having friends who are supportive and accepting.

8. They are healthy alternatives for dealing with stress, and stress is a risk factor for drug use. Section 3 9. A 10. A flashback is an unexpected reoccurrence of a bad trip. It occurs with hallucinogenic drugs. 11. Immediate effects include distorted perceptions, difficulties with thinking and problem solving, loss of motor coordination, increased heart rate, feelings of anxiety or paranoia, and drowsiness. Long-term effects include permanent changes in the brain, damages to short-term memory, loss of motivation, and increased risk of certain cancer.

12. Sample answer: No; most drugs have the potential to cause dangerous side effects, drug interactions, or other risks if missed or abused. Section B 14. Community hospitals, school and government programs 15. Because withdrawal symptoms may be painful or dangerous 16. Sample answer: participating is a sport, becoming involved in a school club, or going to the movies.

17. Sample answer: Risks: decency and liver damage; Benefits: preventing withdrawal symptoms and craving for heroin. Benefits would outweigh the risks when fear of withdrawal symptoms prevents heroin addicts from giving up heroin.