Answer:
1. Central Nervous system - A system of the body divided into two parts: the brain and the spinal cord.
2. Addictive - A substance causes the body to have strong cravings for more of the drug.
3. Psychosis - A mental state where someone has a loss of contact with reality.
4. Disassociation - A sensation of distance someone can feel from his/her environment.
5. Central Nervous system - I guess you've repeated this point (see point 1.)
6. Tolerance - You must take more of the drug to feel the same effects you used to have with smaller amounts of the drug.
7. Self mutilation - Deliberate harm or injury to one's body; it is also known as self-harm or self-injury.
8. Flashbacks - Occur when the user experiences the effects of hallucinogens months or weeks after using the drug.
Hope this helps.