By what criteria do we say that a drug is being misused or abused? What types of illicit drugs are most likely to result in an Emergency Room visit?

Q1
 By what criteria do we say that a drug is being misused or abused? 
Q2
 What types of illicit drugs are most likely to result in an Emergency Room visit? 
Q3
 How does cocaine affect the brain? 
Q4
 What could be the various factors that are responsible for the effects of drugs on the mind and body? 
Q5
 Can LSD result in drug dependence?  Why or why not? 
Q6
 What are the behavioral patterns of heroin abuse? 
Q7
 What are some of the positive effects of marijuana use? What are some of the negative effects? 
Q8
 Examine and describe some of the factors that influence drug-taking behavior. 
Q9
 Distinguish between what is meant by acute versus chronic toxic effects of drug abuse. 
Q10
 Discuss the structure and the functioning of neurons and their role in drug use.