There are many types of drugs and they all have similar, but very different, ways of harming you. They also fall into two types of addiction categories, psychological and physical. First there are the narcotics. These relieve pain by depressing the central nervous system. The main source of these types of drugs is opium. The drug of choice in this category is heroin. Because heroin has high water solubility, street preparation for intravenous administration is simple but instant. It produces a high as well as drowsiness, a deep feeling of well-being but only lasts 3 to 4 hours (Saferstein, 2011 p. 193). Because the effect of this medication only lasts for a certain amount of time, the user takes it constantly to feel the effect it causes. The more they use this type of drug, the more they will physically crave it. There is also a high degree of psychological dependence due to the nature of the drug itself. The feelings it evokes make you want to keep using it. Hallucinogens are another type of drug that causes alterations in mood, attitudes, processes, and perceptions. Marijuana is the most sought-after hallucinogen. It is a weed that can grow just about anywhere, regardless of weather conditions. The most potent part of the marijuana plant is its resin. As you move down the plant, the power decreases. Most people use one of the lower potencies, like flowers or leaves. The most potent of all is transformed from the resin into liquid hashish. It contains a THC content of 8 to 20 percent (Saferstein, 2011 p. 196). Marijuana has no history of physical dependence, although the more you use it, the more your psychological dependence may develop, especially in the more potent uses of marijuana. Heavy use can...... middle of paper ......d to do this you need to test the hair. The drugs will be permanently trapped in the protein structure of the hair (Saferstein, 2011 p.232). These are the three best ways to test drugs during toxicology screening. In conclusion, all the drugs mentioned have some type of addiction. It all depends on how you use it, how often and for what purpose. If you try it once and never again, you won't get this addiction. If you use it and find that you cannot live without the feelings it causes, you will end up with some form of addiction to your drug of choice. Plus, if you think you can fool someone into thinking you haven't taken drugs, you don't know much about them and their addictions. Works Cited Saferstein, Richard. (2011) Criminalistics: an introduction to forensic science. (10th edition) Upper Saddle River; New Jersey: Prentice Hall