Gateway Drugs and Common Drug Abuse The oldest known written record of drug use is a clay tablet from the ancient Sumerian civilization of the Middle East. This tablet, made in 2000 BC, lists about a dozen drug prescriptions. An Egyptian scroll from around 1550 BC names more than 800 prescriptions containing approximately 700 drugs. The ancient Chinese, Greeks and Romans also used many drugs. The Greeks and Romans used opium to relieve pain. The Egyptians used castor oil as a laxative. The Chinese ate liver to cure anemia. In the 1500s and 1600s, doctors and scientists made important advances in pharmacology and other fields of science. In the early 1500s, Swiss physician Philippus Paracelsus pioneered the use of minerals as medicines. He introduces many compounds of lead, mercury and other minerals in the treatment of other diseases. Gateway drugs are substances that people take that, in many cases, lead people to take more drugs. Alcohol and weed are the most obvious gateway drugs. Studies show that if you smoke weed, you're more likely to try things like methamphetamine, cocaine, or heroin. Many people view alcohol and weed as less dangerous and harmful than other drugs, but the truth is that they are just as dangerous as any other drug in more ways than one. Not only are alcohol and weed dangerous in themselves, they also mess up your judgment making you more likely to use other drugs. Gateway drugs work in two main ways. The first, gateway drugs, break down a psychological barrier that prevents the taking of other drugs. Once you've crossed the line with a gateway drug, you're more likely to get there with other drugs. Second, Gateway drugs impair your judgment. If you're drunk, it's easier to say yes to cocaine or whatever else is around. These drugs break down your inhibitions, so you are more susceptible to peer pressure and experimentation. Not only do they impair your judgment when taking them, but they can change the way you perceive drugs in general. LSDLSD (lysergic acid diethylamide) is one of the main drugs that make up the hallucinogen class. LSD was discovered in 1938 and is one of the most powerful mood-altering chemicals according to Schreiber. It is produced commonly called "acid". The effects of LSD are unpredictable.