Medical and pharmaceutical specialists develop drugs to cure illnesses, but some people tend to misuse these substances, which cause their irrational and sometimes violent behavior against themselves and others. Instead of becoming healed, the person eventually develops a medical condition called substance or drug abuse disorder. The most addictive, and therefore, the most abused drugs are basically grouped into three kinds: narcotics, depressants, and stimulants.
Heroin, opium, and codeine are strong painkillers that may either cause lethargic sensations or intense euphoria. Meanwhile, stimulants like cocaine, amphetamines and Ritalin arouse brain activity through the nervous system to treat conditions like attention deficit hyperactivity disorder (ADHD). On the other hand, Valium, Ativan, and Xanax are regular depressants designed to help patients with anxiety and sleeping disorders.