The National Institute on Drug Abuse, or NIDA, characterizes addiction as a disorder that affects the brain and behavior. There are biological components to addiction as well as psychological factors that lead a person to become addicted to a particular substance. Some drugs of abuse are psychologically addicting while others may also induce physiological change. For a person to be classified as addicted, withdrawal, tolerance, dependence and intoxication are typically present.
Cocaine
Cocaine is a stimulant drug that alters the chemical dopamine in the brain. According to NIDA, repeated use of cocaine increases the amount of dopamine in the brain, which causes an internal reward. When cocaine is not present in the body, the brain changes made from prior use influence cravings for the internal reward. This inherent need for the drug makes cocaine a substance that may increase tolerance leading to addiction. Although many cocaine users tend to never achieve the initial high gained when first using cocaine, the brain essentially sends signals for craving the drug as a means for regaining the initial high. Cocaine has a high psychological addictive potential.
Marijuana
Marijuana contains a chemical called tetrahydrocannabinol, or THC, which is the substance leading to addiction. NIDA reports that long-term marijuana use may lead to addiction due to building a tolerance to the drug as well as the compulsive drug seeking that accompanies long-term marijuana use. Marijuana is not physiologically addicting; however, users that try to quit may experience irritability, anxiety and cravings during the initial cessation from the drug.
Club Drugs
Addicting club drugs include ecstasy, gamma hydroxybutyrate or GHB, and rohypnol. According to the Mayo Clinic, club drugs may also prompt addiction and dependence if used regularly. Club drugs are often dangerous due to the chemicals used to make the substance and may cause seizures, coma and death. The Mayo Clinic warns that club drugs are also more dangerous when used with alcohol as this heightens the effects of the drug. Signs of addiction to these drugs involve drug seeking despite the negative consequences of use and the internal reward or euphoria when on the drug. Additionally, the addictive potential of these drugs might include increased tolerance for the drug after long-term use.
