Stimulants are a class of psychoactive drug that increase activity in the brain. These drugs can temporarily elevate alertness, mood and awareness. While some stimulant drugs are legal and widely used, all can be addicting. While stimulants share many commonalities, each has unique properties and mechanisms of action.
Drugs that are classed as stimulants include:
Caffeine is the most widely used psychoactive drug in the world,1 found in coffee, tea, cocoa, chocolate candy and soft drinks. While caffeine has several positive effects such as increasing energy and mental alertness, heavy use can cause symptoms such as anxiety and insomnia. Caffeine is physically addictive,2 and withdrawal symptoms can include headaches, fatigue and irritability.
Nicotine is considered one of the three most widely used psychoactive drugs in the world,1 despite the fact that there are few (if any) medical uses for the drug. During the early to mid-twentieth century, smoking was considered fashionable. Reports of the adverse health consequences have led to cigarette use being increasingly shunned. However, the Substance Abuse And Mental Health Services Administration (SAMHSA) reports that approximately 66.5 million Americans over the age of 12 (or 29 percent of the population) used a nicotine containing product in 2001.3
Cocaine is an illegal psychoactive drug made from the leaves of the coca tree. During the late 1800s, psychoanalyst Sigmund Freud advocated the use of cocaine as a therapeutic treatment for psychological disorder, but later realized the addictive properties of the drug. During the early 1900s, cocaine was legal in the U.S. and could be found in many over-the-counter medications.4
Cocaine is rapidly absorbed from any administration point, including being snorted, inhaled, injected or taken orally. The drug reaches the brain quickly and is then distributed to other tissues throughout the body. Cocaine is rapidly metabolized by enzymes in the liver and plasma in approximately 30 to 60 minutes, but can be detected in urine tests for up to 12 hours after administration.1
Amphetamines, sometimes referred to as "uppers," are a group of psychoactive drugs that affect the central nervous system and autonomic nervous system. Some of the effects of using these drugs include tremors, vasoconstriction, restlessness, tachycardia, insomnia, agitation and loss of appetite. Amphetamines were once widely used in obesity and weight loss treatments, but their addictive properties have caused them to be rarely used today. Today, methamphetamine, also known as meth, is one of the most commonly used illegal amphetamines. Meth is extremely addictive and destroys tissues in the brain, which can lead to brain damage.5
Prescription stimulants are used to treat some physical and psychological disorders, including attention-deficit hyperactivity disorder (ADHD) and narcolepsy. Common names of prescription stimulants include Ritalin, Adderall and Dexedrine. Prescription stimulants work by enhancing the effects of dopamine and norepinephrine,6 and can lead to increased blood pressure, respiratory function and euphoria.