In psychology, stimulants are generally defined as substances that excite functional activity in the central nervous system.

Some stimulant drugs are legal and consumed widely, while others are illegal to possess and use.

Drugs classified as stimulants include:

Each of these stimulants has unique properties and mechanisms of action.

Man has put a drip coffee at the counter

Yagi Studio / Digital Vision / Getty Images

For more mental health resources, see ourNational Helpline Database.

Many people use caffeine for increased energy and mental alertness.

Thenegative effects of caffeinecan be especially problematic for certain individuals.

Some people continue to consume caffeine despite it leading to behavioral, cognitive, or psychological problems.

Nicotine is a primary ingredient in not just cigarettes but also e-cigarettes, andvaping is highly addictive.

Symptoms ofnicotine withdrawalinclude irritability, anxiety, depression, headaches, trouble sleeping, and gastrointestinal issues.

This therapy often involves tapering nicotine use over time, then eventually quitting this drug.

Cocaine

Cocaine is an illegal psychoactive drug made from the leaves of the coca tree.

Cocaine increases dopamine levels in the brain, a neurotransmitter that plays a role in reward and movement control.

Cocaine usecan result in both short- and long-term side effects.

Short-term effects include nausea, increased blood pressure, tremors, and irregular heartbeat.

If methamphetamine overdose is suspected, seek immediate medical attention.

They are used to treat certain physical andpsychological disorders, including attention-deficit hyperactivity disorder (ADHD) and narcolepsy.

Common names of prescription stimulants include:

Prescription stimulants work by enhancing the effects of dopamine and norepinephrine.

Certain effects can also be experienced if prescription stimulants are not taken as prescribed.

2017;8:80. doi:10.3389/fpsyt.2017.00080

National Library of Medicine.Caffeine.

Kohut SJ.Interactions between nicotine and drugs of abuse: A review of preclinical findings.Am J Drug Alcohol Abuse.

2017;43(2):155-170. doi:10.1080/00952990.2016.1209513

Alcohol and Drug Foundation.Nicotine.

Centers for Disease Control and Prevention.More than 2.5 million youth reported e-cigarette use in 2022.

Roetto H.What a lark!

The influence of Sigmund Freud on Virginia Woolf.Int J English Lit.

2019;10(3):21-30. doi:10.5897/IJEL2015.0889

National Institute on Drug Abuse.What is cocaine?

National Institute on Drug Abuse.How is cocaine addiction treated?

2015;9:69. doi:10.3389/fnins.2015.00069

National Institute on Drug Abuse.What are the immediate (short-term effects of methamphetamine misuse?

National Institute on Drug Abuse.What is methamphetamine?

2017;24(2):85-97. doi:10.1111/cns.12788

National Institute of Mental Health.Mental health medications.

National Institute on Drug Abuse.What are prescription stimulants?