Chapter 3: Stimulants

By the end of this chapter, you should be able to:

  • Define the characteristics of the major classes of drugs. (LO2)
  • Identify and summarize the addiction process and the characteristics thereof. (LO3)

Overview of Stimulants

Stimulants are drugs that typically increase overall levels of neural activity (Lumen; Florida State College). Drugs in this category include, but are not limited to: cocaine, amphetamines, bath salts, MDMA, nicotine, and caffeine. The most common routes for using stimulants are , intranasal or snorting, inhalation (usually smoking), and with a hypodermic syringe (Rawson, 1999; Wisconsin Technical College System). This chapter will cover some of the most common stimulants used.

Concepts to Remember:

  • Many of these drugs act as (APA, 2022) of the user system (Vosburg, et al, 2021).
  • The opposite of an agonist is an antagonist, which binds the drug and the receptor and halts natural function of the receptor (Nguyen, 2018).
  • Furthermore, up-regulation and down-regulation play a role in abuse but also withdrawal (and relapse). Up-regulation is when the number of receptors that are fully functioning, without drug use, increases. When the number of receptors decreases, it is called down-regulation. Relapse is so prevalent because the body does not immediately recover from drug use, it needs time to return to its natural function and balance (OpenStax, 2020).
  • The of a drug is important to understand how long a substance remains in the body (APA, 2022). Below are some slides and further information related to half-life. Select the double-pointed arrow, in the lower right corner to enlarge the slides.


Cocaine is derived from a South American shrub called coca (APA, 2022). The coca leaves contain a psychoactive component which is what we know as cocaine. For thousands of years, indigenous people have chewed coca leaves to also know as “khoka” in some cultures (Biondich & Joslin, 2016). It was chewed for numerous purposes including ceremonies and other social and physiological benefits. European and American cultures began limiting their usage of cocaine once its addictive nature and side effects became more widely known (Sanvisens, et al., 2021. However, many indigenous people still chew the coca leaves for the following benefits:

  1. Gastrointestinal Treatment: Relieves stomach pain, spasms, nausea, indigestion, mouth sores, tooth aches, constipation, and diarrhea.
  2. Environmental Stress Treatment: Relieves symptoms of hypoxia and altitude sickness and suppresses feelings of hunger and cold.
  3. Physiological Treatment: Stabilizes blood sugar.

Move the middle bar to the right to view an image of coca leaves; move the middle bar to the left to view cocaine.


"Vintage ad for amphetamines" by Tengrain is licensed under CC BY-NC 2.0.
“Vintage ad for amphetamines” by Tengrain is licensed under CC BY-NC 2.0.

Amphetamines are synthetic drugs that stimulate the brain and have been tricked to release (APA, 2022). First synthesized in 1887 in Germany, it became a common pharmacy drug in the early 1930s. Later, it was introduced during World War II to keep troops on both sides alert for over two full days. In modern treatments, it is used to help reduce or manage the symptoms of attention deficit hyperactivity disorder (ADHD), severe depression, and narcolepsy (IUPHAR/BPS, 2022; Lueithi & Liechti, 2020; Reyes-Parada, et al., 2020). It has been used in the military for extreme cases, as well. Amphetamines produce a wide range of effects on the user, including several parts of the brain (Ferruci, 2019; Tait, et al. 2014; Tran, et al., 2021).

  • Prefrontal Cortex: affects cognition and arousal
  • Hypothalmus: affects food intake, thermoregulation, and arousal
  • Limbic System: affects emotions, learning, memory, rewards, addiction
  • Brainstem-Spinal Cord-Periphery: affects locomotion, cardiovascular and respiratory rhythm, pain perception

Plant-Based Stimulants

Review the following slides to learn more about plant-based stimulants (APA, 2022; Athukorala, et al., 2021; Drug Policy Alliance, 2022; Hon et al., 2021; USFS, 2022) Select the arrow in the lower right corner to expand the slides to full screen.




Caffeine is a socially acceptable stimulant that is widely used to increase alertness and performance (Agoston et al., 2022; Munis, et al., 2017). It is a plant-derived, bitter substance that is found in seeds, fruits, nuts, or leaves in plants indigenous to Africa, East Asia, and South America (“Caffeine”, 2022) (APA, 2022). Caffeine acts as a defense mechanism for plants, due to its bitter taste, keeping plant-eaters away and outliving the competition. The best known source of caffeine is coffee, which millions of people consume daily (often many times daily!) (“History”, 2022). It is the most widely consumed (and sanctioned) psychoactive drug in the world because it is legal and unregulated nearly everywhere in the world (Franke et al. (2021). Caffeine has its own slew of positive and negative affects. Review the graphic below to learn more about the pros and cons of consuming caffeine.

Pros of coffee: Increased alertness Reduced fatigue More clear thoughts Reduces cold symptoms Enhance cognitive performance Less stigmatized Elevates mood Pain reliever. Cons of Coffee: Dependence Withdrawal Tolerance Self-medication Impulsivity Aggression Diuretic Dehydrant:
Pros of coffee: Increased alertness, Reduced fatigue, More clear thoughts, Reduces cold symptoms, Enhance cognitive performance, Less stigmatized, Elevates mood, & Pain reliever. Cons of Coffee: Dependence, Withdrawal, Tolerance, Self-medication, Impulsivity, Aggression, Diuretic, Dehydrant (AlAteeq, et al, 2021; Cusack, 2020; dePaula and Farah, 2019; Mills, et al., 2017; Rosenkranz, et al., 2019; Temple, et al., 2017)


"Nicotine label" by Alachua County is marked with Public Domain Mark 1.0.
Nicotine label” by Alachua County is marked with Public Domain Mark 1.0.

Nicotine is another plant-based stimulant that is mostly derived from tobacco plants (APA, 2022). Like caffeine, it is one of the most widely used psychoactive drugs; it is the leading cause of preventable death and disease worldwide. Nicotine, found when smoking or chewing tobacco, releases a shot of into the system which thereby increases blood pressure, respiration, heart rate, and can lead to addiction (IUPHAR/BPS, 2022). Users are often more alert, feel more calm during stressful situations, and can also act as an appetite suppressant. However, in large doses, nicotine is toxic and can eventually result in death. Some negative effects of nicotine usages include dizziness, diarrha, vomiting, spasms, and heart attact. (Mahajan, et al., 2021; Quach, et al., 2020)

Tobacco smoke is also deadly. Exposure to tobacco smoke, even from electronic cigarettes, can increase the risk for stroke, Alzheimer’s disease, schizophrenia, and other diseases. Even just the tiniest bit of smoke contained thousands of hazardous chemicals and is an addictive substance (Sharma, et al., 2022).

Withdrawal from nicotine can include the following symptoms, read more here about the symptoms and how to manage them: 7 Common Withdrawal Symptoms (CDC)

  • Having the urge to smoke
  • Irritable or crabby
  • Feeling restless and excitable
  • Lack of focus
  • Difficulty sleeping
  • Increase in appetite (and weight)
  • Increased feelings of anxiety, sadness, or depression


Supplement facts
Proprietary Blend: Elation, Euphoria, Pleasure, Social Relationships Impaired, Impaired Cognition, Elevated Blood Pressure, Increased Respiration, Increased Body Temperature, Heart and Respiratory Failure, Hemorrhaging, Seizures/Convulsions, Stroke, Brain Damage


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Psychology of Addiction by Andrea Bearman and Adelle Schwan is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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