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Brain Power: Grades 4-5

Background

The kinds of drugs discussed in this module are known as stimulants. Stimulants cause accelerated heart rate, increased blood pressure, and an increase in the rate of the body’s metabolism. Stimulants also interfere with the functioning of a neurotransmitter, known as dopamine. Dopamine activates the brain’s reward system and is associated with feelings of pleasure, such as the pleasant sensations of eating or riding a roller coaster.

Stimulants vary in the extent to which they interfere with dopamine, and in the effects they have on other neurotransmitters. There are many different kinds of stimulants. The ones focused on here are nicotine, caffeine, cocaine and amphetamine, and methylphenidate (Ritalin). Each kind of drug is explained in the chart below.

Drug Name & Other Terms	How It Is Used	Effects of the Drug	Negative Effects on the Body	How It Works
Nicotine Tobacco; found in cigarettes, cigars, and smokeless tobacco	Smoked or chewed	Reduces appetite, increases alertness	Can cause nausea and vomiting	A mild stimulant, nicotine reaches the brain just 8 seconds after being inhaled. It activates areas in the brain that experience pleasure and reward by increasing the release of the neurotransmitter, dopamine. Causes increased heart rate and blood pressure by interfering with the functioning of the neurotransmitter, acetylcholine.
Caffeine Found in coffee, tea, cocoa, soft drinks, and some medications	Taken orally in pill form or consumed in food and drinks	Increases alertness	Reduces fine motor coordination, alters sleep patterns, and can cause headaches, nervousness, and dizziness	Stimulates the central nervous system by increasing the metabolism inside neurons. Increases wakefulness by blocking the neurotransmitter, adenosine.
Cocaine and amphetamine Cocaine is also called crack; amphetamine is known as speed, uppers, meth, copilots, and crank	Snorted, smoked, or injected	Causes alertness, arousal, and euphoria	Cocaine causes dizziness, headaches, anxiety, insomnia, and depression upon withdrawal in those who use it chronically. Amphetamine can cause increased heart rate, reduced appetite, and insomnia. These drugs also can make people feel anxious, raise blood pressure, cause dangerous and irregular heartbeats, chest pain, shortness of breath, nausea, vomiting, and diarrhea.	Alters the actions of the brain’s neurotransmitters— mostly dopamine. Over time, these drugs change how the dopamine neurons work. This, in part, is why users become addicted to the drugs. The user needs them to feel normal.
Methylphenidate* Ritalin	Taken orally in pill form, crushed up and snorted, or dissolved with water and injected	Causes wakefulness, increased focus and euphoria	Causes nervousness, loss of appetite, headache, increased blood pressure and heart rate, and the inability to fall or stay asleep; when injected, it can block small blood vessels causing damage to the lungs and retinas.	Prescribed for attention-deficit hyperactivity disorder (ADHD). Ritalin has been abused by people who don’t need it because of its pleasurable initial effects. When abused, rather than taken as a prescription, the tablets are often crushed and either smoked or snorted.

* Several studies have shown that children who have ADHD and are treated with methylphenidate are less likely to abuse drugs and alcohol when they are older than those who were not, but more research needs to be done. Methylphenidate taken without a doctor’s prescription can cause addiction and other negative health effects.

This page was last updated August 2008.