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 list below.
- Other Terms - Tobacco; found in cigarettes, cigars, and smokeless tobacco
- How it is used: Smoked, chewed or inhaled
- Effects of the drug: Reduces appetite, increases alertness
- Negative effects on the body: Can cause nausea and vomiting. Nicotine is addicting and use results in the harmful effects of tabacco use, such as lung cancer, emphysema, and bronchial disorders. Prenatal exposure to tabacco can impact the developing baby.
- How it works: 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 acting on the same receptor as the neurotransmitter, acetylcholine.
- Other Terms - Found in coffee, tea, cocoa, soft drinks, and some medications
- How it is used: Taken orally in pill form or consumed in food and drinks
- Effects of the drug: Increases alertness
- Negative effects on the body: Reduces fine motor coordination, alters sleep patterns, and can cause headaches, nervousness, and dizziness.
- How it works: Stimulates the central nervous system by increasing the metabolism inside neurons. Increases wakefulness by blocking the neurotransmitter, adenosine.
Cocaine and Amphetamines
- Other Terms - Cocaine is also called crack; amphetamine is known as speed, uppers, meth, copilots, and crank
- How it is used: Snorted, smoked, or injected
- Effects of the drug: Causes alertness, arousal, and euphoria
- Negative effects on the body: 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.
- How it works: 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 keep from feeling bad.
- Other Terms - Ritalin
- How it is used: Taken orally in pill form, crushed up and snorted, or dissolved with water and injected
- Effects of the drug: When taken as prescribed helps with focus and learning. When abused causes increased wakefulness and euphoria
- Negative effects on the body: When abused, 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.
- How it works: Prescribed for attention-deficit hyperactivity disorder (ADHD). When taken in doses other than those prescribed, Ritalin can rapidly increase brain dopamine and disrupt normal communication between brain cells. This can lead to addiction.
* 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.